1 // SPDX-License-Identifier: GPL-2.0+ OR Apache-2.0
2 /*
3 * Copyright (C) 2021 Gao Xiang <xiang@kernel.org>
4 */
5 #include <stdlib.h>
6 #include "config.h"
7 #ifdef HAVE_LIBLZMA
8 #include <lzma.h>
9 #include "erofs/config.h"
10 #include "erofs/print.h"
11 #include "erofs/internal.h"
12 #include "compressor.h"
13
14 struct erofs_liblzma_context {
15 lzma_options_lzma opt;
16 lzma_stream strm;
17 };
18
erofs_liblzma_compress_destsize(const struct erofs_compress * c,const void * src,unsigned int * srcsize,void * dst,unsigned int dstsize)19 static int erofs_liblzma_compress_destsize(const struct erofs_compress *c,
20 const void *src, unsigned int *srcsize,
21 void *dst, unsigned int dstsize)
22 {
23 struct erofs_liblzma_context *ctx = c->private_data;
24 lzma_stream *strm = &ctx->strm;
25
26 lzma_ret ret = lzma_microlzma_encoder(strm, &ctx->opt);
27 if (ret != LZMA_OK)
28 return -EFAULT;
29
30 strm->next_in = src;
31 strm->avail_in = *srcsize;
32 strm->next_out = dst;
33 strm->avail_out = dstsize;
34
35 ret = lzma_code(strm, LZMA_FINISH);
36 if (ret != LZMA_STREAM_END)
37 return -EBADMSG;
38
39 *srcsize = strm->total_in;
40 return strm->total_out;
41 }
42
erofs_compressor_liblzma_exit(struct erofs_compress * c)43 static int erofs_compressor_liblzma_exit(struct erofs_compress *c)
44 {
45 struct erofs_liblzma_context *ctx = c->private_data;
46
47 if (!ctx)
48 return -EINVAL;
49
50 lzma_end(&ctx->strm);
51 free(ctx);
52 return 0;
53 }
54
erofs_compressor_liblzma_setlevel(struct erofs_compress * c,int compression_level)55 static int erofs_compressor_liblzma_setlevel(struct erofs_compress *c,
56 int compression_level)
57 {
58 struct erofs_liblzma_context *ctx = c->private_data;
59 u32 preset;
60
61 if (compression_level < 0)
62 preset = LZMA_PRESET_DEFAULT;
63 else if (compression_level >= 100)
64 preset = (compression_level - 100) | LZMA_PRESET_EXTREME;
65 else
66 preset = compression_level;
67
68 if (lzma_lzma_preset(&ctx->opt, preset))
69 return -EINVAL;
70
71 /* XXX: temporary hack */
72 if (cfg.c_dict_size) {
73 if (cfg.c_dict_size > Z_EROFS_LZMA_MAX_DICT_SIZE) {
74 erofs_err("dict size %u is too large", cfg.c_dict_size);
75 return -EINVAL;
76 }
77 ctx->opt.dict_size = cfg.c_dict_size;
78 } else {
79 if (ctx->opt.dict_size > Z_EROFS_LZMA_MAX_DICT_SIZE)
80 ctx->opt.dict_size = Z_EROFS_LZMA_MAX_DICT_SIZE;
81 cfg.c_dict_size = ctx->opt.dict_size;
82 }
83 c->compression_level = compression_level;
84 return 0;
85 }
86
erofs_compressor_liblzma_init(struct erofs_compress * c)87 static int erofs_compressor_liblzma_init(struct erofs_compress *c)
88 {
89 struct erofs_liblzma_context *ctx;
90
91 ctx = malloc(sizeof(*ctx));
92 if (!ctx)
93 return -ENOMEM;
94 ctx->strm = (lzma_stream)LZMA_STREAM_INIT;
95 c->private_data = ctx;
96 erofs_warn("EXPERIMENTAL MicroLZMA feature in use. Use at your own risk!");
97 erofs_warn("Note that it may take more time since the compressor is still single-threaded for now.");
98 return 0;
99 }
100
101 const struct erofs_compressor erofs_compressor_lzma = {
102 .default_level = LZMA_PRESET_DEFAULT,
103 .best_level = 109,
104 .init = erofs_compressor_liblzma_init,
105 .exit = erofs_compressor_liblzma_exit,
106 .setlevel = erofs_compressor_liblzma_setlevel,
107 .compress_destsize = erofs_liblzma_compress_destsize,
108 };
109 #endif
110