#include "Python.h"
#include "cStringIO.h"
#include "structmember.h"

PyDoc_STRVAR(cPickle_module_documentation,
"C implementation and optimization of the Python pickle module.");

#ifndef Py_eval_input
#include <graminit.h>
#define Py_eval_input eval_input
#endif /* Py_eval_input */

#define DEL_LIST_SLICE(list, from, to) (PyList_SetSlice(list, from, to, NULL))

#define WRITE_BUF_SIZE 256

/* Bump this when new opcodes are added to the pickle protocol. */
#define HIGHEST_PROTOCOL 2

/*
 * Note: The UNICODE macro controls the TCHAR meaning of the win32 API. Since
 * all headers have already been included here, we can safely redefine it.
 */
#ifdef UNICODE
#  undef UNICODE
#endif

/*
 * Pickle opcodes.  These must be kept in synch with pickle.py.  Extensive
 * docs are in pickletools.py.
 */
#define MARK        '('
#define STOP        '.'
#define POP         '0'
#define POP_MARK    '1'
#define DUP         '2'
#define FLOAT       'F'
#define BINFLOAT    'G'
#define INT         'I'
#define BININT      'J'
#define BININT1     'K'
#define LONG        'L'
#define BININT2     'M'
#define NONE        'N'
#define PERSID      'P'
#define BINPERSID   'Q'
#define REDUCE      'R'
#define STRING      'S'
#define BINSTRING   'T'
#define SHORT_BINSTRING 'U'
#define UNICODE     'V'
#define BINUNICODE  'X'
#define APPEND      'a'
#define BUILD       'b'
#define GLOBAL      'c'
#define DICT        'd'
#define EMPTY_DICT  '}'
#define APPENDS     'e'
#define GET         'g'
#define BINGET      'h'
#define INST        'i'
#define LONG_BINGET 'j'
#define LIST        'l'
#define EMPTY_LIST  ']'
#define OBJ         'o'
#define PUT         'p'
#define BINPUT      'q'
#define LONG_BINPUT 'r'
#define SETITEM     's'
#define TUPLE       't'
#define EMPTY_TUPLE ')'
#define SETITEMS    'u'

/* Protocol 2. */
#define PROTO    '\x80' /* identify pickle protocol */
#define NEWOBJ   '\x81' /* build object by applying cls.__new__ to argtuple */
#define EXT1     '\x82' /* push object from extension registry; 1-byte index */
#define EXT2     '\x83' /* ditto, but 2-byte index */
#define EXT4     '\x84' /* ditto, but 4-byte index */
#define TUPLE1   '\x85' /* build 1-tuple from stack top */
#define TUPLE2   '\x86' /* build 2-tuple from two topmost stack items */
#define TUPLE3   '\x87' /* build 3-tuple from three topmost stack items */
#define NEWTRUE  '\x88' /* push True */
#define NEWFALSE '\x89' /* push False */
#define LONG1    '\x8a' /* push long from < 256 bytes */
#define LONG4    '\x8b' /* push really big long */

/* There aren't opcodes -- they're ways to pickle bools before protocol 2,
 * so that unpicklers written before bools were introduced unpickle them
 * as ints, but unpicklers after can recognize that bools were intended.
 * Note that protocol 2 added direct ways to pickle bools.
 */
#undef TRUE
#define TRUE        "I01\n"
#undef FALSE
#define FALSE       "I00\n"

/* Keep in synch with pickle.Pickler._BATCHSIZE.  This is how many elements
 * batch_list/dict() pumps out before doing APPENDS/SETITEMS.  Nothing will
 * break if this gets out of synch with pickle.py, but it's unclear that
 * would help anything either.
 */
#define BATCHSIZE 1000

static char MARKv = MARK;

static PyObject *PickleError;
static PyObject *PicklingError;
static PyObject *UnpickleableError;
static PyObject *UnpicklingError;
static PyObject *BadPickleGet;

/* As the name says, an empty tuple. */
static PyObject *empty_tuple;

/* copy_reg.dispatch_table, {type_object: pickling_function} */
static PyObject *dispatch_table;

/* For EXT[124] opcodes. */
/* copy_reg._extension_registry, {(module_name, function_name): code} */
static PyObject *extension_registry;
/* copy_reg._inverted_registry, {code: (module_name, function_name)} */
static PyObject *inverted_registry;
/* copy_reg._extension_cache, {code: object} */
static PyObject *extension_cache;

/* For looking up name pairs in copy_reg._extension_registry. */
static PyObject *two_tuple;

static PyObject *__class___str, *__getinitargs___str, *__dict___str,
  *__getstate___str, *__setstate___str, *__name___str, *__reduce___str,
  *__reduce_ex___str,
  *write_str, *append_str,
  *read_str, *readline_str, *__main___str,
  *dispatch_table_str;

/*************************************************************************
 Internal Data type for pickle data.                                     */

typedef struct {
    PyObject_HEAD
    Py_ssize_t length;  /* number of initial slots in data currently used */
    Py_ssize_t size;    /* number of slots in data allocated */
    PyObject **data;
} Pdata;

static void
Pdata_dealloc(Pdata *self)
{
    Py_ssize_t i;
    PyObject **p;

    for (i = self->length, p = self->data; --i >= 0; p++) {
        Py_DECREF(*p);
    }
    if (self->data)
        free(self->data);
    PyObject_Del(self);
}

static PyTypeObject PdataType = {
    PyVarObject_HEAD_INIT(NULL, 0) "cPickle.Pdata", sizeof(Pdata), 0,
    (destructor)Pdata_dealloc,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0L,0L,0L,0L, ""
};

#define Pdata_Check(O) (Py_TYPE(O) == &PdataType)

static PyObject *
Pdata_New(void)
{
    Pdata *self;

    if (!(self = PyObject_New(Pdata, &PdataType)))
        return NULL;
    self->size = 8;
    self->length = 0;
    self->data = malloc(self->size * sizeof(PyObject*));
    if (self->data)
        return (PyObject*)self;
    Py_DECREF(self);
    return PyErr_NoMemory();
}

static int
stackUnderflow(void)
{
    PyErr_SetString(UnpicklingError, "unpickling stack underflow");
    return -1;
}

/* Retain only the initial clearto items.  If clearto >= the current
 * number of items, this is a (non-erroneous) NOP.
 */
static int
Pdata_clear(Pdata *self, Py_ssize_t clearto)
{
    Py_ssize_t i;
    PyObject **p;

    if (clearto < 0) return stackUnderflow();
    if (clearto >= self->length) return 0;

    for (i = self->length, p = self->data + clearto;
         --i >= clearto;
         p++) {
        Py_CLEAR(*p);
    }
    self->length = clearto;

    return 0;
}

static int
Pdata_grow(Pdata *self)
{
    Py_ssize_t bigger;
    Py_ssize_t nbytes;

    PyObject **tmp;

    if (self->size > (PY_SSIZE_T_MAX >> 1))
        goto nomemory;
    bigger = self->size << 1;
    if (bigger > (PY_SSIZE_T_MAX / sizeof(PyObject *)))
        goto nomemory;
    nbytes = bigger * sizeof(PyObject *);
    tmp = realloc(self->data, nbytes);
    if (tmp == NULL)
        goto nomemory;
    self->data = tmp;
    self->size = bigger;
    return 0;

  nomemory:
    PyErr_NoMemory();
    return -1;
}

/* D is a Pdata*.  Pop the topmost element and store it into V, which
 * must be an lvalue holding PyObject*.  On stack underflow, UnpicklingError
 * is raised and V is set to NULL.  D and V may be evaluated several times.
 */
#define PDATA_POP(D, V) {                                       \
    if ((D)->length)                                            \
        (V) = (D)->data[--((D)->length)];                       \
    else {                                                      \
        PyErr_SetString(UnpicklingError, "bad pickle data");            \
        (V) = NULL;                                             \
    }                                                           \
}

/* PDATA_PUSH and PDATA_APPEND both push rvalue PyObject* O on to Pdata*
 * D.  If the Pdata stack can't be grown to hold the new value, both
 * raise MemoryError and execute "return ER".  The difference is in ownership
 * of O after:  _PUSH transfers ownership of O from the caller to the stack
 * (no incref of O is done, and in case of error O is decrefed), while
 * _APPEND pushes a new reference.
 */

/* Push O on stack D, giving ownership of O to the stack. */
#define PDATA_PUSH(D, O, ER) {                                  \
    if (((Pdata*)(D))->length == ((Pdata*)(D))->size &&         \
        Pdata_grow((Pdata*)(D)) < 0) {                          \
        Py_DECREF(O);                                           \
        return ER;                                              \
    }                                                           \
    ((Pdata*)(D))->data[((Pdata*)(D))->length++] = (O);         \
}

/* Push O on stack D, pushing a new reference. */
#define PDATA_APPEND(D, O, ER) {                                \
    if (((Pdata*)(D))->length == ((Pdata*)(D))->size &&         \
        Pdata_grow((Pdata*)(D)) < 0)                            \
        return ER;                                              \
    Py_INCREF(O);                                               \
    ((Pdata*)(D))->data[((Pdata*)(D))->length++] = (O);         \
}


static PyObject *
Pdata_popTuple(Pdata *self, Py_ssize_t start)
{
    PyObject *r;
    Py_ssize_t i, j, l;

    l = self->length-start;
    r = PyTuple_New(l);
    if (r == NULL)
        return NULL;
    for (i = start, j = 0 ; j < l; i++, j++)
        PyTuple_SET_ITEM(r, j, self->data[i]);

    self->length = start;
    return r;
}

static PyObject *
Pdata_popList(Pdata *self, Py_ssize_t start)
{
    PyObject *r;
    Py_ssize_t i, j, l;

    l=self->length-start;
    if (!( r=PyList_New(l)))  return NULL;
    for (i=start, j=0 ; j < l; i++, j++)
        PyList_SET_ITEM(r, j, self->data[i]);

    self->length=start;
    return r;
}

/*************************************************************************/

#define ARG_TUP(self, o) {                          \
  if (self->arg || (self->arg=PyTuple_New(1))) {    \
      Py_XDECREF(PyTuple_GET_ITEM(self->arg,0));    \
      PyTuple_SET_ITEM(self->arg,0,o);              \
  }                                                 \
  else {                                            \
      Py_DECREF(o);                                 \
  }                                                 \
}

#define FREE_ARG_TUP(self) {                        \
    if (Py_REFCNT(self->arg) > 1) {                 \
      Py_CLEAR(self->arg);                          \
    }                                               \
  }

typedef struct Picklerobject {
    PyObject_HEAD
    FILE *fp;
    PyObject *write;
    PyObject *file;
    PyObject *memo;
    PyObject *arg;
    PyObject *pers_func;
    PyObject *inst_pers_func;

    /* pickle protocol number, >= 0 */
    int proto;

    /* bool, true if proto > 0 */
    int bin;

    int fast; /* Fast mode doesn't save in memo, don't use if circ ref */
    Py_ssize_t (*write_func)(struct Picklerobject *, const char *, Py_ssize_t);
    char *write_buf;
    Py_ssize_t buf_size;
    PyObject *dispatch_table;
    int fast_container; /* count nested container dumps */
    PyObject *fast_memo;
} Picklerobject;

#ifndef PY_CPICKLE_FAST_LIMIT
#define PY_CPICKLE_FAST_LIMIT 50
#endif

static PyTypeObject Picklertype;

typedef struct Unpicklerobject {
    PyObject_HEAD
    FILE *fp;
    PyObject *file;
    PyObject *readline;
    PyObject *read;
    PyObject *memo;
    PyObject *arg;
    Pdata *stack;
    PyObject *mark;
    PyObject *pers_func;
    PyObject *last_string;
    Py_ssize_t *marks;
    Py_ssize_t num_marks;
    Py_ssize_t marks_size;
    Py_ssize_t (*read_func)(struct Unpicklerobject *, char **, Py_ssize_t);
    Py_ssize_t (*readline_func)(struct Unpicklerobject *, char **);
    Py_ssize_t buf_size;
    char *buf;
    PyObject *find_class;
} Unpicklerobject;

static PyTypeObject Unpicklertype;

/* Forward decls that need the above structs */
static int save(Picklerobject *, PyObject *, int);
static int put2(Picklerobject *, PyObject *);

static
PyObject *
cPickle_ErrFormat(PyObject *ErrType, char *stringformat, char *format, ...)
{
    va_list va;
    PyObject *args=0, *retval=0;
    va_start(va, format);

    if (format) args = Py_VaBuildValue(format, va);
    va_end(va);
    if (format && ! args) return NULL;
    if (stringformat && !(retval=PyString_FromString(stringformat)))
        return NULL;

    if (retval) {
        if (args) {
            PyObject *v;
            v=PyString_Format(retval, args);
            Py_DECREF(retval);
            Py_DECREF(args);
            if (! v) return NULL;
            retval=v;
        }
    }
    else
        if (args) retval=args;
        else {
            PyErr_SetObject(ErrType,Py_None);
            return NULL;
        }
    PyErr_SetObject(ErrType,retval);
    Py_DECREF(retval);
    return NULL;
}

static Py_ssize_t
write_file(Picklerobject *self, const char *s, Py_ssize_t  n)
{
    size_t nbyteswritten;

    if (s == NULL) {
        return 0;
    }

    PyFile_IncUseCount((PyFileObject *)self->file);
    Py_BEGIN_ALLOW_THREADS
    nbyteswritten = fwrite(s, sizeof(char), n, self->fp);
    Py_END_ALLOW_THREADS
    PyFile_DecUseCount((PyFileObject *)self->file);
    if (nbyteswritten != (size_t)n) {
        PyErr_SetFromErrno(PyExc_IOError);
        return -1;
    }

    return n;
}

static Py_ssize_t
write_cStringIO(Picklerobject *self, const char *s, Py_ssize_t  n)
{
    Py_ssize_t len = n;

    if (s == NULL) {
        return 0;
    }

    while (n > INT_MAX) {
        if (PycStringIO->cwrite((PyObject *)self->file, s, INT_MAX) != INT_MAX) {
            return -1;
        }
        n -= INT_MAX;
    }

    if (PycStringIO->cwrite((PyObject *)self->file, s, n) != n) {
        return -1;
    }

    return len;
}

static Py_ssize_t
write_none(Picklerobject *self, const char *s, Py_ssize_t  n)
{
    if (s == NULL) return 0;
    return n;
}

static Py_ssize_t
write_other(Picklerobject *self, const char *s, Py_ssize_t  n)
{
    PyObject *py_str = 0, *junk = 0;

    if (s == NULL) {
        if (!( self->buf_size ))  return 0;
        py_str = PyString_FromStringAndSize(self->write_buf,
                                            self->buf_size);
        if (!py_str)
            return -1;
    }
    else {
        if (self->buf_size && n > WRITE_BUF_SIZE - self->buf_size) {
            if (write_other(self, NULL, 0) < 0)
                return -1;
        }

        if (n > WRITE_BUF_SIZE) {
            if (!( py_str =
                   PyString_FromStringAndSize(s, n)))
                return -1;
        }
        else {
            memcpy(self->write_buf + self->buf_size, s, n);
            self->buf_size += n;
            return n;
        }
    }

    if (self->write) {
        /* object with write method */
        ARG_TUP(self, py_str);
        if (self->arg) {
            junk = PyObject_Call(self->write, self->arg, NULL);
            FREE_ARG_TUP(self);
        }
        if (junk) Py_DECREF(junk);
        else return -1;
    }
    else
        PDATA_PUSH(self->file, py_str, -1);

    self->buf_size = 0;
    return n;
}


static Py_ssize_t
read_file(Unpicklerobject *self, char **s, Py_ssize_t n)
{
    size_t nbytesread;

    if (self->buf_size == 0) {
        Py_ssize_t size;

        size = ((n < 32) ? 32 : n);
        if (!( self->buf = (char *)malloc(size))) {
            PyErr_NoMemory();
            return -1;
        }

        self->buf_size = size;
    }
    else if (n > self->buf_size) {
        char *newbuf = (char *)realloc(self->buf, n);
        if (!newbuf)  {
            PyErr_NoMemory();
            return -1;
        }
        self->buf = newbuf;
        self->buf_size = n;
    }

    PyFile_IncUseCount((PyFileObject *)self->file);
    Py_BEGIN_ALLOW_THREADS
    nbytesread = fread(self->buf, sizeof(char), n, self->fp);
    Py_END_ALLOW_THREADS
    PyFile_DecUseCount((PyFileObject *)self->file);
    if (nbytesread != (size_t)n) {
        if (feof(self->fp)) {
            PyErr_SetNone(PyExc_EOFError);
            return -1;
        }

        PyErr_SetFromErrno(PyExc_IOError);
        return -1;
    }

    *s = self->buf;

    return n;
}


static Py_ssize_t
readline_file(Unpicklerobject *self, char **s)
{
    Py_ssize_t i;

    if (self->buf_size == 0) {
        if (!( self->buf = (char *)malloc(40))) {
            PyErr_NoMemory();
            return -1;
        }
        self->buf_size = 40;
    }

    i = 0;
    while (1) {
        Py_ssize_t bigger;
        char *newbuf;
        while (i < (self->buf_size - 1)) {
            int newchar = getc(self->fp);
            if (newchar != EOF) {
                self->buf[i++] = newchar;
            }
            if (newchar == EOF || newchar == '\n') {
                self->buf[i] = '\0';
                *s = self->buf;
                return i;
            }
        }
        if (self->buf_size > (PY_SSIZE_T_MAX >> 1)) {
            PyErr_NoMemory();
            return -1;
        }
        bigger = self->buf_size << 1;
        newbuf = (char *)realloc(self->buf, bigger);
        if (newbuf == NULL)  {
            PyErr_NoMemory();
            return -1;
        }
        self->buf = newbuf;
        self->buf_size = bigger;
    }
}


static Py_ssize_t
read_cStringIO(Unpicklerobject *self, char **s, Py_ssize_t  n)
{
    Py_ssize_t len = n;
    char *start, *end = NULL;

    while (1) {
        int k;
        char *ptr;
        if (n > INT_MAX)
            k = INT_MAX;
        else
            k = (int)n;
        if (PycStringIO->cread((PyObject *)self->file, &ptr, k) != k) {
            PyErr_SetNone(PyExc_EOFError);
            return -1;
        }
        if (end == NULL)
            start = ptr;
        else if (ptr != end) {
            /* non-continuous area */
            return -1;
        }
        if (n <= INT_MAX)
            break;
        end = ptr + INT_MAX;
        n -= INT_MAX;
    }

    *s = start;

    return len;
}


static Py_ssize_t
readline_cStringIO(Unpicklerobject *self, char **s)
{
    Py_ssize_t n = 0;
    char *start = NULL, *end = NULL;

    while (1) {
        int k;
        char *ptr;
        if ((k = PycStringIO->creadline((PyObject *)self->file, &ptr)) < 0) {
            return -1;
        }
        n += k;
        if (end == NULL)
            start = ptr;
        else if (ptr != end) {
            /* non-continuous area */
            return -1;
        }
        if (k == 0 || ptr[k - 1] == '\n')
            break;
        end = ptr + k;
    }

    *s = start;

    return n;
}


static Py_ssize_t
read_other(Unpicklerobject *self, char **s, Py_ssize_t  n)
{
    PyObject *bytes, *str=0;

    if (!( bytes = PyInt_FromSsize_t(n)))  return -1;

    ARG_TUP(self, bytes);
    if (self->arg) {
        str = PyObject_Call(self->read, self->arg, NULL);
        FREE_ARG_TUP(self);
    }
    if (! str) return -1;

