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/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
* block_writer.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#define SQFS_BUILDING_DLL
#include "config.h"
#include "sqfs/block_writer.h"
#include "sqfs/error.h"
#include "sqfs/block.h"
#include "sqfs/io.h"
#include "util.h"
#include <stdlib.h>
#define MK_BLK_HASH(chksum, size) \
(((sqfs_u64)(size) << 32) | (sqfs_u64)(chksum))
#define INIT_BLOCK_COUNT (128)
typedef struct {
sqfs_u64 offset;
sqfs_u64 hash;
} blk_info_t;
typedef struct {
sqfs_block_writer_t base;
sqfs_file_t *file;
size_t num_blocks;
size_t max_blocks;
blk_info_t *blocks;
size_t devblksz;
sqfs_u64 blocks_written;
sqfs_u64 data_area_start;
sqfs_u64 start;
size_t file_start;
} block_writer_default_t;
static int store_block_location(block_writer_default_t *wr, sqfs_u64 offset,
sqfs_u32 size, sqfs_u32 chksum)
{
size_t new_sz;
void *new;
if (wr->num_blocks == wr->max_blocks) {
new_sz = wr->max_blocks * 2;
new = realloc(wr->blocks, sizeof(wr->blocks[0]) * new_sz);
if (new == NULL)
return SQFS_ERROR_ALLOC;
wr->blocks = new;
wr->max_blocks = new_sz;
}
wr->blocks[wr->num_blocks].offset = offset;
wr->blocks[wr->num_blocks].hash = MK_BLK_HASH(chksum, size);
wr->num_blocks += 1;
return 0;
}
static size_t deduplicate_blocks(block_writer_default_t *wr, size_t count)
{
size_t i, j;
for (i = 0; i < wr->file_start; ++i) {
for (j = 0; j < count; ++j) {
if (wr->blocks[i + j].hash == 0)
break;
if (wr->blocks[i + j].hash !=
wr->blocks[wr->file_start + j].hash)
break;
}
if (j == count)
break;
}
return i;
}
static int align_file(block_writer_default_t *wr)
{
void *padding;
sqfs_u64 size;
size_t diff;
int ret;
size = wr->file->get_size(wr->file);
diff = size % wr->devblksz;
if (diff == 0)
return 0;
padding = calloc(1, diff);
if (padding == 0)
return SQFS_ERROR_ALLOC;
ret = wr->file->write_at(wr->file, size, padding, diff);
free(padding);
if (ret)
return ret;
return store_block_location(wr, size, 0, 0);
}
static void block_writer_destroy(sqfs_object_t *wr)
{
free(((block_writer_default_t *)wr)->blocks);
free(wr);
}
static int write_data_block(sqfs_block_writer_t *base, sqfs_u32 size,
sqfs_u32 checksum, sqfs_u32 flags,
const sqfs_u8 *data, sqfs_u64 *location)
{
block_writer_default_t *wr = (block_writer_default_t *)base;
size_t start, count;
sqfs_u64 offset;
sqfs_u32 out;
int err;
if (flags & SQFS_BLK_FIRST_BLOCK) {
wr->start = wr->file->get_size(wr->file);
wr->file_start = wr->num_blocks;
if (flags & SQFS_BLK_ALIGN) {
err = align_file(wr);
if (err)
return err;
}
}
offset = wr->file->get_size(wr->file);
*location = offset;
if (size != 0 && !(flags & SQFS_BLK_IS_SPARSE)) {
out = size;
if (!(flags & SQFS_BLK_IS_COMPRESSED))
out |= 1 << 24;
err = store_block_location(wr, offset, out, checksum);
if (err)
return err;
err = wr->file->write_at(wr->file, offset, data, size);
if (err)
return err;
wr->blocks_written = wr->num_blocks;
}
if (flags & SQFS_BLK_LAST_BLOCK) {
if (flags & SQFS_BLK_ALIGN) {
err = align_file(wr);
if (err)
return err;
}
count = wr->num_blocks - wr->file_start;
if (count == 0) {
*location = 0;
} else if (!(flags & SQFS_BLK_DONT_DEDUPLICATE)) {
start = deduplicate_blocks(wr, count);
offset = wr->blocks[start].offset;
*location = offset;
if (start >= wr->file_start)
return 0;
offset = start + count;
if (offset >= wr->file_start) {
count = wr->num_blocks - offset;
wr->num_blocks = offset;
} else {
wr->num_blocks = wr->file_start;
}
err = wr->file->truncate(wr->file, wr->start);
if (err)
return err;
}
wr->blocks_written = wr->num_blocks;
}
return 0;
}
static sqfs_u64 get_block_count(const sqfs_block_writer_t *wr)
{
return ((const block_writer_default_t *)wr)->blocks_written;
}
sqfs_block_writer_t *sqfs_block_writer_create(sqfs_file_t *file,
size_t devblksz, sqfs_u32 flags)
{
block_writer_default_t *wr;
if (flags != 0)
return NULL;
wr = calloc(1, sizeof(*wr));
if (wr == NULL)
return NULL;
((sqfs_block_writer_t *)wr)->write_data_block = write_data_block;
((sqfs_block_writer_t *)wr)->get_block_count = get_block_count;
((sqfs_object_t *)wr)->destroy = block_writer_destroy;
wr->file = file;
wr->devblksz = devblksz;
wr->max_blocks = INIT_BLOCK_COUNT;
wr->data_area_start = wr->file->get_size(wr->file);
wr->blocks = alloc_array(sizeof(wr->blocks[0]), wr->max_blocks);
if (wr->blocks == NULL) {
free(wr);
return NULL;
}
return (sqfs_block_writer_t *)wr;
}
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