Golang engine.Processor類代碼示例

func (self *Coordinator) runListSeriesQuery(querySpec *parser.QuerySpec, p engine.Processor) error {
	allSeries := self.clusterConfiguration.MetaStore.GetSeriesForDatabase(querySpec.Database())
	matchingSeries := allSeries
	if q := querySpec.Query().GetListSeriesQuery(); q.HasRegex() {
		matchingSeries = nil
		regex := q.GetRegex()
		for _, s := range allSeries {
			if !regex.MatchString(s) {
				continue
			}
			matchingSeries = append(matchingSeries, s)
		}
	}
	name := "list_series_result"
	fields := []string{"name"}
	points := make([]*protocol.Point, len(matchingSeries), len(matchingSeries))

	for i, s := range matchingSeries {
		fieldValues := []*protocol.FieldValue{{StringValue: proto.String(s)}}
		points[i] = &protocol.Point{Values: fieldValues}
	}

	seriesResult := &protocol.Series{Name: &name, Fields: fields, Points: points}
	_, err := p.Yield(seriesResult)
	return err
}

func (self *Coordinator) runListContinuousQueries(user common.User, db string, p engine.Processor) error {
	queries, err := self.ListContinuousQueries(user, db)
	if err != nil {
		return err
	}
	for _, q := range queries {
		if ok, err := p.Yield(q); !ok || err != nil {
			return err
		}
	}
	return nil
}

func (self *Coordinator) runListSeriesQuery(querySpec *parser.QuerySpec, p engine.Processor) error {
	allSeries := self.clusterConfiguration.MetaStore.GetSeriesForDatabase(querySpec.Database())
	matchingSeries := allSeries
	q := querySpec.Query().GetListSeriesQuery()
	if q.HasRegex() {
		matchingSeries = nil
		regex := q.GetRegex()
		for _, s := range allSeries {
			if !regex.MatchString(s) {
				continue
			}
			matchingSeries = append(matchingSeries, s)
		}
	}
	name := "list_series_result"
	var fields []string
	points := make([]*protocol.Point, len(matchingSeries))

	if q.IncludeSpaces {
		fields = []string{"name", "space"}
		spaces := self.clusterConfiguration.GetShardSpacesForDatabase(querySpec.Database())

		for i, s := range matchingSeries {
			spaceName := ""
			for _, sp := range spaces {
				if sp.MatchesSeries(s) {
					spaceName = sp.Name
					break
				}
			}
			fieldValues := []*protocol.FieldValue{
				{StringValue: proto.String(s)},
				{StringValue: proto.String(spaceName)},
			}
			points[i] = &protocol.Point{Values: fieldValues}
		}
	} else {
		fields = []string{"name"}
		for i, s := range matchingSeries {
			fieldValues := []*protocol.FieldValue{
				{StringValue: proto.String(s)},
			}
			points[i] = &protocol.Point{Values: fieldValues}
		}
	}

	seriesResult := &protocol.Series{Name: &name, Fields: fields, Points: points}
	_, err := p.Yield(seriesResult)
	return err
}

func yieldToProcessor(s *protocol.Series, p engine.Processor, aliases []string) (bool, error) {
	for _, alias := range aliases {
		series := &protocol.Series{
			Name:   proto.String(alias),
			Fields: s.Fields,
			Points: s.Points,
		}
		log4go.Debug("Yielding to %s %s", p.Name(), series)
		if ok, err := p.Yield(series); !ok || err != nil {
			return ok, err
		}
	}
	return true, nil
}

func (self *Shard) executeSinglePointQuery(querySpec *parser.QuerySpec, name string, columns []string, p engine.Processor) error {
	fields, err := self.getFieldsForSeries(querySpec.Database(), name, columns)
	if err != nil {
		log.Error("Error looking up fields for %s: %s", name, err)
		return err
	}

	query := querySpec.SelectQuery()
	fieldCount := len(fields)
	fieldNames := make([]string, 0, fieldCount)
	point := &protocol.Point{Values: make([]*protocol.FieldValue, 0, fieldCount)}
	timestamp := common.TimeToMicroseconds(query.GetStartTime())
	sequenceNumber, err := query.GetSinglePointQuerySequenceNumber()
	if err != nil {
		return err
	}

