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/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
* io.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#define SQFS_BUILDING_DLL
#include "config.h"
#include "sqfs/io.h"
#include "sqfs/error.h"
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
typedef struct {
sqfs_file_t base;
uint64_t size;
int fd;
} sqfs_file_stdio_t;
static void stdio_destroy(sqfs_file_t *base)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
close(file->fd);
free(file);
}
static int stdio_read_at(sqfs_file_t *base, uint64_t offset,
void *buffer, size_t size)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
ssize_t ret;
while (size > 0) {
ret = pread(file->fd, buffer, size, offset);
if (ret < 0) {
if (errno == EINTR)
continue;
return SQFS_ERROR_IO;
}
if (ret == 0)
return SQFS_ERROR_OUT_OF_BOUNDS;
buffer = (char *)buffer + ret;
size -= ret;
offset += ret;
}
return 0;
}
static int stdio_write_at(sqfs_file_t *base, uint64_t offset,
const void *buffer, size_t size)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
ssize_t ret;
while (size > 0) {
ret = pwrite(file->fd, buffer, size, offset);
if (ret < 0) {
if (errno == EINTR)
continue;
return SQFS_ERROR_IO;
}
if (ret == 0)
return SQFS_ERROR_OUT_OF_BOUNDS;
buffer = (const char *)buffer + ret;
size -= ret;
offset += ret;
}
if (offset >= file->size)
file->size = offset;
return 0;
}
static uint64_t stdio_get_size(const sqfs_file_t *base)
{
const sqfs_file_stdio_t *file = (const sqfs_file_stdio_t *)base;
return file->size;
}
static int stdio_truncate(sqfs_file_t *base, uint64_t size)
{
sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
if (ftruncate(file->fd, size))
return SQFS_ERROR_IO;
file->size = size;
return 0;
}
sqfs_file_t *sqfs_open_file(const char *filename, int flags)
{
sqfs_file_stdio_t *file;
int open_mode, temp;
sqfs_file_t *base;
if (flags & ~SQFS_FILE_OPEN_ALL_FLAGS) {
errno = EINVAL;
return NULL;
}
file = calloc(1, sizeof(*file));
base = (sqfs_file_t *)file;
if (file == NULL)
return NULL;
if (flags & SQFS_FILE_OPEN_READ_ONLY) {
open_mode = O_RDONLY;
} else {
open_mode = O_CREAT | O_RDWR;
if (flags & SQFS_FILE_OPEN_OVERWRITE) {
open_mode |= O_TRUNC;
} else {
open_mode |= O_EXCL;
}
}
file->fd = open(filename, open_mode, 0600);
if (file->fd < 0) {
temp = errno;
free(file);
errno = temp;
return NULL;
}
base->destroy = stdio_destroy;
base->read_at = stdio_read_at;
base->write_at = stdio_write_at;
base->get_size = stdio_get_size;
base->truncate = stdio_truncate;
return base;
}
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