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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
#include "lz4_input_decoder.h"
#include <lz4frame.h>
#include <cassert>
namespace vespalib {
void
Lz4InputDecoder::fail(const char *reason)
{
_failed = true;
_reason = reason;
_eof = true;
}
void
Lz4InputDecoder::decode_more()
{
assert((_pos == _used) && !_eof);
Memory memory = _input.obtain();
size_t input_size = memory.size;
size_t output_size = _buffer.size();
auto decode_res = LZ4F_decompress(_ctx,
&_buffer[0], &output_size,
memory.data, &input_size,
nullptr);
if (LZ4F_isError(decode_res)) {
fail(LZ4F_getErrorName(decode_res));
} else {
assert(input_size <= memory.size);
assert(output_size <= _buffer.size());
_input.evict(input_size);
_used = output_size;
_pos = 0;
if ((input_size == 0) && (output_size == 0)) {
auto fini_res = LZ4F_freeDecompressionContext(_ctx);
_ctx = nullptr;
_eof = true;
if (LZ4F_isError(fini_res)) {
fail(LZ4F_getErrorName(fini_res));
}
}
}
}
Lz4InputDecoder::Lz4InputDecoder(Input &input, size_t buffer_size)
: _input(input),
_buffer(buffer_size, 0),
_used(0),
_pos(0),
_eof(false),
_failed(false),
_reason(),
_ctx(nullptr)
{
auto init_res = LZ4F_createDecompressionContext(&_ctx, LZ4F_VERSION);
if (LZ4F_isError(init_res)) {
fail(LZ4F_getErrorName(init_res));
}
}
Lz4InputDecoder::~Lz4InputDecoder()
{
LZ4F_freeDecompressionContext(_ctx);
}
Memory
Lz4InputDecoder::obtain()
{
while ((_pos == _used) && !_eof) {
decode_more();
}
return Memory(&_buffer[_pos], (_used - _pos));
}
Input &
Lz4InputDecoder::evict(size_t bytes)
{
_pos += bytes;
return *this;
}
} // namespace vespalib
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