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/**
* Copyright (C) 2013 10gen 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 <http://www.gnu.org/licenses/>.
*
* 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 "mongo/bson/timestamp.h"
#include "mongo/db/record_id.h"
namespace mongo {
class Collection;
struct CollectionScanParams {
enum Direction {
FORWARD = 1,
BACKWARD = -1,
};
// What collection?
// not owned
const Collection* collection = nullptr;
// isNull by default. If you specify any value for this, you're responsible for the RecordId
// not being invalidated before the first call to work(...).
RecordId start;
// If present, the collection scan will stop and return EOF the first time it sees a document
// that does not pass the filter and has 'ts' greater than 'maxTs'.
boost::optional<Timestamp> maxTs;
Direction direction = FORWARD;
// Do we want the scan to be 'tailable'? Only meaningful if the collection is capped.
bool tailable = false;
// Should we keep track of the timestamp of the latest oplog entry we've seen? This information
// is needed to merge cursors from the oplog in order of operation time when reading the oplog
// across a sharded cluster.
bool shouldTrackLatestOplogTimestamp = false;
// Once the first matching document is found, assume that all documents after it must match.
// This is useful for oplog queries where we know we will see records ordered by the ts field.
bool stopApplyingFilterAfterFirstMatch = false;
// If non-zero, how many documents will we look at?
size_t maxScan = 0;
// Whether or not to wait for oplog visibility on oplog collection scans.
bool shouldWaitForOplogVisibility = false;
};
} // namespace mongo
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