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/* SPDX-License-Identifier: LGPL-3.0-or-later */
/*
* fileapi.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#define SQFS_BUILDING_DLL
#include "internal.h"
static bool is_zero_block(unsigned char *ptr, size_t size)
{
return ptr[0] == 0 && memcmp(ptr, ptr + 1, size - 1) == 0;
}
static int add_sentinel_block(sqfs_data_writer_t *proc)
{
sqfs_block_t *blk = calloc(1, sizeof(*blk));
if (blk == NULL)
return test_and_set_status(proc, SQFS_ERROR_ALLOC);
blk->inode = proc->inode;
blk->flags = proc->blk_flags | SQFS_BLK_LAST_BLOCK;
return data_writer_enqueue(proc, blk);
}
int sqfs_data_writer_begin_file(sqfs_data_writer_t *proc,
sqfs_inode_generic_t *inode, uint32_t flags)
{
if (proc->inode != NULL)
return test_and_set_status(proc, SQFS_ERROR_INTERNAL);
if (flags & ~SQFS_BLK_USER_SETTABLE_FLAGS)
return test_and_set_status(proc, SQFS_ERROR_UNSUPPORTED);
proc->inode = inode;
proc->blk_flags = flags;
proc->blk_index = 0;
proc->had_fragment = false;
return 0;
}
int sqfs_data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
{
int err;
block->index = proc->blk_index++;
block->flags = proc->blk_flags;
block->inode = proc->inode;
if (is_zero_block(block->data, block->size)) {
sqfs_inode_make_extended(proc->inode);
proc->inode->data.file_ext.sparse += block->size;
proc->inode->num_file_blocks += 1;
proc->inode->block_sizes[block->index] = 0;
free(block);
return 0;
}
if (block->size < proc->max_block_size) {
if (block->index > 0) {
err = add_sentinel_block(proc);
if (err) {
free(block);
return err;
}
}
proc->had_fragment = true;
block->flags |= SQFS_BLK_IS_FRAGMENT;
} else {
if (block->index == 0)
block->flags |= SQFS_BLK_FIRST_BLOCK;
proc->inode->num_file_blocks += 1;
}
return data_writer_enqueue(proc, block);
}
int sqfs_data_writer_end_file(sqfs_data_writer_t *proc)
{
int err;
if (proc->inode == NULL)
return test_and_set_status(proc, SQFS_ERROR_INTERNAL);
if (!proc->had_fragment && proc->inode->num_file_blocks > 0) {
err = add_sentinel_block(proc);
if (err)
return err;
}
proc->inode = NULL;
proc->blk_flags = 0;
proc->blk_index = 0;
proc->had_fragment = false;
return 0;
}
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