/*

/ Author: Sam Rushing <rushing@nightmare.com>

/ Hacked for Unix by AMK

/ $Id$

/ Modified to support mmap with offset - to map a 'window' of a file

/ Author: Yotam Medini yotamm@mellanox.co.il

/

/ mmapmodule.cpp -- map a view of a file into memory

/

/ todo: need permission flags, perhaps a 'chsize' analog

/ not all functions check range yet!!!

/

/

/ This version of mmapmodule.c has been changed significantly

/ from the original mmapfile.c on which it was based.

/ The original version of mmapfile is maintained by Sam at

/ ftp://squirl.nightmare.com/pub/python/python-ext.

*/

#define PY_SSIZE_T_CLEAN

#include <Python.h>

#include "structmember.h"

#ifndef MS_WINDOWS

#define UNIX

# ifdef HAVE_FCNTL_H

# include <fcntl.h>

# endif /* HAVE_FCNTL_H */

#endif

#ifdef MS_WINDOWS

#include <windows.h>

static int

my_getpagesize(void)

{

SYSTEM_INFO si;

GetSystemInfo(&si);

return si.dwPageSize;

}

static int

my_getallocationgranularity (void)

{

SYSTEM_INFO si;

GetSystemInfo(&si);

return si.dwAllocationGranularity;

}

#endif

#ifdef UNIX

#include <sys/mman.h>

#include <sys/stat.h>

#if defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE)

static int

my_getpagesize(void)

{

return sysconf(_SC_PAGESIZE);

}

#define my_getallocationgranularity my_getpagesize

#else

#define my_getpagesize getpagesize

#endif

#endif /* UNIX */

#include <string.h>

#ifdef HAVE_SYS_TYPES_H

#include <sys/types.h>

#endif /* HAVE_SYS_TYPES_H */

/* Prefer MAP_ANONYMOUS since MAP_ANON is deprecated according to man page. */

#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)

# define MAP_ANONYMOUS MAP_ANON

#endif

typedef enum

{

ACCESS_DEFAULT,

ACCESS_READ,

ACCESS_WRITE,

ACCESS_COPY

} access_mode;

typedef struct {

PyObject_HEAD

char * data;

Py_ssize_t size;

Py_ssize_t pos; /* relative to offset */

#ifdef MS_WINDOWS

long long offset;

#else

off_t offset;

#endif

int exports;

#ifdef MS_WINDOWS

HANDLE map_handle;

HANDLE file_handle;

char * tagname;

#endif

#ifdef UNIX

int fd;

#endif

PyObject *weakreflist;

access_mode access;

} mmap_object;

static void

mmap_object_dealloc(mmap_object *m_obj)

{

#ifdef MS_WINDOWS

if (m_obj->data != NULL)

UnmapViewOfFile (m_obj->data);

if (m_obj->map_handle != NULL)

CloseHandle (m_obj->map_handle);

if (m_obj->file_handle != INVALID_HANDLE_VALUE)

CloseHandle (m_obj->file_handle);

if (m_obj->tagname)

PyMem_Free(m_obj->tagname);

#endif /* MS_WINDOWS */

#ifdef UNIX

if (m_obj->fd >= 0)

(void) close(m_obj->fd);

if (m_obj->data!=NULL) {

munmap(m_obj->data, m_obj->size);

}

#endif /* UNIX */

if (m_obj->weakreflist != NULL)

PyObject_ClearWeakRefs((PyObject *) m_obj);

Py_TYPE(m_obj)->tp_free((PyObject*)m_obj);

}

static PyObject *

mmap_close_method(mmap_object *self, PyObject *unused)

{

if (self->exports > 0) {

PyErr_SetString(PyExc_BufferError, "cannot close "\

"exported pointers exist");

return NULL;

}

#ifdef MS_WINDOWS

/* For each resource we maintain, we need to check

the value is valid, and if so, free the resource

and set the member value to an invalid value so

the dealloc does not attempt to resource clearing

again.

TODO - should we check for errors in the close operations???