    Py_XSETREF(self->last_string, str);

    if (! (*s = PyString_AsString(str))) return -1;

    if (PyString_GET_SIZE(str) != n) {
        PyErr_SetNone(PyExc_EOFError);
        return -1;
    }

    return n;
}


static Py_ssize_t
readline_other(Unpicklerobject *self, char **s)
{
    PyObject *str;
    Py_ssize_t str_size;

    if (!( str = PyObject_CallObject(self->readline, empty_tuple)))  {
        return -1;
    }

    if ((str_size = PyString_Size(str)) < 0)
        return -1;

    Py_XSETREF(self->last_string, str);

    if (! (*s = PyString_AsString(str)))
        return -1;

    return str_size;
}

/* Copy the first n bytes from s into newly malloc'ed memory, plus a
 * trailing 0 byte.  Return a pointer to that, or NULL if out of memory.
 * The caller is responsible for free()'ing the return value.
 */
static char *
pystrndup(const char *s, Py_ssize_t n)
{
    char *r = (char *)malloc(n+1);
    if (r == NULL)
        return (char*)PyErr_NoMemory();
    memcpy(r, s, n);
    r[n] = 0;
    return r;
}


static int
get(Picklerobject *self, PyObject *id)
{
    PyObject *value, *mv;
    Py_ssize_t c_value;
    char s[30];
    size_t len;

    if (!( mv = PyDict_GetItem(self->memo, id)))  {
        PyErr_SetObject(PyExc_KeyError, id);
        return -1;
    }

    if (!( value = PyTuple_GetItem(mv, 0)))
        return -1;

    if (!( PyInt_Check(value)))  {
        PyErr_SetString(PicklingError, "no int where int expected in memo");
        return -1;
    }
    c_value = PyInt_AS_LONG((PyIntObject*)value);

    if (!self->bin) {
        s[0] = GET;
        PyOS_snprintf(s + 1, sizeof(s) - 1,
                      "%" PY_FORMAT_SIZE_T "d\n", c_value);
        len = strlen(s);
    }
    else if (Pdata_Check(self->file)) {
        if (write_other(self, NULL, 0) < 0) return -1;
        PDATA_APPEND(self->file, mv, -1);
        return 0;
    }
    else {
        if (c_value < 256) {
            s[0] = BINGET;
            s[1] = (int)(c_value & 0xff);
            len = 2;
        }
        else if (c_value < 0x7fffffffL) {
            s[0] = LONG_BINGET;
            s[1] = (int)(c_value & 0xff);
            s[2] = (int)((c_value >> 8)  & 0xff);
            s[3] = (int)((c_value >> 16) & 0xff);
            s[4] = (int)((c_value >> 24) & 0xff);
            len = 5;
        }
        else { /* unlikely */
            PyErr_SetString(PicklingError,
                            "memo id too large for LONG_BINGET");
            return -1;
        }
    }

    if (self->write_func(self, s, len) < 0)
        return -1;

    return 0;
}


static int
put(Picklerobject *self, PyObject *ob)
{
    if (Py_REFCNT(ob) < 2 || self->fast)
        return 0;

    return put2(self, ob);
}


static int
put2(Picklerobject *self, PyObject *ob)
{
    char c_str[30];
    Py_ssize_t len, p;
    int res = -1;
    PyObject *py_ob_id = 0, *memo_len = 0, *t = 0;

    if (self->fast)
        return 0;

    if ((p = PyDict_Size(self->memo)) < 0)
        goto finally;

    /* Make sure memo keys are positive! */
    /* XXX Why?
     * XXX And does "positive" really mean non-negative?
     * XXX pickle.py starts with PUT index 0, not 1.  This makes for
     * XXX gratuitous differences between the pickling modules.
     */
    p++;

    if (!( py_ob_id = PyLong_FromVoidPtr(ob)))
        goto finally;

    if (!( memo_len = PyInt_FromLong(p)))
        goto finally;

    if (!( t = PyTuple_New(2)))
        goto finally;

    PyTuple_SET_ITEM(t, 0, memo_len);
    Py_INCREF(memo_len);
    PyTuple_SET_ITEM(t, 1, ob);
    Py_INCREF(ob);

    if (PyDict_SetItem(self->memo, py_ob_id, t) < 0)
        goto finally;

    if (!self->bin) {
        c_str[0] = PUT;
        PyOS_snprintf(c_str + 1, sizeof(c_str) - 1,
                      "%" PY_FORMAT_SIZE_T "d\n", p);
        len = strlen(c_str);
    }
    else if (Pdata_Check(self->file)) {
        if (write_other(self, NULL, 0) < 0) return -1;
        PDATA_APPEND(self->file, memo_len, -1);
        res=0;          /* Job well done ;) */
        goto finally;
    }
    else {
        if (p < 256) {
            c_str[0] = BINPUT;
            c_str[1] = p;
            len = 2;
        }
        else if (p < 0x7fffffffL) {
            c_str[0] = LONG_BINPUT;
            c_str[1] = (int)(p & 0xff);
            c_str[2] = (int)((p >> 8)  & 0xff);
            c_str[3] = (int)((p >> 16) & 0xff);
            c_str[4] = (int)((p >> 24) & 0xff);
            len = 5;
        }
        else { /* unlikely */
            PyErr_SetString(PicklingError,
                            "memo id too large for LONG_BINPUT");
            goto finally;
        }
    }

    if (self->write_func(self, c_str, len) < 0)
        goto finally;

    res = 0;

  finally:
    Py_XDECREF(py_ob_id);
    Py_XDECREF(memo_len);
    Py_XDECREF(t);

    return res;
}

static PyObject *
whichmodule(PyObject *global, PyObject *global_name)
{
    Py_ssize_t i, j;
    PyObject *module = 0, *modules_dict = 0,
        *global_name_attr = 0, *name = 0;

    module = PyObject_GetAttrString(global, "__module__");
    if (module)
        return module;
    if (PyErr_ExceptionMatches(PyExc_AttributeError))
        PyErr_Clear();
    else
        return NULL;

    if (!( modules_dict = PySys_GetObject("modules")))
        return NULL;

    i = 0;
    while ((j = PyDict_Next(modules_dict, &i, &name, &module))) {

        if (PyObject_Compare(name, __main___str)==0) continue;

        global_name_attr = PyObject_GetAttr(module, global_name);
        if (!global_name_attr)  {
            if (PyErr_ExceptionMatches(PyExc_AttributeError))
                PyErr_Clear();
            else
                return NULL;
            continue;
        }

        if (global_name_attr != global) {
            Py_DECREF(global_name_attr);
            continue;
        }

        Py_DECREF(global_name_attr);

        break;
    }

    /* The following implements the rule in pickle.py added in 1.5
       that used __main__ if no module is found.  I don't actually
       like this rule. jlf
    */
    if (!j) {
        name=__main___str;
    }

    Py_INCREF(name);
    return name;
}


static int
fast_save_enter(Picklerobject *self, PyObject *obj)
{
    /* if fast_container < 0, we're doing an error exit. */
    if (++self->fast_container >= PY_CPICKLE_FAST_LIMIT) {
        PyObject *key = NULL;
        if (self->fast_memo == NULL) {
            self->fast_memo = PyDict_New();
            if (self->fast_memo == NULL) {
                self->fast_container = -1;
                return 0;
            }
        }
        key = PyLong_FromVoidPtr(obj);
        if (key == NULL)
            return 0;
        if (PyDict_GetItem(self->fast_memo, key)) {
            Py_DECREF(key);
            PyErr_Format(PyExc_ValueError,
                         "fast mode: can't pickle cyclic objects "
                         "including object type %s at %p",
                         Py_TYPE(obj)->tp_name, obj);
            self->fast_container = -1;
            return 0;
        }
        if (PyDict_SetItem(self->fast_memo, key, Py_None) < 0) {
            Py_DECREF(key);
            self->fast_container = -1;
            return 0;
        }
        Py_DECREF(key);
    }
    return 1;
}

int
fast_save_leave(Picklerobject *self, PyObject *obj)
{
    if (self->fast_container-- >= PY_CPICKLE_FAST_LIMIT) {
        PyObject *key = PyLong_FromVoidPtr(obj);
        if (key == NULL)
            return 0;
        if (PyDict_DelItem(self->fast_memo, key) < 0) {
            Py_DECREF(key);
            return 0;
        }
        Py_DECREF(key);
    }
    return 1;
}

static int
save_none(Picklerobject *self, PyObject *args)
{
    static char none = NONE;
    if (self->write_func(self, &none, 1) < 0)
        return -1;

    return 0;
}

static int
save_bool(Picklerobject *self, PyObject *args)
{
    static const char *buf[2] = {FALSE, TRUE};
    static char len[2] = {sizeof(FALSE)-1, sizeof(TRUE)-1};
    long l = PyInt_AS_LONG((PyIntObject *)args);

    if (self->proto >= 2) {
        char opcode = l ? NEWTRUE : NEWFALSE;
        if (self->write_func(self, &opcode, 1) < 0)
            return -1;
    }
    else if (self->write_func(self, buf[l], len[l]) < 0)
        return -1;
    return 0;
}

static int
save_int(Picklerobject *self, PyObject *args)
{
    char c_str[32];
    long l = PyInt_AS_LONG((PyIntObject *)args);
    Py_ssize_t len = 0;

    if (!self->bin
#if SIZEOF_LONG > 4
        || l >  0x7fffffffL
        || l < -0x80000000L
#endif
        ) {
        /* Text-mode pickle, or long too big to fit in the 4-byte
         * signed BININT format:  store as a string.
         */
        c_str[0] = INT;
        PyOS_snprintf(c_str + 1, sizeof(c_str) - 1, "%ld\n", l);
        if (self->write_func(self, c_str, strlen(c_str)) < 0)
            return -1;
    }
    else {
        /* Binary pickle and l fits in a signed 4-byte int. */
        c_str[1] = (int)( l        & 0xff);
        c_str[2] = (int)((l >> 8)  & 0xff);
        c_str[3] = (int)((l >> 16) & 0xff);
        c_str[4] = (int)((l >> 24) & 0xff);

        if ((c_str[4] == 0) && (c_str[3] == 0)) {
            if (c_str[2] == 0) {
                c_str[0] = BININT1;
                len = 2;
            }
            else {
                c_str[0] = BININT2;
                len = 3;
            }
        }
        else {
            c_str[0] = BININT;
            len = 5;
        }

        if (self->write_func(self, c_str, len) < 0)
            return -1;
    }

    return 0;
}


static int
save_long(Picklerobject *self, PyObject *args)
{
    Py_ssize_t size;
    int res = -1;
    PyObject *repr = NULL;

    static char l = LONG;

    if (self->proto >= 2) {
        /* Linear-time pickling. */
        size_t nbits;
        size_t nbytes;
        unsigned char *pdata;
        char c_str[5];
        int i;
        int sign = _PyLong_Sign(args);

        if (sign == 0) {
            /* It's 0 -- an empty bytestring. */
            c_str[0] = LONG1;
            c_str[1] = 0;
            i = self->write_func(self, c_str, 2);
            if (i < 0) goto finally;
            res = 0;
            goto finally;
        }
        nbits = _PyLong_NumBits(args);
        if (nbits == (size_t)-1 && PyErr_Occurred())
            goto finally;
        /* How many bytes do we need?  There are nbits >> 3 full
         * bytes of data, and nbits & 7 leftover bits.  If there
         * are any leftover bits, then we clearly need another
         * byte.  Wnat's not so obvious is that we *probably*
         * need another byte even if there aren't any leftovers:
         * the most-significant bit of the most-significant byte
         * acts like a sign bit, and it's usually got a sense
         * opposite of the one we need.  The exception is longs
         * of the form -(2**(8*j-1)) for j > 0.  Such a long is
         * its own 256's-complement, so has the right sign bit
         * even without the extra byte.  That's a pain to check
         * for in advance, though, so we always grab an extra
         * byte at the start, and cut it back later if possible.
         */
        nbytes = (nbits >> 3) + 1;
        if (nbytes > INT_MAX) {
            PyErr_SetString(PyExc_OverflowError, "long too large "
                "to pickle");
            goto finally;
        }
        repr = PyString_FromStringAndSize(NULL, (int)nbytes);
        if (repr == NULL) goto finally;
        pdata = (unsigned char *)PyString_AS_STRING(repr);
        i = _PyLong_AsByteArray((PyLongObject *)args,
                        pdata, nbytes,
                        1 /* little endian */, 1 /* signed */);
        if (i < 0) goto finally;
        /* If the long is negative, this may be a byte more than
         * needed.  This is so iff the MSB is all redundant sign
         * bits.
         */
        if (sign < 0 && nbytes > 1 && pdata[nbytes - 1] == 0xff &&
            (pdata[nbytes - 2] & 0x80) != 0)
            --nbytes;

        if (nbytes < 256) {
            c_str[0] = LONG1;
            c_str[1] = (char)nbytes;
            size = 2;
        }
        else {
            c_str[0] = LONG4;
            size = (int)nbytes;
            for (i = 1; i < 5; i++) {
                c_str[i] = (char)(size & 0xff);
                size >>= 8;
            }
            size = 5;
        }
        i = self->write_func(self, c_str, size);
        if (i < 0) goto finally;
        i = self->write_func(self, (char *)pdata, (int)nbytes);
        if (i < 0) goto finally;
        res = 0;
        goto finally;
    }

    /* proto < 2:  write the repr and newline.  This is quadratic-time
     * (in the number of digits), in both directions.
     */
    if (!( repr = PyObject_Repr(args)))
        goto finally;

    if ((size = PyString_Size(repr)) < 0)
        goto finally;

    if (self->write_func(self, &l, 1) < 0)
        goto finally;

    if (self->write_func(self,
                         PyString_AS_STRING((PyStringObject *)repr),
                                            size) < 0)
        goto finally;

    if (self->write_func(self, "\n", 1) < 0)
        goto finally;

    res = 0;

  finally:
    Py_XDECREF(repr);
    return res;
}


static int
save_float(Picklerobject *self, PyObject *args)
{
    double x = PyFloat_AS_DOUBLE((PyFloatObject *)args);

    if (self->bin) {
        char str[9];
        str[0] = BINFLOAT;
        if (_PyFloat_Pack8(x, (unsigned char *)&str[1], 0) < 0)
            return -1;
        if (self->write_func(self, str, 9) < 0)
            return -1;
    }
    else {
        int result = -1;
        char *buf = NULL;
        char op = FLOAT;

        if (self->write_func(self, &op, 1) < 0)
            goto done;

        buf = PyOS_double_to_string(x, 'g', 17, 0, NULL);
        if (!buf) {
            PyErr_NoMemory();
            goto done;
        }

        if (self->write_func(self, buf, strlen(buf)) < 0)
            goto done;

        if (self->write_func(self, "\n", 1) < 0)
            goto done;

        result = 0;
done:
        PyMem_Free(buf);
        return result;
    }

    return 0;
}


static int
save_string(Picklerobject *self, PyObject *args, int doput)
{
    Py_ssize_t size, len;
    PyObject *repr=0;

    if ((size = PyString_Size(args)) < 0)
        return -1;

    if (!self->bin) {
        char *repr_str;

        static char string = STRING;

        if (!( repr = PyObject_Repr(args)))
            return -1;

        if ((len = PyString_Size(repr)) < 0)
            goto err;
        repr_str = PyString_AS_STRING((PyStringObject *)repr);

        if (self->write_func(self, &string, 1) < 0)
            goto err;

        if (self->write_func(self, repr_str, len) < 0)
            goto err;

        if (self->write_func(self, "\n", 1) < 0)
            goto err;

        Py_XDECREF(repr);
    }
    else {
        int i;
        char c_str[5];

        if (size < 256) {
            c_str[0] = SHORT_BINSTRING;
            c_str[1] = size;
            len = 2;
        }
        else if (size <= 0x7fffffffL) {
            c_str[0] = BINSTRING;
            for (i = 1; i < 5; i++)
                c_str[i] = (int)(size >> ((i - 1) * 8));
            len = 5;
        }
        else {
            PyErr_SetString(PyExc_OverflowError,
                            "cannot serialize a string larger than 2 GiB");
            return -1;    /* string too large */
        }

        if (self->write_func(self, c_str, len) < 0)
            return -1;

        if (size > 128 && Pdata_Check(self->file)) {
            if (write_other(self, NULL, 0) < 0) return -1;
            PDATA_APPEND(self->file, args, -1);
        }
        else {
            if (self->write_func(self,
                                 PyString_AS_STRING(
                                    (PyStringObject *)args),
                                 size) < 0)
                return -1;
        }
    }

    if (doput)
        if (put(self, args) < 0)
            return -1;

    return 0;

  err:
    Py_XDECREF(repr);
    return -1;
}


#ifdef Py_USING_UNICODE
/* A copy of PyUnicode_EncodeRawUnicodeEscape() that also translates
   backslash and newline characters to \uXXXX escapes. */
static PyObject *
modified_EncodeRawUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size)
{
    PyObject *repr;
    char *p;
    char *q;

    static const char *hexdigit = "0123456789abcdef";
#ifdef Py_UNICODE_WIDE
    const Py_ssize_t expandsize = 10;
#else
    const Py_ssize_t expandsize = 6;
#endif

    if (size > PY_SSIZE_T_MAX / expandsize)
        return PyErr_NoMemory();

    repr = PyString_FromStringAndSize(NULL, expandsize * size);
    if (repr == NULL)
        return NULL;
    if (size == 0)
        return repr;

    p = q = PyString_AS_STRING(repr);
    while (size-- > 0) {
        Py_UNICODE ch = *s++;
#ifdef Py_UNICODE_WIDE
        /* Map 32-bit characters to '\Uxxxxxxxx' */
        if (ch >= 0x10000) {
            *p++ = '\\';
            *p++ = 'U';
            *p++ = hexdigit[(ch >> 28) & 0xf];
            *p++ = hexdigit[(ch >> 24) & 0xf];
            *p++ = hexdigit[(ch >> 20) & 0xf];
            *p++ = hexdigit[(ch >> 16) & 0xf];
            *p++ = hexdigit[(ch >> 12) & 0xf];
            *p++ = hexdigit[(ch >> 8) & 0xf];
            *p++ = hexdigit[(ch >> 4) & 0xf];
            *p++ = hexdigit[ch & 15];
        }
        else
#else
        /* Map UTF-16 surrogate pairs to '\U00xxxxxx' */
        if (ch >= 0xD800 && ch < 0xDC00) {
            Py_UNICODE ch2;
            Py_UCS4 ucs;

            ch2 = *s++;
            size--;
            if (ch2 >= 0xDC00 && ch2 <= 0xDFFF) {
                ucs = (((ch & 0x03FF) << 10) | (ch2 & 0x03FF)) + 0x00010000;
                *p++ = '\\';
                *p++ = 'U';
                *p++ = hexdigit[(ucs >> 28) & 0xf];
                *p++ = hexdigit[(ucs >> 24) & 0xf];
                *p++ = hexdigit[(ucs >> 20) & 0xf];
                *p++ = hexdigit[(ucs >> 16) & 0xf];
                *p++ = hexdigit[(ucs >> 12) & 0xf];
                *p++ = hexdigit[(ucs >> 8) & 0xf];
                *p++ = hexdigit[(ucs >> 4) & 0xf];
                *p++ = hexdigit[ucs & 0xf];
                continue;
            }
            /* Fall through: isolated surrogates are copied as-is */
            s--;
            size++;
        }
#endif
        /* Map 16-bit characters to '\uxxxx' */
        if (ch >= 256 || ch == '\\' || ch == '\n') {
            *p++ = '\\';
            *p++ = 'u';
            *p++ = hexdigit[(ch >> 12) & 0xf];
            *p++ = hexdigit[(ch >> 8) & 0xf];
            *p++ = hexdigit[(ch >> 4) & 0xf];
            *p++ = hexdigit[ch & 15];
        }
        /* Copy everything else as-is */
        else
            *p++ = (char) ch;
    }
    *p = '\0';
    _PyString_Resize(&repr, p - q);
    return repr;
}

static int
save_unicode(Picklerobject *self, PyObject *args, int doput)
{
    Py_ssize_t size, len;
    PyObject *repr=0;

    if (!PyUnicode_Check(args))
        return -1;

    if (!self->bin) {
        char *repr_str;
        static char string = UNICODE;

        repr = modified_EncodeRawUnicodeEscape(
            PyUnicode_AS_UNICODE(args), PyUnicode_GET_SIZE(args));
        if (!repr)
            return -1;

        if ((len = PyString_Size(repr)) < 0)
            goto err;
        repr_str = PyString_AS_STRING((PyStringObject *)repr);

        if (self->write_func(self, &string, 1) < 0)
            goto err;

        if (self->write_func(self, repr_str, len) < 0)
            goto err;

        if (self->write_func(self, "\n", 1) < 0)
            goto err;

