ClickHouse/dbms/include/DB/IO/ZlibInflatingReadBuffer.h

#pragma once

#include <DB/IO/ReadBuffer.h>
#include <DB/IO/BufferWithOwnMemory.h>
#include <DB/IO/ZlibCompressionMethod.h>

#include <zlib.h>


namespace DB
{

namespace ErrorCodes
{
	extern const int ZLIB_INFLATE_FAILED;
}

/// Reads compressed data from ReadBuffer in_ and performs decompression using zlib library.
/// This buffer is able to seamlessly decompress multiple concatenated zlib streams.
class ZlibInflatingReadBuffer : public BufferWithOwnMemory<ReadBuffer>
{
public:
	ZlibInflatingReadBuffer(
			ReadBuffer & in_,
			ZlibCompressionMethod compression_method,
			size_t buf_size = DBMS_DEFAULT_BUFFER_SIZE,
			char * existing_memory = nullptr,
			size_t alignment = 0);

	~ZlibInflatingReadBuffer() override;

private:
	bool nextImpl() override;

	ReadBuffer & in;
	z_stream zstr;
	bool eof;
};

}