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