1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file alone_encoder.c
4 /// \brief Encoder for LZMA_Alone files
5 //
6 // Author: Lasse Collin
7 //
8 // This file has been put into the public domain.
9 // You can do whatever you want with this file.
10 //
11 ///////////////////////////////////////////////////////////////////////////////
12
13 #include "common.h"
14 #include "lzma_encoder.h"
15
16
17 #define ALONE_HEADER_SIZE (1 + 4 + 8)
18
19
20 typedef struct {
21 lzma_next_coder next;
22
23 enum {
24 SEQ_HEADER,
25 SEQ_CODE,
26 } sequence;
27
28 size_t header_pos;
29 uint8_t header[ALONE_HEADER_SIZE];
30 } lzma_alone_coder;
31
32
33 static lzma_ret
alone_encode(void * coder_ptr,const lzma_allocator * allocator,const uint8_t * restrict in,size_t * restrict in_pos,size_t in_size,uint8_t * restrict out,size_t * restrict out_pos,size_t out_size,lzma_action action)34 alone_encode(void *coder_ptr, const lzma_allocator *allocator,
35 const uint8_t *restrict in, size_t *restrict in_pos,
36 size_t in_size, uint8_t *restrict out,
37 size_t *restrict out_pos, size_t out_size,
38 lzma_action action)
39 {
40 lzma_alone_coder *coder = coder_ptr;
41
42 while (*out_pos < out_size)
43 switch (coder->sequence) {
44 case SEQ_HEADER:
45 lzma_bufcpy(coder->header, &coder->header_pos,
46 ALONE_HEADER_SIZE,
47 out, out_pos, out_size);
48 if (coder->header_pos < ALONE_HEADER_SIZE)
49 return LZMA_OK;
50
51 coder->sequence = SEQ_CODE;
52 break;
53
54 case SEQ_CODE:
55 return coder->next.code(coder->next.coder,
56 allocator, in, in_pos, in_size,
57 out, out_pos, out_size, action);
58
59 default:
60 assert(0);
61 return LZMA_PROG_ERROR;
62 }
63
64 return LZMA_OK;
65 }
66
67
68 static void
alone_encoder_end(void * coder_ptr,const lzma_allocator * allocator)69 alone_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
70 {
71 lzma_alone_coder *coder = coder_ptr;
72 lzma_next_end(&coder->next, allocator);
73 lzma_free(coder, allocator);
74 return;
75 }
76
77
78 // At least for now, this is not used by any internal function.
79 static lzma_ret
alone_encoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_options_lzma * options)80 alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
81 const lzma_options_lzma *options)
82 {
83 lzma_next_coder_init(&alone_encoder_init, next, allocator);
84
85 lzma_alone_coder *coder = next->coder;
86
87 if (coder == NULL) {
88 coder = lzma_alloc(sizeof(lzma_alone_coder), allocator);
89 if (coder == NULL)
90 return LZMA_MEM_ERROR;
91
92 next->coder = coder;
93 next->code = &alone_encode;
94 next->end = &alone_encoder_end;
95 coder->next = LZMA_NEXT_CODER_INIT;
96 }
97
98 // Basic initializations
99 coder->sequence = SEQ_HEADER;
100 coder->header_pos = 0;
101
102 // Encode the header:
103 // - Properties (1 byte)
104 if (lzma_lzma_lclppb_encode(options, coder->header))
105 return LZMA_OPTIONS_ERROR;
106
107 // - Dictionary size (4 bytes)
108 if (options->dict_size < LZMA_DICT_SIZE_MIN)
109 return LZMA_OPTIONS_ERROR;
110
111 // Round up to the next 2^n or 2^n + 2^(n - 1) depending on which
112 // one is the next unless it is UINT32_MAX. While the header would
113 // allow any 32-bit integer, we do this to keep the decoder of liblzma
114 // accepting the resulting files.
115 uint32_t d = options->dict_size - 1;
116 d |= d >> 2;
117 d |= d >> 3;
118 d |= d >> 4;
119 d |= d >> 8;
120 d |= d >> 16;
121 if (d != UINT32_MAX)
122 ++d;
123
124 write32le(coder->header + 1, d);
125
126 // - Uncompressed size (always unknown and using EOPM)
127 memset(coder->header + 1 + 4, 0xFF, 8);
128
129 // Initialize the LZMA encoder.
130 const lzma_filter_info filters[2] = {
131 {
132 .init = &lzma_lzma_encoder_init,
133 .options = (void *)(options),
134 }, {
135 .init = NULL,
136 }
137 };
138
139 return lzma_next_filter_init(&coder->next, allocator, filters);
140 }
141
142
143 /*
144 extern lzma_ret
145 lzma_alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
146 const lzma_options_alone *options)
147 {
148 lzma_next_coder_init(&alone_encoder_init, next, allocator, options);
149 }
150 */
151
152
153 extern LZMA_API(lzma_ret)
lzma_alone_encoder(lzma_stream * strm,const lzma_options_lzma * options)154 lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options)
155 {
156 lzma_next_strm_init(alone_encoder_init, strm, options);
157
158 strm->internal->supported_actions[LZMA_RUN] = true;
159 strm->internal->supported_actions[LZMA_FINISH] = true;
160
161 return LZMA_OK;
162 }
163