	// set the timestamp and sequence number
	point.SequenceNumber = &sequenceNumber
	point.SetTimestampInMicroseconds(timestamp)

	for _, field := range fields {
		sk := newStorageKey(field.Id, timestamp, sequenceNumber)
		data, err := self.db.Get(sk.bytes())
		if err != nil {
			return err
		}

		if data == nil {
			continue
		}

		fieldValue := &protocol.FieldValue{}
		err = proto.Unmarshal(data, fieldValue)
		if err != nil {
			return err
		}
		fieldNames = append(fieldNames, field.Name)
		point.Values = append(point.Values, fieldValue)
	}

	result := &protocol.Series{Name: &name, Fields: fieldNames, Points: []*protocol.Point{point}}

	if len(result.Points) > 0 {
		_, err := p.Yield(result)
		return err
	}
	return nil
}

func (self *ShardData) Query(querySpec *parser.QuerySpec, response chan<- *p.Response) {
	log.Debug("QUERY: shard %d, query '%s'", self.Id(), querySpec.GetQueryStringWithTimeCondition())
	defer common.RecoverFunc(querySpec.Database(), querySpec.GetQueryStringWithTimeCondition(), func(err interface{}) {
		response <- &p.Response{
			Type:         p.Response_ERROR.Enum(),
			ErrorMessage: p.String(fmt.Sprintf("%s", err)),
		}
	})

	// This is only for queries that are deletes or drops. They need to be sent everywhere as opposed to just the local or one of the remote shards.
	// But this boolean should only be set to true on the server that receives the initial query.
	if querySpec.RunAgainstAllServersInShard {
		if querySpec.IsDeleteFromSeriesQuery() {
			self.logAndHandleDeleteQuery(querySpec, response)
		} else if querySpec.IsDropSeriesQuery() {
			self.logAndHandleDropSeriesQuery(querySpec, response)
		}
	}

	if self.IsLocal {
		var processor engine.Processor = NewResponseChannelProcessor(NewResponseChannelWrapper(response))
		var err error

		processor = NewShardIdInserterProcessor(self.Id(), processor)

		processor, err = self.getProcessor(querySpec, processor)
		if err != nil {
			response <- &p.Response{
				Type:         p.Response_ERROR.Enum(),
				ErrorMessage: p.String(err.Error()),
			}
			log.Error("Error while creating engine: %s", err)
			return
		}
		shard, err := self.store.GetOrCreateShard(self.id)
		if err != nil {
			response <- &p.Response{
				Type:         p.Response_ERROR.Enum(),
				ErrorMessage: p.String(err.Error()),
			}
			log.Error("Error while getting shards: %s", err)
			return
		}
		defer self.store.ReturnShard(self.id)

		log.Debug("Processor chain:  %s\n", engine.ProcessorChain(processor))

		err = shard.Query(querySpec, processor)
		// if we call Close() in case of an error it will mask the error
		if err != nil {
			response <- &p.Response{
				Type:         p.Response_ERROR.Enum(),
				ErrorMessage: p.String(err.Error()),
			}
			return
		}
		processor.Close()
		response <- &p.Response{Type: p.Response_END_STREAM.Enum()}
		return
	}

	if server := self.randomHealthyServer(); server != nil {
		log.Debug("Querying server %d for shard %d", server.GetId(), self.Id())
		request := self.createRequest(querySpec)
		server.MakeRequest(request, response)
		return
	}

	message := fmt.Sprintf("No servers up to query shard %d", self.id)
	response <- &p.Response{
		Type:         p.Response_ERROR.Enum(),
		ErrorMessage: &message,
	}
	log.Error(message)
}