*/

if (self->data != NULL) {

UnmapViewOfFile(self->data);

self->data = NULL;

}

if (self->map_handle != NULL) {

CloseHandle(self->map_handle);

self->map_handle = NULL;

}

if (self->file_handle != INVALID_HANDLE_VALUE) {

CloseHandle(self->file_handle);

self->file_handle = INVALID_HANDLE_VALUE;

}

#endif /* MS_WINDOWS */

#ifdef UNIX

if (0 <= self->fd)

(void) close(self->fd);

self->fd = -1;

if (self->data != NULL) {

munmap(self->data, self->size);

self->data = NULL;

}

#endif

Py_RETURN_NONE;

}

#ifdef MS_WINDOWS

#define CHECK_VALID(err) \

do { \

if (self->map_handle == NULL) { \

PyErr_SetString(PyExc_ValueError, "mmap closed or invalid"); \

return err; \

} \

} while (0)

#endif /* MS_WINDOWS */

#ifdef UNIX

#define CHECK_VALID(err) \

do { \

if (self->data == NULL) { \

PyErr_SetString(PyExc_ValueError, "mmap closed or invalid"); \

return err; \

} \

} while (0)

#endif /* UNIX */

static PyObject *

mmap_read_byte_method(mmap_object *self,

PyObject *unused)

{

CHECK_VALID(NULL);

if (self->pos >= self->size) {

PyErr_SetString(PyExc_ValueError, "read byte out of range");

return NULL;

}

return PyLong_FromLong((unsigned char)self->data[self->pos++]);

}

static PyObject *

mmap_read_line_method(mmap_object *self,

PyObject *unused)

{

Py_ssize_t remaining;

char *start, *eol;

PyObject *result;

CHECK_VALID(NULL);

remaining = (self->pos < self->size) ? self->size - self->pos : 0;

if (!remaining)

return PyBytes_FromString("");

start = self->data + self->pos;

eol = memchr(start, '\n', remaining);

if (!eol)

eol = self->data + self->size;

else

++eol; /* advance past newline */

result = PyBytes_FromStringAndSize(start, (eol - start));

self->pos += (eol - start);

return result;

}

static PyObject *

mmap_read_method(mmap_object *self,

PyObject *args)

{

Py_ssize_t num_bytes = PY_SSIZE_T_MAX, remaining;

PyObject *result;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "|O&:read", _Py_convert_optional_to_ssize_t, &num_bytes))

return(NULL);

/* silently 'adjust' out-of-range requests */

remaining = (self->pos < self->size) ? self->size - self->pos : 0;

if (num_bytes < 0 || num_bytes > remaining)

num_bytes = remaining;

result = PyBytes_FromStringAndSize(&self->data[self->pos], num_bytes);

self->pos += num_bytes;

return result;

}

static PyObject *

mmap_gfind(mmap_object *self,

PyObject *args,

int reverse)

{

Py_ssize_t start = self->pos;

Py_ssize_t end = self->size;

Py_buffer view;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, reverse ? "y*|nn:rfind" : "y*|nn:find",

&view, &start, &end)) {

return NULL;

} else {

const char *p, *start_p, *end_p;

int sign = reverse ? -1 : 1;

const char *needle = view.buf;

Py_ssize_t len = view.len;

if (start < 0)

start += self->size;

if (start < 0)

start = 0;

else if (start > self->size)

start = self->size;

if (end < 0)

end += self->size;

if (end < 0)

end = 0;

else if (end > self->size)

end = self->size;

start_p = self->data + start;

end_p = self->data + end;

for (p = (reverse ? end_p - len : start_p);

(p >= start_p) && (p + len <= end_p); p += sign) {

Py_ssize_t i;

for (i = 0; i < len && needle[i] == p[i]; ++i)

/* nothing */;

if (i == len) {

PyBuffer_Release(&view);

return PyLong_FromSsize_t(p - self->data);

}

}

PyBuffer_Release(&view);

return PyLong_FromLong(-1);

