/**
* Copyright (C) 2016 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include
#include
#include "mongo/base/disallow_copying.h"
#include "mongo/db/repl/oplog_buffer.h"
#include "mongo/stdx/mutex.h"
namespace mongo {
namespace repl {
class StorageInterface;
/**
* Oplog buffer proxy that caches front and back (most recently pushed) oplog entries in the target
* oplog buffer.
*/
class OplogBufferProxy : public OplogBuffer {
MONGO_DISALLOW_COPYING(OplogBufferProxy);
public:
explicit OplogBufferProxy(std::unique_ptr target);
/**
* Returns target oplog buffer.
*/
OplogBuffer* getTarget() const;
void startup(OperationContext* opCtx) override;
void shutdown(OperationContext* opCtx) override;
void pushEvenIfFull(OperationContext* opCtx, const Value& value) override;
void push(OperationContext* opCtx, const Value& value) override;
void pushAllNonBlocking(OperationContext* opCtx,
Batch::const_iterator begin,
Batch::const_iterator end) override;
void waitForSpace(OperationContext* opCtx, std::size_t size) override;
bool isEmpty() const override;
std::size_t getMaxSize() const override;
std::size_t getSize() const override;
std::size_t getCount() const override;
void clear(OperationContext* opCtx) override;
bool tryPop(OperationContext* opCtx, Value* value) override;
bool waitForData(Seconds waitDuration) override;
bool peek(OperationContext* opCtx, Value* value) override;
boost::optional lastObjectPushed(OperationContext* opCtx) const override;
// ---- Testing API ----
boost::optional getLastPeeked_forTest() const;
private:
// Target oplog buffer. Owned by us.
std::unique_ptr _target;
// If both mutexes have to be acquired, acquire _lastPushedMutex first.
mutable stdx::mutex _lastPushedMutex;
boost::optional _lastPushed;
mutable stdx::mutex _lastPeekedMutex;
boost::optional _lastPeeked;
};
} // namespace repl
} // namespace mongo