Golang QuerySpec.IsExplainQuery方法代码示例

func (self *CoordinatorImpl) runQuerySpec(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	shards, processor, seriesClosed, err := self.getShardsAndProcessor(querySpec, seriesWriter)
	if err != nil {
		return err
	}

	defer func() {
		if processor != nil {
			processor.Close()
			<-seriesClosed
		} else {
			seriesWriter.Close()
		}
	}()

	shardConcurrentLimit := self.config.ConcurrentShardQueryLimit
	if self.shouldQuerySequentially(shards, querySpec) {
		log.Debug("Querying shards sequentially")
		shardConcurrentLimit = 1
	}
	log.Debug("Shard concurrent limit: ", shardConcurrentLimit)

	errors := make(chan error, shardConcurrentLimit)
	for i := 0; i < shardConcurrentLimit; i++ {
		errors <- nil
	}
	responseChannels := make(chan (<-chan *protocol.Response), shardConcurrentLimit)

	go self.readFromResposneChannels(processor, seriesWriter, querySpec.IsExplainQuery(), errors, responseChannels)

	err = self.queryShards(querySpec, shards, errors, responseChannels)

	// make sure we read the rest of the errors and responses
	for _err := range errors {
		if err == nil {
			err = _err
		}
	}

	for responsechan := range responseChannels {
		for response := range responsechan {
			if response.GetType() != endStreamResponse {
				continue
			}
			if response.ErrorMessage != nil && err == nil {
				err = common.NewQueryError(common.InvalidArgument, *response.ErrorMessage)
			}
			break
		}
	}
	return err
}

func (self *CoordinatorImpl) getShardsAndProcessor(querySpec *parser.QuerySpec, writer SeriesWriter) ([]*cluster.ShardData, cluster.QueryProcessor, chan bool, error) {
	shards := self.clusterConfiguration.GetShards(querySpec)
	shouldAggregateLocally := self.shouldAggregateLocally(shards, querySpec)

	var err error
	var processor cluster.QueryProcessor

	responseChan := make(chan *protocol.Response)
	seriesClosed := make(chan bool)

	selectQuery := querySpec.SelectQuery()
	if selectQuery != nil {
		if !shouldAggregateLocally {
			// if we should aggregate in the coordinator (i.e. aggregation
			// isn't happening locally at the shard level), create an engine
			processor, err = engine.NewQueryEngine(querySpec.SelectQuery(), responseChan)
		} else {
			// if we have a query with limit, then create an engine, or we can
			// make the passthrough limit aware
			processor = engine.NewPassthroughEngineWithLimit(responseChan, 100, selectQuery.Limit)
		}
	} else if !shouldAggregateLocally {
		processor = engine.NewPassthroughEngine(responseChan, 100)
	}

	if err != nil {
		return nil, nil, nil, err
	}

	if processor == nil {
		return shards, nil, nil, nil
	}

	go func() {
		for {
			response := <-responseChan

			if *response.Type == endStreamResponse || *response.Type == accessDeniedResponse {
				writer.Close()
				seriesClosed <- true
				return
			}
			if !(*response.Type == queryResponse && querySpec.IsExplainQuery()) {
				if response.Series != nil && len(response.Series.Points) > 0 {
					writer.Write(response.Series)
				}
			}
		}
	}()

	return shards, processor, seriesClosed, nil
}

func (self *CoordinatorImpl) runQuerySpec(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	shards, processor, seriesClosed, err := self.getShardsAndProcessor(querySpec, seriesWriter)
	if err != nil {
		return err
	}

	shardConcurrentLimit := self.config.ConcurrentShardQueryLimit
	if self.shouldQuerySequentially(shards, querySpec) {
		log.Debug("Querying shards sequentially")
		shardConcurrentLimit = 1
	}
	log.Debug("Shard concurrent limit: ", shardConcurrentLimit)
	for i := 0; i < len(shards); i += shardConcurrentLimit {
		responses := make([]<-chan *protocol.Response, 0, shardConcurrentLimit)

		for j := 0; j < shardConcurrentLimit && i+j < len(shards); j++ {
			shard := shards[i+j]
			responseChan := make(chan *protocol.Response, shard.QueryResponseBufferSize(querySpec, self.config.LevelDbPointBatchSize))
			// We query shards for data and stream them to query processor
			log.Debug("QUERYING: shard: ", i+j, shard.String())
			go shard.Query(querySpec, responseChan)
			responses = append(responses, responseChan)
		}

		err := self.readFromResposneChannels(processor, seriesWriter, querySpec.IsExplainQuery(), responses)
		if err != nil {
			log.Error("Reading responses from channels returned an error: %s", err)
			return err
		}
	}

	if processor != nil {
		processor.Close()
		<-seriesClosed
		return err
	}
	seriesWriter.Close()
	return err
}

func (self *CoordinatorImpl) runQuerySpec(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	shards, processor, seriesClosed, err := self.getShardsAndProcessor(querySpec, seriesWriter)
	if err != nil {
		return err
	}

	responses := make([]chan *protocol.Response, 0)
	for _, shard := range shards {
		responseChan := make(chan *protocol.Response, self.config.QueryShardBufferSize)
		// We query shards for data and stream them to query processor
		go shard.Query(querySpec, responseChan)
		responses = append(responses, responseChan)
	}

	for i, responseChan := range responses {
		log.Debug("READING: shard: ", shards[i].String())
		for {
			response := <-responseChan

			//log.Debug("GOT RESPONSE: ", response.Type, response.Series)
			log.Debug("GOT RESPONSE: ", response.Type)
			if *response.Type == endStreamResponse || *response.Type == accessDeniedResponse {
				if response.ErrorMessage != nil && err == nil {
					err = common.NewQueryError(common.InvalidArgument, *response.ErrorMessage)
				}
				break
			}

			if response.Series == nil || len(response.Series.Points) == 0 {
				log.Debug("Series has no points, continue")
				continue
			}

			// if we don't have a processor, yield the point to the writer
			// this happens if shard took care of the query
			// otherwise client will get points from passthrough engine
			if processor != nil {
				// if the data wasn't aggregated at the shard level, aggregate
				// the data here
				log.Debug("YIELDING: %d points", len(response.Series.Points))
				processor.YieldSeries(response.Series)
				continue
			}

			// If we have EXPLAIN query, we don't write actual points (of
			// response.Type Query) to the client
			if !(*response.Type == queryResponse && querySpec.IsExplainQuery()) {
				seriesWriter.Write(response.Series)
			}
		}
		log.Debug("DONE: shard: ", shards[i].String())
	}

	if processor != nil {
		processor.Close()
		<-seriesClosed
		return err
	}
	seriesWriter.Close()
	return err
}