        Py_XDECREF(repr);
    }
    else {
        int i;
        char c_str[5];

        if (!( repr = PyUnicode_AsUTF8String(args)))
            return -1;

        if ((size = PyString_Size(repr)) < 0)
            goto err;
        if (size > 0x7fffffffL) {
            PyErr_SetString(PyExc_OverflowError,
                            "cannot serialize a Unicode string larger than 2 GiB");
            goto err;   /* string too large */
        }

        c_str[0] = BINUNICODE;
        for (i = 1; i < 5; i++)
            c_str[i] = (int)(size >> ((i - 1) * 8));
        len = 5;

        if (self->write_func(self, c_str, len) < 0)
            goto err;

        if (size > 128 && Pdata_Check(self->file)) {
            if (write_other(self, NULL, 0) < 0)
                goto err;
            PDATA_APPEND(self->file, repr, -1);
        }
        else {
            if (self->write_func(self, PyString_AS_STRING(repr),
                                 size) < 0)
                goto err;
        }

        Py_DECREF(repr);
    }

    if (doput)
        if (put(self, args) < 0)
            return -1;

    return 0;

  err:
    Py_XDECREF(repr);
    return -1;
}
#endif

/* A helper for save_tuple.  Push the len elements in tuple t on the stack. */
static int
store_tuple_elements(Picklerobject *self, PyObject *t, int len)
{
    Py_ssize_t i;
    int res = -1;       /* guilty until proved innocent */

    assert(PyTuple_Size(t) == len);

    for (i = 0; i < len; i++) {
        PyObject *element = PyTuple_GET_ITEM(t, i);

        if (element == NULL)
            goto finally;
        if (save(self, element, 0) < 0)
            goto finally;
    }
    res = 0;

  finally:
    return res;
}

/* Tuples are ubiquitous in the pickle protocols, so many techniques are
 * used across protocols to minimize the space needed to pickle them.
 * Tuples are also the only builtin immutable type that can be recursive
 * (a tuple can be reached from itself), and that requires some subtle
 * magic so that it works in all cases.  IOW, this is a long routine.
 */
static int
save_tuple(Picklerobject *self, PyObject *args)
{
    PyObject *py_tuple_id = NULL;
    Py_ssize_t len, i;
    int res = -1;

    static char tuple = TUPLE;
    static char pop = POP;
    static char pop_mark = POP_MARK;
    static char len2opcode[] = {EMPTY_TUPLE, TUPLE1, TUPLE2, TUPLE3};

    if ((len = PyTuple_Size(args)) < 0)
        goto finally;

    if (len == 0) {
        char c_str[2];

        if (self->proto) {
            c_str[0] = EMPTY_TUPLE;
            len = 1;
        }
        else {
            c_str[0] = MARK;
            c_str[1] = TUPLE;
            len = 2;
        }
        if (self->write_func(self, c_str, len) >= 0)
            res = 0;
        /* Don't memoize an empty tuple. */
        goto finally;
    }

    /* A non-empty tuple. */

    /* id(tuple) isn't in the memo now.  If it shows up there after
     * saving the tuple elements, the tuple must be recursive, in
     * which case we'll pop everything we put on the stack, and fetch
     * its value from the memo.
     */
    py_tuple_id = PyLong_FromVoidPtr(args);
    if (py_tuple_id == NULL)
        goto finally;

    if (len <= 3 && self->proto >= 2) {
        /* Use TUPLE{1,2,3} opcodes. */
        if (store_tuple_elements(self, args, len) < 0)
            goto finally;
        if (PyDict_GetItem(self->memo, py_tuple_id)) {
            /* pop the len elements */
            for (i = 0; i < len; ++i)
                if (self->write_func(self, &pop, 1) < 0)
                    goto finally;
            /* fetch from memo */
            if (get(self, py_tuple_id) < 0)
                goto finally;
            res = 0;
            goto finally;
        }
        /* Not recursive. */
        if (self->write_func(self, len2opcode + len, 1) < 0)
            goto finally;
        goto memoize;
    }

    /* proto < 2 and len > 0, or proto >= 2 and len > 3.
     * Generate MARK elt1 elt2 ... TUPLE
     */
    if (self->write_func(self, &MARKv, 1) < 0)
        goto finally;

    if (store_tuple_elements(self, args, len) < 0)
        goto finally;

    if (PyDict_GetItem(self->memo, py_tuple_id)) {
        /* pop the stack stuff we pushed */
        if (self->bin) {
            if (self->write_func(self, &pop_mark, 1) < 0)
                goto finally;
        }
        else {
            /* Note that we pop one more than len, to remove
             * the MARK too.
             */
            for (i = 0; i <= len; i++)
                if (self->write_func(self, &pop, 1) < 0)
                    goto finally;
        }
        /* fetch from memo */
        if (get(self, py_tuple_id) >= 0)
            res = 0;
        goto finally;
    }

    /* Not recursive. */
    if (self->write_func(self, &tuple, 1) < 0)
        goto finally;

  memoize:
    if (put(self, args) >= 0)
        res = 0;

  finally:
    Py_XDECREF(py_tuple_id);
    return res;
}

/* iter is an iterator giving items, and we batch up chunks of
 *     MARK item item ... item APPENDS
 * opcode sequences.  Calling code should have arranged to first create an
 * empty list, or list-like object, for the APPENDS to operate on.
 * Returns 0 on success, <0 on error.
 */
static int
batch_list(Picklerobject *self, PyObject *iter)
{
    PyObject *obj = NULL;
    PyObject *firstitem = NULL;
    int i, n;

    static char append = APPEND;
    static char appends = APPENDS;

    assert(iter != NULL);

    if (self->proto == 0) {
        /* APPENDS isn't available; do one at a time. */
        for (;;) {
            obj = PyIter_Next(iter);
            if (obj == NULL) {
                if (PyErr_Occurred())
                    return -1;
                break;
            }
            i = save(self, obj, 0);
            Py_DECREF(obj);
            if (i < 0)
                return -1;
            if (self->write_func(self, &append, 1) < 0)
                return -1;
        }
        return 0;
    }

    /* proto > 0:  write in batches of BATCHSIZE. */
    do {
        /* Get first item */
        firstitem = PyIter_Next(iter);
        if (firstitem == NULL) {
            if (PyErr_Occurred())
                goto BatchFailed;

            /* nothing more to add */
            break;
        }

        /* Try to get a second item */
        obj = PyIter_Next(iter);
        if (obj == NULL) {
            if (PyErr_Occurred())
                goto BatchFailed;

            /* Only one item to write */
            if (save(self, firstitem, 0) < 0)
                goto BatchFailed;
            if (self->write_func(self, &append, 1) < 0)
                goto BatchFailed;
            Py_CLEAR(firstitem);
            break;
        }

        /* More than one item to write */

        /* Pump out MARK, items, APPENDS. */
        if (self->write_func(self, &MARKv, 1) < 0)
            goto BatchFailed;

        if (save(self, firstitem, 0) < 0)
            goto BatchFailed;
        Py_CLEAR(firstitem);
        n = 1;

        /* Fetch and save up to BATCHSIZE items */
        while (obj) {
            if (save(self, obj, 0) < 0)
                goto BatchFailed;
            Py_CLEAR(obj);
            n += 1;

            if (n == BATCHSIZE)
                break;

            obj = PyIter_Next(iter);
            if (obj == NULL) {
                if (PyErr_Occurred())
                    goto BatchFailed;
                break;
            }
        }

        if (self->write_func(self, &appends, 1) < 0)
            goto BatchFailed;

    } while (n == BATCHSIZE);
    return 0;

BatchFailed:
    Py_XDECREF(firstitem);
    Py_XDECREF(obj);
    return -1;
}

static int
save_list(Picklerobject *self, PyObject *args)
{
    int res = -1;
    char s[3];
    Py_ssize_t len;
    PyObject *iter;

    if (self->fast && !fast_save_enter(self, args))
        goto finally;

    /* Create an empty list. */
    if (self->bin) {
        s[0] = EMPTY_LIST;
        len = 1;
    }
    else {
        s[0] = MARK;
        s[1] = LIST;
        len = 2;
    }

    if (self->write_func(self, s, len) < 0)
        goto finally;

    /* Get list length, and bow out early if empty. */
    if ((len = PyList_Size(args)) < 0)
        goto finally;

    /* Memoize. */
    if (len == 0) {
        if (put(self, args) >= 0)
            res = 0;
        goto finally;
    }
    if (put2(self, args) < 0)
        goto finally;

    /* Materialize the list elements. */
    iter = PyObject_GetIter(args);
    if (iter == NULL)
        goto finally;

    if (Py_EnterRecursiveCall(" while pickling an object") == 0)
    {
        res = batch_list(self, iter);
        Py_LeaveRecursiveCall();
    }
    Py_DECREF(iter);

  finally:
    if (self->fast && !fast_save_leave(self, args))
        res = -1;

    return res;
}


/* iter is an iterator giving (key, value) pairs, and we batch up chunks of
 *     MARK key value ... key value SETITEMS
 * opcode sequences.  Calling code should have arranged to first create an
 * empty dict, or dict-like object, for the SETITEMS to operate on.
 * Returns 0 on success, <0 on error.
 *
 * This is very much like batch_list().  The difference between saving
 * elements directly, and picking apart two-tuples, is so long-winded at
 * the C level, though, that attempts to combine these routines were too
 * ugly to bear.
 */
static int
batch_dict(Picklerobject *self, PyObject *iter)
{
    PyObject *p = NULL;
    PyObject *firstitem = NULL;
    int i, n;

    static char setitem = SETITEM;
    static char setitems = SETITEMS;

    assert(iter != NULL);

    if (self->proto == 0) {
        /* SETITEMS isn't available; do one at a time. */
        for (;;) {
            p = PyIter_Next(iter);
            if (p == NULL) {
                if (PyErr_Occurred())
                    return -1;
                break;
            }
            if (!PyTuple_Check(p) || PyTuple_Size(p) != 2) {
                PyErr_SetString(PyExc_TypeError, "dict items "
                    "iterator must return 2-tuples");
                return -1;
            }
            i = save(self, PyTuple_GET_ITEM(p, 0), 0);
            if (i >= 0)
                i = save(self, PyTuple_GET_ITEM(p, 1), 0);
            Py_DECREF(p);
            if (i < 0)
                return -1;
            if (self->write_func(self, &setitem, 1) < 0)
                return -1;
        }
        return 0;
    }

    /* proto > 0:  write in batches of BATCHSIZE. */
    do {
        /* Get first item */
        firstitem = PyIter_Next(iter);
        if (firstitem == NULL) {
            if (PyErr_Occurred())
                goto BatchFailed;

            /* nothing more to add */
            break;
        }
        if (!PyTuple_Check(firstitem) || PyTuple_Size(firstitem) != 2) {
            PyErr_SetString(PyExc_TypeError, "dict items "
                            "iterator must return 2-tuples");
            goto BatchFailed;
        }

        /* Try to get a second item */
        p = PyIter_Next(iter);
        if (p == NULL) {
            if (PyErr_Occurred())
                goto BatchFailed;

            /* Only one item to write */
            if (save(self, PyTuple_GET_ITEM(firstitem, 0), 0) < 0)
                goto BatchFailed;
            if (save(self, PyTuple_GET_ITEM(firstitem, 1), 0) < 0)
                goto BatchFailed;
            if (self->write_func(self, &setitem, 1) < 0)
                goto BatchFailed;
            Py_CLEAR(firstitem);
            break;
        }

        /* More than one item to write */

        /* Pump out MARK, items, SETITEMS. */
        if (self->write_func(self, &MARKv, 1) < 0)
            goto BatchFailed;

        if (save(self, PyTuple_GET_ITEM(firstitem, 0), 0) < 0)
            goto BatchFailed;
        if (save(self, PyTuple_GET_ITEM(firstitem, 1), 0) < 0)
            goto BatchFailed;
        Py_CLEAR(firstitem);
        n = 1;

        /* Fetch and save up to BATCHSIZE items */
        while (p) {
            if (!PyTuple_Check(p) || PyTuple_Size(p) != 2) {
                PyErr_SetString(PyExc_TypeError, "dict items "
                    "iterator must return 2-tuples");
                goto BatchFailed;
            }
            if (save(self, PyTuple_GET_ITEM(p, 0), 0) < 0)
                goto BatchFailed;
            if (save(self, PyTuple_GET_ITEM(p, 1), 0) < 0)
                goto BatchFailed;
            Py_CLEAR(p);
            n += 1;

            if (n == BATCHSIZE)
                break;

            p = PyIter_Next(iter);
            if (p == NULL) {
                if (PyErr_Occurred())
                    goto BatchFailed;
                break;
            }
        }

        if (self->write_func(self, &setitems, 1) < 0)
            goto BatchFailed;

    } while (n == BATCHSIZE);
    return 0;

BatchFailed:
    Py_XDECREF(firstitem);
    Py_XDECREF(p);
    return -1;
}

/* This is a variant of batch_dict() above that specializes for dicts, with no
 * support for dict subclasses. Like batch_dict(), we batch up chunks of
 *     MARK key value ... key value SETITEMS
 * opcode sequences.  Calling code should have arranged to first create an
 * empty dict, or dict-like object, for the SETITEMS to operate on.
 * Returns 0 on success, -1 on error.
 *
 * Note that this currently doesn't work for protocol 0.
 */
static int
batch_dict_exact(Picklerobject *self, PyObject *obj)
{
    PyObject *key = NULL, *value = NULL;
    int i;
    Py_ssize_t dict_size, ppos = 0;

    static char setitem = SETITEM;
    static char setitems = SETITEMS;

    assert(obj != NULL);
    assert(self->proto > 0);

    dict_size = PyDict_Size(obj);

    /* Special-case len(d) == 1 to save space. */
    if (dict_size == 1) {
        PyDict_Next(obj, &ppos, &key, &value);
        if (save(self, key, 0) < 0)
            return -1;
        if (save(self, value, 0) < 0)
            return -1;
        if (self->write_func(self, &setitem, 1) < 0)
            return -1;
        return 0;
    }

    /* Write in batches of BATCHSIZE. */
    do {
        i = 0;
        if (self->write_func(self, &MARKv, 1) < 0)
            return -1;
        while (PyDict_Next(obj, &ppos, &key, &value)) {
            if (save(self, key, 0) < 0)
                return -1;
            if (save(self, value, 0) < 0)
                return -1;
            if (++i == BATCHSIZE)
                break;
        }
        if (self->write_func(self, &setitems, 1) < 0)
            return -1;
        if (PyDict_Size(obj) != dict_size) {
            PyErr_Format(
                PyExc_RuntimeError,
                "dictionary changed size during iteration");
            return -1;
        }

    } while (i == BATCHSIZE);
    return 0;
}

static int
save_dict(Picklerobject *self, PyObject *args)
{
    int res = -1;
    char s[3];
    Py_ssize_t len;

    if (self->fast && !fast_save_enter(self, args))
        goto finally;

    /* Create an empty dict. */
    if (self->bin) {
        s[0] = EMPTY_DICT;
        len = 1;
    }
    else {
        s[0] = MARK;
        s[1] = DICT;
        len = 2;
    }

    if (self->write_func(self, s, len) < 0)
        goto finally;

    /* Get dict size, and bow out early if empty. */
    if ((len = PyDict_Size(args)) < 0)
        goto finally;

    if (len == 0) {
        if (put(self, args) >= 0)
            res = 0;
        goto finally;
    }
    if (put2(self, args) < 0)
        goto finally;

    /* Materialize the dict items. */
    if (PyDict_CheckExact(args) && self->proto > 0) {
        /* We can take certain shortcuts if we know this is a dict and
           not a dict subclass. */
        if (Py_EnterRecursiveCall(" while pickling an object") == 0) {
            res = batch_dict_exact(self, args);
            Py_LeaveRecursiveCall();
        }
    } else {
        PyObject *iter = PyObject_CallMethod(args, "iteritems", "()");
        if (iter == NULL)
            goto finally;
        if (Py_EnterRecursiveCall(" while pickling an object") == 0) {
            res = batch_dict(self, iter);
            Py_LeaveRecursiveCall();
        }
        Py_DECREF(iter);
    }

  finally:
    if (self->fast && !fast_save_leave(self, args))
        res = -1;

    return res;
}


static int
save_inst(Picklerobject *self, PyObject *args)
{
    PyObject *class = 0, *module = 0, *name = 0, *state = 0,
        *getinitargs_func = 0, *getstate_func = 0, *class_args = 0;
    char *module_str, *name_str;
    int module_size, name_size, res = -1;

    static char inst = INST, obj = OBJ, build = BUILD;

    if (self->fast && !fast_save_enter(self, args))
        goto finally;

    if (self->write_func(self, &MARKv, 1) < 0)
        goto finally;

    if (!( class = PyObject_GetAttr(args, __class___str)))
        goto finally;

    if (self->bin) {
        if (save(self, class, 0) < 0)
            goto finally;
    }

    if ((getinitargs_func = PyObject_GetAttr(args, __getinitargs___str))) {
        PyObject *element = 0;
        Py_ssize_t i, len;

        if (!( class_args =
               PyObject_Call(getinitargs_func, empty_tuple, NULL)))
            goto finally;

        if ((len = PyObject_Size(class_args)) < 0)
            goto finally;

        for (i = 0; i < len; i++) {
            if (!( element = PySequence_GetItem(class_args, i)))
                goto finally;

            if (save(self, element, 0) < 0) {
                Py_DECREF(element);
                goto finally;
            }

            Py_DECREF(element);
        }
    }
    else {
        if (PyErr_ExceptionMatches(PyExc_AttributeError))
            PyErr_Clear();
        else
            goto finally;
    }

    if (!self->bin) {
        if (!( name = ((PyClassObject *)class)->cl_name ))  {
            PyErr_SetString(PicklingError, "class has no name");
            goto finally;
        }

        if (!( module = whichmodule(class, name)))
            goto finally;


        if ((module_size = PyString_Size(module)) < 0 ||
            (name_size = PyString_Size(name)) < 0)
            goto finally;

        module_str = PyString_AS_STRING((PyStringObject *)module);
        name_str   = PyString_AS_STRING((PyStringObject *)name);

        if (self->write_func(self, &inst, 1) < 0)
            goto finally;

        if (self->write_func(self, module_str, module_size) < 0)
            goto finally;

        if (self->write_func(self, "\n", 1) < 0)
            goto finally;

        if (self->write_func(self, name_str, name_size) < 0)
            goto finally;

        if (self->write_func(self, "\n", 1) < 0)
            goto finally;
    }
    else if (self->write_func(self, &obj, 1) < 0) {
        goto finally;
    }

    if ((getstate_func = PyObject_GetAttr(args, __getstate___str))) {
        state = PyObject_Call(getstate_func, empty_tuple, NULL);
        if (!state)
            goto finally;
    }
    else {
        if (PyErr_ExceptionMatches(PyExc_AttributeError))
            PyErr_Clear();
        else
            goto finally;

        if (!( state = PyObject_GetAttr(args, __dict___str)))  {
            if (PyErr_ExceptionMatches(PyExc_AttributeError))
                PyErr_Clear();
            else
                goto finally;
            res = 0;
            goto finally;
        }
    }

    if (!PyDict_Check(state)) {
        if (put2(self, args) < 0)
            goto finally;
    }
    else {
        if (put(self, args) < 0)
            goto finally;
    }

    if (save(self, state, 0) < 0)
        goto finally;

    if (self->write_func(self, &build, 1) < 0)
        goto finally;

    res = 0;

  finally:
    if (self->fast && !fast_save_leave(self, args))
        res = -1;

