C++ LastError::appendSelfStatus方法代码示例

        bool run(const string& dbname, BSONObj& _cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
            LastError *le = lastError.disableForCommand();

            if ( le->nPrev != 1 ) {
                LastError::noError.appendSelf( result , false );
                le->appendSelfStatus( result );
            }
            else {
                le->appendSelf( result , false );
            }

            Client& c = cc();
            c.appendLastOp( result );

            result.appendNumber( "connectionId" , c.getConnectionId() ); // for sharding; also useful in general for debugging

            BSONObj cmdObj = _cmdObj;
            {
                BSONObj::iterator i(_cmdObj);
                i.next();
                if( !i.more() ) {
                    /* empty, use default */
                    BSONObj *def = getLastErrorDefault;
                    if( def )
                        cmdObj = *def;
                }
            }

            WriteConcernOptions writeConcern;
            Status status = writeConcern.parse( cmdObj );
            if ( !status.isOK() ) {
                result.append( "badGLE", cmdObj );
                errmsg = status.toString();
                return false;
            }

            WriteConcernResult res;
            status = waitForWriteConcern( cc(), writeConcern, &res );
            res.appendTo( &result );
            if ( status.code() == ErrorCodes::WriteConcernLegacyOK ) {
                result.append( "wnote", status.toString() );
                return true;
            }
            return appendCommandStatus( result, status );
        }

        bool run(OperationContext* txn, const string& dbname,
                  BSONObj& cmdObj,
                  int,
                  string& errmsg,
                  BSONObjBuilder& result,
                  bool fromRepl ) {

            //
            // Correct behavior here is very finicky.
            //
            // 1.  The first step is to append the error that occurred on the previous operation.
            // This adds an "err" field to the command, which is *not* the command failing.
            //
            // 2.  Next we parse and validate write concern options.  If these options are invalid
            // the command fails no matter what, even if we actually had an error earlier.  The
            // reason for checking here is to match legacy behavior on these kind of failures -
            // we'll still get an "err" field for the write error.
            //
            // 3.  If we had an error on the previous operation, we then return immediately.
            //
            // 4.  Finally, we actually enforce the write concern.  All errors *except* timeout are
            // reported with ok : 0.0, to match legacy behavior.
            //
            // There is a special case when "wOpTime" and "wElectionId" are explicitly provided by 
            // the client (mongos) - in this case we *only* enforce the write concern if it is 
            // valid.
            //
            // We always need to either report "err" (if ok : 1) or "errmsg" (if ok : 0), even if
            // err is null.
            //

            LastError *le = lastError.disableForCommand();

            // Always append lastOp and connectionId
            Client& c = cc();
            c.appendLastOp( result );

            // for sharding; also useful in general for debugging
            result.appendNumber( "connectionId" , c.getConnectionId() );

            OpTime lastOpTime;
            BSONField<OpTime> wOpTimeField("wOpTime");
            FieldParser::FieldState extracted = FieldParser::extract(cmdObj, wOpTimeField, 
                                                                     &lastOpTime, &errmsg);
            if (!extracted) {
                result.append("badGLE", cmdObj);
                appendCommandStatus(result, false, errmsg);
                return false;
            }
            bool lastOpTimePresent = extracted != FieldParser::FIELD_NONE;
            if (!lastOpTimePresent) {
                // Use the client opTime if no wOpTime is specified
                lastOpTime = cc().getLastOp();
            }
            
            OID electionId;
            BSONField<OID> wElectionIdField("wElectionId");
            extracted = FieldParser::extract(cmdObj, wElectionIdField, 
                                             &electionId, &errmsg);
            if (!extracted) {
                result.append("badGLE", cmdObj);
                appendCommandStatus(result, false, errmsg);
                return false;
            }

            bool electionIdPresent = extracted != FieldParser::FIELD_NONE;
            bool errorOccurred = false;

            // Errors aren't reported when wOpTime is used
            if ( !lastOpTimePresent ) {
                if ( le->nPrev != 1 ) {
                    errorOccurred = LastError::noError.appendSelf( result, false );
                    le->appendSelfStatus( result );
                }
                else {
                    errorOccurred = le->appendSelf( result, false );
                }
            }

            BSONObj writeConcernDoc = cmdObj;
            // Use the default options if we have no gle options aside from wOpTime/wElectionId
            const int nFields = cmdObj.nFields();
            bool useDefaultGLEOptions = (nFields == 1) || 
                (nFields == 2 && lastOpTimePresent) ||
                (nFields == 3 && lastOpTimePresent && electionIdPresent);

            if ( useDefaultGLEOptions && getLastErrorDefault ) {
                writeConcernDoc = *getLastErrorDefault;
            }

            //
            // Validate write concern no matter what, this matches 2.4 behavior
            //

            WriteConcernOptions writeConcern;
            Status status = writeConcern.parse( writeConcernDoc );

            if ( status.isOK() ) {
                // Ensure options are valid for this host
                status = validateWriteConcern( writeConcern );
//.........这里部分代码省略.........