1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file stream_buffer_decoder.c 4 /// \brief Single-call .xz Stream 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 "stream_decoder.h" 14 15 16 extern LZMA_API(lzma_ret) 17 lzma_stream_buffer_decode(uint64_t *memlimit, uint32_t flags, 18 const lzma_allocator *allocator, 19 const uint8_t *in, size_t *in_pos, size_t in_size, 20 uint8_t *out, size_t *out_pos, size_t out_size) 21 { 22 // Sanity checks 23 if (in_pos == NULL || (in == NULL && *in_pos != in_size) 24 || *in_pos > in_size || out_pos == NULL 25 || (out == NULL && *out_pos != out_size) 26 || *out_pos > out_size) 27 return LZMA_PROG_ERROR; 28 29 // Catch flags that are not allowed in buffer-to-buffer decoding. 30 if (flags & LZMA_TELL_ANY_CHECK) 31 return LZMA_PROG_ERROR; 32 33 // Initialize the Stream decoder. 34 // TODO: We need something to tell the decoder that it can use the 35 // output buffer as workspace, and thus save significant amount of RAM. 36 lzma_next_coder stream_decoder = LZMA_NEXT_CODER_INIT; 37 lzma_ret ret = lzma_stream_decoder_init( 38 &stream_decoder, allocator, *memlimit, flags); 39 40 if (ret == LZMA_OK) { 41 // Save the positions so that we can restore them in case 42 // an error occurs. 43 const size_t in_start = *in_pos; 44 const size_t out_start = *out_pos; 45 46 // Do the actual decoding. 47 ret = stream_decoder.code(stream_decoder.coder, allocator, 48 in, in_pos, in_size, out, out_pos, out_size, 49 LZMA_FINISH); 50 51 if (ret == LZMA_STREAM_END) { 52 ret = LZMA_OK; 53 } else { 54 // Something went wrong, restore the positions. 55 *in_pos = in_start; 56 *out_pos = out_start; 57 58 if (ret == LZMA_OK) { 59 // Either the input was truncated or the 60 // output buffer was too small. 61 assert(*in_pos == in_size 62 || *out_pos == out_size); 63 64 // If all the input was consumed, then the 65 // input is truncated, even if the output 66 // buffer is also full. This is because 67 // processing the last byte of the Stream 68 // never produces output. 69 if (*in_pos == in_size) 70 ret = LZMA_DATA_ERROR; 71 else 72 ret = LZMA_BUF_ERROR; 73 74 } else if (ret == LZMA_MEMLIMIT_ERROR) { 75 // Let the caller know how much memory would 76 // have been needed. 77 uint64_t memusage; 78 (void)stream_decoder.memconfig( 79 stream_decoder.coder, 80 memlimit, &memusage, 0); 81 } 82 } 83 } 84 85 // Free the decoder memory. This needs to be done even if 86 // initialization fails, because the internal API doesn't 87 // require the initialization function to free its memory on error. 88 lzma_next_end(&stream_decoder, allocator); 89 90 return ret; 91 } 92