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600bb5f29a
* introduce ZlibDeflatingWriteBuffer and ZlibInflatingReadBuffer * use them instead of Poco streams * seamlessly uncompress multiple concatenated gzip streams
46 lines
1021 B
C++
46 lines
1021 B
C++
#pragma once
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#include <DB/IO/WriteBuffer.h>
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#include <DB/IO/BufferWithOwnMemory.h>
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#include <DB/IO/ZlibCompressionMethod.h>
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#include <zlib.h>
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namespace DB
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{
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namespace ErrorCodes
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{
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extern const int ZLIB_DEFLATE_FAILED;
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}
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/// Performs compression using zlib library and writes compressed data to out_ WriteBuffer.
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class ZlibDeflatingWriteBuffer : public BufferWithOwnMemory<WriteBuffer>
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{
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public:
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ZlibDeflatingWriteBuffer(
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WriteBuffer & out_,
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ZlibCompressionMethod compression_method,
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int compression_level,
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size_t buf_size = DBMS_DEFAULT_BUFFER_SIZE,
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char * existing_memory = nullptr,
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size_t alignment = 0);
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/// Flush all pending data and write zlib footer to the underlying buffer.
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/// After the first call to this function, subsequent calls will have no effect and
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/// an attempt to write to this buffer will result in exception.
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void finish();
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~ZlibDeflatingWriteBuffer() override;
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private:
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void nextImpl() override;
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WriteBuffer & out;
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z_stream zstr;
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bool finished = false;
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};
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}
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