    Py_XDECREF(module);
    Py_XDECREF(class);
    Py_XDECREF(state);
    Py_XDECREF(getinitargs_func);
    Py_XDECREF(getstate_func);
    Py_XDECREF(class_args);

    return res;
}


static int
save_global(Picklerobject *self, PyObject *args, PyObject *name)
{
    PyObject *global_name = 0, *module = 0, *mod = 0, *klass = 0;
    char *name_str, *module_str;
    int module_size, name_size, res = -1;

    static char global = GLOBAL;

    if (name) {
        global_name = name;
        Py_INCREF(global_name);
    }
    else {
        if (!( global_name = PyObject_GetAttr(args, __name___str)))
            goto finally;
    }

    if (!( module = whichmodule(args, global_name)))
        goto finally;

    if ((module_size = PyString_Size(module)) < 0 ||
        (name_size = PyString_Size(global_name)) < 0)
        goto finally;

    module_str = PyString_AS_STRING((PyStringObject *)module);
    name_str   = PyString_AS_STRING((PyStringObject *)global_name);

    /* XXX This can be doing a relative import.  Clearly it shouldn't,
       but I don't know how to stop it. :-( */
    mod = PyImport_ImportModule(module_str);
    if (mod == NULL) {
        cPickle_ErrFormat(PicklingError,
                          "Can't pickle %s: import of module %s "
                          "failed",
                          "OS", args, module);
        goto finally;
    }
    klass = PyObject_GetAttrString(mod, name_str);
    if (klass == NULL) {
        cPickle_ErrFormat(PicklingError,
                          "Can't pickle %s: attribute lookup %s.%s "
                          "failed",
                          "OSS", args, module, global_name);
        goto finally;
    }
    if (klass != args) {
        Py_DECREF(klass);
        cPickle_ErrFormat(PicklingError,
                          "Can't pickle %s: it's not the same object "
                                "as %s.%s",
                          "OSS", args, module, global_name);
        goto finally;
    }
    Py_DECREF(klass);

    if (self->proto >= 2) {
        /* See whether this is in the extension registry, and if
         * so generate an EXT opcode.
         */
        PyObject *py_code;              /* extension code as Python object */
        long code;                      /* extension code as C value */
        char c_str[5];
        int n;

        PyTuple_SET_ITEM(two_tuple, 0, module);
        PyTuple_SET_ITEM(two_tuple, 1, global_name);
        py_code = PyDict_GetItem(extension_registry, two_tuple);
        if (py_code == NULL)
            goto gen_global;                    /* not registered */

        /* Verify py_code has the right type and value. */
        if (!PyInt_Check(py_code)) {
            cPickle_ErrFormat(PicklingError, "Can't pickle %s: "
                "extension code %s isn't an integer",
                "OO", args, py_code);
            goto finally;
        }
        code = PyInt_AS_LONG(py_code);
        if (code <= 0 ||  code > 0x7fffffffL) {
            cPickle_ErrFormat(PicklingError, "Can't pickle %s: "
                "extension code %ld is out of range",
                "Ol", args, code);
            goto finally;
        }

        /* Generate an EXT opcode. */
        if (code <= 0xff) {
            c_str[0] = EXT1;
            c_str[1] = (char)code;
            n = 2;
        }
        else if (code <= 0xffff) {
            c_str[0] = EXT2;
            c_str[1] = (char)(code & 0xff);
            c_str[2] = (char)((code >> 8) & 0xff);
            n = 3;
        }
        else {
            c_str[0] = EXT4;
            c_str[1] = (char)(code & 0xff);
            c_str[2] = (char)((code >> 8) & 0xff);
            c_str[3] = (char)((code >> 16) & 0xff);
            c_str[4] = (char)((code >> 24) & 0xff);
            n = 5;
        }

        if (self->write_func(self, c_str, n) >= 0)
            res = 0;
        goto finally;           /* and don't memoize */
    }

  gen_global:
    if (self->write_func(self, &global, 1) < 0)
        goto finally;

    if (self->write_func(self, module_str, module_size) < 0)
        goto finally;

    if (self->write_func(self, "\n", 1) < 0)
        goto finally;

    if (self->write_func(self, name_str, name_size) < 0)
        goto finally;

    if (self->write_func(self, "\n", 1) < 0)
        goto finally;

    if (put(self, args) < 0)
        goto finally;

    res = 0;

  finally:
    Py_XDECREF(module);
    Py_XDECREF(global_name);
    Py_XDECREF(mod);

    return res;
}

static int
save_pers(Picklerobject *self, PyObject *args, PyObject *f)
{
    PyObject *pid = 0;
    Py_ssize_t size;
    int res = -1;

    static char persid = PERSID, binpersid = BINPERSID;

    Py_INCREF(args);
    ARG_TUP(self, args);
    if (self->arg) {
        pid = PyObject_Call(f, self->arg, NULL);
        FREE_ARG_TUP(self);
    }
    if (! pid) return -1;

    if (pid != Py_None) {
        if (!self->bin) {
            if (!PyString_Check(pid)) {
                PyErr_SetString(PicklingError,
                                "persistent id must be string");
                goto finally;
            }

            if (self->write_func(self, &persid, 1) < 0)
                goto finally;

            if ((size = PyString_Size(pid)) < 0)
                goto finally;

            if (self->write_func(self,
                                 PyString_AS_STRING(
                                    (PyStringObject *)pid),
                                 size) < 0)
                goto finally;

            if (self->write_func(self, "\n", 1) < 0)
                goto finally;

            res = 1;
            goto finally;
        }
        else if (save(self, pid, 1) >= 0) {
            if (self->write_func(self, &binpersid, 1) < 0)
                res = -1;
            else
                res = 1;
        }

        goto finally;
    }

    res = 0;

  finally:
    Py_XDECREF(pid);

    return res;
}

/* We're saving ob, and args is the 2-thru-5 tuple returned by the
 * appropriate __reduce__ method for ob.
 */
static int
save_reduce(Picklerobject *self, PyObject *args, PyObject *fn, PyObject *ob)
{
    PyObject *callable;
    PyObject *argtup;
    PyObject *state = NULL;
    PyObject *listitems = Py_None;
    PyObject *dictitems = Py_None;
    Py_ssize_t size;

    int use_newobj = self->proto >= 2;

    static char reduce = REDUCE;
    static char build = BUILD;
    static char newobj = NEWOBJ;

    size = PyTuple_Size(args);
    if (size < 2 || size > 5) {
        cPickle_ErrFormat(PicklingError, "tuple returned by "
            "%s must contain 2 through 5 elements",
            "O", fn);
        return -1;
    }

    if (! PyArg_UnpackTuple(args, "save_reduce", 2, 5,
                            &callable,
                            &argtup,
                            &state,
                            &listitems,
                            &dictitems))
        return -1;

    if (!PyTuple_Check(argtup)) {
        cPickle_ErrFormat(PicklingError, "Second element of "
            "tuple returned by %s must be a tuple",
            "O", fn);
        return -1;
    }

    if (state == Py_None)
        state = NULL;

    if (listitems == Py_None)
        listitems = NULL;
    else if (!PyIter_Check(listitems)) {
        cPickle_ErrFormat(PicklingError, "Fourth element of "
            "tuple returned by %s must be an iterator, not %s",
            "Os", fn, Py_TYPE(listitems)->tp_name);
        return -1;
    }

    if (dictitems == Py_None)
        dictitems = NULL;
    else if (!PyIter_Check(dictitems)) {
        cPickle_ErrFormat(PicklingError, "Fifth element of "
            "tuple returned by %s must be an iterator, not %s",
            "Os", fn, Py_TYPE(dictitems)->tp_name);
        return -1;
    }

    /* Protocol 2 special case: if callable's name is __newobj__, use
     * NEWOBJ.  This consumes a lot of code.
     */
    if (use_newobj) {
        PyObject *temp = PyObject_GetAttr(callable, __name___str);

        if (temp == NULL) {
            if (PyErr_ExceptionMatches(PyExc_AttributeError))
                PyErr_Clear();
            else
                return -1;
            use_newobj = 0;
        }
        else {
            use_newobj = PyString_Check(temp) &&
                         strcmp(PyString_AS_STRING(temp),
                                "__newobj__") == 0;
            Py_DECREF(temp);
        }
    }
    if (use_newobj) {
        PyObject *cls;
        PyObject *newargtup;
        Py_ssize_t n, i;

        /* Sanity checks. */
        n = PyTuple_Size(argtup);
        if (n < 1) {
            PyErr_SetString(PicklingError, "__newobj__ arglist "
                "is empty");
            return -1;
        }

        cls = PyTuple_GET_ITEM(argtup, 0);
        if (! PyObject_HasAttrString(cls, "__new__")) {
            PyErr_SetString(PicklingError, "args[0] from "
                "__newobj__ args has no __new__");
            return -1;
        }

        /* XXX How could ob be NULL? */
        if (ob != NULL) {
            PyObject *ob_dot_class;

            ob_dot_class = PyObject_GetAttr(ob, __class___str);
            if (ob_dot_class == NULL) {
                if (PyErr_ExceptionMatches(
                            PyExc_AttributeError))
                    PyErr_Clear();
                else
                    return -1;
            }
            i = ob_dot_class != cls; /* true iff a problem */
            Py_XDECREF(ob_dot_class);
            if (i) {
                PyErr_SetString(PicklingError, "args[0] from "
                    "__newobj__ args has the wrong class");
                return -1;
            }
        }

        /* Save the class and its __new__ arguments. */
        if (save(self, cls, 0) < 0)
            return -1;

        newargtup = PyTuple_New(n-1);  /* argtup[1:] */
        if (newargtup == NULL)
            return -1;
        for (i = 1; i < n; ++i) {
            PyObject *temp = PyTuple_GET_ITEM(argtup, i);
            Py_INCREF(temp);
            PyTuple_SET_ITEM(newargtup, i-1, temp);
        }
        i = save(self, newargtup, 0);
        Py_DECREF(newargtup);
        if (i < 0)
            return -1;

        /* Add NEWOBJ opcode. */
        if (self->write_func(self, &newobj, 1) < 0)
            return -1;
    }
    else {
        /* Not using NEWOBJ. */
        if (save(self, callable, 0) < 0 ||
            save(self, argtup, 0) < 0 ||
            self->write_func(self, &reduce, 1) < 0)
            return -1;
    }

    /* Memoize. */
    /* XXX How can ob be NULL? */
    if (ob != NULL) {
        /* If the object is already in the memo, this means it is
           recursive. In this case, throw away everything we put on the
           stack, and fetch the object back from the memo. */
        if (Py_REFCNT(ob) > 1 && !self->fast) {
            PyObject *py_ob_id = PyLong_FromVoidPtr(ob);
            if (!py_ob_id)
                return -1;
            if (PyDict_GetItem(self->memo, py_ob_id)) {
                const char pop_op = POP;
                if (self->write_func(self, &pop_op, 1) < 0 ||
                    get(self, py_ob_id) < 0) {
                    Py_DECREF(py_ob_id);
                    return -1;
                }
                Py_DECREF(py_ob_id);
                return 0;
            }
            Py_DECREF(py_ob_id);
            if (PyErr_Occurred())
                return -1;
        }
        if (state && !PyDict_Check(state)) {
            if (put2(self, ob) < 0)
                return -1;
        }
        else if (put(self, ob) < 0)
                        return -1;
    }


    if (listitems && batch_list(self, listitems) < 0)
        return -1;

    if (dictitems && batch_dict(self, dictitems) < 0)
        return -1;

    if (state) {
        if (save(self, state, 0) < 0 ||
            self->write_func(self, &build, 1) < 0)
            return -1;
    }

    return 0;
}

static int
save(Picklerobject *self, PyObject *args, int pers_save)
{
    PyTypeObject *type;
    PyObject *py_ob_id = 0, *__reduce__ = 0, *t = 0;
    int res = -1;
    int tmp;

    if (Py_EnterRecursiveCall(" while pickling an object"))
        return -1;

    if (!pers_save && self->pers_func) {
        if ((tmp = save_pers(self, args, self->pers_func)) != 0) {
            res = tmp;
            goto finally;
        }
    }

    if (args == Py_None) {
        res = save_none(self, args);
        goto finally;
    }

    type = Py_TYPE(args);

    switch (type->tp_name[0]) {
    case 'b':
        if (args == Py_False || args == Py_True) {
            res = save_bool(self, args);
            goto finally;
        }
        break;
    case 'i':
        if (type == &PyInt_Type) {
            res = save_int(self, args);
            goto finally;
        }
        break;

    case 'l':
        if (type == &PyLong_Type) {
            res = save_long(self, args);
            goto finally;
        }
        break;

    case 'f':
        if (type == &PyFloat_Type) {
            res = save_float(self, args);
            goto finally;
        }
        break;

    case 't':
        if (type == &PyTuple_Type && PyTuple_Size(args) == 0) {
            res = save_tuple(self, args);
            goto finally;
        }
        break;

    case 's':
        if ((type == &PyString_Type) && (PyString_GET_SIZE(args) < 2)) {
            res = save_string(self, args, 0);
            goto finally;
        }
        break;

#ifdef Py_USING_UNICODE
    case 'u':
        if ((type == &PyUnicode_Type) && (PyString_GET_SIZE(args) < 2)) {
            res = save_unicode(self, args, 0);
            goto finally;
        }
        break;
#endif
    }

    if (Py_REFCNT(args) > 1) {
        if (!( py_ob_id = PyLong_FromVoidPtr(args)))
            goto finally;

        if (PyDict_GetItem(self->memo, py_ob_id)) {
            if (get(self, py_ob_id) < 0)
                goto finally;

            res = 0;
            goto finally;
        }
    }

    switch (type->tp_name[0]) {
    case 's':
        if (type == &PyString_Type) {
            res = save_string(self, args, 1);
            goto finally;
        }
        break;

#ifdef Py_USING_UNICODE
    case 'u':
        if (type == &PyUnicode_Type) {
            res = save_unicode(self, args, 1);
            goto finally;
        }
        break;
#endif

    case 't':
        if (type == &PyTuple_Type) {
            res = save_tuple(self, args);
            goto finally;
        }
        if (type == &PyType_Type) {
            res = save_global(self, args, NULL);
            goto finally;
        }
        break;

    case 'l':
        if (type == &PyList_Type) {
            res = save_list(self, args);
            goto finally;
        }
        break;

    case 'd':
        if (type == &PyDict_Type) {
            res = save_dict(self, args);
            goto finally;
        }
        break;

    case 'i':
        if (type == &PyInstance_Type) {
            res = save_inst(self, args);
            goto finally;
        }
        break;

    case 'c':
        if (type == &PyClass_Type) {
            res = save_global(self, args, NULL);
            goto finally;
        }
        break;

    case 'f':
        if (type == &PyFunction_Type) {
            res = save_global(self, args, NULL);
            if (res && PyErr_ExceptionMatches(PickleError)) {
                /* fall back to reduce */
                PyErr_Clear();
                break;
            }
            goto finally;
        }
        break;

    case 'b':
        if (type == &PyCFunction_Type) {
            res = save_global(self, args, NULL);
            goto finally;
        }
    }

    if (!pers_save && self->inst_pers_func) {
        if ((tmp = save_pers(self, args, self->inst_pers_func)) != 0) {
            res = tmp;
            goto finally;
        }
    }

    /* Get a reduction callable, and call it.  This may come from
     * copy_reg.dispatch_table, the object's __reduce_ex__ method,
     * or the object's __reduce__ method.
     */
    __reduce__ = PyDict_GetItem(dispatch_table, (PyObject *)type);
    if (__reduce__ != NULL) {
        Py_INCREF(__reduce__);
        Py_INCREF(args);
        ARG_TUP(self, args);
        if (self->arg) {
            t = PyObject_Call(__reduce__, self->arg, NULL);
            FREE_ARG_TUP(self);
        }
    }
    else {
        if (PyType_IsSubtype(type, &PyType_Type)) {
            res = save_global(self, args, NULL);
            goto finally;
        }

        /* Check for a __reduce_ex__ method. */
        __reduce__ = PyObject_GetAttr(args, __reduce_ex___str);
        if (__reduce__ != NULL) {
            t = PyInt_FromLong(self->proto);
            if (t != NULL) {
                ARG_TUP(self, t);
                t = NULL;
                if (self->arg) {
                    t = PyObject_Call(__reduce__,
                                      self->arg, NULL);
                    FREE_ARG_TUP(self);
                }
            }
        }
        else {
            if (PyErr_ExceptionMatches(PyExc_AttributeError))
                PyErr_Clear();
            else
                goto finally;
            /* Check for a __reduce__ method. */
            __reduce__ = PyObject_GetAttr(args, __reduce___str);
            if (__reduce__ != NULL) {
                t = PyObject_Call(__reduce__,
                                  empty_tuple, NULL);
            }
            else {
                PyErr_SetObject(UnpickleableError, args);
                goto finally;
            }
        }
    }

    if (t == NULL)
        goto finally;

    if (PyString_Check(t)) {
        res = save_global(self, args, t);
        goto finally;
    }

    if (!PyTuple_Check(t)) {
        cPickle_ErrFormat(PicklingError, "Value returned by "
                        "%s must be string or tuple",
                        "O", __reduce__);
        goto finally;
    }

    res = save_reduce(self, t, __reduce__, args);

  finally:
    Py_LeaveRecursiveCall();
    Py_XDECREF(py_ob_id);
    Py_XDECREF(__reduce__);
    Py_XDECREF(t);

    return res;
}


static int
dump(Picklerobject *self, PyObject *args)
{
    static char stop = STOP;

    if (self->proto >= 2) {
        char bytes[2];

        bytes[0] = PROTO;
        assert(self->proto >= 0 && self->proto < 256);
        bytes[1] = (char)self->proto;
        if (self->write_func(self, bytes, 2) < 0)
            return -1;
    }

    if (save(self, args, 0) < 0)
        return -1;

    if (self->write_func(self, &stop, 1) < 0)
        return -1;

    if (self->write_func(self, NULL, 0) < 0)
        return -1;

    return 0;
}

static PyObject *
Pickle_clear_memo(Picklerobject *self, PyObject *args)
{
    if (self->memo)
        PyDict_Clear(self->memo);
    Py_INCREF(Py_None);
    return Py_None;
}

static PyObject *
Pickle_getvalue(Picklerobject *self, PyObject *args)
{
    Py_ssize_t l, i, rsize, ssize, clear=1, lm;
    long ik;
    PyObject *k, *r;
    char *s, *p, *have_get;
    Pdata *data;

    /* Can be called by Python code or C code */
    if (args && !PyArg_ParseTuple(args, "|i:getvalue", &clear))
        return NULL;

    /* Check to make sure we are based on a list */
    if (! Pdata_Check(self->file)) {
        PyErr_SetString(PicklingError,
                        "Attempt to getvalue() a non-list-based pickler");
        return NULL;
    }

    /* flush write buffer */
    if (write_other(self, NULL, 0) < 0) return NULL;

    data=(Pdata*)self->file;
    l=data->length;

    /* set up an array to hold get/put status */
    lm = PyDict_Size(self->memo);
    if (lm < 0) return NULL;
    lm++;
    have_get = malloc(lm);
    if (have_get == NULL) return PyErr_NoMemory();
    memset(have_get, 0, lm);

