1 ///////////////////////////////////////////////////////////////////////////////
2 //
3 /// \file alone_decoder.c
4 /// \brief Decoder 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 lzma_attribute ((__unused__)),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,
35 const lzma_allocator *allocator lzma_attribute((__unused__)),
36 const uint8_t *restrict in, size_t *restrict in_pos,
37 size_t in_size, uint8_t *restrict out,
38 size_t *restrict out_pos, size_t out_size,
39 lzma_action action)
40 {
41 lzma_alone_coder *coder = coder_ptr;
42
43 while (*out_pos < out_size)
44 switch (coder->sequence) {
45 case SEQ_HEADER:
46 lzma_bufcpy(coder->header, &coder->header_pos,
47 ALONE_HEADER_SIZE,
48 out, out_pos, out_size);
49 if (coder->header_pos < ALONE_HEADER_SIZE)
50 return LZMA_OK;
51
52 coder->sequence = SEQ_CODE;
53 break;
54
55 case SEQ_CODE:
56 return coder->next.code(coder->next.coder,
57 allocator, in, in_pos, in_size,
58 out, out_pos, out_size, action);
59
60 default:
61 assert(0);
62 return LZMA_PROG_ERROR;
63 }
64
65 return LZMA_OK;
66 }
67
68
69 static void
alone_encoder_end(void * coder_ptr,const lzma_allocator * allocator)70 alone_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
71 {
72 lzma_alone_coder *coder = coder_ptr;
73 lzma_next_end(&coder->next, allocator);
74 lzma_free(coder, allocator);
75 return;
76 }
77
78
79 // At least for now, this is not used by any internal function.
80 static lzma_ret
alone_encoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_options_lzma * options)81 alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
82 const lzma_options_lzma *options)
83 {
84 lzma_next_coder_init(&alone_encoder_init, next, allocator);
85
86 lzma_alone_coder *coder = next->coder;
87
88 if (coder == NULL) {
89 coder = lzma_alloc(sizeof(lzma_alone_coder), allocator);
90 if (coder == NULL)
91 return LZMA_MEM_ERROR;
92
93 next->coder = coder;
94 next->code = &alone_encode;
95 next->end = &alone_encoder_end;
96 coder->next = LZMA_NEXT_CODER_INIT;
97 }
98
99 // Basic initializations
100 coder->sequence = SEQ_HEADER;
101 coder->header_pos = 0;
102
103 // Encode the header:
104 // - Properties (1 byte)
105 if (lzma_lzma_lclppb_encode(options, coder->header))
106 return LZMA_OPTIONS_ERROR;
107
108 // - Dictionary size (4 bytes)
109 if (options->dict_size < LZMA_DICT_SIZE_MIN)
110 return LZMA_OPTIONS_ERROR;
111
112 // Round up to the next 2^n or 2^n + 2^(n - 1) depending on which
113 // one is the next unless it is UINT32_MAX. While the header would
114 // allow any 32-bit integer, we do this to keep the decoder of liblzma
115 // accepting the resulting files.
116 uint32_t d = options->dict_size - 1;
117 d |= d >> 2;
118 d |= d >> 3;
119 d |= d >> 4;
120 d |= d >> 8;
121 d |= d >> 16;
122 if (d != UINT32_MAX)
123 ++d;
124
125 unaligned_write32le(coder->header + 1, d);
126
127 // - Uncompressed size (always unknown and using EOPM)
128 memset(coder->header + 1 + 4, 0xFF, 8);
129
130 // Initialize the LZMA encoder.
131 const lzma_filter_info filters[2] = {
132 {
133 .init = &lzma_lzma_encoder_init,
134 .options = (void *)(options),
135 }, {
136 .init = NULL,
137 }
138 };
139
140 return lzma_next_filter_init(&coder->next, allocator, filters);
141 }
142
143
144 /*
145 extern lzma_ret
146 lzma_alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
147 const lzma_options_alone *options)
148 {
149 lzma_next_coder_init(&alone_encoder_init, next, allocator, options);
150 }
151 */
152
153
154 extern LZMA_API(lzma_ret)
lzma_alone_encoder(lzma_stream * strm,const lzma_options_lzma * options)155 lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options)
156 {
157 lzma_next_strm_init(alone_encoder_init, strm, options);
158
159 strm->internal->supported_actions[LZMA_RUN] = true;
160 strm->internal->supported_actions[LZMA_FINISH] = true;
161
162 return LZMA_OK;
163 }
164