mirror of https://git.tukaani.org/xz.git
92 lines
2.7 KiB
C
92 lines
2.7 KiB
C
///////////////////////////////////////////////////////////////////////////////
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//
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/// \file stream_buffer_decoder.c
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/// \brief Single-call .xz Stream decoder
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//
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// Author: Lasse Collin
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//
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// This file has been put into the public domain.
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// You can do whatever you want with this file.
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//
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///////////////////////////////////////////////////////////////////////////////
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#include "stream_decoder.h"
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extern LZMA_API(lzma_ret)
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lzma_stream_buffer_decode(uint64_t *memlimit, uint32_t flags,
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lzma_allocator *allocator,
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const uint8_t *in, size_t *in_pos, size_t in_size,
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uint8_t *out, size_t *out_pos, size_t out_size)
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{
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// Sanity checks
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if (in_pos == NULL || (in == NULL && *in_pos != in_size)
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|| *in_pos > in_size || out_pos == NULL
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|| (out == NULL && *out_pos != out_size)
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|| *out_pos > out_size)
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return LZMA_PROG_ERROR;
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// Catch flags that are not allowed in buffer-to-buffer decoding.
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if (flags & LZMA_TELL_ANY_CHECK)
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return LZMA_PROG_ERROR;
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// Initialize the Stream decoder.
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// TODO: We need something to tell the decoder that it can use the
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// output buffer as workspace, and thus save significant amount of RAM.
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lzma_next_coder stream_decoder = LZMA_NEXT_CODER_INIT;
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lzma_ret ret = lzma_stream_decoder_init(
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&stream_decoder, allocator, *memlimit, flags);
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if (ret == LZMA_OK) {
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// Save the positions so that we can restore them in case
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// an error occurs.
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const size_t in_start = *in_pos;
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const size_t out_start = *out_pos;
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// Do the actual decoding.
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ret = stream_decoder.code(stream_decoder.coder, allocator,
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in, in_pos, in_size, out, out_pos, out_size,
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LZMA_FINISH);
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if (ret == LZMA_STREAM_END) {
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ret = LZMA_OK;
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} else {
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// Something went wrong, restore the positions.
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*in_pos = in_start;
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*out_pos = out_start;
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if (ret == LZMA_OK) {
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// Either the input was truncated or the
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// output buffer was too small.
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assert(*in_pos == in_size
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|| *out_pos == out_size);
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// If all the input was consumed, then the
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// input is truncated, even if the output
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// buffer is also full. This is because
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// processing the last byte of the Stream
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// never produces output.
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if (*in_pos == in_size)
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ret = LZMA_DATA_ERROR;
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else
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ret = LZMA_BUF_ERROR;
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} else if (ret == LZMA_MEMLIMIT_ERROR) {
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// Let the caller know how much memory would
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// have been needed.
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uint64_t memusage;
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(void)stream_decoder.memconfig(
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stream_decoder.coder,
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memlimit, &memusage, 0);
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}
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}
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}
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// Free the decoder memory. This needs to be done even if
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// initialization fails, because the internal API doesn't
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// require the initialization function to free its memory on error.
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lzma_next_end(&stream_decoder, allocator);
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return ret;
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}
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