1 /* -*- mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 // vim: expandtab:ts=8:sw=4:softtabstop=4:
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file alone_decoder.c
6 /// \brief Decoder for LZMA_Alone files
7 //
8 // Author: Lasse Collin
9 //
10 // This file has been put into the public domain.
11 // You can do whatever you want with this file.
12 //
13 ///////////////////////////////////////////////////////////////////////////////
14
15 #include "common.h"
16 #include "lzma_encoder.h"
17
18
19 #define ALONE_HEADER_SIZE (1 + 4 + 8)
20
21
22 struct lzma_coder_s {
23 lzma_next_coder next;
24
25 enum {
26 SEQ_HEADER,
27 SEQ_CODE,
28 } sequence;
29
30 size_t header_pos;
31 uint8_t header[ALONE_HEADER_SIZE];
32 };
33
34
35 static lzma_ret
alone_encode(lzma_coder * coder,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)36 alone_encode(lzma_coder *coder,
37 lzma_allocator *allocator lzma_attribute((unused)),
38 const uint8_t *restrict in, size_t *restrict in_pos,
39 size_t in_size, uint8_t *restrict out,
40 size_t *restrict out_pos, size_t out_size,
41 lzma_action action)
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(lzma_coder * coder,lzma_allocator * allocator)70 alone_encoder_end(lzma_coder *coder, lzma_allocator *allocator)
71 {
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,lzma_allocator * allocator,const lzma_options_lzma * options)80 alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
81 const lzma_options_lzma *options)
82 {
83 lzma_next_coder_init(&alone_encoder_init, next, allocator);
84
85 if (next->coder == NULL) {
86 next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
87 if (next->coder == NULL)
88 return LZMA_MEM_ERROR;
89
90 next->code = &alone_encode;
91 next->end = &alone_encoder_end;
92 next->coder->next = LZMA_NEXT_CODER_INIT;
93 }
94
95 // Basic initializations
96 next->coder->sequence = SEQ_HEADER;
97 next->coder->header_pos = 0;
98
99 // Encode the header:
100 // - Properties (1 byte)
101 if (lzma_lzma_lclppb_encode(options, next->coder->header))
102 return LZMA_OPTIONS_ERROR;
103
104 // - Dictionary size (4 bytes)
105 if (options->dict_size < LZMA_DICT_SIZE_MIN)
106 return LZMA_OPTIONS_ERROR;
107
108 // Round up to to the next 2^n or 2^n + 2^(n - 1) depending on which
109 // one is the next unless it is UINT32_MAX. While the header would
110 // allow any 32-bit integer, we do this to keep the decoder of liblzma
111 // accepting the resulting files.
112 uint32_t d = options->dict_size - 1;
113 d |= d >> 2;
114 d |= d >> 3;
115 d |= d >> 4;
116 d |= d >> 8;
117 d |= d >> 16;
118 if (d != UINT32_MAX)
119 ++d;
120
121 integer_write_32(next->coder->header + 1, d);
122
123 // - Uncompressed size (always unknown and using EOPM)
124 memset(next->coder->header + 1 + 4, 0xFF, 8);
125
126 // Initialize the LZMA encoder.
127 const lzma_filter_info filters[2] = {
128 {
129 .init = &lzma_lzma_encoder_init,
130 .options = (void *)(options),
131 }, {
132 .init = NULL,
133 }
134 };
135
136 return lzma_next_filter_init(&next->coder->next, allocator, filters);
137 }
138
139
140 /*
141 extern lzma_ret
142 lzma_alone_encoder_init(lzma_next_coder *next, lzma_allocator *allocator,
143 const lzma_options_alone *options)
144 {
145 lzma_next_coder_init(&alone_encoder_init, next, allocator, options);
146 }
147 */
148
149
150 extern LZMA_API(lzma_ret)
lzma_alone_encoder(lzma_stream * strm,const lzma_options_lzma * options)151 lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options)
152 {
153 lzma_next_strm_init(alone_encoder_init, strm, options);
154
155 strm->internal->supported_actions[LZMA_RUN] = true;
156 strm->internal->supported_actions[LZMA_FINISH] = true;
157
158 return LZMA_OK;
159 }
160