Golang parser.QuerySpec类代码示例

func (self *ShardData) QueryResponseBufferSize(querySpec *parser.QuerySpec, batchPointSize int) int {
	groupByTime := querySpec.GetGroupByInterval()
	if groupByTime == nil {
		// If the group by time is nil, we shouldn't have to use a buffer since the shards should be queried sequentially.
		// However, set this to something high just to be safe.
		log.Debug("BUFFER SIZE: 1000")
		return 1000
	}

	tickCount := int(self.shardNanoseconds / uint64(*groupByTime))
	if tickCount < 10 {
		tickCount = 100
	} else if tickCount > 1000 {
		// cap this because each response should have up to this number of points in it.
		tickCount = tickCount / batchPointSize

		// but make sure it's at least 1k
		if tickCount < 1000 {
			tickCount = 1000
		}
	}
	columnCount := querySpec.GetGroupByColumnCount()
	if columnCount > 1 {
		// we don't really know the cardinality for any column up front. This is a just a multiplier so we'll see how this goes.
		// each response can have many points, so having a buffer of the ticks * 100 should be safe, but we'll see.
		tickCount = tickCount * 100
	}
	log.Debug("BUFFER SIZE: %d", tickCount)
	return tickCount
}

func (self *Shard) Query(querySpec *parser.QuerySpec, processor cluster.QueryProcessor) error {
	if querySpec.IsListSeriesQuery() {
		return self.executeListSeriesQuery(querySpec, processor)
	} else if querySpec.IsDeleteFromSeriesQuery() {
		return self.executeDeleteQuery(querySpec, processor)
	}

	seriesAndColumns := querySpec.SelectQuery().GetReferencedColumns()

	if !self.hasReadAccess(querySpec) {
		return errors.New("User does not have access to one or more of the series requested.")
	}

	for series, columns := range seriesAndColumns {
		if regex, ok := series.GetCompiledRegex(); ok {
			seriesNames := self.metaStore.GetSeriesForDatabaseAndRegex(querySpec.Database(), regex)
			for _, name := range seriesNames {
				if !querySpec.HasReadAccess(name) {
					continue
				}
				err := self.executeQueryForSeries(querySpec, name, columns, processor)
				if err != nil {
					return err
				}
			}
		} else {
			err := self.executeQueryForSeries(querySpec, series.Name, columns, processor)
			if err != nil {
				return err
			}
		}
	}
	return nil
}

func (self *LevelDbShard) executeListSeriesQuery(querySpec *parser.QuerySpec, processor cluster.QueryProcessor) error {
	it := self.db.NewIterator(self.readOptions)
	defer it.Close()

	database := querySpec.Database()
	seekKey := append(DATABASE_SERIES_INDEX_PREFIX, []byte(querySpec.Database()+"~")...)
	it.Seek(seekKey)
	dbNameStart := len(DATABASE_SERIES_INDEX_PREFIX)
	for it = it; it.Valid(); it.Next() {
		key := it.Key()
		if len(key) < dbNameStart || !bytes.Equal(key[:dbNameStart], DATABASE_SERIES_INDEX_PREFIX) {
			break
		}
		dbSeries := string(key[dbNameStart:])
		parts := strings.Split(dbSeries, "~")
		if len(parts) > 1 {
			if parts[0] != database {
				break
			}
			name := parts[1]
			shouldContinue := processor.YieldPoint(&name, nil, nil)
			if !shouldContinue {
				return nil
			}
		}
	}
	return nil
}

func (self *CoordinatorImpl) runDeleteQuery(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	db := querySpec.Database()
	if !querySpec.User().IsDbAdmin(db) {
		return common.NewAuthorizationError("Insufficient permission to write to %s", db)
	}
	querySpec.RunAgainstAllServersInShard = true
	return self.runQuerySpec(querySpec, seriesWriter)
}

func (self *CoordinatorImpl) runDeleteQuery(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	user := querySpec.User()
	db := querySpec.Database()
	if ok, err := self.permissions.AuthorizeDeleteQuery(user, db); !ok {
		return err
	}
	querySpec.RunAgainstAllServersInShard = true
	return self.runQuerySpec(querySpec, seriesWriter)
}

func (self *Shard) executeDropSeriesQuery(querySpec *parser.QuerySpec, processor cluster.QueryProcessor) error {
	database := querySpec.Database()
	series := querySpec.Query().DropSeriesQuery.GetTableName()
	err := self.dropSeries(database, series)
	if err != nil {
		return err
	}
	self.db.Compact()
	return nil
}

func (self *Shard) hasReadAccess(querySpec *parser.QuerySpec) bool {
	for series := range querySpec.SeriesValuesAndColumns() {
		if _, isRegex := series.GetCompiledRegex(); !isRegex {
			if !querySpec.HasReadAccess(series.Name) {
				return false
			}
		}
	}
	return true
}

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) checkPermission(user common.User, querySpec *parser.QuerySpec) error {
	// if this isn't a regex query do the permission check here
	fromClause := querySpec.SelectQuery().GetFromClause()

	for _, n := range fromClause.Names {
		if _, ok := n.Name.GetCompiledRegex(); ok {
			break
		} else if name := n.Name.Name; !user.HasReadAccess(name) {
			return fmt.Errorf("User doesn't have read access to %s", name)
		}
	}
	return nil
}

func (self *CoordinatorImpl) runListSeriesQuery(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	series := self.clusterConfiguration.MetaStore.GetSeriesForDatabase(querySpec.Database())
	name := "list_series_result"
	fields := []string{"name"}
	points := make([]*protocol.Point, len(series), len(series))

