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mmapmodule.c
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1518 lines (1378 loc) · 44.6 KB
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/*
/ 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>
#ifndef MS_WINDOWS
#define UNIX
# ifdef __APPLE__
# include <fcntl.h>
# endif
#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;
size_t size;
size_t pos; /* relative to offset */
#ifdef MS_WINDOWS
PY_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
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 */
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_INCREF(Py_None);
return Py_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 i
82B7
nvalid"); \
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) {
char value = self->data[self->pos];
self->pos += 1;
return Py_BuildValue("B", (unsigned char)value);
} else {
PyErr_SetString(PyExc_ValueError, "read byte out of range");
return NULL;
}
}
static PyObject *
mmap_read_line_method(mmap_object *self,
PyObject *unused)
{
char *start = self->data+self->pos;
char *eof = self->data+self->size;
char *eol;
PyObject *result;
CHECK_VALID(NULL);
eol = memchr(start, '\n', self->size - self->pos);
if (!eol)
eol = eof;
else
++eol; /* we're interested in the position after the
newline. */
result = PyBytes_FromStringAndSize(start, (eol - start));
self->pos += (eol - start);
return result;
}
/* Basically the "n" format code with the ability to turn None into -1. */
static int
mmap_convert_ssize_t(PyObject *obj, void *result) {
Py_ssize_t limit;
if (obj == Py_None) {
limit = -1;
}
else if (PyNumber_Check(obj)) {
limit = PyNumber_AsSsize_t(obj, PyExc_OverflowError);
if (limit == -1 && PyErr_Occurred())
return 0;
}
else {
PyErr_Format(PyExc_TypeError,
"integer argument expected, got '%.200s'",
Py_TYPE(obj)->tp_name);
return 0;
}
*((Py_ssize_t *)result) = limit;
return 1;
}
static PyObject *
mmap_read_method(mmap_object *self,
PyObject *args)
{
Py_ssize_t num_bytes = -1, n;
PyObject *result;
CHECK_VALID(NULL);
if (!PyArg_ParseTuple(args, "|O&:read", mmap_convert_ssize_t, &num_bytes))
return(NULL);
/* silently 'adjust' out-of-range requests */
assert(self->size >= self->pos);
n = self->size - self->pos;
/* The difference can overflow, only if self->size is greater than
* PY_SSIZE_T_MAX. But then the operation cannot possibly succeed,
* because the mapped area and the returned string each need more
* than half of the addressable memory. So we clip the size, and let
* the code below raise MemoryError.
*/
if (n < 0)
n = PY_SSIZE_T_MAX;
if (num_bytes < 0 || num_bytes > n) {
num_bytes = n;
}
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;
const char *needle;
Py_ssize_t len;
CHECK_VALID(NULL);
if (!PyArg_ParseTuple(args, reverse ? "y#|nn:rfind" : "y#|nn:find",
&needle, &len, &start, &end)) {
return NULL;
} else {
const char *p, *start_p, *end_p;
int sign = reverse ? -1 : 1;
if (start < 0)
start += self->size;
if (start < 0)
start = 0;
else if ((size_t)start > self->size)
start = self->size;
if (end < 0)
end += self->size;
if (end < 0)
end = 0;
else if ((size_t)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) {
return PyLong_FromSsize_t(p - self->data);
}
}
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_ssize_t length;
char *data;
CHECK_VALID(NULL);
if (!PyArg_ParseTuple(args, "y#:write", &data, &length))
return(NULL);
if (!is_writable(self))
return NULL;
if ((self->pos + length) > self->size) {
PyErr_SetString(PyExc_ValueError, "data out of range");
return NULL;
}
memcpy(self->data+self->pos, data, length);
self->pos = self->pos+length;
Py_INCREF(Py_None);
return Py_None;
}
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;
self->pos += 1;
Py_INCREF(Py_None);
return Py_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;
PY_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 = (((PY_LONG_LONG)high)<<32) + low;
return PyLong_FromLongLong(size);
} else {
return PyLong_FromSsize_t(self->size);
}
#endif /* MS_WINDOWS */
#ifdef UNIX
{
struct stat buf;
if (-1 == fstat(self->fd, &buf)) {
PyErr_SetFromErrno(PyExc_OSError);
return NULL;
}
#ifdef HAVE_LARGEFILE_SUPPORT
return PyLong_FromLongLong(buf.st_size);
#else
return PyLong_FromLong(buf.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;
#ifdef MS_WINDOWS
} else {
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_INCREF(Py_None);
return Py_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
} else {
PyErr_SetString(PyExc_SystemError,
"mmap: resizing not available--no mremap()");
return NULL;
#else
} else {
void *newmap;
if (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_INCREF(Py_None);
return Py_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_t)(offset + size) > self->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 {
size_t where;
switch (how) {
case 0: /* relative to start */
if (dist < 0)
goto onoutofrange;
where = dist;
break;
case 1: /* relative to current position */
if ((Py_ssize_t)self->pos + dist < 0)
goto onoutofrange;
where = self->pos + dist;
break;
case 2: /* relative to end */
if ((Py_ssize_t)self->size + dist < 0)
goto onoutofrange;
where = self->size + dist;
break;
default:
PyErr_SetString(PyExc_ValueError, "unknown seek type");
return NULL;
}
if (where > self->size)
goto onoutofrange;
self->pos = where;
Py_INCREF(Py_None);
return Py_None;
}
onoutofrange:
PyErr_SetString(PyExc_ValueError, "seek out of range");
return NULL;
}
static PyObject *
mmap_move_method(mmap_object *self, PyObject *args)
{
unsigned long dest, src, cnt;
CHECK_VALID(NULL);
if (!PyArg_ParseTuple(args, "kkk:move", &dest, &src, &cnt) ||
!is_writable(self)) {
return NULL;
} else {
/* bounds check the values */
if ((cnt + dest) < cnt || (cnt + src) < cnt ||
src > self->size || (src + cnt) > self->size ||
dest > self->size || (dest + cnt) > self->size) {
PyErr_SetString(PyExc_ValueError,
"source, destination, or count out of range");
return NULL;
}
memmove(self->data+dest, self->data+src, cnt);
Py_INCREF(Py_None);
return Py_None;
}
}
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);
}
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},
{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 || (size_t)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 || (size_t)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_GetIndicesEx(item, self->size,
&start, &stop, &step, &slicelen) < 0) {
return NULL;
}
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 || (size_t)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 || (size_t)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_GetIndicesEx(item,
self->size, &start, &stop,
&step, &slicelen) < 0) {
return -1;
}
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\