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)
lzma_block_buffer_decode(lzma_block * block,const lzma_allocator * allocator,const uint8_t * in,size_t * in_pos,size_t in_size,uint8_t * out,size_t * out_pos,size_t out_size)17 lzma_block_buffer_decode(lzma_block *block, const 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