aggregation

type Aggregator struct {
	DownSampling AggregatorSpec
	Aggregator   AggregatorSpec
}

type AggregatorSpec interface {
	// FieldName returns field name.
	FieldName() field.Name
	// GetFieldType sets field type
	GetFieldType() field.Type
	// AddFunctionType adds function type for down sampling.
	AddFunctionType(funcType function.FuncType)
	// Functions returns function types for down sampling.
	Functions() map[function.FuncType]function.FuncType
}

type AggregatorSpecs []AggregatorSpec

type Expression interface {
	// Eval evaluates the select item's expression.
	Eval(timeSeries series.GroupedIterator)
	// ResultSet returns the eval result, returns field name(alias) => series data.
	ResultSet() map[string]*collections.FloatArray
	// Reset resets the Expression context for reusing.
	Reset()
}

type FieldAggregates []SeriesAggregator

type FieldAggregator interface {
	// Aggregate aggregates the field series into current aggregator.
	Aggregate(it series.FieldIterator)
	// AggregateBySlot aggregates the field series into current aggregator.
	AggregateBySlot(slot int, value float64)
	// ResultSet returns the result set of field aggregator.
	ResultSet() (startTime int64, it series.FieldIterator)
	// contains filtered or unexported methods
}

type GroupingAggregator interface {
	// Aggregate aggregates the time series data
	Aggregate(it series.GroupedIterator)
	// ResultSet returns the result set of aggregator
	ResultSet() series.GroupedIterators
	// TimeRange returns the time range of aggregator.
	TimeRange() timeutil.TimeRange
	// Interval returns the time interval of aggregator.
	Interval() timeutil.Interval
	// Fields returns all fields.
	Fields() []field.Name
}

type OrderBy interface {
	// Push pushes row into container.
	Push(row Row)
	// ResultSet returns result set of order by.
	ResultSet() []Row
}

type OrderByItem struct {
	Expr     *stmt.OrderByExpr
	Name     string
	FuncType function.FuncType
	Desc     bool
}

type OrderByRow struct {
	// contains filtered or unexported fields
}

type Row interface {
	// GetValue returns the value based on given field name and function type.
	GetValue(fieldName string, funcType function.FuncType) float64
	// ResultSet returns the result set(tags/fields).
	ResultSet() (tags string, fields map[string]*collections.FloatArray)
}

type SeriesAggregator interface {
	// FieldName returns field name
	FieldName() field.Name
	// GetFieldType returns field type
	GetFieldType() field.Type
	// GetAggregator gets field aggregator by start time of query for the segment.
	GetAggregator(segmentStartTime int64) FieldAggregator

	// GetAggregates returns all field aggregators.
	GetAggregates() []FieldAggregator
	// ResultSet returns the result set of series aggregator.
	ResultSet() series.Iterator
	// Reset resets the aggregator's context for reusing.
	Reset()
	// contains filtered or unexported methods
}