1 // SPDX-License-Identifier: 0BSD
2
3 ///////////////////////////////////////////////////////////////////////////////
4 //
5 /// \file alone_encoder.c
6 /// \brief Encoder for LZMA_Alone files
7 //
8 // Author: Lasse Collin
9 //
10 ///////////////////////////////////////////////////////////////////////////////
11
12 #include "common.h"
13 #include "lzma_encoder.h"
14
15
16 #define ALONE_HEADER_SIZE (1 + 4 + 8)
17
18
19 typedef struct {
20 lzma_next_coder next;
21
22 enum {
23 SEQ_HEADER,
24 SEQ_CODE,
25 } sequence;
26
27 size_t header_pos;
28 uint8_t header[ALONE_HEADER_SIZE];
29 } lzma_alone_coder;
30
31
32 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)33 alone_encode(void *coder_ptr, const lzma_allocator *allocator,
34 const uint8_t *restrict in, size_t *restrict in_pos,
35 size_t in_size, uint8_t *restrict out,
36 size_t *restrict out_pos, size_t out_size,
37 lzma_action action)
38 {
39 lzma_alone_coder *coder = coder_ptr;
40
41 while (*out_pos < out_size)
42 switch (coder->sequence) {
43 case SEQ_HEADER:
44 lzma_bufcpy(coder->header, &coder->header_pos,
45 ALONE_HEADER_SIZE,
46 out, out_pos, out_size);
47 if (coder->header_pos < ALONE_HEADER_SIZE)
48 return LZMA_OK;
49
50 coder->sequence = SEQ_CODE;
51 break;
52
53 case SEQ_CODE:
54 return coder->next.code(coder->next.coder,
55 allocator, in, in_pos, in_size,
56 out, out_pos, out_size, action);
57
58 default:
59 assert(0);
60 return LZMA_PROG_ERROR;
61 }
62
63 return LZMA_OK;
64 }
65
66
67 static void
alone_encoder_end(void * coder_ptr,const lzma_allocator * allocator)68 alone_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
69 {
70 lzma_alone_coder *coder = coder_ptr;
71 lzma_next_end(&coder->next, allocator);
72 lzma_free(coder, allocator);
73 return;
74 }
75
76
77 static lzma_ret
alone_encoder_init(lzma_next_coder * next,const lzma_allocator * allocator,const lzma_options_lzma * options)78 alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
79 const lzma_options_lzma *options)
80 {
81 lzma_next_coder_init(&alone_encoder_init, next, allocator);
82
83 lzma_alone_coder *coder = next->coder;
84
85 if (coder == NULL) {
86 coder = lzma_alloc(sizeof(lzma_alone_coder), allocator);
87 if (coder == NULL)
88 return LZMA_MEM_ERROR;
89
90 next->coder = coder;
91 next->code = &alone_encode;
92 next->end = &alone_encoder_end;
93 coder->next = LZMA_NEXT_CODER_INIT;
94 }
95
96 // Basic initializations
97 coder->sequence = SEQ_HEADER;
98 coder->header_pos = 0;
99
100 // Encode the header:
101 // - Properties (1 byte)
102 if (lzma_lzma_lclppb_encode(options, coder->header))
103 return LZMA_OPTIONS_ERROR;
104
105 // - Dictionary size (4 bytes)
106 if (options->dict_size < LZMA_DICT_SIZE_MIN)
107 return LZMA_OPTIONS_ERROR;
108
109 // Round up to the next 2^n or 2^n + 2^(n - 1) depending on which
110 // one is the next unless it is UINT32_MAX. While the header would
111 // allow any 32-bit integer, we do this to keep the decoder of liblzma
112 // accepting the resulting files.
113 uint32_t d = options->dict_size - 1;
114 d |= d >> 2;
115 d |= d >> 3;
116 d |= d >> 4;
117 d |= d >> 8;
118 d |= d >> 16;
119 if (d != UINT32_MAX)
120 ++d;
121
122 write32le(coder->header + 1, d);
123
124 // - Uncompressed size (always unknown and using EOPM)
125 memset(coder->header + 1 + 4, 0xFF, 8);
126
127 // Initialize the LZMA encoder.
128 const lzma_filter_info filters[2] = {
129 {
130 .id = LZMA_FILTER_LZMA1,
131 .init = &lzma_lzma_encoder_init,
132 .options = (void *)(options),
133 }, {
134 .init = NULL,
135 }
136 };
137
138 return lzma_next_filter_init(&coder->next, allocator, filters);
139 }
140
141
142 extern LZMA_API(lzma_ret)
lzma_alone_encoder(lzma_stream * strm,const lzma_options_lzma * options)143 lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options)
144 {
145 lzma_next_strm_init(alone_encoder_init, strm, options);
146
147 strm->internal->supported_actions[LZMA_RUN] = true;
148 strm->internal->supported_actions[LZMA_FINISH] = true;
149
150 return LZMA_OK;
151 }
152