}

}

static PyObject *

mmap_find_method(mmap_object *self,

PyObject *args)

{

return mmap_gfind(self, args, 0);

}

static PyObject *

mmap_rfind_method(mmap_object *self,

PyObject *args)

{

return mmap_gfind(self, args, 1);

}

static int

is_writable(mmap_object *self)

{

if (self->access != ACCESS_READ)

return 1;

PyErr_Format(PyExc_TypeError, "mmap can't modify a readonly memory map.");

return 0;

}

static int

is_resizeable(mmap_object *self)

{

if (self->exports > 0) {

PyErr_SetString(PyExc_BufferError,

"mmap can't resize with extant buffers exported.");

return 0;

}

if ((self->access == ACCESS_WRITE) || (self->access == ACCESS_DEFAULT))

return 1;

PyErr_Format(PyExc_TypeError,

"mmap can't resize a readonly or copy-on-write memory map.");

return 0;

}

static PyObject *

mmap_write_method(mmap_object *self,

PyObject *args)

{

Py_buffer data;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "y*:write", &data))

return(NULL);

if (!is_writable(self)) {

PyBuffer_Release(&data);

return NULL;

}

if (self->pos > self->size || self->size - self->pos < data.len) {

PyBuffer_Release(&data);

PyErr_SetString(PyExc_ValueError, "data out of range");

return NULL;

}

memcpy(&self->data[self->pos], data.buf, data.len);

self->pos += data.len;

PyBuffer_Release(&data);

return PyLong_FromSsize_t(data.len);

}

static PyObject *

mmap_write_byte_method(mmap_object *self,

PyObject *args)

{

char value;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "b:write_byte", &value))

return(NULL);

if (!is_writable(self))

return NULL;

if (self->pos < self->size) {

self->data[self->pos++] = value;

Py_RETURN_NONE;

}

else {

PyErr_SetString(PyExc_ValueError, "write byte out of range");

return NULL;

}

}

static PyObject *

mmap_size_method(mmap_object *self,

PyObject *unused)

{

CHECK_VALID(NULL);

#ifdef MS_WINDOWS

if (self->file_handle != INVALID_HANDLE_VALUE) {

DWORD low,high;

long long size;

low = GetFileSize(self->file_handle, &high);

if (low == INVALID_FILE_SIZE) {

/* It might be that the function appears to have failed,

when indeed its size equals INVALID_FILE_SIZE */

DWORD error = GetLastError();

if (error != NO_ERROR)

return PyErr_SetFromWindowsErr(error);

}

if (!high && low < LONG_MAX)

return PyLong_FromLong((long)low);

size = (((long long)high)<<32) + low;

return PyLong_FromLongLong(size);

} else {

return PyLong_FromSsize_t(self->size);

}

#endif /* MS_WINDOWS */

#ifdef UNIX

{

struct _Py_stat_struct status;

if (_Py_fstat(self->fd, &status) == -1)

return NULL;

#ifdef HAVE_LARGEFILE_SUPPORT

return PyLong_FromLongLong(status.st_size);

#else

return PyLong_FromLong(status.st_size);

#endif

}

#endif /* UNIX */

}

/* This assumes that you want the entire file mapped,

/ and when recreating the map will make the new file

/ have the new size

/

/ Is this really necessary? This could easily be done

/ from python by just closing and re-opening with the

/ new size?

*/

static PyObject *

mmap_resize_method(mmap_object *self,

PyObject *args)

{

Py_ssize_t new_size;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "n:resize", &new_size) ||

!is_resizeable(self)) {

return NULL;

}

if (new_size < 0 || PY_SSIZE_T_MAX - new_size < self->offset) {

PyErr_SetString(PyExc_ValueError, "new size out of range");

return NULL;

}

{

#ifdef MS_WINDOWS

DWORD dwErrCode = 0;

DWORD off_hi, off_lo, newSizeLow, newSizeHigh;

/* First, unmap the file view */

UnmapViewOfFile(self->data);

self->data = NULL;

