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

#pragma once

#include <DB/IO/WriteBuffer.h>
#include <DB/IO/HashingWriteBuffer.h>

#include <Poco/SharedPtr.h>
#include <Poco/Net/HTTPClientSession.h>

namespace DB
{

namespace
{

constexpr auto DEFAULT_REMOTE_WRITE_BUFFER_CONNECTION_TIMEOUT = 1;
constexpr auto DEFAULT_REMOTE_WRITE_BUFFER_RECEIVE_TIMEOUT = 1800;
constexpr auto DEFAULT_REMOTE_WRITE_BUFFER_SEND_TIMEOUT = 1800;

}

/** Позволяет писать файл на удалённый сервер.
  */
class InterserverWriteBuffer final : public WriteBuffer
{
public:
	InterserverWriteBuffer(const std::string & host_, int port_,
		const std::string & endpoint_,
		const std::string & path_,
		bool compress_ = false,
		size_t buffer_size_ = DBMS_DEFAULT_BUFFER_SIZE,
		const Poco::Timespan & connection_timeout = Poco::Timespan(DEFAULT_REMOTE_WRITE_BUFFER_CONNECTION_TIMEOUT, 0),
		const Poco::Timespan & send_timeout = Poco::Timespan(DEFAULT_REMOTE_WRITE_BUFFER_SEND_TIMEOUT, 0),
		const Poco::Timespan & receive_timeout = Poco::Timespan(DEFAULT_REMOTE_WRITE_BUFFER_RECEIVE_TIMEOUT, 0));

	~InterserverWriteBuffer();
	void finalize();
	void cancel();

private:
	void nextImpl() override;

private:
	std::string host;
	int port;
	std::string path;

	Poco::Net::HTTPClientSession session;
	std::ostream * ostr;	/// этим владеет session
	std::unique_ptr<WriteBuffer> impl;

	/// Отправили все данные и переименовали файл
	bool finalized = false;
};

}