diff options
Diffstat (limited to 'lib/sqfs/block_processor/block.c')
| -rw-r--r-- | lib/sqfs/block_processor/block.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/lib/sqfs/block_processor/block.c b/lib/sqfs/block_processor/block.c new file mode 100644 index 0000000..49892be --- /dev/null +++ b/lib/sqfs/block_processor/block.c @@ -0,0 +1,203 @@ +/* SPDX-License-Identifier: LGPL-3.0-or-later */ +/* + * process_block.c + * + * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at> + */ +#define SQFS_BUILDING_DLL +#include "internal.h" + +#include <string.h> + +static int store_block_location(sqfs_block_processor_t *proc, sqfs_u64 offset, + sqfs_u32 size, sqfs_u32 chksum) +{ + size_t new_sz; + void *new; + + if (proc->num_blocks == proc->max_blocks) { + new_sz = proc->max_blocks * 2; + new = realloc(proc->blocks, sizeof(proc->blocks[0]) * new_sz); + + if (new == NULL) + return SQFS_ERROR_ALLOC; + + proc->blocks = new; + proc->max_blocks = new_sz; + } + + proc->blocks[proc->num_blocks].offset = offset; + proc->blocks[proc->num_blocks].hash = MK_BLK_HASH(chksum, size); + proc->num_blocks += 1; + return 0; +} + +static size_t deduplicate_blocks(sqfs_block_processor_t *proc, size_t count) +{ + size_t i, j; + + for (i = 0; i < proc->file_start; ++i) { + for (j = 0; j < count; ++j) { + if (proc->blocks[i + j].hash != + proc->blocks[proc->file_start + j].hash) + break; + } + + if (j == count) + break; + } + + return i; +} + +static int align_file(sqfs_block_processor_t *proc, sqfs_block_t *blk) +{ + sqfs_u32 chksum; + void *padding; + sqfs_u64 size; + size_t diff; + int ret; + + if (!(blk->flags & SQFS_BLK_ALIGN)) + return 0; + + size = proc->file->get_size(proc->file); + diff = size % proc->devblksz; + if (diff == 0) + return 0; + + padding = calloc(1, diff); + if (padding == 0) + return SQFS_ERROR_ALLOC; + + if (proc->hooks != NULL && proc->hooks->prepare_padding != NULL) + proc->hooks->prepare_padding(proc->user_ptr, padding, diff); + + chksum = crc32(0, padding, diff); + + ret = proc->file->write_at(proc->file, size, padding, diff); + free(padding); + if (ret) + return ret; + + return store_block_location(proc, size, diff | (1 << 24), chksum); +} + +int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk) +{ + sqfs_u64 offset, bytes; + size_t start, count; + sqfs_u32 out; + int err; + + if (proc->hooks != NULL && proc->hooks->pre_block_write != NULL) { + proc->hooks->pre_block_write(proc->user_ptr, blk, proc->file); + } + + if (blk->flags & SQFS_BLK_FIRST_BLOCK) { + proc->start = proc->file->get_size(proc->file); + proc->file_start = proc->num_blocks; + + err = align_file(proc, blk); + if (err) + return err; + } + + if (blk->size != 0) { + out = blk->size; + if (!(blk->flags & SQFS_BLK_IS_COMPRESSED)) + out |= 1 << 24; + + offset = proc->file->get_size(proc->file); + + if (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) { + err = sqfs_frag_table_set(proc->frag_tbl, blk->index, + offset, out); + if (err) + return err; + } else { + blk->inode->extra[blk->index] = out; + } + + err = store_block_location(proc, offset, out, blk->checksum); + if (err) + return err; + + err = proc->file->write_at(proc->file, offset, + blk->data, blk->size); + if (err) + return err; + } + + if (proc->hooks != NULL && proc->hooks->post_block_write != NULL) { + proc->hooks->post_block_write(proc->user_ptr, blk, proc->file); + } + + if (blk->flags & SQFS_BLK_LAST_BLOCK) { + err = align_file(proc, blk); + if (err) + return err; + + count = proc->num_blocks - proc->file_start; + start = deduplicate_blocks(proc, count); + offset = proc->blocks[start].offset; + + sqfs_inode_set_file_block_start(blk->inode, offset); + + if (start >= proc->file_start) + return 0; + + offset = start + count; + if (offset >= proc->file_start) { + count = proc->num_blocks - offset; + proc->num_blocks = offset; + } else { + proc->num_blocks = proc->file_start; + } + + if (proc->hooks != NULL && + proc->hooks->notify_blocks_erased != NULL) { + bytes = proc->file->get_size(proc->file) - proc->start; + + proc->hooks->notify_blocks_erased(proc->user_ptr, + count, bytes); + } + + err = proc->file->truncate(proc->file, proc->start); + if (err) + return err; + } + + return 0; +} + +int block_processor_do_block(sqfs_block_t *block, sqfs_compressor_t *cmp, + sqfs_u8 *scratch, size_t scratch_size) +{ + ssize_t ret; + + if (block->size == 0) { + block->checksum = 0; + return 0; + } + + block->checksum = crc32(0, block->data, block->size); + + if (block->flags & SQFS_BLK_IS_FRAGMENT) + return 0; + + if (!(block->flags & SQFS_BLK_DONT_COMPRESS)) { + ret = cmp->do_block(cmp, block->data, block->size, + scratch, scratch_size); + if (ret < 0) + return ret; + + if (ret > 0) { + memcpy(block->data, scratch, ret); + block->size = ret; + block->flags |= SQFS_BLK_IS_COMPRESSED; + } + } + + return 0; +} |