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 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 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 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) 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