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///////////////////////////////////////////////////////////////////////////////
//
/// \file stream_buffer_decoder.c
/// \brief Single-call .xz Stream decoder
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include "stream_decoder.h"
extern LZMA_API(lzma_ret)
lzma_stream_buffer_decode(uint64_t *memlimit, uint32_t flags,
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)
{
// Sanity checks
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;
// Catch flags that are not allowed in buffer-to-buffer decoding.
if (flags & LZMA_TELL_ANY_CHECK)
return LZMA_PROG_ERROR;
// Initialize the Stream decoder.
// TODO: We need something to tell the decoder that it can use the
// output buffer as workspace, and thus save significant amount of RAM.
lzma_next_coder stream_decoder = LZMA_NEXT_CODER_INIT;
lzma_ret ret = lzma_stream_decoder_init(
&stream_decoder, allocator, *memlimit, flags);
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 = stream_decoder.code(stream_decoder.coder, allocator,
in, in_pos, in_size, out, out_pos, out_size,
LZMA_FINISH);
if (ret == LZMA_STREAM_END) {
ret = LZMA_OK;
} else {
// Something went wrong, restore the positions.
*in_pos = in_start;
*out_pos = out_start;
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 Stream
// never produces output.
if (*in_pos == in_size)
ret = LZMA_DATA_ERROR;
else
ret = LZMA_BUF_ERROR;
} else if (ret == LZMA_MEMLIMIT_ERROR) {
// Let the caller know how much memory would
// have been needed.
uint64_t memusage;
(void)stream_decoder.memconfig(
stream_decoder.coder,
memlimit, &memusage, 0);
}
}
}
// 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(&stream_decoder, allocator);
return ret;
}
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