/**
* 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 .
*
* 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/db/exec/working_set.h"
#include "mongo/util/unowned_ptr.h"
namespace mongo {
class CanonicalQuery;
class Collection;
class OperationContext;
class SeekableRecordCursor;
class WorkingSetCommon {
public:
/**
* Get an owned copy of the BSONObj the WSM refers to.
* Requires either a valid BSONObj or valid RecordId.
* Returns true if the fetch and invalidate succeeded, false otherwise.
*/
static bool fetchAndInvalidateRecordId(OperationContext* opCtx,
WorkingSetMember* member,
const Collection* collection);
/**
* This must be called as part of "saveState" operations after all nodes in the tree save their
* state.
*
* Iterates over WorkingSetIDs in 'workingSet' which are "sensitive to yield". These are ids
* that have transitioned into the RID_AND_IDX state since the previous yield.
*
* The RID_AND_IDX members are tagged as suspicious so that they can be handled properly in case
* the document keyed by the index key is deleted or updated during the yield.
*/
static void prepareForSnapshotChange(WorkingSet* workingSet);
/**
* Transitions the WorkingSetMember with WorkingSetID 'id' from the RID_AND_IDX state to the
* RID_AND_OBJ state by fetching a document. Does the fetch using 'cursor'.
*
* If false is returned, the document should not be considered for the result set. It is the
* caller's responsibility to free 'id' in this case.
*
* WriteConflict exceptions may be thrown. When they are, 'member' will be unmodified.
*/
static bool fetch(OperationContext* opCtx,
WorkingSet* workingSet,
WorkingSetID id,
unowned_ptr cursor);
static bool fetchIfUnfetched(OperationContext* opCtx,
WorkingSet* workingSet,
WorkingSetID id,
unowned_ptr cursor) {
WorkingSetMember* member = workingSet->get(id);
if (member->hasObj())
return true;
return fetch(opCtx, workingSet, id, cursor);
}
/**
* Build a BSONObj which represents a Status to return in a WorkingSet.
*/
static BSONObj buildMemberStatusObject(const Status& status);
/**
* Allocate a new WSM and initialize it with
* the code and reason from the status.
* Owned BSON object will have the following layout:
* {
* ok: , // 1 for OK; 0 otherwise.
* code: , // Status::code()
* errmsg: // Status::reason()
* }
*/
static WorkingSetID allocateStatusMember(WorkingSet* ws, const Status& status);
/**
* Returns true if object was created by allocateStatusMember().
*/
static bool isValidStatusMemberObject(const BSONObj& obj);
/**
* Returns object in working set member created with allocateStatusMember().
* Does not assume isValidStatusMemberObject.
* If the WSID is invalid or the working set member is created by
* allocateStatusMember, objOut will not be updated.
*/
static void getStatusMemberObject(const WorkingSet& ws, WorkingSetID wsid, BSONObj* objOut);
/**
* Returns status from working set member object.
* Assumes isValidStatusMemberObject().
*/
static Status getMemberObjectStatus(const BSONObj& memberObj);
/**
* Returns status from working set member created with allocateStatusMember().
* Assumes isValidStatusMemberObject().
*/
static Status getMemberStatus(const WorkingSetMember& member);
/**
* Formats working set member object created with allocateStatusMember().
*/
static std::string toStatusString(const BSONObj& obj);
};
} // namespace mongo