/* Close the mapping object */

CloseHandle(self->map_handle);

self->map_handle = NULL;

/* Move to the desired EOF position */

newSizeHigh = (DWORD)((self->offset + new_size) >> 32);

newSizeLow = (DWORD)((self->offset + new_size) & 0xFFFFFFFF);

off_hi = (DWORD)(self->offset >> 32);

off_lo = (DWORD)(self->offset & 0xFFFFFFFF);

SetFilePointer(self->file_handle,

newSizeLow, &newSizeHigh, FILE_BEGIN);

/* Change the size of the file */

SetEndOfFile(self->file_handle);

/* Create another mapping object and remap the file view */

self->map_handle = CreateFileMapping(

self->file_handle,

NULL,

PAGE_READWRITE,

0,

0,

self->tagname);

if (self->map_handle != NULL) {

self->data = (char *) MapViewOfFile(self->map_handle,

FILE_MAP_WRITE,

off_hi,

off_lo,

new_size);

if (self->data != NULL) {

self->size = new_size;

Py_RETURN_NONE;

} else {

dwErrCode = GetLastError();

CloseHandle(self->map_handle);

self->map_handle = NULL;

}

} else {

dwErrCode = GetLastError();

}

PyErr_SetFromWindowsErr(dwErrCode);

return NULL;

#endif /* MS_WINDOWS */

#ifdef UNIX

#ifndef HAVE_MREMAP

PyErr_SetString(PyExc_SystemError,

"mmap: resizing not available--no mremap()");

return NULL;

#else

void *newmap;

if (self->fd != -1 && ftruncate(self->fd, self->offset + new_size) == -1) {

PyErr_SetFromErrno(PyExc_OSError);

return NULL;

}

#ifdef MREMAP_MAYMOVE

newmap = mremap(self->data, self->size, new_size, MREMAP_MAYMOVE);

#else

#if defined(__NetBSD__)

newmap = mremap(self->data, self->size, self->data, new_size, 0);

#else

newmap = mremap(self->data, self->size, new_size, 0);

#endif /* __NetBSD__ */

#endif

if (newmap == (void *)-1)

{

PyErr_SetFromErrno(PyExc_OSError);

return NULL;

}

self->data = newmap;

self->size = new_size;

Py_RETURN_NONE;

#endif /* HAVE_MREMAP */

#endif /* UNIX */

}

}

static PyObject *

mmap_tell_method(mmap_object *self, PyObject *unused)

{

CHECK_VALID(NULL);

return PyLong_FromSize_t(self->pos);

}

static PyObject *

mmap_flush_method(mmap_object *self, PyObject *args)

{

Py_ssize_t offset = 0;

Py_ssize_t size = self->size;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "|nn:flush", &offset, &size))

return NULL;

if (size < 0 || offset < 0 || self->size - offset < size) {

PyErr_SetString(PyExc_ValueError, "flush values out of range");

return NULL;

}

if (self->access == ACCESS_READ || self->access == ACCESS_COPY)

return PyLong_FromLong(0);

#ifdef MS_WINDOWS

return PyLong_FromLong((long) FlushViewOfFile(self->data+offset, size));

#elif defined(UNIX)

/* XXX semantics of return value? */

/* XXX flags for msync? */

if (-1 == msync(self->data + offset, size, MS_SYNC)) {

PyErr_SetFromErrno(PyExc_OSError);

return NULL;

}

return PyLong_FromLong(0);

#else

PyErr_SetString(PyExc_ValueError, "flush not supported on this system");

return NULL;

#endif

}

static PyObject *

mmap_seek_method(mmap_object *self, PyObject *args)

{

Py_ssize_t dist;

int how=0;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "n|i:seek", &dist, &how))

return NULL;

else {

Py_ssize_t where;

switch (how) {

case 0: /* relative to start */

where = dist;

break;

case 1: /* relative to current position */

if (PY_SSIZE_T_MAX - self->pos < dist)

goto onoutofrange;

where = self->pos + dist;

break;

case 2: /* relative to end */

if (PY_SSIZE_T_MAX - self->size < dist)

goto onoutofrange;

where = self->size + dist;

break;

default:

