xref: /aosp_15_r20/external/erofs-utils/lib/compressor_lz4hc.c (revision 33b1fccf6a0fada2c2875d400ed01119b7676ee5)
1 // SPDX-License-Identifier: GPL-2.0+ OR Apache-2.0
2 /*
3  * Copyright (C) 2018-2019 HUAWEI, Inc.
4  *             http://www.huawei.com/
5  * Created by Gao Xiang <[email protected]>
6  */
7 #define LZ4_HC_STATIC_LINKING_ONLY (1)
8 #include <lz4hc.h>
9 #include "erofs/internal.h"
10 #include "erofs/print.h"
11 #include "compressor.h"
12 
13 #ifndef LZ4_DISTANCE_MAX	/* history window size */
14 #define LZ4_DISTANCE_MAX 65535	/* set to maximum value by default */
15 #endif
16 
lz4hc_compress_destsize(const struct erofs_compress * c,const void * src,unsigned int * srcsize,void * dst,unsigned int dstsize)17 static int lz4hc_compress_destsize(const struct erofs_compress *c,
18 				   const void *src, unsigned int *srcsize,
19 				   void *dst, unsigned int dstsize)
20 {
21 	int srcSize = (int)*srcsize;
22 	int rc = LZ4_compress_HC_destSize(c->private_data, src, dst,
23 					  &srcSize, (int)dstsize,
24 					  c->compression_level);
25 	if (!rc)
26 		return -EFAULT;
27 	*srcsize = srcSize;
28 	return rc;
29 }
30 
compressor_lz4hc_exit(struct erofs_compress * c)31 static int compressor_lz4hc_exit(struct erofs_compress *c)
32 {
33 	if (!c->private_data)
34 		return -EINVAL;
35 
36 	LZ4_freeStreamHC(c->private_data);
37 	return 0;
38 }
39 
compressor_lz4hc_init(struct erofs_compress * c)40 static int compressor_lz4hc_init(struct erofs_compress *c)
41 {
42 	c->private_data = LZ4_createStreamHC();
43 	if (!c->private_data)
44 		return -ENOMEM;
45 
46 	c->sbi->lz4.max_distance = max_t(u16, c->sbi->lz4.max_distance,
47 					 LZ4_DISTANCE_MAX);
48 	return 0;
49 }
50 
compressor_lz4hc_setlevel(struct erofs_compress * c,int compression_level)51 static int compressor_lz4hc_setlevel(struct erofs_compress *c,
52 				     int compression_level)
53 {
54 	if (compression_level > erofs_compressor_lz4hc.best_level) {
55 		erofs_err("invalid compression level %d", compression_level);
56 		return -EINVAL;
57 	}
58 
59 	c->compression_level = compression_level < 0 ?
60 		LZ4HC_CLEVEL_DEFAULT : compression_level;
61 	return 0;
62 }
63 
64 const struct erofs_compressor erofs_compressor_lz4hc = {
65 	.default_level = LZ4HC_CLEVEL_DEFAULT,
66 	.best_level = LZ4HC_CLEVEL_MAX,
67 	.init = compressor_lz4hc_init,
68 	.exit = compressor_lz4hc_exit,
69 	.setlevel = compressor_lz4hc_setlevel,
70 	.compress_destsize = lz4hc_compress_destsize,
71 };
72