    /* Scan for gets. */
    for (rsize = 0, i = l; --i >= 0; ) {
        k = data->data[i];

        if (PyString_Check(k))
            rsize += PyString_GET_SIZE(k);

        else if (PyInt_Check(k)) { /* put */
            ik = PyInt_AS_LONG((PyIntObject*)k);
            if (ik >= lm || ik == 0) {
                PyErr_SetString(PicklingError,
                                "Invalid get data");
                goto err;
            }
            if (have_get[ik]) /* with matching get */
                rsize += ik < 256 ? 2 : 5;
        }

        else if (! (PyTuple_Check(k) &&
                    PyTuple_GET_SIZE(k) == 2 &&
                    PyInt_Check((k = PyTuple_GET_ITEM(k, 0))))
            ) {
            PyErr_SetString(PicklingError,
                            "Unexpected data in internal list");
            goto err;
        }

        else { /* put */
            ik = PyInt_AS_LONG((PyIntObject *)k);
            if (ik >= lm || ik == 0) {
                PyErr_SetString(PicklingError,
                                "Invalid get data");
                goto err;
            }
            have_get[ik] = 1;
            rsize += ik < 256 ? 2 : 5;
        }
    }

    /* Now generate the result */
    r = PyString_FromStringAndSize(NULL, rsize);
    if (r == NULL) goto err;
    s = PyString_AS_STRING((PyStringObject *)r);

    for (i = 0; i < l; i++) {
        k = data->data[i];

        if (PyString_Check(k)) {
            ssize = PyString_GET_SIZE(k);
            if (ssize) {
                p=PyString_AS_STRING((PyStringObject *)k);
                while (--ssize >= 0)
                    *s++ = *p++;
            }
        }

        else if (PyTuple_Check(k)) { /* get */
            ik = PyInt_AS_LONG((PyIntObject *)
                                PyTuple_GET_ITEM(k, 0));
            if (ik < 256) {
                *s++ = BINGET;
                *s++ = (int)(ik & 0xff);
            }
            else {
                *s++ = LONG_BINGET;
                *s++ = (int)(ik & 0xff);
                *s++ = (int)((ik >> 8)  & 0xff);
                *s++ = (int)((ik >> 16) & 0xff);
                *s++ = (int)((ik >> 24) & 0xff);
            }
        }

        else { /* put */
            ik = PyInt_AS_LONG((PyIntObject*)k);

            if (have_get[ik]) { /* with matching get */
                if (ik < 256) {
                    *s++ = BINPUT;
                    *s++ = (int)(ik & 0xff);
                }
                else {
                    *s++ = LONG_BINPUT;
                    *s++ = (int)(ik & 0xff);
                    *s++ = (int)((ik >> 8)  & 0xff);
                    *s++ = (int)((ik >> 16) & 0xff);
                    *s++ = (int)((ik >> 24) & 0xff);
                }
            }
        }
    }

    if (clear) {
        PyDict_Clear(self->memo);
        Pdata_clear(data, 0);
    }

    free(have_get);
    return r;
  err:
    free(have_get);
    return NULL;
}

static PyObject *
Pickler_dump(Picklerobject *self, PyObject *args)
{
    PyObject *ob;
    int get=0;

    if (!( PyArg_ParseTuple(args, "O|i:dump", &ob, &get)))
        return NULL;

    if (dump(self, ob) < 0)
        return NULL;

    if (get) return Pickle_getvalue(self, NULL);

    /* XXX Why does dump() return self? */
    Py_INCREF(self);
    return (PyObject*)self;
}


static struct PyMethodDef Pickler_methods[] =
{
  {"dump",          (PyCFunction)Pickler_dump,  METH_VARARGS,
   PyDoc_STR("dump(object) -- "
   "Write an object in pickle format to the object's pickle stream")},
  {"clear_memo",  (PyCFunction)Pickle_clear_memo,  METH_NOARGS,
   PyDoc_STR("clear_memo() -- Clear the picklers memo")},
  {"getvalue",  (PyCFunction)Pickle_getvalue,  METH_VARARGS,
   PyDoc_STR("getvalue() -- Finish picking a list-based pickle")},
  {NULL,                NULL}           /* sentinel */
};


static Picklerobject *
newPicklerobject(PyObject *file, int proto)
{
    Picklerobject *self;

    if (proto < 0)
        proto = HIGHEST_PROTOCOL;
    if (proto > HIGHEST_PROTOCOL) {
        PyErr_Format(PyExc_ValueError, "pickle protocol %d asked for; "
                     "the highest available protocol is %d",
                     proto, HIGHEST_PROTOCOL);
        return NULL;
    }

    self = PyObject_GC_New(Picklerobject, &Picklertype);
    if (self == NULL)
        return NULL;
    self->proto = proto;
    self->bin = proto > 0;
    self->fp = NULL;
    self->write = NULL;
    self->memo = NULL;
    self->arg = NULL;
    self->pers_func = NULL;
    self->inst_pers_func = NULL;
    self->write_buf = NULL;
    self->fast = 0;
    self->fast_container = 0;
    self->fast_memo = NULL;
    self->buf_size = 0;
    self->dispatch_table = NULL;

    self->file = NULL;
    if (file)
        Py_INCREF(file);
    else {
        file = Pdata_New();
        if (file == NULL)
            goto err;
    }
    self->file = file;

    if (!( self->memo = PyDict_New()))
        goto err;

    if (PyFile_Check(file)) {
        self->fp = PyFile_AsFile(file);
        if (self->fp == NULL) {
            PyErr_SetString(PyExc_ValueError,
                            "I/O operation on closed file");
            goto err;
        }
        self->write_func = write_file;
    }
    else if (PycStringIO_OutputCheck(file)) {
        self->write_func = write_cStringIO;
    }
    else if (file == Py_None) {
        self->write_func = write_none;
    }
    else {
        self->write_func = write_other;

        if (! Pdata_Check(file)) {
            self->write = PyObject_GetAttr(file, write_str);
            if (!self->write)  {
                PyErr_Clear();
                PyErr_SetString(PyExc_TypeError,
                                "argument must have 'write' "
                                "attribute");
                goto err;
            }
        }

        self->write_buf = (char *)PyMem_Malloc(WRITE_BUF_SIZE);
        if (self->write_buf == NULL) {
            PyErr_NoMemory();
            goto err;
        }
    }

    if (PyEval_GetRestricted()) {
        /* Restricted execution, get private tables */
        PyObject *m = PyImport_ImportModule("copy_reg");

        if (m == NULL)
            goto err;
        self->dispatch_table = PyObject_GetAttr(m, dispatch_table_str);
        Py_DECREF(m);
        if (self->dispatch_table == NULL)
            goto err;
    }
    else {
        self->dispatch_table = dispatch_table;
        Py_INCREF(dispatch_table);
    }
    PyObject_GC_Track(self);

    return self;

  err:
    Py_DECREF(self);
    return NULL;
}


static PyObject *
get_Pickler(PyObject *self, PyObject *args, PyObject *kwds)
{
    static char *kwlist[] = {"file", "protocol", NULL};
    PyObject *file = NULL;
    int proto = 0;

    /* XXX
     * The documented signature is Pickler(file, protocol=0), but this
     * accepts Pickler() and Pickler(integer) too.  The meaning then
     * is clear as mud, undocumented, and not supported by pickle.py.
     * I'm told Zope uses this, but I haven't traced into this code
     * far enough to figure out what it means.
     */
    if (!PyArg_ParseTuple(args, "|i:Pickler", &proto)) {
        PyErr_Clear();
        proto = 0;
        if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|i:Pickler",
                    kwlist, &file, &proto))
            return NULL;
    }
    return (PyObject *)newPicklerobject(file, proto);
}


static void
Pickler_dealloc(Picklerobject *self)
{
    PyObject_GC_UnTrack(self);
    Py_XDECREF(self->write);
    Py_XDECREF(self->memo);
    Py_XDECREF(self->fast_memo);
    Py_XDECREF(self->arg);
    Py_XDECREF(self->file);
    Py_XDECREF(self->pers_func);
    Py_XDECREF(self->inst_pers_func);
    Py_XDECREF(self->dispatch_table);
    PyMem_Free(self->write_buf);
    Py_TYPE(self)->tp_free((PyObject *)self);
}

static int
Pickler_traverse(Picklerobject *self, visitproc visit, void *arg)
{
    Py_VISIT(self->write);
    Py_VISIT(self->memo);
    Py_VISIT(self->fast_memo);
    Py_VISIT(self->arg);
    Py_VISIT(self->file);
    Py_VISIT(self->pers_func);
    Py_VISIT(self->inst_pers_func);
    Py_VISIT(self->dispatch_table);
    return 0;
}

static int
Pickler_clear(Picklerobject *self)
{
    Py_CLEAR(self->write);
    Py_CLEAR(self->memo);
    Py_CLEAR(self->fast_memo);
    Py_CLEAR(self->arg);
    Py_CLEAR(self->file);
    Py_CLEAR(self->pers_func);
    Py_CLEAR(self->inst_pers_func);
    Py_CLEAR(self->dispatch_table);
    return 0;
}

static PyObject *
Pickler_get_pers_func(Picklerobject *p)
{
    if (p->pers_func == NULL)
        PyErr_SetString(PyExc_AttributeError, "persistent_id");
    else
        Py_INCREF(p->pers_func);
    return p->pers_func;
}

static int
Pickler_set_pers_func(Picklerobject *p, PyObject *v)
{
    if (v == NULL) {
        PyErr_SetString(PyExc_TypeError,
                        "attribute deletion is not supported");
        return -1;
    }
    Py_INCREF(v);
    Py_XSETREF(p->pers_func, v);
    return 0;
}

static int
Pickler_set_inst_pers_func(Picklerobject *p, PyObject *v)
{
    if (v == NULL) {
        PyErr_SetString(PyExc_TypeError,
                        "attribute deletion is not supported");
        return -1;
    }
    Py_INCREF(v);
    Py_XSETREF(p->inst_pers_func, v);
    return 0;
}

static PyObject *
Pickler_get_memo(Picklerobject *p)
{
    if (p->memo == NULL)
        PyErr_SetString(PyExc_AttributeError, "memo");
    else
        Py_INCREF(p->memo);
    return p->memo;
}

static int
Pickler_set_memo(Picklerobject *p, PyObject *v)
{
    if (v == NULL) {
        PyErr_SetString(PyExc_TypeError,
                        "attribute deletion is not supported");
        return -1;
    }
    if (!PyDict_Check(v)) {
        PyErr_SetString(PyExc_TypeError, "memo must be a dictionary");
        return -1;
    }
    Py_INCREF(v);
    Py_XSETREF(p->memo, v);
    return 0;
}

static PyObject *
Pickler_get_error(Picklerobject *p)
{
    /* why is this an attribute on the Pickler? */
    Py_INCREF(PicklingError);
    return PicklingError;
}

static PyMemberDef Pickler_members[] = {
    {"binary", T_INT, offsetof(Picklerobject, bin)},
    {"fast", T_INT, offsetof(Picklerobject, fast)},
    {NULL}
};

static PyGetSetDef Pickler_getsets[] = {
    {"persistent_id", (getter)Pickler_get_pers_func,
                     (setter)Pickler_set_pers_func},
    {"inst_persistent_id", NULL, (setter)Pickler_set_inst_pers_func},
    {"memo", (getter)Pickler_get_memo, (setter)Pickler_set_memo},
    {"PicklingError", (getter)Pickler_get_error, NULL},
    {NULL}
};

PyDoc_STRVAR(Picklertype__doc__,
"Objects that know how to pickle objects\n");

static PyTypeObject Picklertype = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "cPickle.Pickler",            /*tp_name*/
    sizeof(Picklerobject),              /*tp_basicsize*/
    0,
    (destructor)Pickler_dealloc,        /* tp_dealloc */
    0,                                  /* tp_print */
    0,                                  /* tp_getattr */
    0,                                  /* tp_setattr */
    0,                                  /* tp_compare */
    0,                                  /* tp_repr */
    0,                                  /* tp_as_number */
    0,                                  /* tp_as_sequence */
    0,                                  /* tp_as_mapping */
    0,                                  /* tp_hash */
    0,                                  /* tp_call */
    0,                                  /* tp_str */
    PyObject_GenericGetAttr,            /* tp_getattro */
    PyObject_GenericSetAttr,            /* tp_setattro */
    0,                                  /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
    Picklertype__doc__,                 /* tp_doc */
    (traverseproc)Pickler_traverse,     /* tp_traverse */
    (inquiry)Pickler_clear,             /* tp_clear */
    0,                                  /* tp_richcompare */
    0,                                  /* tp_weaklistoffset */
    0,                                  /* tp_iter */
    0,                                  /* tp_iternext */
    Pickler_methods,                    /* tp_methods */
    Pickler_members,                    /* tp_members */
    Pickler_getsets,                    /* tp_getset */
};

static PyObject *
find_class(PyObject *py_module_name, PyObject *py_global_name, PyObject *fc)
{
    PyObject *global = 0, *module;

    if (fc) {
        if (fc==Py_None) {
            PyErr_SetString(UnpicklingError, "Global and instance "
                            "pickles are not supported.");
            return NULL;
        }
        return PyObject_CallFunctionObjArgs(fc, py_module_name,
                                            py_global_name, NULL);
    }

    module = PySys_GetObject("modules");
    if (module == NULL)
        return NULL;

    module = PyDict_GetItem(module, py_module_name);
    if (module == NULL) {
        module = PyImport_Import(py_module_name);
        if (!module)
            return NULL;
        global = PyObject_GetAttr(module, py_global_name);
        Py_DECREF(module);
    }
    else
        global = PyObject_GetAttr(module, py_global_name);
    return global;
}

static Py_ssize_t
marker(Unpicklerobject *self)
{
    if (self->num_marks < 1) {
        PyErr_SetString(UnpicklingError, "could not find MARK");
        return -1;
    }

    return self->marks[--self->num_marks];
}


static int
load_none(Unpicklerobject *self)
{
    PDATA_APPEND(self->stack, Py_None, -1);
    return 0;
}

static int
bad_readline(void)
{
    PyErr_SetString(UnpicklingError, "pickle data was truncated");
    return -1;
}

static int
load_int(Unpicklerobject *self)
{
    PyObject *py_int = 0;
    char *endptr, *s;
    Py_ssize_t len;
    int res = -1;
    long l;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();
    if (!( s=pystrndup(s,len)))  return -1;

    errno = 0;
    l = strtol(s, &endptr, 0);

    if (errno || (*endptr != '\n') || (endptr[1] != '\0')) {
        /* Hm, maybe we've got something long.  Let's try reading
           it as a Python long object. */
        errno = 0;
        py_int = PyLong_FromString(s, NULL, 0);
        if (py_int == NULL) {
            PyErr_SetString(PyExc_ValueError,
                            "could not convert string to int");
            goto finally;
        }
    }
    else {
        if (len == 3 && (l == 0 || l == 1)) {
            if (!( py_int = PyBool_FromLong(l)))  goto finally;
        }
        else {
            if (!( py_int = PyInt_FromLong(l)))  goto finally;
        }
    }

    free(s);
    PDATA_PUSH(self->stack, py_int, -1);
    return 0;

  finally:
    free(s);

    return res;
}

static int
load_bool(Unpicklerobject *self, PyObject *boolean)
{
    assert(boolean == Py_True || boolean == Py_False);
    PDATA_APPEND(self->stack, boolean, -1);
    return 0;
}

/* s contains x bytes of a little-endian integer.  Return its value as a
 * C int.  Obscure:  when x is 1 or 2, this is an unsigned little-endian
 * int, but when x is 4 it's a signed one.  This is a historical source
 * of x-platform bugs.
 */
static long
calc_binint(char *s, int x)
{
    unsigned char c;
    int i;
    long l;

    for (i = 0, l = 0L; i < x; i++) {
        c = (unsigned char)s[i];
        l |= (long)c << (i * 8);
    }
#if SIZEOF_LONG > 4
    /* Unlike BININT1 and BININT2, BININT (more accurately BININT4)
     * is signed, so on a box with longs bigger than 4 bytes we need
     * to extend a BININT's sign bit to the full width.
     */
    if (x == 4 && l & (1L << 31))
        l |= (~0UL) << 32;
#endif
    return l;
}


static int
load_binintx(Unpicklerobject *self, char *s, int  x)
{
    PyObject *py_int = 0;
    long l;

    l = calc_binint(s, x);

    if (!( py_int = PyInt_FromLong(l)))
        return -1;

    PDATA_PUSH(self->stack, py_int, -1);
    return 0;
}


static int
load_binint(Unpicklerobject *self)
{
    char *s;

    if (self->read_func(self, &s, 4) < 0)
        return -1;

    return load_binintx(self, s, 4);
}


static int
load_binint1(Unpicklerobject *self)
{
    char *s;

    if (self->read_func(self, &s, 1) < 0)
        return -1;

    return load_binintx(self, s, 1);
}


static int
load_binint2(Unpicklerobject *self)
{
    char *s;

    if (self->read_func(self, &s, 2) < 0)
        return -1;

    return load_binintx(self, s, 2);
}

static int
load_long(Unpicklerobject *self)
{
    PyObject *l = 0;
    char *end, *s;
    Py_ssize_t len;
    int res = -1;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();
    if (!( s=pystrndup(s,len)))  return -1;

    if (!( l = PyLong_FromString(s, &end, 0)))
        goto finally;

    free(s);
    PDATA_PUSH(self->stack, l, -1);
    return 0;

  finally:
    free(s);

    return res;
}

/* 'size' bytes contain the # of bytes of little-endian 256's-complement
 * data following.
 */
static int
load_counted_long(Unpicklerobject *self, int size)
{
    Py_ssize_t i;
    char *nbytes;
    unsigned char *pdata;
    PyObject *along;

    assert(size == 1 || size == 4);
    i = self->read_func(self, &nbytes, size);
    if (i < 0) return -1;

    size = calc_binint(nbytes, size);
    if (size < 0) {
        /* Corrupt or hostile pickle -- we never write one like
         * this.
         */
        PyErr_SetString(UnpicklingError, "LONG pickle has negative "
                        "byte count");
        return -1;
    }

    if (size == 0)
        along = PyLong_FromLong(0L);
    else {
        /* Read the raw little-endian bytes & convert. */
        i = self->read_func(self, (char **)&pdata, size);
        if (i < 0) return -1;
        along = _PyLong_FromByteArray(pdata, (size_t)size,
                        1 /* little endian */, 1 /* signed */);
    }
    if (along == NULL)
        return -1;
    PDATA_PUSH(self->stack, along, -1);
    return 0;
}

static int
load_float(Unpicklerobject *self)
{
    PyObject *py_float = 0;
    char *endptr, *s;
    Py_ssize_t len;
    int res = -1;
    double d;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();
    if (!( s=pystrndup(s,len)))  return -1;

    d = PyOS_string_to_double(s, &endptr, PyExc_OverflowError);

    if (d == -1.0 && PyErr_Occurred()) {
        goto finally;
    } else if ((endptr[0] != '\n') || (endptr[1] != '\0')) {
        PyErr_SetString(PyExc_ValueError,
                        "could not convert string to float");
        goto finally;
    }

    if (!( py_float = PyFloat_FromDouble(d)))
        goto finally;

    free(s);
    PDATA_PUSH(self->stack, py_float, -1);
    return 0;

  finally:
    free(s);

    return res;
}

static int
load_binfloat(Unpicklerobject *self)
{
    PyObject *py_float;
    double x;
    char *p;

    if (self->read_func(self, &p, 8) < 0)
        return -1;

    x = _PyFloat_Unpack8((unsigned char *)p, 0);
    if (x == -1.0 && PyErr_Occurred())
        return -1;

    py_float = PyFloat_FromDouble(x);
    if (py_float == NULL)
        return -1;

