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Diffstat (limited to '')
-rw-r--r-- | src/liblzma/common/block_buffer_decoder.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/liblzma/common/block_buffer_decoder.c b/src/liblzma/common/block_buffer_decoder.c new file mode 100644 index 0000000..b0ded90 --- /dev/null +++ b/src/liblzma/common/block_buffer_decoder.c @@ -0,0 +1,80 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file block_buffer_decoder.c +/// \brief Single-call .xz Block decoder +// +// Author: Lasse Collin +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#include "block_decoder.h" + + +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) +{ + if (in_pos == NULL || (in == NULL && *in_pos != in_size) + || *in_pos > in_size || out_pos == NULL + || (out == NULL && *out_pos != out_size) + || *out_pos > out_size) + return LZMA_PROG_ERROR; + + // Initialize the Block decoder. + lzma_next_coder block_decoder = LZMA_NEXT_CODER_INIT; + lzma_ret ret = lzma_block_decoder_init( + &block_decoder, allocator, block); + + if (ret == LZMA_OK) { + // Save the positions so that we can restore them in case + // an error occurs. + const size_t in_start = *in_pos; + const size_t out_start = *out_pos; + + // Do the actual decoding. + ret = block_decoder.code(block_decoder.coder, allocator, + in, in_pos, in_size, out, out_pos, out_size, + LZMA_FINISH); + + if (ret == LZMA_STREAM_END) { + ret = LZMA_OK; + } else { + if (ret == LZMA_OK) { + // Either the input was truncated or the + // output buffer was too small. + assert(*in_pos == in_size + || *out_pos == out_size); + + // If all the input was consumed, then the + // input is truncated, even if the output + // buffer is also full. This is because + // processing the last byte of the Block + // never produces output. + // + // NOTE: This assumption may break when new + // filters are added, if the end marker of + // the filter doesn't consume at least one + // complete byte. + if (*in_pos == in_size) + ret = LZMA_DATA_ERROR; + else + ret = LZMA_BUF_ERROR; + } + + // Restore the positions. + *in_pos = in_start; + *out_pos = out_start; + } + } + + // Free the decoder memory. This needs to be done even if + // initialization fails, because the internal API doesn't + // require the initialization function to free its memory on error. + lzma_next_end(&block_decoder, allocator); + + return ret; +} |