PyErr_SetString(PyExc_ValueError, "unknown seek type");

return NULL;

}

if (where > self->size || where < 0)

goto onoutofrange;

self->pos = where;

Py_RETURN_NONE;

}

onoutofrange:

PyErr_SetString(PyExc_ValueError, "seek out of range");

return NULL;

}

static PyObject *

mmap_move_method(mmap_object *self, PyObject *args)

{

Py_ssize_t dest, src, cnt;

CHECK_VALID(NULL);

if (!PyArg_ParseTuple(args, "nnn:move", &dest, &src, &cnt) ||

!is_writable(self)) {

return NULL;

} else {

/* bounds check the values */

if (dest < 0 || src < 0 || cnt < 0)

goto bounds;

if (self->size - dest < cnt || self->size - src < cnt)

goto bounds;

memmove(&self->data[dest], &self->data[src], cnt);

Py_RETURN_NONE;

bounds:

PyErr_SetString(PyExc_ValueError,

"source, destination, or count out of range");

return NULL;

}

}

static PyObject *

mmap_closed_get(mmap_object *self)

{

#ifdef MS_WINDOWS

return PyBool_FromLong(self->map_handle == NULL ? 1 : 0);

#elif defined(UNIX)

return PyBool_FromLong(self->data == NULL ? 1 : 0);

#endif

}

static PyObject *

mmap__enter__method(mmap_object *self, PyObject *args)

{

CHECK_VALID(NULL);

Py_INCREF(self);

return (PyObject *)self;

}

static PyObject *

mmap__exit__method(PyObject *self, PyObject *args)

{

_Py_IDENTIFIER(close);

return _PyObject_CallMethodId(self, &PyId_close, NULL);

}

#ifdef MS_WINDOWS

static PyObject *

mmap__sizeof__method(mmap_object *self, void *unused)

{

Py_ssize_t res;

res = _PyObject_SIZE(Py_TYPE(self));

if (self->tagname)

res += strlen(self->tagname) + 1;

return PyLong_FromSsize_t(res);

}

#endif

static struct PyMethodDef mmap_object_methods[] = {

{"close", (PyCFunction) mmap_close_method, METH_NOARGS},

{"find", (PyCFunction) mmap_find_method, METH_VARARGS},

{"rfind", (PyCFunction) mmap_rfind_method, METH_VARARGS},

{"flush", (PyCFunction) mmap_flush_method, METH_VARARGS},

{"move", (PyCFunction) mmap_move_method, METH_VARARGS},

{"read", (PyCFunction) mmap_read_method, METH_VARARGS},

{"read_byte", (PyCFunction) mmap_read_byte_method, METH_NOARGS},

{"readline", (PyCFunction) mmap_read_line_method, METH_NOARGS},

{"resize", (PyCFunction) mmap_resize_method, METH_VARARGS},

{"seek", (PyCFunction) mmap_seek_method, METH_VARARGS},

{"size", (PyCFunction) mmap_size_method, METH_NOARGS},

{"tell", (PyCFunction) mmap_tell_method, METH_NOARGS},

{"write", (PyCFunction) mmap_write_method, METH_VARARGS},

{"write_byte", (PyCFunction) mmap_write_byte_method, METH_VARARGS},

{"__enter__", (PyCFunction) mmap__enter__method, METH_NOARGS},

{"__exit__", (PyCFunction) mmap__exit__method, METH_VARARGS},

#ifdef MS_WINDOWS

{"__sizeof__", (PyCFunction) mmap__sizeof__method, METH_NOARGS},

#endif

{NULL, NULL} /* sentinel */

};

static PyGetSetDef mmap_object_getset[] = {

{"closed", (getter) mmap_closed_get, NULL, NULL},

{NULL}

};

/* Functions for treating an mmap'ed file as a buffer */

static int

mmap_buffer_getbuf(mmap_object *self, Py_buffer *view, int flags)

