/**
* Copyright (C) 2015 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
#include
#include "mongo/base/disallow_copying.h"
#include "mongo/base/status.h"
#include "mongo/base/status_with.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/repl/oplog_entry.h"
#include "mongo/db/service_context.h"
#include "mongo/executor/task_executor.h"
#include "mongo/stdx/condition_variable.h"
#include "mongo/stdx/functional.h"
#include "mongo/stdx/mutex.h"
namespace mongo {
namespace repl {
class OpTime;
class MultiApplier {
MONGO_DISALLOW_COPYING(MultiApplier);
public:
/**
* Operations sorted by timestamp in ascending order.
*/
using Operations = std::vector;
using OperationPtrs = std::vector;
/**
* Callback function to report final status of applying operations.
*/
using CallbackFn = stdx::function;
/**
* Type of function to to apply a single operation. In production, this function
* would have the same outcome as calling SyncTail::syncApply() ('convertUpdatesToUpserts'
* value will be embedded in the function implementation).
*/
using ApplyOperationFn = stdx::function;
using MultiApplyFn = stdx::function(
OperationContext*, MultiApplier::Operations, MultiApplier::ApplyOperationFn)>;
/**
* Creates MultiApplier in inactive state.
*
* Accepts list of oplog entries to apply in 'operations'.
*
* The callback function will be invoked (after schedule()) when the applied has
* successfully applied all the operations or encountered a failure. Failures may occur if
* we failed to apply an operation; or if the underlying scheduled work item
* on the replication executor was canceled.
*
* It is an error for 'operations' to be empty but individual oplog entries
* contained in 'operations' are not validated.
*/
MultiApplier(executor::TaskExecutor* executor,
const Operations& operations,
const ApplyOperationFn& applyOperation,
const MultiApplyFn& multiApply,
const CallbackFn& onCompletion);
/**
* Blocks while applier is active.
*/
virtual ~MultiApplier();
/**
* Returns diagnostic information.
*/
std::string getDiagnosticString() const;
/**
* Returns an informational string.
*/
std::string toString() const;
/**
* Returns true if the applier has been started (but has not completed).
*/
bool isActive() const;
/**
* Starts applier by scheduling initial db work to be run by the executor.
*/
Status startup();
/**
* Cancels current db work request.
* Returns immediately if applier is not active.
*
* Callback function may be invoked with an ErrorCodes::CallbackCanceled status.
*/
void shutdown();
/**
* Waits for active database worker to complete.
* Returns immediately if applier is not active.
*/
void join();
private:
/**
* DB worker callback function - applies all operations.
*/
void _callback(const executor::TaskExecutor::CallbackArgs& cbd);
void _finishCallback(const Status& result);
// Not owned by us.
executor::TaskExecutor* _executor;
Operations _operations;
ApplyOperationFn _applyOperation;
MultiApplyFn _multiApply;
CallbackFn _onCompletion;
// Protects member data of this MultiApplier.
mutable stdx::mutex _mutex;
stdx::condition_variable _condition;
// _active is true when MultiApplier is scheduled to be run by the executor.
bool _active;
executor::TaskExecutor::CallbackHandle _dbWorkCallbackHandle;
};
} // namespace repl
} // namespace mongo