// merges two time series making sure that the resulting series has
// the union of the two series columns and the values set
// properly. will panic if the two series don't have the same name
func MergeSeries(s1, s2 *protocol.Series) *protocol.Series {
if s1.GetName() != s2.GetName() {
panic("the two series don't have the same name")
}
// if the two series have the same columns and in the same order
// append the points and return.
if reflect.DeepEqual(s1.Fields, s2.Fields) {
s1.Points = append(s1.Points, s2.Points...)
return s1
}
columns := map[string]struct{}{}
for _, cs := range [][]string{s1.Fields, s2.Fields} {
for _, c := range cs {
columns[c] = struct{}{}
}
}
points := append(pointMaps(s1), pointMaps(s2)...)
fieldsSlice := make([]string, 0, len(columns))
for c := range columns {
fieldsSlice = append(fieldsSlice, c)
}
resultPoints := make([]*protocol.Point, 0, len(points))
for idx, point := range points {
resultPoint := &protocol.Point{}
for _, field := range fieldsSlice {
value := point[field]
if value == nil {
value = &protocol.FieldValue{
IsNull: &TRUE,
}
}
resultPoint.Values = append(resultPoint.Values, value)
if idx < len(s1.Points) {
resultPoint.Timestamp = s1.Points[idx].Timestamp
resultPoint.SequenceNumber = s1.Points[idx].SequenceNumber
} else {
resultPoint.Timestamp = s2.Points[idx-len(s1.Points)].Timestamp
resultPoint.SequenceNumber = s2.Points[idx-len(s1.Points)].SequenceNumber
}
}
resultPoints = append(resultPoints, resultPoint)
}
// otherwise, merge the columns
result := &protocol.Series{
Name: s1.Name,
Fields: fieldsSlice,
Points: resultPoints,
}
return result
}
func (self *AllPointsWriter) yield(series *protocol.Series) error {
oldSeries := self.memSeries[*series.Name]
if oldSeries == nil {
self.memSeries[*series.Name] = series
return nil
}
self.memSeries[series.GetName()] = MergeSeries(self.memSeries[series.GetName()], series)
return nil
}
func (je *JoinEngine) Yield(s *protocol.Series) (bool, error) {
log4go.Fine("JoinEngine.Yield(): %s", s)
idx := je.tableIdx[s.GetName()]
state := &je.tablesState[idx]
// If the state for this table didn't contain a point already,
// increment the number of tables ready to emit a point by
// incrementing `pts`
if state.lastPoint == nil {
je.pts++
}
state.lastPoint = s.Points[len(s.Points)-1]
// update the fields for this table. the fields shouldn't change
// after the first point, so we only need to set them once
if state.lastFields == nil {
for _, f := range s.Fields {
state.lastFields = append(state.lastFields, s.GetName()+"."+f)
}
}
log4go.Fine("JoinEngine: pts = %d", je.pts)
// if the number of tables ready to emit a point isn't equal to the
// total number of tables being joined, then return
if je.pts != len(je.tablesState) {
return true, nil
}
// we arbitrarily use the timestamp of the first table's point as
// the timestamp of the resulting point. may be we should use the
// smalles (or largest) timestamp.
ts := je.tablesState[0].lastPoint.Timestamp
newSeries := &protocol.Series{
Name: &je.name,
Fields: je.fields(),
Points: []*protocol.Point{
{
Timestamp: ts,
Values: je.values(),
},
},
}
// filter the point. the user may have a where clause with the join,
// e.g. `select * from join(foo1, foo2) where foo1.val > 10`. we
// can't evaluate the where clause until after join happens
filteredSeries, err := Filter(je.query, newSeries)
if err != nil {
return false, err
}
if len(filteredSeries.Points) > 0 {
return je.next.Yield(newSeries)
}
return true, nil
}
// We have three types of queries:
// 1. time() without fill
// 2. time() with fill
// 3. no time()
//
// For (1) we flush as soon as a new bucket start, the prefix tree
// keeps track of the other group by columns without the time
// bucket. We reset the trie once the series is yielded. For (2), we
// keep track of all group by columns with time being the last level
// in the prefix tree. At the end of the query we step through [start
// time, end time] in self.duration steps and get the state from the
// prefix tree, using default values for groups without state in the
// prefix tree. For the last case we keep the groups in the prefix
// tree and on close() we loop through the groups and flush their
// values with a timestamp equal to now()
func (self *AggregatorEngine) aggregateValuesForSeries(series *protocol.Series) (bool, error) {
for _, aggregator := range self.aggregators {
if err := aggregator.InitializeFieldsMetadata(series); err != nil {
return false, err
}
}
seriesState := self.getSeriesState(series.GetName())
currentRange := seriesState.pointsRange
includeTimestampInGroup := self.duration != nil && self.isFillQuery
var group []*protocol.FieldValue
if !includeTimestampInGroup {
group = make([]*protocol.FieldValue, len(self.elems))
} else {
group = make([]*protocol.FieldValue, len(self.elems)+1)
}
for _, point := range series.Points {
currentRange.UpdateRange(point)
// this is a groupby with time() and no fill, flush as soon as we
// start a new bucket
if self.duration != nil && !self.isFillQuery {
timestamp := self.getTimestampFromPoint(point)
// this is the timestamp aggregator
if seriesState.started && seriesState.lastTimestamp != timestamp {
self.runAggregatesForTable(series.GetName())
}
seriesState.lastTimestamp = timestamp
seriesState.started = true
}
// get the group this point belongs to
for idx, elem := range self.elems {
// TODO: create an index from fieldname to index
// TODO: We shouldn't rely on GetValue() to do arithmetic
// operations. Instead we should cascade the arithmetic engine
// with the aggregator engine and possibly add another
// arithmetic engine to be able to do arithmetics on the
// resulting aggregated data.
value, err := GetValue(elem, series.Fields, point)
if err != nil {
return false, err
}
group[idx] = value
}
// if this is a fill() query, add the timestamp at the end
if includeTimestampInGroup {
timestamp := self.getTimestampFromPoint(point)
group[len(self.elems)] = &protocol.FieldValue{Int64Value: protocol.Int64(timestamp)}
}
// update the state of the given group
node := seriesState.trie.GetNode(group)
var err error
log4go.Debug("Aggregating for group %v", group)
for idx, aggregator := range self.aggregators {
log4go.Debug("Aggregating value for %T for group %v and state %v", aggregator, group, node.states[idx])
node.states[idx], err = aggregator.AggregatePoint(node.states[idx], point)
if err != nil {
return false, err
}
}
}
return true, nil
}