{

CHECK_VALID(-1);

if (PyBuffer_FillInfo(view, (PyObject*)self, self->data, self->size,

(self->access == ACCESS_READ), flags) < 0)

return -1;

self->exports++;

return 0;

}

static void

mmap_buffer_releasebuf(mmap_object *self, Py_buffer *view)

{

self->exports--;

}

static Py_ssize_t

mmap_length(mmap_object *self)

{

CHECK_VALID(-1);

return self->size;

}

static PyObject *

mmap_item(mmap_object *self, Py_ssize_t i)

{

CHECK_VALID(NULL);

if (i < 0 || i >= self->size) {

PyErr_SetString(PyExc_IndexError, "mmap index out of range");

return NULL;

}

return PyBytes_FromStringAndSize(self->data + i, 1);

}

static PyObject *

mmap_subscript(mmap_object *self, PyObject *item)

{

CHECK_VALID(NULL);

if (PyIndex_Check(item)) {

Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);

if (i == -1 && PyErr_Occurred())

return NULL;

if (i < 0)

i += self->size;

if (i < 0 || i >= self->size) {

PyErr_SetString(PyExc_IndexError,

"mmap index out of range");

return NULL;

}

return PyLong_FromLong(Py_CHARMASK(self->data[i]));

}

else if (PySlice_Check(item)) {

Py_ssize_t start, stop, step, slicelen;

if (PySlice_Unpack(item, &start, &stop, &step) < 0) {

return NULL;

}

slicelen = PySlice_AdjustIndices(self->size, &start, &stop, step);

if (slicelen <= 0)

return PyBytes_FromStringAndSize("", 0);

else if (step == 1)

return PyBytes_FromStringAndSize(self->data + start,

slicelen);

else {

char *result_buf = (char *)PyMem_Malloc(slicelen);

Py_ssize_t cur, i;

PyObject *result;

if (result_buf == NULL)

return PyErr_NoMemory();

for (cur = start, i = 0; i < slicelen;

cur += step, i++) {

result_buf[i] = self->data[cur];

}

result = PyBytes_FromStringAndSize(result_buf,

slicelen);

PyMem_Free(result_buf);

return result;

}

}

else {

PyErr_SetString(PyExc_TypeError,

"mmap indices must be integers");

return NULL;

}

}

static PyObject *

mmap_concat(mmap_object *self, PyObject *bb)

{

CHECK_VALID(NULL);

PyErr_SetString(PyExc_SystemError,

"mmaps don't support concatenation");

return NULL;

}

static PyObject *

mmap_repeat(mmap_object *self, Py_ssize_t n)

{

CHECK_VALID(NULL);

PyErr_SetString(PyExc_SystemError,

"mmaps don't support repeat operation");

return NULL;

}

static int

mmap_ass_item(mmap_object *self, Py_ssize_t i, PyObject *v)

{

const char *buf;

CHECK_VALID(-1);

if (i < 0 || i >= self->size) {

PyErr_SetString(PyExc_IndexError, "mmap index out of range");

return -1;

}

if (v == NULL) {

PyErr_SetString(PyExc_TypeError,

"mmap object doesn't support item deletion");

return -1;

}

if (! (PyBytes_Check(v) && PyBytes_Size(v)==1) ) {

PyErr_SetString(PyExc_IndexError,

"mmap assignment must be length-1 bytes()");

return -1;

}

if (!is_writable(self))

return -1;

buf = PyBytes_AsString(v);

self->data[i] = buf[0];

return 0;

}

static int

mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)

{

CHECK_VALID(-1);

if (!is_writable(self))

return -1;

if (PyIndex_Check(item)) {

Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);

Py_ssize_t v;

if (i == -1 && PyErr_Occurred())

return -1;

if (i < 0)

i += self->size;

if (i < 0 || i >= self->size) {

PyErr_SetString(PyExc_IndexError,

"mmap index out of range");

return -1;

