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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
 * data_reader.h
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#ifndef DATA_READER_H
#define DATA_READER_H

#include "config.h"

#include "sqfs/compress.h"
#include "sqfs/data.h"
#include "fstree.h"

typedef struct data_reader_t data_reader_t;

/*
  Create a data reader for accessing data blocks in a squashfs image.

  Internally creates a fragment_reader_t (if applicable) to resolve
  fragment indices.

  Prints error messsages to stderr on failure.
 */
data_reader_t *data_reader_create(sqfs_file_t *file, sqfs_super_t *super,
				  sqfs_compressor_t *cmp);

void data_reader_destroy(data_reader_t *data);

int data_reader_dump(data_reader_t *data, const sqfs_inode_generic_t *inode,
		     int outfd, bool allow_sparse);

/*
  Read a chunk of data from a file. Starting from 'offset' into the
  uncompressed file, read 'size' bytes into 'buffer'.

  Returns the number of bytes read, 0 if EOF, -1 on failure. Prints an
  error message to stderr on failure.
 */
ssize_t data_reader_read(data_reader_t *data,
			 const sqfs_inode_generic_t *inode,
			 uint64_t offset, void *buffer, size_t size);

#endif /* DATA_READER_H */