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 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 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 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) 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