}

if (value == NULL) {

PyErr_SetString(PyExc_TypeError,

"mmap doesn't support item deletion");

return -1;

}

if (!PyIndex_Check(value)) {

PyErr_SetString(PyExc_TypeError,

"mmap item value must be an int");

return -1;

}

v = PyNumber_AsSsize_t(value, PyExc_TypeError);

if (v == -1 && PyErr_Occurred())

return -1;

if (v < 0 || v > 255) {

PyErr_SetString(PyExc_ValueError,

"mmap item value must be "

"in range(0, 256)");

return -1;

}

self->data[i] = (char) v;

return 0;

}

else if (PySlice_Check(item)) {

Py_ssize_t start, stop, step, slicelen;

Py_buffer vbuf;

if (PySlice_Unpack(item, &start, &stop, &step) < 0) {

return -1;

}

slicelen = PySlice_AdjustIndices(self->size, &start, &stop, step);

if (value == NULL) {

PyErr_SetString(PyExc_TypeError,

"mmap object doesn't support slice deletion");

return -1;

}

if (PyObject_GetBuffer(value, &vbuf, PyBUF_SIMPLE) < 0)

return -1;

if (vbuf.len != slicelen) {

PyErr_SetString(PyExc_IndexError,

"mmap slice assignment is wrong size");

PyBuffer_Release(&vbuf);

return -1;

}

if (slicelen == 0) {

}

else if (step == 1) {

memcpy(self->data + start, vbuf.buf, slicelen);

}

else {

Py_ssize_t cur, i;

for (cur = start, i = 0;

i < slicelen;

cur += step, i++)

{

self->data[cur] = ((char *)vbuf.buf)[i];

}

}

PyBuffer_Release(&vbuf);

return 0;

}

else {

PyErr_SetString(PyExc_TypeError,

"mmap indices must be integer");

return -1;

}

}

static PySequenceMethods mmap_as_sequence = {

(lenfunc)mmap_length, /*sq_length*/

(binaryfunc)mmap_concat, /*sq_concat*/

(ssizeargfunc)mmap_repeat, /*sq_repeat*/

(ssizeargfunc)mmap_item, /*sq_item*/

0, /*sq_slice*/

(ssizeobjargproc)mmap_ass_item, /*sq_ass_item*/

0, /*sq_ass_slice*/

};

static PyMappingMethods mmap_as_mapping = {

(lenfunc)mmap_length,

(binaryfunc)mmap_subscript,

(objobjargproc)mmap_ass_subscript,

};

static PyBufferProcs mmap_as_buffer = {

(getbufferproc)mmap_buffer_getbuf,

(releasebufferproc)mmap_buffer_releasebuf,

};

static PyObject *

new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict);

PyDoc_STRVAR(mmap_doc,

"Windows: mmap(fileno, length[, tagname[, access[, offset]]])\n\

\n\

Maps length bytes from the file specified by the file handle fileno,\n\

and returns a mmap object. If length is larger than the current size\n\

of the file, the file is extended to contain length bytes. If length\n\

is 0, the maximum length of the map is the current size of the file,\n\

except that if the file is empty Windows raises an exception (you cannot\n\

create an empty mapping on Windows).\n\

\n\

Unix: mmap(fileno, length[, flags[, prot[, access[, offset]]]])\n\

\n\

Maps length bytes from the file specified by the file descriptor fileno,\n\

and returns a mmap object. If length is 0, the maximum length of the map\n\

will be the current size of the file when mmap is called.\n\

flags specifies the nature of the mapping. MAP_PRIVATE creates a\n\

private copy-on-write mapping, so changes to the contents of the mmap\n\

object will be private to this process, and MAP_SHARED creates a mapping\n\

that's shared with all other processes mapping the same areas of the file.\n\

The default value is MAP_SHARED.\n\

\n\

To map anonymous memory, pass -1 as the fileno (both versions).");

static PyTypeObject mmap_object_type = {

PyVarObject_HEAD_INIT(NULL, 0)

"mmap.mmap", /* tp_name */