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/* Copyright (C) 2010-2018 The RetroArch team
*
* ---------------------------------------------------------------------------------------
* The following license statement only applies to this file (nbio_unixmmap.c).
* ---------------------------------------------------------------------------------------
*
* Permission is hereby granted, free of charge,
* to any person obtaining a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <file/nbio.h>
#if defined(HAVE_MMAP) && defined(BSD)
#ifdef _WIN32
#include <direct.h>
#else
#include <unistd.h>
#endif
#include <fcntl.h>
#include <sys/mman.h>
#ifdef __APPLE__
#ifndef O_CLOEXEC
#define O_CLOEXEC 0x1000000
#endif
#else
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif
#endif
struct nbio_mmap_unix_t
{
int fd;
int map_flags;
size_t len;
void* ptr;
};
static void *nbio_mmap_unix_open(const char * filename, unsigned mode)
{
static const int o_flags[] = { O_RDONLY, O_RDWR|O_CREAT|O_TRUNC, O_RDWR, O_RDONLY, O_RDWR|O_CREAT|O_TRUNC };
static const int map_flags[] = { PROT_READ, PROT_WRITE|PROT_READ, PROT_WRITE|PROT_READ, PROT_READ, PROT_WRITE|PROT_READ };
size_t len;
void* ptr = NULL;
struct nbio_mmap_unix_t* handle = NULL;
int fd = open(filename, o_flags[mode]|O_CLOEXEC, 0644);
if (fd < 0)
return NULL;
len = lseek(fd, 0, SEEK_END);
if (len != 0)
ptr = mmap(NULL, len, map_flags[mode], MAP_SHARED, fd, 0);
if (ptr == MAP_FAILED)
{
close(fd);
return NULL;
}
handle = malloc(sizeof(struct nbio_mmap_unix_t));
handle->fd = fd;
handle->map_flags = map_flags[mode];
handle->len = len;
handle->ptr = ptr;
return handle;
}
static void nbio_mmap_unix_begin_read(void *data)
{
/* not needed */
}
static void nbio_mmap_unix_begin_write(void *data)
{
/* not needed */
}
static bool nbio_mmap_unix_iterate(void *data)
{
return true; /* not needed */
}
static void nbio_mmap_unix_resize(void *data, size_t len)
{
struct nbio_mmap_unix_t* handle = (struct nbio_mmap_unix_t*)data;
if (!handle)
return;
if (len < handle->len)
{
/* this works perfectly fine if this check is removed, but it
* won't work on other nbio implementations */
/* therefore, it's blocked so nobody accidentally relies on it */
puts("ERROR - attempted file shrink operation, not implemented");
abort();
}
if (ftruncate(handle->fd, len) != 0)
{
puts("ERROR - couldn't resize file (ftruncate)");
abort(); /* this one returns void and I can't find any other
way for it to report failure */
}
munmap(handle->ptr, handle->len);
handle->ptr = mmap(NULL, len, handle->map_flags, MAP_SHARED, handle->fd, 0);
handle->len = len;
if (handle->ptr == MAP_FAILED)
{
puts("ERROR - couldn't resize file (mmap)");
abort();
}
}
static void *nbio_mmap_unix_get_ptr(void *data, size_t* len)
{
struct nbio_mmap_unix_t* handle = (struct nbio_mmap_unix_t*)data;
if (!handle)
return NULL;
if (len)
*len = handle->len;
return handle->ptr;
}
static void nbio_mmap_unix_cancel(void *data)
{
/* not needed */
}
static void nbio_mmap_unix_free(void *data)
{
struct nbio_mmap_unix_t* handle = (struct nbio_mmap_unix_t*)data;
if (!handle)
return;
close(handle->fd);
munmap(handle->ptr, handle->len);
free(handle);
}
nbio_intf_t nbio_mmap_unix = {
nbio_mmap_unix_open,
nbio_mmap_unix_begin_read,
nbio_mmap_unix_begin_write,
nbio_mmap_unix_iterate,
nbio_mmap_unix_resize,
nbio_mmap_unix_get_ptr,
nbio_mmap_unix_cancel,
nbio_mmap_unix_free,
"nbio_mmap_unix",
};
#else
nbio_intf_t nbio_mmap_unix = {
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
"nbio_mmap_unix",
};
#endif
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