func Filter(query *parser.SelectQuery, series *protocol.Series) (*protocol.Series, error) {
if query.GetWhereCondition() == nil {
return series, nil
}
columns := map[string]struct{}{}
if query.GetFromClause().Type == parser.FromClauseInnerJoin {
outer:
for t, cs := range query.GetResultColumns() {
for _, c := range cs {
// if this is a wildcard select, then drop all columns and
// just use '*'
if c == "*" {
columns = make(map[string]struct{}, 1)
columns[c] = struct{}{}
break outer
}
columns[t.Name+"."+c] = struct{}{}
}
}
} else {
for _, cs := range query.GetResultColumns() {
for _, c := range cs {
columns[c] = struct{}{}
}
}
}
points := series.Points
series.Points = nil
for _, point := range points {
ok, err := matches(query.GetWhereCondition(), series.Fields, point)
if err != nil {
return nil, err
}
if ok {
filterColumns(columns, series.Fields, point)
series.Points = append(series.Points, point)
}
}
if _, ok := columns["*"]; !ok {
newFields := []string{}
for _, f := range series.Fields {
if _, ok := columns[f]; !ok {
continue
}
newFields = append(newFields, f)
}
series.Fields = newFields
}
return series, nil
}
func (self *Limiter) calculateLimitAndSlicePoints(series *protocol.Series) {
if self.shouldLimit {
// if the limit is 0, stop returning any points
limit := self.limitForSeries(*series.Name)
defer func() { self.limits[*series.Name] = limit }()
if limit == 0 {
series.Points = nil
return
}
limit -= len(series.Points)
if limit <= 0 {
sliceTo := len(series.Points) + limit
series.Points = series.Points[0:sliceTo]
limit = 0
}
}
}
// 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
}