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/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
* meta_writer.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#define SQFS_BUILDING_DLL
#include "config.h"
#include "sqfs/meta_writer.h"
#include "sqfs/compress.h"
#include "sqfs/error.h"
#include "sqfs/block.h"
#include "sqfs/io.h"
#include "util.h"
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
typedef struct meta_block_t {
struct meta_block_t *next;
/* possibly compressed data with 2 byte header */
sqfs_u8 data[SQFS_META_BLOCK_SIZE + 2];
} meta_block_t;
struct sqfs_meta_writer_t {
/* A byte offset into the uncompressed data of the current block */
size_t offset;
/* The location of the current block in the file */
size_t block_offset;
/* The underlying file descriptor to write to */
sqfs_file_t *file;
/* A pointer to the compressor to use for compressing the data */
sqfs_compressor_t *cmp;
/* The raw data chunk that data is appended to */
sqfs_u8 data[SQFS_META_BLOCK_SIZE];
int flags;
meta_block_t *list;
meta_block_t *list_end;
};
static int write_block(sqfs_file_t *file, meta_block_t *outblk)
{
size_t count = le16toh(((sqfs_u16 *)outblk->data)[0]) & 0x7FFF;
sqfs_u64 off = file->get_size(file);
return file->write_at(file, off, outblk->data, count + 2);
}
sqfs_meta_writer_t *sqfs_meta_writer_create(sqfs_file_t *file,
sqfs_compressor_t *cmp,
int flags)
{
sqfs_meta_writer_t *m;
if (flags & ~SQFS_META_WRITER_ALL_FLAGS)
return NULL;
m = calloc(1, sizeof(*m));
if (m == NULL)
return NULL;
m->cmp = cmp;
m->file = file;
m->flags = flags;
return m;
}
void sqfs_meta_writer_destroy(sqfs_meta_writer_t *m)
{
meta_block_t *blk;
while (m->list != NULL) {
blk = m->list;
m->list = blk->next;
free(blk);
}
free(m);
}
int sqfs_meta_writer_flush(sqfs_meta_writer_t *m)
{
meta_block_t *outblk;
size_t count;
ssize_t ret;
if (m->offset == 0)
return 0;
outblk = calloc(1, sizeof(*outblk));
if (outblk == NULL)
return SQFS_ERROR_ALLOC;
ret = m->cmp->do_block(m->cmp, m->data, m->offset,
outblk->data + 2, sizeof(outblk->data) - 2);
if (ret < 0) {
free(outblk);
return ret;
}
if (ret > 0) {
((sqfs_u16 *)outblk->data)[0] = htole16(ret);
count = ret + 2;
} else {
((sqfs_u16 *)outblk->data)[0] = htole16(m->offset | 0x8000);
memcpy(outblk->data + 2, m->data, m->offset);
count = m->offset + 2;
}
ret = 0;
if (m->flags & SQFS_META_WRITER_KEEP_IN_MEMORY) {
if (m->list == NULL) {
m->list = outblk;
} else {
m->list_end->next = outblk;
}
m->list_end = outblk;
} else {
ret = write_block(m->file, outblk);
free(outblk);
}
memset(m->data, 0, sizeof(m->data));
m->offset = 0;
m->block_offset += count;
return ret;
}
int sqfs_meta_writer_append(sqfs_meta_writer_t *m, const void *data,
size_t size)
{
size_t diff;
int ret;
while (size != 0) {
diff = sizeof(m->data) - m->offset;
if (diff == 0) {
ret = sqfs_meta_writer_flush(m);
if (ret)
return ret;
diff = sizeof(m->data);
}
if (diff > size)
diff = size;
memcpy(m->data + m->offset, data, diff);
m->offset += diff;
size -= diff;
data = (const char *)data + diff;
}
if (m->offset == sizeof(m->data))
return sqfs_meta_writer_flush(m);
return 0;
}
void sqfs_meta_writer_get_position(const sqfs_meta_writer_t *m,
sqfs_u64 *block_start,
sqfs_u32 *offset)
{
*block_start = m->block_offset;
*offset = m->offset;
}
void sqfs_meta_writer_reset(sqfs_meta_writer_t *m)
{
m->block_offset = 0;
m->offset = 0;
}
int sqfs_meta_write_write_to_file(sqfs_meta_writer_t *m)
{
meta_block_t *blk;
int ret;
while (m->list != NULL) {
blk = m->list;
ret = write_block(m->file, blk);
if (ret)
return ret;
m->list = blk->next;
free(blk);
}
m->list_end = NULL;
return 0;
}
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