1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file block_buffer_decoder.c 4 /// \brief Single-call .xz Block decoder 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 "block_decoder.h" 14 15 16 extern LZMA_API(lzma_ret) 17 lzma_block_buffer_decode(lzma_block *block, lzma_allocator *allocator, 18 const uint8_t *in, size_t *in_pos, size_t in_size, 19 uint8_t *out, size_t *out_pos, size_t out_size) 20 { 21 if (in_pos == NULL || (in == NULL && *in_pos != in_size) 22 || *in_pos > in_size || out_pos == NULL 23 || (out == NULL && *out_pos != out_size) 24 || *out_pos > out_size) 25 return LZMA_PROG_ERROR; 26 27 // Initialize the Block decoder. 28 lzma_next_coder block_decoder = LZMA_NEXT_CODER_INIT; 29 lzma_ret ret = lzma_block_decoder_init( 30 &block_decoder, allocator, block); 31 32 if (ret == LZMA_OK) { 33 // Save the positions so that we can restore them in case 34 // an error occurs. 35 const size_t in_start = *in_pos; 36 const size_t out_start = *out_pos; 37 38 // Do the actual decoding. 39 ret = block_decoder.code(block_decoder.coder, allocator, 40 in, in_pos, in_size, out, out_pos, out_size, 41 LZMA_FINISH); 42 43 if (ret == LZMA_STREAM_END) { 44 ret = LZMA_OK; 45 } else { 46 if (ret == LZMA_OK) { 47 // Either the input was truncated or the 48 // output buffer was too small. 49 assert(*in_pos == in_size 50 || *out_pos == out_size); 51 52 // If all the input was consumed, then the 53 // input is truncated, even if the output 54 // buffer is also full. This is because 55 // processing the last byte of the Block 56 // never produces output. 57 // 58 // NOTE: This assumption may break when new 59 // filters are added, if the end marker of 60 // the filter doesn't consume at least one 61 // complete byte. 62 if (*in_pos == in_size) 63 ret = LZMA_DATA_ERROR; 64 else 65 ret = LZMA_BUF_ERROR; 66 } 67 68 // Restore the positions. 69 *in_pos = in_start; 70 *out_pos = out_start; 71 } 72 } 73 74 // Free the decoder memory. This needs to be done even if 75 // initialization fails, because the internal API doesn't 76 // require the initialization function to free its memory on error. 77 lzma_next_end(&block_decoder, allocator); 78 79 return ret; 80 } 81