    PDATA_PUSH(self->stack, py_float, -1);
    return 0;
}

static int
load_string(Unpicklerobject *self)
{
    PyObject *str = 0;
    Py_ssize_t len;
    int res = -1;
    char *s, *p;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();
    if (!( s=pystrndup(s,len)))  return -1;


    /* Strip outermost quotes */
    while (len > 0 && s[len-1] <= ' ')
        len--;
    if (len > 1 && s[0]=='"' && s[len-1]=='"') {
        s[len-1] = '\0';
        p = s + 1 ;
        len -= 2;
    }
    else if (len > 1 && s[0]=='\'' && s[len-1]=='\'') {
        s[len-1] = '\0';
        p = s + 1 ;
        len -= 2;
    }
    else
        goto insecure;
    /********************************************/

    str = PyString_DecodeEscape(p, len, NULL, 0, NULL);
    free(s);
    if (str) {
        PDATA_PUSH(self->stack, str, -1);
        res = 0;
    }
    return res;

  insecure:
    free(s);
    PyErr_SetString(PyExc_ValueError,"insecure string pickle");
    return -1;
}


static int
load_binstring(Unpicklerobject *self)
{
    PyObject *py_string = 0;
    Py_ssize_t l;
    char *s;

    if (self->read_func(self, &s, 4) < 0) return -1;

    l = calc_binint(s, 4);
    if (l < 0) {
        /* Corrupt or hostile pickle -- we never write one like
         * this.
         */
        PyErr_SetString(UnpicklingError,
                        "BINSTRING pickle has negative byte count");
        return -1;
    }

    if (self->read_func(self, &s, l) < 0)
        return -1;

    if (!( py_string = PyString_FromStringAndSize(s, l)))
        return -1;

    PDATA_PUSH(self->stack, py_string, -1);
    return 0;
}


static int
load_short_binstring(Unpicklerobject *self)
{
    PyObject *py_string = 0;
    unsigned char l;
    char *s;

    if (self->read_func(self, &s, 1) < 0)
        return -1;

    l = (unsigned char)s[0];

    if (self->read_func(self, &s, l) < 0) return -1;

    if (!( py_string = PyString_FromStringAndSize(s, l)))  return -1;

    PDATA_PUSH(self->stack, py_string, -1);
    return 0;
}


#ifdef Py_USING_UNICODE
static int
load_unicode(Unpicklerobject *self)
{
    PyObject *str = 0;
    Py_ssize_t len;
    char *s;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 1) return bad_readline();

    if (!( str = PyUnicode_DecodeRawUnicodeEscape(s, len - 1, NULL)))
        return -1;

    PDATA_PUSH(self->stack, str, -1);
    return 0;
}
#endif


#ifdef Py_USING_UNICODE
static int
load_binunicode(Unpicklerobject *self)
{
    PyObject *unicode;
    Py_ssize_t l;
    char *s;

    if (self->read_func(self, &s, 4) < 0) return -1;

    l = calc_binint(s, 4);
    if (l < 0) {
        /* Corrupt or hostile pickle -- we never write one like
         * this.
         */
        PyErr_SetString(UnpicklingError,
                        "BINUNICODE pickle has negative byte count");
        return -1;
    }

    if (self->read_func(self, &s, l) < 0)
        return -1;

    if (!( unicode = PyUnicode_DecodeUTF8(s, l, NULL)))
        return -1;

    PDATA_PUSH(self->stack, unicode, -1);
    return 0;
}
#endif


static int
load_counted_tuple(Unpicklerobject *self, int len)
{
    PyObject *tup;

    if (self->stack->length < len)
        return stackUnderflow();

    if (!(tup = Pdata_popTuple(self->stack, self->stack->length - len)))
        return -1;
    PDATA_PUSH(self->stack, tup, -1);
    return 0;
}

static int
load_tuple(Unpicklerobject *self)
{
    Py_ssize_t i;

    if ((i = marker(self)) < 0) return -1;
    return load_counted_tuple(self, self->stack->length - i);
}

static int
load_empty_list(Unpicklerobject *self)
{
    PyObject *list;

    if (!( list=PyList_New(0)))  return -1;
    PDATA_PUSH(self->stack, list, -1);
    return 0;
}

static int
load_empty_dict(Unpicklerobject *self)
{
    PyObject *dict;

    if (!( dict=PyDict_New()))  return -1;
    PDATA_PUSH(self->stack, dict, -1);
    return 0;
}


static int
load_list(Unpicklerobject *self)
{
    PyObject *list = 0;
    Py_ssize_t i;

    if ((i = marker(self)) < 0) return -1;
    if (!( list=Pdata_popList(self->stack, i)))  return -1;
    PDATA_PUSH(self->stack, list, -1);
    return 0;
}

static int
load_dict(Unpicklerobject *self)
{
    PyObject *dict, *key, *value;
    Py_ssize_t i, j, k;

    if ((i = marker(self)) < 0) return -1;
    j=self->stack->length;

    if (!( dict = PyDict_New()))  return -1;

    for (k = i+1; k < j; k += 2) {
        key  =self->stack->data[k-1];
        value=self->stack->data[k  ];
        if (PyDict_SetItem(dict, key, value) < 0) {
            Py_DECREF(dict);
            return -1;
        }
    }
    Pdata_clear(self->stack, i);
    PDATA_PUSH(self->stack, dict, -1);
    return 0;
}

static PyObject *
Instance_New(PyObject *cls, PyObject *args)
{
    if (PyClass_Check(cls)) {
        int l;

        if ((l=PyObject_Size(args)) < 0) return NULL;
        if (!( l ))  {
            if (!PyObject_HasAttr(cls, __getinitargs___str))  {
                /* We have a class with no __getinitargs__,
                   so bypass usual construction  */
                return PyInstance_NewRaw(cls, NULL);
            }
        }

        return PyInstance_New(cls, args, NULL);
    }

    return PyObject_CallObject(cls, args);
}


static int
load_obj(Unpicklerobject *self)
{
    PyObject *class, *tup, *obj=0;
    Py_ssize_t i;

    if ((i = marker(self)) < 0) return -1;

    if (self->stack->length - i < 1)
        return stackUnderflow();

    if (!( tup=Pdata_popTuple(self->stack, i+1)))  return -1;
    PDATA_POP(self->stack, class);
    if (class) {
        obj = Instance_New(class, tup);
        Py_DECREF(class);
    }
    Py_DECREF(tup);

    if (! obj) return -1;
    PDATA_PUSH(self->stack, obj, -1);
    return 0;
}


static int
load_inst(Unpicklerobject *self)
{
    PyObject *tup, *class=0, *obj=0, *module_name, *class_name;
    Py_ssize_t i, len;
    char *s;

    if ((i = marker(self)) < 0) return -1;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();
    module_name = PyString_FromStringAndSize(s, len - 1);
    if (!module_name)  return -1;

    if ((len = self->readline_func(self, &s)) >= 0) {
        if (len < 2) {
            Py_DECREF(module_name);
            return bad_readline();
        }
        if ((class_name = PyString_FromStringAndSize(s, len - 1))) {
            class = find_class(module_name, class_name,
                               self->find_class);
            Py_DECREF(class_name);
        }
    }
    Py_DECREF(module_name);

    if (! class) return -1;

    if ((tup=Pdata_popTuple(self->stack, i))) {
        obj = Instance_New(class, tup);
        Py_DECREF(tup);
    }
    Py_DECREF(class);

    if (! obj) return -1;

    PDATA_PUSH(self->stack, obj, -1);
    return 0;
}

static int
load_newobj(Unpicklerobject *self)
{
    PyObject *args = NULL;
    PyObject *clsraw = NULL;
    PyTypeObject *cls;          /* clsraw cast to its true type */
    PyObject *obj;

    /* Stack is ... cls argtuple, and we want to call
     * cls.__new__(cls, *argtuple).
     */
    PDATA_POP(self->stack, args);
    if (args == NULL) goto Fail;
    if (! PyTuple_Check(args)) {
        PyErr_SetString(UnpicklingError, "NEWOBJ expected an arg "
                                         "tuple.");
        goto Fail;
    }

    PDATA_POP(self->stack, clsraw);
    cls = (PyTypeObject *)clsraw;
    if (cls == NULL) goto Fail;
    if (! PyType_Check(cls)) {
        PyErr_SetString(UnpicklingError, "NEWOBJ class argument "
                                         "isn't a type object");
        goto Fail;
    }
    if (cls->tp_new == NULL) {
        PyErr_SetString(UnpicklingError, "NEWOBJ class argument "
                                         "has NULL tp_new");
        goto Fail;
    }

    /* Call __new__. */
    obj = cls->tp_new(cls, args, NULL);
    if (obj == NULL) goto Fail;

    Py_DECREF(args);
    Py_DECREF(clsraw);
    PDATA_PUSH(self->stack, obj, -1);
    return 0;

 Fail:
    Py_XDECREF(args);
    Py_XDECREF(clsraw);
    return -1;
}

static int
load_global(Unpicklerobject *self)
{
    PyObject *class = 0, *module_name = 0, *class_name = 0;
    Py_ssize_t len;
    char *s;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();
    module_name = PyString_FromStringAndSize(s, len - 1);
    if (!module_name)  return -1;

    if ((len = self->readline_func(self, &s)) >= 0) {
        if (len < 2) {
            Py_DECREF(module_name);
            return bad_readline();
        }
        if ((class_name = PyString_FromStringAndSize(s, len - 1))) {
            class = find_class(module_name, class_name,
                               self->find_class);
            Py_DECREF(class_name);
        }
    }
    Py_DECREF(module_name);

    if (! class) return -1;
    PDATA_PUSH(self->stack, class, -1);
    return 0;
}


static int
load_persid(Unpicklerobject *self)
{
    PyObject *pid = 0;
    Py_ssize_t len;
    char *s;

    if (self->pers_func) {
        if ((len = self->readline_func(self, &s)) < 0) return -1;
        if (len < 2) return bad_readline();

        pid = PyString_FromStringAndSize(s, len - 1);
        if (!pid)  return -1;

        if (PyList_Check(self->pers_func)) {
            if (PyList_Append(self->pers_func, pid) < 0) {
                Py_DECREF(pid);
                return -1;
            }
        }
        else {
            ARG_TUP(self, pid);
            if (self->arg) {
                pid = PyObject_Call(self->pers_func, self->arg,
                                    NULL);
                FREE_ARG_TUP(self);
            }
        }

        if (! pid) return -1;

        PDATA_PUSH(self->stack, pid, -1);
        return 0;
    }
    else {
        PyErr_SetString(UnpicklingError,
                        "A load persistent id instruction was encountered,\n"
                        "but no persistent_load function was specified.");
        return -1;
    }
}

static int
load_binpersid(Unpicklerobject *self)
{
    PyObject *pid = 0;

    if (self->pers_func) {
        PDATA_POP(self->stack, pid);
        if (! pid) return -1;

        if (PyList_Check(self->pers_func)) {
            if (PyList_Append(self->pers_func, pid) < 0) {
                Py_DECREF(pid);
                return -1;
            }
        }
        else {
            ARG_TUP(self, pid);
            if (self->arg) {
                pid = PyObject_Call(self->pers_func, self->arg,
                                    NULL);
                FREE_ARG_TUP(self);
            }
            if (! pid) return -1;
        }

        PDATA_PUSH(self->stack, pid, -1);
        return 0;
    }
    else {
        PyErr_SetString(UnpicklingError,
                        "A load persistent id instruction was encountered,\n"
                        "but no persistent_load function was specified.");
        return -1;
    }
}


static int
load_pop(Unpicklerobject *self)
{
    Py_ssize_t len = self->stack->length;

    /* Note that we split the (pickle.py) stack into two stacks,
       an object stack and a mark stack. We have to be clever and
       pop the right one. We do this by looking at the top of the
       mark stack first, and only signalling a stack underflow if
       the object stack is empty and the mark stack doesn't match
       our expectations.
    */
    if (self->num_marks > 0 && self->marks[self->num_marks - 1] == len) {
        self->num_marks--;
    } else if (len > 0) {
        len--;
        Py_DECREF(self->stack->data[len]);
        self->stack->length = len;
    } else {
        return stackUnderflow();
    }
    return 0;
}


static int
load_pop_mark(Unpicklerobject *self)
{
    Py_ssize_t i;

    if ((i = marker(self)) < 0)
        return -1;

    Pdata_clear(self->stack, i);

    return 0;
}


static int
load_dup(Unpicklerobject *self)
{
    PyObject *last;
    Py_ssize_t len;

    if ((len = self->stack->length) <= 0) return stackUnderflow();
    last=self->stack->data[len-1];
    Py_INCREF(last);
    PDATA_PUSH(self->stack, last, -1);
    return 0;
}


static int
load_get(Unpicklerobject *self)
{
    PyObject *py_str = 0, *value = 0;
    Py_ssize_t len;
    char *s;
    int rc;

    if ((len = self->readline_func(self, &s)) < 0) return -1;
    if (len < 2) return bad_readline();

    if (!( py_str = PyString_FromStringAndSize(s, len - 1)))  return -1;

    value = PyDict_GetItem(self->memo, py_str);
    if (! value) {
        PyErr_SetObject(BadPickleGet, py_str);
        rc = -1;
    }
    else {
        PDATA_APPEND(self->stack, value, -1);
        rc = 0;
    }

    Py_DECREF(py_str);
    return rc;
}


static int
load_binget(Unpicklerobject *self)
{
    PyObject *py_key = 0, *value = 0;
    unsigned char key;
    char *s;
    int rc;

    if (self->read_func(self, &s, 1) < 0) return -1;

    key = (unsigned char)s[0];
    if (!( py_key = PyInt_FromLong((long)key)))  return -1;

    value = PyDict_GetItem(self->memo, py_key);
    if (! value) {
        PyErr_SetObject(BadPickleGet, py_key);
        rc = -1;
    }
    else {
        PDATA_APPEND(self->stack, value, -1);
        rc = 0;
    }

    Py_DECREF(py_key);
    return rc;
}


static int
load_long_binget(Unpicklerobject *self)
{
    PyObject *py_key = 0, *value = 0;
    unsigned char c;
    char *s;
    Py_ssize_t key;
    int rc;

    if (self->read_func(self, &s, 4) < 0) return -1;

    c = (unsigned char)s[0];
    key = (long)c;
    c = (unsigned char)s[1];
    key |= (long)c << 8;
    c = (unsigned char)s[2];
    key |= (long)c << 16;
    c = (unsigned char)s[3];
    key |= (long)c << 24;

    if (!( py_key = PyInt_FromLong((long)key)))  return -1;

    value = PyDict_GetItem(self->memo, py_key);
    if (! value) {
        PyErr_SetObject(BadPickleGet, py_key);
        rc = -1;
    }
    else {
        PDATA_APPEND(self->stack, value, -1);
        rc = 0;
    }

    Py_DECREF(py_key);
    return rc;
}

/* Push an object from the extension registry (EXT[124]).  nbytes is
 * the number of bytes following the opcode, holding the index (code) value.
 */
static int
load_extension(Unpicklerobject *self, int nbytes)
{
    char *codebytes;            /* the nbytes bytes after the opcode */
    long code;                  /* calc_binint returns long */
    PyObject *py_code;          /* code as a Python int */
    PyObject *obj;              /* the object to push */
    PyObject *pair;             /* (module_name, class_name) */
    PyObject *module_name, *class_name;

    assert(nbytes == 1 || nbytes == 2 || nbytes == 4);
    if (self->read_func(self, &codebytes, nbytes) < 0) return -1;
    code = calc_binint(codebytes,  nbytes);
    if (code <= 0) {                    /* note that 0 is forbidden */
        /* Corrupt or hostile pickle. */
        PyErr_SetString(UnpicklingError, "EXT specifies code <= 0");
        return -1;
    }

    /* Look for the code in the cache. */
    py_code = PyInt_FromLong(code);
    if (py_code == NULL) return -1;
    obj = PyDict_GetItem(extension_cache, py_code);
    if (obj != NULL) {
        /* Bingo. */
        Py_DECREF(py_code);
        PDATA_APPEND(self->stack, obj, -1);
        return 0;
    }

    /* Look up the (module_name, class_name) pair. */
    pair = PyDict_GetItem(inverted_registry, py_code);
    if (pair == NULL) {
        Py_DECREF(py_code);
        PyErr_Format(PyExc_ValueError, "unregistered extension "
                     "code %ld", code);
        return -1;
    }
    /* Since the extension registry is manipulable via Python code,
     * confirm that pair is really a 2-tuple of strings.
     */
    if (!PyTuple_Check(pair) || PyTuple_Size(pair) != 2 ||
        !PyString_Check(module_name = PyTuple_GET_ITEM(pair, 0)) ||
        !PyString_Check(class_name = PyTuple_GET_ITEM(pair, 1))) {
        Py_DECREF(py_code);
        PyErr_Format(PyExc_ValueError, "_inverted_registry[%ld] "
                     "isn't a 2-tuple of strings", code);
        return -1;
    }
    /* Load the object. */
    obj = find_class(module_name, class_name, self->find_class);
    if (obj == NULL) {
        Py_DECREF(py_code);
        return -1;
    }
    /* Cache code -> obj. */
    code = PyDict_SetItem(extension_cache, py_code, obj);
    Py_DECREF(py_code);
    if (code < 0) {
        Py_DECREF(obj);
        return -1;
    }
    PDATA_PUSH(self->stack, obj, -1);
    return 0;
}

static int
load_put(Unpicklerobject *self)
{
    PyObject *py_str = 0, *value = 0;
    Py_ssize_t len, l;
    char *s;

    if ((l = self->readline_func(self, &s)) < 0) return -1;
    if (l < 2) return bad_readline();
    if (!( len=self->stack->length ))  return stackUnderflow();
    if (!( py_str = PyString_FromStringAndSize(s, l - 1)))  return -1;
    value=self->stack->data[len-1];
    l=PyDict_SetItem(self->memo, py_str, value);
    Py_DECREF(py_str);
    return l;
}


static int
load_binput(Unpicklerobject *self)
{
    PyObject *py_key = 0, *value = 0;
    unsigned char key;
    char *s;
    Py_ssize_t len;

    if (self->read_func(self, &s, 1) < 0) return -1;
    if (!( (len=self->stack->length) > 0 ))  return stackUnderflow();

    key = (unsigned char)s[0];

    if (!( py_key = PyInt_FromLong((long)key)))  return -1;
    value=self->stack->data[len-1];
    len=PyDict_SetItem(self->memo, py_key, value);
    Py_DECREF(py_key);
    return len;
}


static int
load_long_binput(Unpicklerobject *self)
{
    PyObject *py_key = 0, *value = 0;
    Py_ssize_t key;
    unsigned char c;
    char *s;
    Py_ssize_t len;

    if (self->read_func(self, &s, 4) < 0) return -1;
    if (!( len=self->stack->length ))  return stackUnderflow();

    c = (unsigned char)s[0];
    key = (long)c;
    c = (unsigned char)s[1];
    key |= (long)c << 8;
    c = (unsigned char)s[2];
    key |= (long)c << 16;
    c = (unsigned char)s[3];
    key |= (long)c << 24;

    if (!( py_key = PyInt_FromLong(key)))  return -1;
    value=self->stack->data[len-1];
    len=PyDict_SetItem(self->memo, py_key, value);
    Py_DECREF(py_key);
    return len;
}


static int
do_append(Unpicklerobject *self, Py_ssize_t  x)
{
    PyObject *value = 0, *list = 0, *append_method = 0;
    Py_ssize_t len, i;

    len=self->stack->length;
    if (!( len >= x && x > 0 ))  return stackUnderflow();
    /* nothing to do */
    if (len==x) return 0;

    list=self->stack->data[x-1];

    if (PyList_Check(list)) {
        PyObject *slice;
        int list_len;

        slice=Pdata_popList(self->stack, x);
        if (! slice) return -1;
        list_len = PyList_GET_SIZE(list);
        i=PyList_SetSlice(list, list_len, list_len, slice);
        Py_DECREF(slice);
        return i;
    }
    else {

        if (!( append_method = PyObject_GetAttr(list, append_str)))
            return -1;

        for (i = x; i < len; i++) {
            PyObject *junk;

            value=self->stack->data[i];
            junk=0;
            ARG_TUP(self, value);
            if (self->arg) {
                junk = PyObject_Call(append_method, self->arg,
                                     NULL);
                FREE_ARG_TUP(self);
            }
            if (! junk) {
                Pdata_clear(self->stack, i+1);
                self->stack->length=x;
                Py_DECREF(append_method);
                return -1;
            }
            Py_DECREF(junk);
        }
        self->stack->length=x;
        Py_DECREF(append_method);
    }

    return 0;
}


static int
load_append(Unpicklerobject *self)
{
    if (self->stack->length - 1 <= 0)
        return stackUnderflow();
    return do_append(self, self->stack->length - 1);
}


static int
load_appends(Unpicklerobject *self)
{
    Py_ssize_t i = marker(self);
    if (i < 0)
        return -1;
    return do_append(self, i);
}


static Py_ssize_t
do_setitems(Unpicklerobject *self, Py_ssize_t x)
{
    PyObject *value = 0, *key = 0, *dict = 0;
    Py_ssize_t len, i, r=0;

    if (!( (len=self->stack->length) >= x
           && x > 0 ))  return stackUnderflow();
    if (len == x)  /* nothing to do */
        return 0;
    if ((len - x) % 2 != 0) {
        /* Currupt or hostile pickle -- we never write one like this. */
        PyErr_SetString(UnpicklingError,
                        "odd number of items for SETITEMS");
        return -1;
    }

    dict=self->stack->data[x-1];

    for (i = x+1; i < len; i += 2) {
        key  =self->stack->data[i-1];
        value=self->stack->data[i  ];
        if (PyObject_SetItem(dict, key, value) < 0) {
            r=-1;
            break;
        }
    }

