// SPDX-License-Identifier: GPL-2.0+ OR Apache-2.0
/*
 * Copyright (C) 2018-2019 HUAWEI, Inc.
 *             http://www.huawei.com/
 * Created by Gao Xiang <xiang@kernel.org>
 */
#include <lz4.h>
#include "erofs/internal.h"
#include "compressor.h"

#ifndef LZ4_DISTANCE_MAX	/* history window size */
#define LZ4_DISTANCE_MAX 65535	/* set to maximum value by default */
#endif

static int lz4_compress_destsize(const struct erofs_compress *c,
				 const void *src, unsigned int *srcsize,
				 void *dst, unsigned int dstsize)
{
	int srcSize = (int)*srcsize;
	int rc = LZ4_compress_destSize(src, dst, &srcSize, (int)dstsize);

	if (!rc)
		return -EFAULT;
	*srcsize = srcSize;
	return rc;
}

static int compressor_lz4_exit(struct erofs_compress *c)
{
	return 0;
}

static int compressor_lz4_init(struct erofs_compress *c)
{
	c->sbi->lz4.max_distance = max_t(u16, c->sbi->lz4.max_distance,
					 LZ4_DISTANCE_MAX);
	return 0;
}

const struct erofs_compressor erofs_compressor_lz4 = {
	.init = compressor_lz4_init,
	.exit = compressor_lz4_exit,
	.compress_destsize = lz4_compress_destsize,
};