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

	seriesResult := &protocol.Series{Name: &name, Fields: fields, Points: points}
	seriesWriter.Write(seriesResult)
	seriesWriter.Close()
	return nil
}

func (self *Shard) fetchSinglePoint(querySpec *parser.QuerySpec, series string, fields []*metastore.Field) (*protocol.Series, error) {
	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 nil, err
	}

	timeAndSequenceBuffer := bytes.NewBuffer(make([]byte, 0, 16))
	binary.Write(timeAndSequenceBuffer, binary.BigEndian, self.convertTimestampToUint(&timestamp))
	binary.Write(timeAndSequenceBuffer, binary.BigEndian, sequenceNumber)
	sequenceNumber_uint64 := uint64(sequenceNumber)
	point.SequenceNumber = &sequenceNumber_uint64
	point.SetTimestampInMicroseconds(timestamp)

	timeAndSequenceBytes := timeAndSequenceBuffer.Bytes()
	for _, field := range fields {
		pointKeyBuff := bytes.NewBuffer(make([]byte, 0, 24))
		pointKeyBuff.Write(field.IdAsBytes())
		pointKeyBuff.Write(timeAndSequenceBytes)

		if data, err := self.db.Get(pointKeyBuff.Bytes()); err != nil {
			return nil, err
		} else {
			fieldValue := &protocol.FieldValue{}
			err := proto.Unmarshal(data, fieldValue)
			if err != nil {
				return nil, err
			}
			if data != nil {
				fieldNames = append(fieldNames, field.Name)
				point.Values = append(point.Values, fieldValue)
			}
		}
	}

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

	return result, nil
}

func (self *CoordinatorImpl) runDropSeriesQuery(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	user := querySpec.User()
	db := querySpec.Database()
	series := querySpec.Query().DropSeriesQuery.GetTableName()
	if !user.IsClusterAdmin() && !user.IsDbAdmin(db) && !user.HasWriteAccess(series) {
		return common.NewAuthorizationError("Insufficient permissions to drop series")
	}
	querySpec.RunAgainstAllServersInShard = true
	return self.runQuerySpec(querySpec, seriesWriter)
}

func (self *CoordinatorImpl) runDropSeriesQuery(querySpec *parser.QuerySpec, seriesWriter SeriesWriter) error {
	user := querySpec.User()
	db := querySpec.Database()
	series := querySpec.Query().DropSeriesQuery.GetTableName()
	if ok, err := self.permissions.AuthorizeDropSeries(user, db, series); !ok {
		return err
	}
	querySpec.RunAgainstAllServersInShard = true
	return self.runQuerySpec(querySpec, seriesWriter)
}

func (self *CoordinatorImpl) shouldQuerySequentially(shards []*cluster.ShardData, querySpec *parser.QuerySpec) bool {
	// if the query isn't a select, then it doesn't matter
	if querySpec.SelectQuery != nil {
		return false
	}

	// if the query is a regex, we can't predic the number of responses
	// we get back
	if querySpec.IsRegex() {
		return true
	}
	groupByClause := querySpec.SelectQuery().GetGroupByClause()
	// if there's no group by clause, then we're returning raw points
	// with some math done on them, thus we can't predict the number of
	// points
	if groupByClause == nil {
		return true
	}
	// if there's a group by clause but no group by interval, we can't
	// predict the cardinality of the columns used in the group by
	// interval, thus we can't predict the number of responses returned
	// from the shard
	if querySpec.GetGroupByInterval() == nil {
		return true
	}
	// if there's a group by time and other columns, then the previous
	// logic holds
	if len(groupByClause.Elems) > 1 {
		return true
	}

	// parallel querying only if we're querying a single series, with
	// group by time only
	return false
}

func (self *ClusterConfiguration) GetShards(querySpec *parser.QuerySpec) []*ShardData {
	self.shardsByIdLock.RLock()
	defer self.shardsByIdLock.RUnlock()

	shouldQueryShortTerm, shouldQueryLongTerm := querySpec.ShouldQueryShortTermAndLongTerm()

	if shouldQueryLongTerm && shouldQueryShortTerm {
		shards := make([]*ShardData, 0)
		shards = append(shards, self.getShardRange(querySpec, self.shortTermShards)...)
		shards = append(shards, self.getShardRange(querySpec, self.longTermShards)...)
		if querySpec.IsAscending() {
			SortShardsByTimeAscending(shards)
		} else {
			SortShardsByTimeDescending(shards)
		}
		return shards
	}

	var shards []*ShardData
	if shouldQueryLongTerm {
		shards = self.getShardRange(querySpec, self.longTermShards)
	} else {
		shards = self.getShardRange(querySpec, self.shortTermShards)
	}
	if querySpec.IsAscending() {
		newShards := append([]*ShardData{}, shards...)
		SortShardsByTimeAscending(newShards)
		return newShards
	}
	return shards
}