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/***********************************************************************/
/* */
/* 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 <string.h>
#include "bigarray.h"
#include "custom.h"
#include "fail.h"
#include "mlvalues.h"
#include "sys.h"
extern int bigarray_element_size[]; /* from bigarray_stubs.c */
#ifdef HAS_UNISTD
#include <unistd.h>
#endif
#ifdef HAS_MMAP
#include <sys/types.h>
#include <sys/mman.h>
#endif
#if defined(HAS_MMAP)
#ifndef MAP_FAILED
#define MAP_FAILED ((void *) -1)
#endif
CAMLprim value bigarray_map_file(value vfd, value vkind, value vlayout,
value vshared, value vdim)
{
int fd, flags, major_dim, shared;
long num_dims, i;
long dim[MAX_NUM_DIMS];
long currpos, file_size;
unsigned long array_size;
char c;
void * addr;
fd = Int_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 = lseek(fd, 0, SEEK_CUR);
if (currpos == -1) sys_error(NO_ARG);
file_size = lseek(fd, 0, SEEK_END);
if (file_size == -1) sys_error(NO_ARG);
/* 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;
} else {
/* Check that file is large enough, and grow it otherwise */
if (file_size < array_size) {
if (lseek(fd, array_size - 1, SEEK_SET) == -1) sys_error(NO_ARG);
c = 0;
if (write(fd, &c, 1) != 1) sys_error(NO_ARG);
}
}
/* Restore original file position */
lseek(fd, currpos, SEEK_SET);
/* Do the mmap */
shared = Bool_val(vshared) ? MAP_SHARED : MAP_PRIVATE;
addr = mmap(NULL, array_size, PROT_READ | PROT_WRITE, shared, fd, 0);
if (addr == (void *) MAP_FAILED) sys_error(NO_ARG);
/* Build and return the Caml bigarray */
return alloc_bigarray(flags | BIGARRAY_MAPPED_FILE, num_dims, addr, dim);
}
#else
value bigarray_map_file(value vfd, value vkind, value vlayout,
value vshared, value vdim)
{
invalid_argument("Bigarray.map_file: not supported");
return Val_unit;
}
#endif
void bigarray_unmap_file(void * addr, unsigned long len)
{
#if defined(HAS_MMAP)
munmap(addr, len);
#endif
}
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