    Pdata_clear(self->stack, x);

    return r;
}


static int
load_setitem(Unpicklerobject *self)
{
    return do_setitems(self, self->stack->length - 2);
}

static int
load_setitems(Unpicklerobject *self)
{
    Py_ssize_t i = marker(self);
    if (i < 0)
        return -1;
    return do_setitems(self, i);
}


static int
load_build(Unpicklerobject *self)
{
    PyObject *state, *inst, *slotstate;
    PyObject *__setstate__;
    PyObject *d_key, *d_value;
    int res = -1;
    Py_ssize_t i;

    /* Stack is ... instance, state.  We want to leave instance at
     * the stack top, possibly mutated via instance.__setstate__(state).
     */
    if (self->stack->length < 2)
        return stackUnderflow();
    PDATA_POP(self->stack, state);
    if (state == NULL)
        return -1;
    inst = self->stack->data[self->stack->length - 1];

    __setstate__ = PyObject_GetAttr(inst, __setstate___str);
    if (__setstate__ != NULL) {
        PyObject *junk = NULL;

        /* The explicit __setstate__ is responsible for everything. */
        ARG_TUP(self, state);
        if (self->arg) {
            junk = PyObject_Call(__setstate__, self->arg, NULL);
            FREE_ARG_TUP(self);
        }
        Py_DECREF(__setstate__);
        if (junk == NULL)
            return -1;
        Py_DECREF(junk);
        return 0;
    }
    if (!PyErr_ExceptionMatches(PyExc_AttributeError))
        return -1;
    PyErr_Clear();

    /* A default __setstate__.  First see whether state embeds a
     * slot state dict too (a proto 2 addition).
     */
    if (PyTuple_Check(state) && PyTuple_Size(state) == 2) {
        PyObject *temp = state;
        state = PyTuple_GET_ITEM(temp, 0);
        slotstate = PyTuple_GET_ITEM(temp, 1);
        Py_INCREF(state);
        Py_INCREF(slotstate);
        Py_DECREF(temp);
    }
    else
        slotstate = NULL;

    /* Set inst.__dict__ from the state dict (if any). */
    if (state != Py_None) {
        PyObject *dict;
        if (! PyDict_Check(state)) {
            PyErr_SetString(UnpicklingError, "state is not a "
                            "dictionary");
            goto finally;
        }
        dict = PyObject_GetAttr(inst, __dict___str);
        if (dict == NULL)
            goto finally;

        i = 0;
        while (PyDict_Next(state, &i, &d_key, &d_value)) {
            /* normally the keys for instance attributes are
               interned.  we should try to do that here. */
            Py_INCREF(d_key);
            if (PyString_CheckExact(d_key))
                PyString_InternInPlace(&d_key);
            if (PyObject_SetItem(dict, d_key, d_value) < 0) {
                Py_DECREF(d_key);
                goto finally;
            }
            Py_DECREF(d_key);
        }
        Py_DECREF(dict);
    }

    /* Also set instance attributes from the slotstate dict (if any). */
    if (slotstate != NULL) {
        if (! PyDict_Check(slotstate)) {
            PyErr_SetString(UnpicklingError, "slot state is not "
                            "a dictionary");
            goto finally;
        }
        i = 0;
        while (PyDict_Next(slotstate, &i, &d_key, &d_value)) {
            if (PyObject_SetAttr(inst, d_key, d_value) < 0)
                goto finally;
        }
    }
    res = 0;

  finally:
    Py_DECREF(state);
    Py_XDECREF(slotstate);
    return res;
}


static int
load_mark(Unpicklerobject *self)
{
    Py_ssize_t s;

    /* Note that we split the (pickle.py) stack into two stacks, an
       object stack and a mark stack. Here we push a mark onto the
       mark stack.
    */

    if ((self->num_marks + 1) >= self->marks_size) {
        Py_ssize_t *marks;
        s=self->marks_size+20;
        if (s <= self->num_marks) s=self->num_marks + 1;
        if (self->marks == NULL)
            marks=(Py_ssize_t *)malloc(s * sizeof(Py_ssize_t));
        else
            marks=(Py_ssize_t *)realloc(self->marks,
                                        s * sizeof(Py_ssize_t));
        if (!marks) {
            PyErr_NoMemory();
            return -1;
        }
        self->marks = marks;
        self->marks_size = s;
    }

    self->marks[self->num_marks++] = self->stack->length;

    return 0;
}

static int
load_reduce(Unpicklerobject *self)
{
    PyObject *callable = 0, *arg_tup = 0, *ob = 0;

    PDATA_POP(self->stack, arg_tup);
    if (! arg_tup) return -1;
    PDATA_POP(self->stack, callable);
    if (callable) {
        ob = Instance_New(callable, arg_tup);
        Py_DECREF(callable);
    }
    Py_DECREF(arg_tup);

    if (! ob) return -1;

    PDATA_PUSH(self->stack, ob, -1);
    return 0;
}

/* Just raises an error if we don't know the protocol specified.  PROTO
 * is the first opcode for protocols >= 2.
 */
static int
load_proto(Unpicklerobject *self)
{
    int i;
    char *protobyte;

    i = self->read_func(self, &protobyte, 1);
    if (i < 0)
        return -1;

    i = calc_binint(protobyte, 1);
    /* No point checking for < 0, since calc_binint returns an unsigned
     * int when chewing on 1 byte.
     */
    assert(i >= 0);
    if (i <= HIGHEST_PROTOCOL)
        return 0;

    PyErr_Format(PyExc_ValueError, "unsupported pickle protocol: %d", i);
    return -1;
}

static PyObject *
load(Unpicklerobject *self)
{
    PyObject *err = 0, *val = 0;
    char *s;

    self->num_marks = 0;
    if (self->stack->length) Pdata_clear(self->stack, 0);

    while (1) {
        if (self->read_func(self, &s, 1) < 0)
            break;

        switch (s[0]) {
        case NONE:
            if (load_none(self) < 0)
                break;
            continue;

        case BININT:
            if (load_binint(self) < 0)
                break;
            continue;

        case BININT1:
            if (load_binint1(self) < 0)
                break;
            continue;

        case BININT2:
            if (load_binint2(self) < 0)
                break;
            continue;

        case INT:
            if (load_int(self) < 0)
                break;
            continue;

        case LONG:
            if (load_long(self) < 0)
                break;
            continue;

        case LONG1:
            if (load_counted_long(self, 1) < 0)
                break;
            continue;

        case LONG4:
            if (load_counted_long(self, 4) < 0)
                break;
            continue;

        case FLOAT:
            if (load_float(self) < 0)
                break;
            continue;

        case BINFLOAT:
            if (load_binfloat(self) < 0)
                break;
            continue;

        case BINSTRING:
            if (load_binstring(self) < 0)
                break;
            continue;

        case SHORT_BINSTRING:
            if (load_short_binstring(self) < 0)
                break;
            continue;

        case STRING:
            if (load_string(self) < 0)
                break;
            continue;

#ifdef Py_USING_UNICODE
        case UNICODE:
            if (load_unicode(self) < 0)
                break;
            continue;

        case BINUNICODE:
            if (load_binunicode(self) < 0)
                break;
            continue;
#endif

        case EMPTY_TUPLE:
            if (load_counted_tuple(self, 0) < 0)
                break;
            continue;

        case TUPLE1:
            if (load_counted_tuple(self, 1) < 0)
                break;
            continue;

        case TUPLE2:
            if (load_counted_tuple(self, 2) < 0)
                break;
            continue;

        case TUPLE3:
            if (load_counted_tuple(self, 3) < 0)
                break;
            continue;

        case TUPLE:
            if (load_tuple(self) < 0)
                break;
            continue;

        case EMPTY_LIST:
            if (load_empty_list(self) < 0)
                break;
            continue;

        case LIST:
            if (load_list(self) < 0)
                break;
            continue;

        case EMPTY_DICT:
            if (load_empty_dict(self) < 0)
                break;
            continue;

        case DICT:
            if (load_dict(self) < 0)
                break;
            continue;

        case OBJ:
            if (load_obj(self) < 0)
                break;
            continue;

        case INST:
            if (load_inst(self) < 0)
                break;
            continue;

        case NEWOBJ:
            if (load_newobj(self) < 0)
                break;
            continue;

        case GLOBAL:
            if (load_global(self) < 0)
                break;
            continue;

        case APPEND:
            if (load_append(self) < 0)
                break;
            continue;

        case APPENDS:
            if (load_appends(self) < 0)
                break;
            continue;

        case BUILD:
            if (load_build(self) < 0)
                break;
            continue;

        case DUP:
            if (load_dup(self) < 0)
                break;
            continue;

        case BINGET:
            if (load_binget(self) < 0)
                break;
            continue;

        case LONG_BINGET:
            if (load_long_binget(self) < 0)
                break;
            continue;

        case GET:
            if (load_get(self) < 0)
                break;
            continue;

        case EXT1:
            if (load_extension(self, 1) < 0)
                break;
            continue;

        case EXT2:
            if (load_extension(self, 2) < 0)
                break;
            continue;

        case EXT4:
            if (load_extension(self, 4) < 0)
                break;
            continue;
        case MARK:
            if (load_mark(self) < 0)
                break;
            continue;

        case BINPUT:
            if (load_binput(self) < 0)
                break;
            continue;

        case LONG_BINPUT:
            if (load_long_binput(self) < 0)
                break;
            continue;

        case PUT:
            if (load_put(self) < 0)
                break;
            continue;

        case POP:
            if (load_pop(self) < 0)
                break;
            continue;

        case POP_MARK:
            if (load_pop_mark(self) < 0)
                break;
            continue;

        case SETITEM:
            if (load_setitem(self) < 0)
                break;
            continue;

        case SETITEMS:
            if (load_setitems(self) < 0)
                break;
            continue;

        case STOP:
            break;

        case PERSID:
            if (load_persid(self) < 0)
                break;
            continue;

        case BINPERSID:
            if (load_binpersid(self) < 0)
                break;
            continue;

        case REDUCE:
            if (load_reduce(self) < 0)
                break;
            continue;

        case PROTO:
            if (load_proto(self) < 0)
                break;
            continue;

        case NEWTRUE:
            if (load_bool(self, Py_True) < 0)
                break;
            continue;

        case NEWFALSE:
            if (load_bool(self, Py_False) < 0)
                break;
            continue;

        case '\0':
            /* end of file */
            PyErr_SetNone(PyExc_EOFError);
            break;

        default:
            cPickle_ErrFormat(UnpicklingError,
                              "invalid load key, '%s'.",
                              "c", s[0]);
            return NULL;
        }

        break;
    }

    if ((err = PyErr_Occurred())) {
        if (err == PyExc_EOFError) {
            PyErr_SetNone(PyExc_EOFError);
        }
        return NULL;
    }

    PDATA_POP(self->stack, val);
    return val;
}


/* No-load functions to support noload, which is used to
   find persistent references. */

static int
noload_obj(Unpicklerobject *self)
{
    Py_ssize_t i;

    if ((i = marker(self)) < 0) return -1;
    return Pdata_clear(self->stack, i+1);
}


static int
noload_inst(Unpicklerobject *self)
{
    Py_ssize_t i;
    char *s;

    if ((i = marker(self)) < 0) return -1;
    Pdata_clear(self->stack, i);
    if (self->readline_func(self, &s) < 0) return -1;
    if (self->readline_func(self, &s) < 0) return -1;
    PDATA_APPEND(self->stack, Py_None, -1);
    return 0;
}

static int
noload_newobj(Unpicklerobject *self)
{
    PyObject *obj;

    PDATA_POP(self->stack, obj);        /* pop argtuple */
    if (obj == NULL) return -1;
    Py_DECREF(obj);

    PDATA_POP(self->stack, obj);        /* pop cls */
    if (obj == NULL) return -1;
    Py_DECREF(obj);

    PDATA_APPEND(self->stack, Py_None, -1);
    return 0;
}

static int
noload_global(Unpicklerobject *self)
{
    char *s;

    if (self->readline_func(self, &s) < 0) return -1;
    if (self->readline_func(self, &s) < 0) return -1;
    PDATA_APPEND(self->stack, Py_None,-1);
    return 0;
}

static int
noload_reduce(Unpicklerobject *self)
{

    if (self->stack->length < 2) return stackUnderflow();
    Pdata_clear(self->stack, self->stack->length-2);
    PDATA_APPEND(self->stack, Py_None,-1);
    return 0;
}

static int
noload_build(Unpicklerobject *self) {

  if (self->stack->length < 1) return stackUnderflow();
  Pdata_clear(self->stack, self->stack->length-1);
  return 0;
}

static int
noload_extension(Unpicklerobject *self, int nbytes)
{
    char *codebytes;

    assert(nbytes == 1 || nbytes == 2 || nbytes == 4);
    if (self->read_func(self, &codebytes, nbytes) < 0) return -1;
    PDATA_APPEND(self->stack, Py_None, -1);
    return 0;
}

static int
noload_append(Unpicklerobject *self)
{
    return Pdata_clear(self->stack, self->stack->length - 1);
}

static int
noload_appends(Unpicklerobject *self)
{
    Py_ssize_t i;
    if ((i = marker(self)) < 0) return -1;
    return Pdata_clear(self->stack, i);
}

static int
noload_setitem(Unpicklerobject *self)
{
    return Pdata_clear(self->stack, self->stack->length - 2);
}

static int
noload_setitems(Unpicklerobject *self)
{
    Py_ssize_t i;
    if ((i = marker(self)) < 0) return -1;
    return Pdata_clear(self->stack, i);
}

static PyObject *
noload(Unpicklerobject *self)
{
    PyObject *err = 0, *val = 0;
    char *s;

    self->num_marks = 0;
    Pdata_clear(self->stack, 0);

    while (1) {
        if (self->read_func(self, &s, 1) < 0)
            break;

        switch (s[0]) {
        case NONE:
            if (load_none(self) < 0)
                break;
            continue;

        case BININT:
            if (load_binint(self) < 0)
                break;
            continue;

        case BININT1:
            if (load_binint1(self) < 0)
                break;
            continue;

        case BININT2:
            if (load_binint2(self) < 0)
                break;
            continue;

        case INT:
            if (load_int(self) < 0)
                break;
            continue;

        case LONG:
            if (load_long(self) < 0)
                break;
            continue;

        case LONG1:
            if (load_counted_long(self, 1) < 0)
                break;
            continue;

        case LONG4:
            if (load_counted_long(self, 4) < 0)
                break;
            continue;

        case FLOAT:
            if (load_float(self) < 0)
                break;
            continue;

        case BINFLOAT:
            if (load_binfloat(self) < 0)
                break;
            continue;

        case BINSTRING:
            if (load_binstring(self) < 0)
                break;
            continue;

        case SHORT_BINSTRING:
            if (load_short_binstring(self) < 0)
                break;
            continue;

        case STRING:
            if (load_string(self) < 0)
                break;
            continue;

#ifdef Py_USING_UNICODE
        case UNICODE:
            if (load_unicode(self) < 0)
                break;
            continue;

        case BINUNICODE:
            if (load_binunicode(self) < 0)
                break;
            continue;
#endif

        case EMPTY_TUPLE:
            if (load_counted_tuple(self, 0) < 0)
                break;
            continue;

        case TUPLE1:
            if (load_counted_tuple(self, 1) < 0)
                break;
            continue;

        case TUPLE2:
            if (load_counted_tuple(self, 2) < 0)
                break;
            continue;

        case TUPLE3:
            if (load_counted_tuple(self, 3) < 0)
                break;
            continue;

        case TUPLE:
            if (load_tuple(self) < 0)
                break;
            continue;

        case EMPTY_LIST:
            if (load_empty_list(self) < 0)
                break;
            continue;

        case LIST:
            if (load_list(self) < 0)
                break;
            continue;

        case EMPTY_DICT:
            if (load_empty_dict(self) < 0)
                break;
            continue;

        case DICT:
            if (load_dict(self) < 0)
                break;
            continue;

        case OBJ:
            if (noload_obj(self) < 0)
                break;
            continue;

        case INST:
            if (noload_inst(self) < 0)
                break;
            continue;

        case NEWOBJ:
            if (noload_newobj(self) < 0)
                break;
            continue;

        case GLOBAL:
            if (noload_global(self) < 0)
                break;
            continue;

        case APPEND:
            if (noload_append(self) < 0)
                break;
            continue;

        case APPENDS:
            if (noload_appends(self) < 0)
                break;
            continue;

        case BUILD:
            if (noload_build(self) < 0)
                break;
            continue;

        case DUP:
            if (load_dup(self) < 0)
                break;
            continue;

        case BINGET:
            if (load_binget(self) < 0)
                break;
            continue;

        case LONG_BINGET:
            if (load_long_binget(self) < 0)
                break;
            continue;

        case GET:
            if (load_get(self) < 0)
                break;
            continue;

        case EXT1:
            if (noload_extension(self, 1) < 0)
                break;
            continue;

        case EXT2:
            if (noload_extension(self, 2) < 0)
                break;
            continue;

        case EXT4:
            if (noload_extension(self, 4) < 0)
                break;
            continue;

        case MARK:
            if (load_mark(self) < 0)
                break;
            continue;

        case BINPUT:
            if (load_binput(self) < 0)
                break;
            continue;

        case LONG_BINPUT:
            if (load_long_binput(self) < 0)
                break;
            continue;

        case PUT:
            if (load_put(self) < 0)
                break;
            continue;

        case POP:
            if (load_pop(self) < 0)
                break;
            continue;

        case POP_MARK:
            if (load_pop_mark(self) < 0)
                break;
            continue;

        case SETITEM:
            if (noload_setitem(self) < 0)
                break;
            continue;

        case SETITEMS:
            if (noload_setitems(self) < 0)
                break;
            continue;

        case STOP:
            break;

        case PERSID:
            if (load_persid(self) < 0)
                break;
            continue;

        case BINPERSID:
            if (load_binpersid(self) < 0)
                break;
            continue;

        case REDUCE:
            if (noload_reduce(self) < 0)
                break;
            continue;

        case PROTO:
            if (load_proto(self) < 0)
                break;
            continue;

        case NEWTRUE:
            if (load_bool(self, Py_True) < 0)
                break;
            continue;

        case NEWFALSE:
            if (load_bool(self, Py_False) < 0)
                break;
            continue;
        default:
            cPickle_ErrFormat(UnpicklingError,
                              "invalid load key, '%s'.",
                              "c", s[0]);
            return NULL;
        }

        break;
    }

    if ((err = PyErr_Occurred())) {
        if (err == PyExc_EOFError) {
            PyErr_SetNone(PyExc_EOFError);
        }
        return NULL;
    }

