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/* Copyright (C) 2007-2010 The Android Open Source Project
**
** This software is licensed under the terms of the GNU General Public
** License version 2, as published by the Free Software Foundation, and
** may be copied, distributed, and modified under those terms.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
*/
/*
* Contains implementation of routines that implement platform-independent
* file I/O.
*/
#include "stddef.h"
#include "sys/types.h"
#include "errno.h"
#ifdef WIN32
#include "windows.h"
#else // WIN32
#include <sys/mman.h>
#endif // WIN32
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "mapfile.h"
MapFile*
mapfile_open(const char* path, int oflag, int share_mode)
{
#ifdef WIN32
DWORD win32_share;
DWORD win32_desired_access = GENERIC_READ;
DWORD win32_disposition = OPEN_EXISTING;
DWORD win32_flags;
/* Convert to Win32 desired access. */
if ((oflag & O_RDWR) == O_RDWR) {
win32_desired_access = GENERIC_READ | GENERIC_WRITE;
} else if ((oflag & O_ACCMODE) == O_RDONLY) {
win32_desired_access = GENERIC_READ;
} else if ((oflag & O_WRONLY) == O_WRONLY) {
win32_desired_access = GENERIC_WRITE;
}
/* Convert to Win32 sharing. */
win32_share = 0;
if ((share_mode & S_IWRITE) != 0) {
win32_share |= FILE_SHARE_WRITE;
}
if ((share_mode & S_IREAD) != 0) {
win32_share |= FILE_SHARE_READ;
}
/* Convert to Win32 disposition. */
if ((oflag & O_CREAT) == O_CREAT) {
if ((oflag & O_EXCL) == O_EXCL) {
win32_disposition = CREATE_NEW;
} else {
win32_disposition = OPEN_ALWAYS;
}
} if ((oflag & O_TRUNC) == O_TRUNC) {
win32_desired_access = TRUNCATE_EXISTING;
} else {
win32_disposition = OPEN_EXISTING;
}
/* Convert to Win32 flags. */
win32_flags = 0;
#if defined(O_DSYNC)
if ((oflag & O_DSYNC) == O_DSYNC ||
(oflag & O_RSYNC) == O_RSYNC ||
(oflag & O_RSYNC) == O_SYNC) {
win32_flags |= FILE_FLAG_WRITE_THROUGH;
}
#endif // O_DSYNC
HANDLE file_handle = CreateFile(path, win32_desired_access, win32_share,
NULL, win32_disposition, win32_flags, NULL);
if (file_handle == INVALID_HANDLE_VALUE) {
errno = GetLastError();
}
#else // WIN32
int file_handle = open(path, oflag, share_mode);
#endif // WIN32
return (MapFile*)(ptrdiff_t)file_handle;
}
int
mapfile_close(MapFile* handle)
{
#ifdef WIN32
if (CloseHandle(handle)) {
return 0;
} else {
errno = GetLastError();
return -1;
}
#else // WIN32
return close((int)(ptrdiff_t)handle);
#endif // WIN32
}
ssize_t
mapfile_read(MapFile* handle, void* buf, size_t nbyte)
{
#ifdef WIN32
ssize_t ret_bytes;
DWORD read_bytes;
if (ReadFile(handle, buf, nbyte, &read_bytes, NULL)) {
ret_bytes = (ssize_t)read_bytes;
} else {
errno = GetLastError();
ret_bytes = -1;
}
return ret_bytes;
#else // WIN32
ssize_t ret;
do {
ret = read((int)(ptrdiff_t)handle, buf, nbyte);
} while (ret < 0 && errno == EINTR);
return ret;
#endif // WIN32
}
ssize_t
mapfile_read_at(MapFile* handle, size_t offset, void* buf, size_t nbyte)
{
#ifdef WIN32
LARGE_INTEGER convert;
convert.QuadPart = offset;
if ((SetFilePointer(handle, convert.LowPart, &convert.HighPart,
FILE_BEGIN) == INVALID_SET_FILE_POINTER) &&
(GetLastError() != NO_ERROR)) {
errno = GetLastError();
return -1;
}
return mapfile_read(handle, buf, nbyte);
#else // WIN32
ssize_t res = lseek((int)(ptrdiff_t)handle, offset, SEEK_SET);
return res >= 0 ? mapfile_read(handle, buf, nbyte) : res;
#endif // WIN32
}
void*
mapfile_map(MapFile* handle,
size_t offset,
size_t size,
int prot,
void** mapped_offset,
size_t* mapped_size)
{
void* mapped_at = NULL;
size_t align_mask;
size_t map_offset;
size_t map_size;
/* Get the mask for mapping offset alignment. */
#ifdef WIN32
DWORD win32_prot;
DWORD win32_map;
HANDLE map_handle;
LARGE_INTEGER converter;
SYSTEM_INFO sys_info;
GetSystemInfo(&sys_info);
align_mask = sys_info.dwAllocationGranularity - 1;
#else // WIN32
align_mask = getpagesize() - 1;
#endif // WIN32
/* Adjust mapping offset and mapping size accordingly to
* the mapping alignment requirements. */
map_offset = offset & ~align_mask;
map_size = (size_t)(offset - map_offset + size);
/* Make sure mapping size doesn't exceed 4G. */
if (map_size < size) {
errno = EFBIG;
return NULL;
}
/* Map the section. */
#ifdef WIN32
/* Convert to Win32 page protection and mapping type. */
win32_prot = PAGE_READONLY;
win32_map = FILE_MAP_READ;
if (prot != PROT_NONE) {
if ((prot & (PROT_WRITE | PROT_EXEC)) == 0) {
win32_prot = PAGE_READONLY;
win32_map = FILE_MAP_READ;
} else if ((prot & (PROT_WRITE | PROT_EXEC)) ==
(PROT_WRITE | PROT_EXEC)) {
win32_prot = PAGE_EXECUTE_READWRITE;
win32_map = FILE_MAP_WRITE;
} else if ((prot & PROT_WRITE) == PROT_WRITE) {
win32_prot = PAGE_READWRITE;
win32_map = FILE_MAP_WRITE;
} else if ((prot & PROT_EXEC) == PROT_EXEC) {
win32_prot = PAGE_EXECUTE_READ;
win32_map = FILE_MAP_READ;
}
}
converter.QuadPart = map_offset + map_size;
map_handle = CreateFileMapping(handle, NULL, win32_prot,
converter.HighPart, converter.LowPart, NULL);
if (map_handle != NULL) {
converter.QuadPart = map_offset;
mapped_at = MapViewOfFile(map_handle, win32_map, converter.HighPart,
converter.LowPart, map_size);
/* Memory mapping (if successful) will hold extra references to the
* mapping, so we can close it right after we mapped file view. */
CloseHandle(map_handle);
}
if (mapped_at == NULL) {
errno = GetLastError();
return NULL;
}
#else // WIN32
mapped_at =
mmap(0, map_size, PROT_READ, MAP_SHARED, (int)(ptrdiff_t)handle, map_offset);
if (mapped_at == MAP_FAILED) {
return NULL;
}
#endif // WIN32
*mapped_offset = (char*)mapped_at + (offset - map_offset);
*mapped_size = size;
return mapped_at;
}
int
mapfile_unmap(void* mapped_at, size_t len)
{
#ifdef WIN32
if (!UnmapViewOfFile(mapped_at)) {
errno = GetLastError();
return -1;
}
return 0;
#else // WIN32
return munmap(mapped_at, len);
#endif // WIN32
}
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