/**
* 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.
*/
#include "mongo/platform/basic.h"
#include "mongo/db/repl/oplog_interface_local.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/query/internal_plans.h"
#include "mongo/db/query/plan_executor.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
namespace repl {
namespace {
class OplogIteratorLocal : public OplogInterface::Iterator {
public:
OplogIteratorLocal(OperationContext* opCtx, const std::string& collectionName);
StatusWith next() override;
private:
Lock::DBLock _dbLock;
Lock::CollectionLock _collectionLock;
OldClientContext _ctx;
std::unique_ptr _exec;
};
OplogIteratorLocal::OplogIteratorLocal(OperationContext* opCtx, const std::string& collectionName)
: _dbLock(opCtx, nsToDatabase(collectionName), MODE_IS),
_collectionLock(opCtx->lockState(), collectionName, MODE_S),
_ctx(opCtx, collectionName),
_exec(InternalPlanner::collectionScan(opCtx,
collectionName,
_ctx.db()->getCollection(opCtx, collectionName),
PlanExecutor::NO_YIELD,
InternalPlanner::BACKWARD)) {}
StatusWith OplogIteratorLocal::next() {
BSONObj obj;
RecordId recordId;
PlanExecutor::ExecState state;
if (PlanExecutor::ADVANCED != (state = _exec->getNext(&obj, &recordId))) {
return StatusWith(ErrorCodes::CollectionIsEmpty,
"no more operations in local oplog");
}
// Non-yielding collection scans from InternalPlanner will never error.
invariant(PlanExecutor::ADVANCED == state || PlanExecutor::IS_EOF == state);
return StatusWith(std::make_pair(obj, recordId));
}
} // namespace
OplogInterfaceLocal::OplogInterfaceLocal(OperationContext* opCtx, const std::string& collectionName)
: _opCtx(opCtx), _collectionName(collectionName) {
invariant(opCtx);
invariant(!collectionName.empty());
}
std::string OplogInterfaceLocal::toString() const {
return str::stream() << "LocalOplogInterface: "
"operation context: "
<< _opCtx->getOpID() << "; collection: " << _collectionName;
}
std::unique_ptr OplogInterfaceLocal::makeIterator() const {
return std::unique_ptr(
new OplogIteratorLocal(_opCtx, _collectionName));
}
} // namespace repl
} // namespace mongo