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 struct lzma_coder_s { 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 }; 31 32 33 static lzma_ret 34 alone_encode(lzma_coder *coder, 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 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 68 alone_encoder_end(lzma_coder *coder, const lzma_allocator *allocator) 69 { 70 lzma_next_end(&coder->next, allocator); 71 lzma_free(coder, allocator); 72 return; 73 } 74 75 76 // At least for now, this is not used by any internal function. 77 static lzma_ret 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 if (next->coder == NULL) { 84 next->coder = lzma_alloc(sizeof(lzma_coder), allocator); 85 if (next->coder == NULL) 86 return LZMA_MEM_ERROR; 87 88 next->code = &alone_encode; 89 next->end = &alone_encoder_end; 90 next->coder->next = LZMA_NEXT_CODER_INIT; 91 } 92 93 // Basic initializations 94 next->coder->sequence = SEQ_HEADER; 95 next->coder->header_pos = 0; 96 97 // Encode the header: 98 // - Properties (1 byte) 99 if (lzma_lzma_lclppb_encode(options, next->coder->header)) 100 return LZMA_OPTIONS_ERROR; 101 102 // - Dictionary size (4 bytes) 103 if (options->dict_size < LZMA_DICT_SIZE_MIN) 104 return LZMA_OPTIONS_ERROR; 105 106 // Round up to the next 2^n or 2^n + 2^(n - 1) depending on which 107 // one is the next unless it is UINT32_MAX. While the header would 108 // allow any 32-bit integer, we do this to keep the decoder of liblzma 109 // accepting the resulting files. 110 uint32_t d = options->dict_size - 1; 111 d |= d >> 2; 112 d |= d >> 3; 113 d |= d >> 4; 114 d |= d >> 8; 115 d |= d >> 16; 116 if (d != UINT32_MAX) 117 ++d; 118 119 unaligned_write32le(next->coder->header + 1, d); 120 121 // - Uncompressed size (always unknown and using EOPM) 122 memset(next->coder->header + 1 + 4, 0xFF, 8); 123 124 // Initialize the LZMA encoder. 125 const lzma_filter_info filters[2] = { 126 { 127 .init = &lzma_lzma_encoder_init, 128 .options = (void *)(options), 129 }, { 130 .init = NULL, 131 } 132 }; 133 134 return lzma_next_filter_init(&next->coder->next, allocator, filters); 135 } 136 137 138 /* 139 extern lzma_ret 140 lzma_alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, 141 const lzma_options_alone *options) 142 { 143 lzma_next_coder_init(&alone_encoder_init, next, allocator, options); 144 } 145 */ 146 147 148 extern LZMA_API(lzma_ret) 149 lzma_alone_encoder(lzma_stream *strm, const lzma_options_lzma *options) 150 { 151 lzma_next_strm_init(alone_encoder_init, strm, options); 152 153 strm->internal->supported_actions[LZMA_RUN] = true; 154 strm->internal->supported_actions[LZMA_FINISH] = true; 155 156 return LZMA_OK; 157 } 158