ocaml/otherlibs/bigarray/mmap_win32.c

115 lines
4.0 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Manuel Serrano and Xavier Leroy, INRIA Rocquencourt */
/* */
/* Copyright 2000 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License. */
/* */
/***********************************************************************/
/* $Id$ */
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include "bigarray.h"
#include "custom.h"
#include "fail.h"
#include "mlvalues.h"
#include "sys.h"
#include "unixsupport.h"
extern int bigarray_element_size[]; /* from bigarray_stubs.c */
static void bigarray_sys_error(void);
CAMLprim value bigarray_map_file(value vfd, value vkind, value vlayout,
value vshared, value vdim)
{
HANDLE fd, fmap;
int flags, major_dim, mode, perm;
long num_dims, i;
long dim[MAX_NUM_DIMS];
long currpos, file_size;
unsigned long array_size;
char c;
void * addr;
fd = Handle_val(vfd);
flags = Int_val(vkind) | Int_val(vlayout);
num_dims = Wosize_val(vdim);
major_dim = flags & BIGARRAY_FORTRAN_LAYOUT ? num_dims - 1 : 0;
/* Extract dimensions from Caml array */
num_dims = Wosize_val(vdim);
if (num_dims < 1 || num_dims > MAX_NUM_DIMS)
invalid_argument("Bigarray.mmap: bad number of dimensions");
for (i = 0; i < num_dims; i++) {
dim[i] = Long_val(Field(vdim, i));
if (dim[i] == -1 && i == major_dim) continue;
if (dim[i] < 0 || dim[i] > 0x7FFFFFFFL)
invalid_argument("Bigarray.create: negative dimension");
}
/* Determine file size */
currpos = SetFilePointer(fd, 0, NULL, FILE_CURRENT);
if (currpos == -1) bigarray_sys_error();
file_size = SetFilePointer(fd, 0, NULL, FILE_END);
if (file_size == -1) bigarray_sys_error();
/* Determine array size in bytes (or size of array without the major
dimension if that dimension wasn't specified) */
array_size = bigarray_element_size[flags & BIGARRAY_KIND_MASK];
for (i = 0; i < num_dims; i++)
if (dim[i] != -1) array_size *= dim[i];
/* Check if the first/last dimension is unknown */
if (dim[major_dim] == -1) {
/* Determine first/last dimension from file size */
if ((unsigned long) file_size % array_size != 0)
failwith("Bigarray.mmap: file size doesn't match array dimensions");
dim[major_dim] = (unsigned long) file_size / array_size;
array_size = file_size;
}
/* Restore original file position */
SetFilePointer(fd, currpos, NULL, FILE_BEGIN);
/* Create the file mapping */
if (Bool_val(vshared)) {
perm = PAGE_READWRITE;
mode = FILE_MAP_WRITE;
} else {
perm = PAGE_READONLY; /* doesn't work under Win98 */
mode = FILE_MAP_COPY;
}
fmap = CreateFileMapping(fd, NULL, perm, 0, array_size, NULL);
if (fmap == NULL) bigarray_sys_error();
/* Map the mapping in memory */
addr = MapViewOfFile(fmap, mode, 0, 0, array_size);
if (addr == NULL) bigarray_sys_error();
/* Close the file mapping */
CloseHandle(fmap);
/* Build and return the Caml bigarray */
return alloc_bigarray(flags | BIGARRAY_MAPPED_FILE, num_dims, addr, dim);
}
void bigarray_unmap_file(void * addr, unsigned long len)
{
UnmapViewOfFile(addr);
}
static void bigarray_sys_error(void)
{
char buffer[512];
unsigned long errnum;
errnum = GetLastError();
if (!FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
errnum,
0,
buffer,
sizeof(buffer),
NULL))
sprintf(buffer, "Unknown error %d\n", errnum);
raise_sys_error(copy_string(buffer));
}