diff options
Diffstat (limited to 'Modules/mmapmodule.c')
| -rw-r--r-- | Modules/mmapmodule.c | 113 |
1 files changed, 77 insertions, 36 deletions
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c index c2ed5d1..e5d7711 100644 --- a/Modules/mmapmodule.c +++ b/Modules/mmapmodule.c @@ -3,6 +3,9 @@ / 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 @@ -31,6 +34,16 @@ my_getpagesize(void) GetSystemInfo(&si); return si.dwPageSize; } + +static int +my_getallocationgranularity (void) +{ + + SYSTEM_INFO si; + GetSystemInfo(&si); + return si.dwAllocationGranularity; +} + #endif #ifdef UNIX @@ -43,6 +56,8 @@ my_getpagesize(void) { return sysconf(_SC_PAGESIZE); } + +#define my_getallocationgranularity my_getpagesize #else #define my_getpagesize getpagesize #endif @@ -74,7 +89,8 @@ typedef struct { PyObject_HEAD char * data; size_t size; - size_t pos; + size_t pos; /* relative to offset */ + size_t offset; int exports; #ifdef MS_WINDOWS @@ -398,18 +414,22 @@ mmap_resize_method(mmap_object *self, #ifdef MS_WINDOWS } else { DWORD dwErrCode = 0; - DWORD newSizeLow, newSizeHigh; + DWORD off_hi, off_lo, newSizeLow, newSizeHigh; /* First, unmap the file view */ UnmapViewOfFile(self->data); /* Close the mapping object */ CloseHandle(self->map_handle); /* Move to the desired EOF position */ #if SIZEOF_SIZE_T > 4 - newSizeHigh = (DWORD)(new_size >> 32); - newSizeLow = (DWORD)(new_size & 0xFFFFFFFF); + 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); #else newSizeHigh = 0; newSizeLow = (DWORD)new_size; + off_hi = 0; + off_lo = (DWORD)self->offset; #endif SetFilePointer(self->file_handle, newSizeLow, &newSizeHigh, FILE_BEGIN); @@ -420,15 +440,15 @@ mmap_resize_method(mmap_object *self, self->file_handle, NULL, PAGE_READWRITE, - newSizeHigh, - newSizeLow, + 0, + 0, self->tagname); if (self->map_handle != NULL) { self->data = (char *) MapViewOfFile(self->map_handle, FILE_MAP_WRITE, - 0, - 0, - 0); + off_hi, + off_lo, + new_size); if (self->data != NULL) { self->size = new_size; Py_INCREF(Py_None); @@ -651,7 +671,7 @@ mmap_subscript(mmap_object *self, PyObject *item) return NULL; if (i < 0) i += self->size; - 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; @@ -753,7 +773,7 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value) return -1; if (i < 0) i += self->size; - 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; @@ -882,15 +902,18 @@ static PyTypeObject mmap_object_type = { Returns -1 on error, with an appropriate Python exception raised. On success, the map size is returned. */ static Py_ssize_t -_GetMapSize(PyObject *o) +_GetMapSize(PyObject *o, const char* param) { + if (o == NULL) + return 0; if (PyIndex_Check(o)) { Py_ssize_t i = PyNumber_AsSsize_t(o, PyExc_OverflowError); if (i==-1 && PyErr_Occurred()) return -1; if (i < 0) { - PyErr_SetString(PyExc_OverflowError, - "memory mapped size must be positive"); + PyErr_Format(PyExc_OverflowError, + "memory mapped %s must be positive", + param); return -1; } return i; @@ -908,22 +931,25 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) struct stat st; #endif mmap_object *m_obj; - PyObject *map_size_obj = NULL; - Py_ssize_t map_size; + PyObject *map_size_obj = NULL, *offset_obj = NULL; + Py_ssize_t map_size, offset; int fd, flags = MAP_SHARED, prot = PROT_WRITE | PROT_READ; int devzero = -1; int access = (int)ACCESS_DEFAULT; static char *keywords[] = {"fileno", "length", "flags", "prot", - "access", NULL}; + "access", "offset", NULL}; - if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|iii", keywords, + if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|iiiO", keywords, &fd, &map_size_obj, &flags, &prot, - &access)) + &access, &offset_obj)) return NULL; - map_size = _GetMapSize(map_size_obj); + map_size = _GetMapSize(map_size_obj, "size"); if (map_size < 0) return NULL; + offset = _GetMapSize(offset_obj, "offset"); + if (offset < 0) + return NULL; if ((access != (int)ACCESS_DEFAULT) && ((flags != MAP_SHARED) || (prot != (PROT_WRITE | PROT_READ)))) @@ -958,7 +984,7 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) if (fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) { if (map_size == 0) { map_size = st.st_size; - } else if ((size_t)map_size > st.st_size) { + } else if ((size_t)offset + (size_t)map_size > st.st_size) { PyErr_SetString(PyExc_ValueError, "mmap length is greater than file size"); return NULL; @@ -971,6 +997,7 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) m_obj->size = (size_t) map_size; m_obj->pos = (size_t) 0; m_obj->exports = 0; + m_obj->offset = offset; if (fd == -1) { m_obj->fd = -1; /* Assume the caller wants to map anonymous memory. @@ -997,10 +1024,10 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) return NULL; } } - + m_obj->data = mmap(NULL, map_size, prot, flags, - fd, 0); + fd, offset); if (devzero != -1) { close(devzero); @@ -1022,10 +1049,12 @@ static PyObject * new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) { mmap_object *m_obj; - PyObject *map_size_obj = NULL; - Py_ssize_t map_size; - DWORD size_hi; /* upper 32 bits of m_obj->size */ - DWORD size_lo; /* lower 32 bits of m_obj->size */ + PyObject *map_size_obj = NULL, *offset_obj = NULL; + Py_ssize_t map_size, offset; + DWORD off_hi; /* upper 32 bits of offset */ + DWORD off_lo; /* lower 32 bits of offset */ + DWORD size_hi; /* upper 32 bits of size */ + DWORD size_lo; /* lower 32 bits of size */ char *tagname = ""; DWORD dwErr = 0; int fileno; @@ -1034,11 +1063,11 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) DWORD flProtect, dwDesiredAccess; static char *keywords[] = { "fileno", "length", "tagname", - "access", NULL }; + "access", "offset", NULL }; - if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|zi", keywords, + if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iO|ziO", keywords, &fileno, &map_size_obj, - &tagname, &access)) { + &tagname, &access, &offset_obj)) { return NULL; } @@ -1060,9 +1089,12 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) "mmap invalid access parameter."); } - map_size = _GetMapSize(map_size_obj); + map_size = _GetMapSize(map_size_obj, "size"); if (map_size < 0) return NULL; + offset = _GetMapSize(offset_obj, "offset"); + if (offset < 0) + return NULL; /* assume -1 and 0 both mean invalid filedescriptor to 'anonymously' map memory. @@ -1092,6 +1124,7 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) m_obj->file_handle = INVALID_HANDLE_VALUE; m_obj->map_handle = INVALID_HANDLE_VALUE; m_obj->tagname = NULL; + m_obj->offset = offset; if (fh) { /* It is necessary to duplicate the handle, so the @@ -1161,12 +1194,18 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) * right by 32, so we need different code. */ #if SIZEOF_SIZE_T > 4 - size_hi = (DWORD)(m_obj->size >> 32); - size_lo = (DWORD)(m_obj->size & 0xFFFFFFFF); + size_hi = (DWORD)((offset + m_obj->size) >> 32); + size_lo = (DWORD)((offset + m_obj->size) & 0xFFFFFFFF); + off_hi = (DWORD)(offset >> 32); + off_lo = (DWORD)(offset & 0xFFFFFFFF); #else size_hi = 0; - size_lo = (DWORD)m_obj->size; + size_lo = (DWORD)(offset + m_obj->size); + off_hi = 0; + off_lo = (DWORD)offset; #endif + /* For files, it would be sufficient to pass 0 as size. + For anonymous maps, we have to pass the size explicitly. */ m_obj->map_handle = CreateFileMapping(m_obj->file_handle, NULL, flProtect, @@ -1176,8 +1215,8 @@ new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict) if (m_obj->map_handle != NULL) { m_obj->data = (char *) MapViewOfFile(m_obj->map_handle, dwDesiredAccess, - 0, - 0, + off_hi, + off_lo, 0); if (m_obj->data != NULL) return (PyObject *)m_obj; @@ -1252,6 +1291,8 @@ PyMODINIT_FUNC setint(dict, "PAGESIZE", (long)my_getpagesize()); + setint(dict, "ALLOCATIONGRANULARITY", (long)my_getallocationgranularity()); + setint(dict, "ACCESS_READ", ACCESS_READ); setint(dict, "ACCESS_WRITE", ACCESS_WRITE); setint(dict, "ACCESS_COPY", ACCESS_COPY); |