    PDATA_POP(self->stack, val);
    return val;
}


static PyObject *
Unpickler_load(Unpicklerobject *self, PyObject *unused)
{
    return load(self);
}

static PyObject *
Unpickler_noload(Unpicklerobject *self, PyObject *unused)
{
    return noload(self);
}


static struct PyMethodDef Unpickler_methods[] = {
  {"load",         (PyCFunction)Unpickler_load,   METH_NOARGS,
   PyDoc_STR("load() -- Load a pickle")
  },
  {"noload",         (PyCFunction)Unpickler_noload,   METH_NOARGS,
   PyDoc_STR(
   "noload() -- not load a pickle, but go through most of the motions\n"
   "\n"
   "This function can be used to read past a pickle without instantiating\n"
   "any objects or importing any modules.  It can also be used to find all\n"
   "persistent references without instantiating any objects or importing\n"
   "any modules.\n")
  },
  {NULL,              NULL}           /* sentinel */
};


static Unpicklerobject *
newUnpicklerobject(PyObject *f)
{
    Unpicklerobject *self;

    if (!( self = PyObject_GC_New(Unpicklerobject, &Unpicklertype)))
        return NULL;

    self->file = NULL;
    self->arg = NULL;
    self->stack = (Pdata*)Pdata_New();
    self->pers_func = NULL;
    self->last_string = NULL;
    self->marks = NULL;
    self->num_marks = 0;
    self->marks_size = 0;
    self->buf_size = 0;
    self->read = NULL;
    self->readline = NULL;
    self->find_class = NULL;

    if (!( self->memo = PyDict_New()))
        goto err;

    if (!self->stack)
        goto err;

    Py_INCREF(f);
    self->file = f;

    /* Set read, readline based on type of f */
    if (PyFile_Check(f)) {
        self->fp = PyFile_AsFile(f);
        if (self->fp == NULL) {
            PyErr_SetString(PyExc_ValueError,
                            "I/O operation on closed file");
            goto err;
        }
        self->read_func = read_file;
        self->readline_func = readline_file;
    }
    else if (PycStringIO_InputCheck(f)) {
        self->fp = NULL;
        self->read_func = read_cStringIO;
        self->readline_func = readline_cStringIO;
    }
    else {

        self->fp = NULL;
        self->read_func = read_other;
        self->readline_func = readline_other;

        if (!( (self->readline = PyObject_GetAttr(f, readline_str)) &&
               (self->read = PyObject_GetAttr(f, read_str))))  {
            PyErr_Clear();
            PyErr_SetString( PyExc_TypeError,
                             "argument must have 'read' and "
                             "'readline' attributes" );
            goto err;
        }
    }
    PyObject_GC_Track(self);

    return self;

  err:
    Py_DECREF((PyObject *)self);
    return NULL;
}


static PyObject *
get_Unpickler(PyObject *self, PyObject *file)
{
    return (PyObject *)newUnpicklerobject(file);
}


static void
Unpickler_dealloc(Unpicklerobject *self)
{
    PyObject_GC_UnTrack((PyObject *)self);
    Py_XDECREF(self->readline);
    Py_XDECREF(self->read);
    Py_XDECREF(self->file);
    Py_XDECREF(self->memo);
    Py_XDECREF(self->stack);
    Py_XDECREF(self->pers_func);
    Py_XDECREF(self->arg);
    Py_XDECREF(self->last_string);
    Py_XDECREF(self->find_class);

    if (self->marks) {
        free(self->marks);
    }

    if (self->buf_size) {
        free(self->buf);
    }

    Py_TYPE(self)->tp_free((PyObject *)self);
}

static int
Unpickler_traverse(Unpicklerobject *self, visitproc visit, void *arg)
{
    Py_VISIT(self->readline);
    Py_VISIT(self->read);
    Py_VISIT(self->file);
    Py_VISIT(self->memo);
    Py_VISIT(self->stack);
    Py_VISIT(self->pers_func);
    Py_VISIT(self->arg);
    Py_VISIT(self->last_string);
    Py_VISIT(self->find_class);
    return 0;
}

static int
Unpickler_clear(Unpicklerobject *self)
{
    Py_CLEAR(self->readline);
    Py_CLEAR(self->read);
    Py_CLEAR(self->file);
    Py_CLEAR(self->memo);
    Py_CLEAR(self->stack);
    Py_CLEAR(self->pers_func);
    Py_CLEAR(self->arg);
    Py_CLEAR(self->last_string);
    Py_CLEAR(self->find_class);
    return 0;
}

static PyObject *
Unpickler_getattr(Unpicklerobject *self, char *name)
{
    if (!strcmp(name, "persistent_load")) {
        if (!self->pers_func) {
            PyErr_SetString(PyExc_AttributeError, name);
            return NULL;
        }

        Py_INCREF(self->pers_func);
        return self->pers_func;
    }

    if (!strcmp(name, "find_global")) {
        if (!self->find_class) {
            PyErr_SetString(PyExc_AttributeError, name);
            return NULL;
        }

        Py_INCREF(self->find_class);
        return self->find_class;
    }

    if (!strcmp(name, "memo")) {
        if (!self->memo) {
            PyErr_SetString(PyExc_AttributeError, name);
            return NULL;
        }

        Py_INCREF(self->memo);
        return self->memo;
    }

    if (!strcmp(name, "UnpicklingError")) {
        Py_INCREF(UnpicklingError);
        return UnpicklingError;
    }

    return Py_FindMethod(Unpickler_methods, (PyObject *)self, name);
}


static int
Unpickler_setattr(Unpicklerobject *self, char *name, PyObject *value)
{

    if (!strcmp(name, "persistent_load")) {
        Py_XINCREF(value);
        Py_XSETREF(self->pers_func, value);
        return 0;
    }

    if (!strcmp(name, "find_global")) {
        Py_XINCREF(value);
        Py_XSETREF(self->find_class, value);
        return 0;
    }

    if (! value) {
        PyErr_SetString(PyExc_TypeError,
                        "attribute deletion is not supported");
        return -1;
    }

    if (strcmp(name, "memo") == 0) {
        if (!PyDict_Check(value)) {
            PyErr_SetString(PyExc_TypeError,
                            "memo must be a dictionary");
            return -1;
        }
        Py_INCREF(value);
        Py_XSETREF(self->memo, value);
        return 0;
    }

    PyErr_SetString(PyExc_AttributeError, name);
    return -1;
}

/* ---------------------------------------------------------------------------
 * Module-level functions.
 */

/* dump(obj, file, protocol=0). */
static PyObject *
cpm_dump(PyObject *self, PyObject *args, PyObject *kwds)
{
    static char *kwlist[] = {"obj", "file", "protocol", NULL};
    PyObject *ob, *file, *res = NULL;
    Picklerobject *pickler = 0;
    int proto = 0;

    if (!( PyArg_ParseTupleAndKeywords(args, kwds, "OO|i", kwlist,
               &ob, &file, &proto)))
        goto finally;

    if (!( pickler = newPicklerobject(file, proto)))
        goto finally;

    if (dump(pickler, ob) < 0)
        goto finally;

    Py_INCREF(Py_None);
    res = Py_None;

  finally:
    Py_XDECREF(pickler);

    return res;
}


/* dumps(obj, protocol=0). */
static PyObject *
cpm_dumps(PyObject *self, PyObject *args, PyObject *kwds)
{
    static char *kwlist[] = {"obj", "protocol", NULL};
    PyObject *ob, *file = 0, *res = NULL;
    Picklerobject *pickler = 0;
    int proto = 0;

    if (!( PyArg_ParseTupleAndKeywords(args, kwds, "O|i:dumps", kwlist,
               &ob, &proto)))
        goto finally;

    if (!( file = PycStringIO->NewOutput(128)))
        goto finally;

    if (!( pickler = newPicklerobject(file, proto)))
        goto finally;

    if (dump(pickler, ob) < 0)
        goto finally;

    res = PycStringIO->cgetvalue(file);

  finally:
    Py_XDECREF(pickler);
    Py_XDECREF(file);

    return res;
}


/* load(fileobj). */
static PyObject *
cpm_load(PyObject *self, PyObject *ob)
{
    Unpicklerobject *unpickler = 0;
    PyObject *res = NULL;

    if (!( unpickler = newUnpicklerobject(ob)))
        goto finally;

    res = load(unpickler);

  finally:
    Py_XDECREF(unpickler);

    return res;
}


/* loads(string) */
static PyObject *
cpm_loads(PyObject *self, PyObject *args)
{
    PyObject *ob, *file = 0, *res = NULL;
    Unpicklerobject *unpickler = 0;

    if (!( PyArg_ParseTuple(args, "S:loads", &ob)))
        goto finally;

    if (!( file = PycStringIO->NewInput(ob)))
        goto finally;

    if (!( unpickler = newUnpicklerobject(file)))
        goto finally;

    res = load(unpickler);

  finally:
    Py_XDECREF(file);
    Py_XDECREF(unpickler);

    return res;
}


PyDoc_STRVAR(Unpicklertype__doc__,
"Objects that know how to unpickle");

static PyTypeObject Unpicklertype = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "cPickle.Unpickler",                 /*tp_name*/
    sizeof(Unpicklerobject),             /*tp_basicsize*/
    0,
    (destructor)Unpickler_dealloc,      /* tp_dealloc */
    0,                                  /* tp_print */
    (getattrfunc)Unpickler_getattr,     /* tp_getattr */
    (setattrfunc)Unpickler_setattr,     /* tp_setattr */
    0,                                  /* tp_compare */
    0,                                  /* tp_repr */
    0,                                  /* tp_as_number */
    0,                                  /* tp_as_sequence */
    0,                                  /* tp_as_mapping */
    0,                                  /* tp_hash */
    0,                                  /* tp_call */
    0,                                  /* tp_str */
    0,                                  /* tp_getattro */
    0,                                  /* tp_setattro */
    0,                                  /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC,
    Unpicklertype__doc__,               /* tp_doc */
    (traverseproc)Unpickler_traverse,   /* tp_traverse */
    (inquiry)Unpickler_clear,           /* tp_clear */
};

static struct PyMethodDef cPickle_methods[] = {
  {"dump",         (PyCFunction)cpm_dump,         METH_VARARGS | METH_KEYWORDS,
   PyDoc_STR("dump(obj, file, protocol=0) -- "
   "Write an object in pickle format to the given file.\n"
   "\n"
   "See the Pickler docstring for the meaning of optional argument proto.")
  },

  {"dumps",        (PyCFunction)cpm_dumps,        METH_VARARGS | METH_KEYWORDS,
   PyDoc_STR("dumps(obj, protocol=0) -- "
   "Return a string containing an object in pickle format.\n"
   "\n"
   "See the Pickler docstring for the meaning of optional argument proto.")
  },

  {"load",         (PyCFunction)cpm_load,         METH_O,
   PyDoc_STR("load(file) -- Load a pickle from the given file")},

  {"loads",        (PyCFunction)cpm_loads,        METH_VARARGS,
   PyDoc_STR("loads(string) -- Load a pickle from the given string")},

  {"Pickler",      (PyCFunction)get_Pickler,      METH_VARARGS | METH_KEYWORDS,
   PyDoc_STR("Pickler(file, protocol=0) -- Create a pickler.\n"
   "\n"
   "This takes a file-like object for writing a pickle data stream.\n"
   "The optional proto argument tells the pickler to use the given\n"
   "protocol; supported protocols are 0, 1, 2.  The default\n"
   "protocol is 0, to be backwards compatible.  (Protocol 0 is the\n"
   "only protocol that can be written to a file opened in text\n"
   "mode and read back successfully.  When using a protocol higher\n"
   "than 0, make sure the file is opened in binary mode, both when\n"
   "pickling and unpickling.)\n"
   "\n"
   "Protocol 1 is more efficient than protocol 0; protocol 2 is\n"
   "more efficient than protocol 1.\n"
   "\n"
   "Specifying a negative protocol version selects the highest\n"
   "protocol version supported.  The higher the protocol used, the\n"
   "more recent the version of Python needed to read the pickle\n"
   "produced.\n"
   "\n"
   "The file parameter must have a write() method that accepts a single\n"
   "string argument.  It can thus be an open file object, a StringIO\n"
   "object, or any other custom object that meets this interface.\n")
  },

  {"Unpickler",    (PyCFunction)get_Unpickler,    METH_O,
   PyDoc_STR("Unpickler(file) -- Create an unpickler.")},

  { NULL, NULL }
};

static int
init_stuff(PyObject *module_dict)
{
    PyObject *copyreg, *t, *r;

#define INIT_STR(S) if (!( S ## _str=PyString_InternFromString(#S)))  return -1;

    if (PyType_Ready(&Unpicklertype) < 0)
        return -1;
    if (PyType_Ready(&Picklertype) < 0)
        return -1;

    INIT_STR(__class__);
    INIT_STR(__getinitargs__);
    INIT_STR(__dict__);
    INIT_STR(__getstate__);
    INIT_STR(__setstate__);
    INIT_STR(__name__);
    INIT_STR(__main__);
    INIT_STR(__reduce__);
    INIT_STR(__reduce_ex__);
    INIT_STR(write);
    INIT_STR(append);
    INIT_STR(read);
    INIT_STR(readline);
    INIT_STR(dispatch_table);

    if (!( copyreg = PyImport_ImportModule("copy_reg")))
        return -1;

    /* This is special because we want to use a different
       one in restricted mode. */
    dispatch_table = PyObject_GetAttr(copyreg, dispatch_table_str);
    if (!dispatch_table) return -1;

    extension_registry = PyObject_GetAttrString(copyreg,
                            "_extension_registry");
    if (!extension_registry) return -1;

    inverted_registry = PyObject_GetAttrString(copyreg,
                            "_inverted_registry");
    if (!inverted_registry) return -1;

    extension_cache = PyObject_GetAttrString(copyreg,
                            "_extension_cache");
    if (!extension_cache) return -1;

    Py_DECREF(copyreg);

    if (!(empty_tuple = PyTuple_New(0)))
        return -1;

    two_tuple = PyTuple_New(2);
    if (two_tuple == NULL)
        return -1;
    /* We use this temp container with no regard to refcounts, or to
     * keeping containees alive.  Exempt from GC, because we don't
     * want anything looking at two_tuple() by magic.
     */
    PyObject_GC_UnTrack(two_tuple);

    /* Ugh */
    if (!( t=PyImport_ImportModule("__builtin__")))  return -1;
    if (PyDict_SetItemString(module_dict, "__builtins__", t) < 0)
        return -1;

    if (!( t=PyDict_New()))  return -1;
    if (!( r=PyRun_String(
                   "def __str__(self):\n"
                   "  return self.args and ('%s' % self.args[0]) or '(what)'\n",
                   Py_file_input,
                   module_dict, t)  ))  return -1;
    Py_DECREF(r);

    PickleError = PyErr_NewException("cPickle.PickleError", NULL, t);
    if (!PickleError)
        return -1;

    Py_DECREF(t);

    PicklingError = PyErr_NewException("cPickle.PicklingError",
                                       PickleError, NULL);
    if (!PicklingError)
        return -1;

    if (!( t=PyDict_New()))  return -1;
    if (!( r=PyRun_String(
                   "def __str__(self):\n"
                   "  a=self.args\n"
                   "  a=a and type(a[0]) or '(what)'\n"
                   "  return 'Cannot pickle %s objects' % a\n"
                   , Py_file_input,
                   module_dict, t)  ))  return -1;
    Py_DECREF(r);

    if (!( UnpickleableError = PyErr_NewException(
                   "cPickle.UnpickleableError", PicklingError, t)))
        return -1;

    Py_DECREF(t);

    if (!( UnpicklingError = PyErr_NewException("cPickle.UnpicklingError",
                                                PickleError, NULL)))
        return -1;

    if (!( BadPickleGet = PyErr_NewException("cPickle.BadPickleGet",
                                             UnpicklingError, NULL)))
        return -1;

    if (PyDict_SetItemString(module_dict, "PickleError",
                             PickleError) < 0)
        return -1;

    if (PyDict_SetItemString(module_dict, "PicklingError",
                             PicklingError) < 0)
        return -1;

    if (PyDict_SetItemString(module_dict, "UnpicklingError",
                             UnpicklingError) < 0)
        return -1;

    if (PyDict_SetItemString(module_dict, "UnpickleableError",
                             UnpickleableError) < 0)
        return -1;

    if (PyDict_SetItemString(module_dict, "BadPickleGet",
                             BadPickleGet) < 0)
        return -1;

    PycString_IMPORT;

    return 0;
}

#ifndef PyMODINIT_FUNC  /* declarations for DLL import/export */
#define PyMODINIT_FUNC void
#endif
PyMODINIT_FUNC
initcPickle(void)
{
    PyObject *m, *d, *di, *v, *k;
    Py_ssize_t i;
    char *rev = "1.71";         /* XXX when does this change? */
    PyObject *format_version;
    PyObject *compatible_formats;

    Py_TYPE(&Picklertype) = &PyType_Type;
    Py_TYPE(&Unpicklertype) = &PyType_Type;
    Py_TYPE(&PdataType) = &PyType_Type;

    /* Initialize some pieces. We need to do this before module creation,
     * so we're forced to use a temporary dictionary. :(
     */
    di = PyDict_New();
    if (!di) return;
    if (init_stuff(di) < 0) return;

    /* Create the module and add the functions */
    m = Py_InitModule4("cPickle", cPickle_methods,
                       cPickle_module_documentation,
                       (PyObject*)NULL,PYTHON_API_VERSION);
    if (m == NULL)
        return;

    /* Add some symbolic constants to the module */
    d = PyModule_GetDict(m);
    v = PyString_FromString(rev);
    PyDict_SetItemString(d, "__version__", v);
    Py_XDECREF(v);

    /* Copy data from di. Waaa. */
    for (i=0; PyDict_Next(di, &i, &k, &v); ) {
        if (PyObject_SetItem(d, k, v) < 0) {
            Py_DECREF(di);
            return;
        }
    }
    Py_DECREF(di);

    i = PyModule_AddIntConstant(m, "HIGHEST_PROTOCOL", HIGHEST_PROTOCOL);
    if (i < 0)
        return;

    /* These are purely informational; no code uses them. */
    /* File format version we write. */
    format_version = PyString_FromString("2.0");
    /* Format versions we can read. */
    compatible_formats = Py_BuildValue("[sssss]",
        "1.0",          /* Original protocol 0 */
        "1.1",          /* Protocol 0 + INST */
        "1.2",          /* Original protocol 1 */
        "1.3",          /* Protocol 1 + BINFLOAT */
        "2.0");         /* Original protocol 2 */
    PyDict_SetItemString(d, "format_version", format_version);
    PyDict_SetItemString(d, "compatible_formats", compatible_formats);
    Py_XDECREF(format_version);
    Py_XDECREF(compatible_formats);
}
