// Ensure the emitter can group iterators together into rows.
func TestEmitter_Emit(t *testing.T) {
// Build an emitter that pulls from two iterators.
e := influxql.NewEmitter([]influxql.Iterator{
&FloatIterator{Points: []influxql.FloatPoint{
{Name: "cpu", Tags: ParseTags("region=west"), Time: 0, Value: 1},
{Name: "cpu", Tags: ParseTags("region=west"), Time: 1, Value: 2},
}},
&FloatIterator{Points: []influxql.FloatPoint{
{Name: "cpu", Tags: ParseTags("region=west"), Time: 1, Value: 4},
{Name: "cpu", Tags: ParseTags("region=north"), Time: 0, Value: 4},
{Name: "mem", Time: 4, Value: 5},
}},
}, true, 0)
e.Columns = []string{"col1", "col2"}
// Verify the cpu region=west is emitted first.
if row := e.Emit(); !deep.Equal(row, &models.Row{
Name: "cpu",
Tags: map[string]string{"region": "west"},
Columns: []string{"col1", "col2"},
Values: [][]interface{}{
{time.Unix(0, 0).UTC(), float64(1), nil},
{time.Unix(0, 1).UTC(), float64(2), float64(4)},
},
}) {
t.Fatalf("unexpected row(0): %s", spew.Sdump(row))
}
// Verify the cpu region=north is emitted next.
if row := e.Emit(); !deep.Equal(row, &models.Row{
Name: "cpu",
Tags: map[string]string{"region": "north"},
Columns: []string{"col1", "col2"},
Values: [][]interface{}{
{time.Unix(0, 0).UTC(), nil, float64(4)},
},
}) {
t.Fatalf("unexpected row(1): %s", spew.Sdump(row))
}
// Verify the mem series is emitted last.
if row := e.Emit(); !deep.Equal(row, &models.Row{
Name: "mem",
Columns: []string{"col1", "col2"},
Values: [][]interface{}{
{time.Unix(0, 4).UTC(), nil, float64(5)},
},
}) {
t.Fatalf("unexpected row(2): %s", spew.Sdump(row))
}
// Verify EOF.
if row := e.Emit(); row != nil {
t.Fatalf("unexpected eof: %s", spew.Sdump(row))
}
}
// Ensure the emitter will limit the chunked output from a series.
func TestEmitter_ChunkSize(t *testing.T) {
// Build an emitter that pulls from one iterator with multiple points in the same series.
e := influxql.NewEmitter([]influxql.Iterator{
&FloatIterator{Points: []influxql.FloatPoint{
{Name: "cpu", Tags: ParseTags("region=west"), Time: 0, Value: 1},
{Name: "cpu", Tags: ParseTags("region=west"), Time: 1, Value: 2},
}},
}, true, 1)
e.Columns = []string{"col1"}
// Verify the cpu region=west is emitted first.
if row := e.Emit(); !deep.Equal(row, &models.Row{
Name: "cpu",
Tags: map[string]string{"region": "west"},
Columns: []string{"col1"},
Values: [][]interface{}{
{time.Unix(0, 0).UTC(), float64(1)},
},
}) {
t.Fatalf("unexpected row(0): %s", spew.Sdump(row))
}
// Verify the cpu region=north is emitted next.
if row := e.Emit(); !deep.Equal(row, &models.Row{
Name: "cpu",
Tags: map[string]string{"region": "west"},
Columns: []string{"col1"},
Values: [][]interface{}{
{time.Unix(0, 1).UTC(), float64(2)},
},
}) {
t.Fatalf("unexpected row(1): %s", spew.Sdump(row))
}
// Verify EOF.
if row := e.Emit(); row != nil {
t.Fatalf("unexpected eof: %s", spew.Sdump(row))
}
}
func (e *QueryExecutor) executeSelectStatement(stmt *influxql.SelectStatement, chunkSize, statementID int, qid uint64, results chan *influxql.Result, closing <-chan struct{}) error {
// It is important to "stamp" this time so that everywhere we evaluate `now()` in the statement is EXACTLY the same `now`
now := time.Now().UTC()
opt := influxql.SelectOptions{InterruptCh: closing}
// Replace instances of "now()" with the current time, and check the resultant times.
stmt.Condition = influxql.Reduce(stmt.Condition, &influxql.NowValuer{Now: now})
var err error
opt.MinTime, opt.MaxTime, err = influxql.TimeRange(stmt.Condition)
if err != nil {
return err
}
if opt.MaxTime.IsZero() {
opt.MaxTime = now
}
if opt.MinTime.IsZero() {
opt.MinTime = time.Unix(0, 0)
}
// Convert DISTINCT into a call.
stmt.RewriteDistinct()
// Remove "time" from fields list.
stmt.RewriteTimeFields()
// Create an iterator creator based on the shards in the cluster.
ic, err := e.iteratorCreator(stmt, &opt)
if err != nil {
return err
}
// Expand regex sources to their actual source names.
if stmt.Sources.HasRegex() {
sources, err := ic.ExpandSources(stmt.Sources)
if err != nil {
return err
}
stmt.Sources = sources
}
// Rewrite wildcards, if any exist.
tmp, err := stmt.RewriteWildcards(ic)
if err != nil {
return err
}
stmt = tmp
if e.MaxSelectBucketsN > 0 && !stmt.IsRawQuery {
interval, err := stmt.GroupByInterval()
if err != nil {
return err
}
if interval > 0 {
// Determine the start and end time matched to the interval (may not match the actual times).
min := opt.MinTime.Truncate(interval)
max := opt.MaxTime.Truncate(interval).Add(interval)
// Determine the number of buckets by finding the time span and dividing by the interval.
buckets := int64(max.Sub(min)) / int64(interval)
if int(buckets) > e.MaxSelectBucketsN {
return fmt.Errorf("max select bucket count exceeded: %d buckets", buckets)
}
}
}
// Create a set of iterators from a selection.
itrs, err := influxql.Select(stmt, ic, &opt)
if err != nil {
return err
}
if qid != 0 && e.MaxSelectPointN > 0 {
monitor := influxql.PointLimitMonitor(itrs, influxql.DefaultStatsInterval, e.MaxSelectPointN)
e.QueryManager.MonitorQuery(qid, monitor)
}
// Generate a row emitter from the iterator set.
em := influxql.NewEmitter(itrs, stmt.TimeAscending(), chunkSize)
em.Columns = stmt.ColumnNames()
em.OmitTime = stmt.OmitTime
defer em.Close()
// Calculate initial stats across all iterators.
stats := influxql.Iterators(itrs).Stats()
if e.MaxSelectSeriesN > 0 && stats.SeriesN > e.MaxSelectSeriesN {
return fmt.Errorf("max select series count exceeded: %d series", stats.SeriesN)
}
// Emit rows to the results channel.
var writeN int64
var emitted bool
for {
row := em.Emit()
if row == nil {
// Check if the query was interrupted while emitting.
select {
case <-closing:
return influxql.ErrQueryInterrupted
default:
}
break
}
result := &influxql.Result{
StatementID: statementID,
Series: []*models.Row{row},
}
// Write points back into system for INTO statements.
if stmt.Target != nil {
if err := e.writeInto(stmt, row); err != nil {
return err
}
writeN += int64(len(row.Values))
continue
}
// Send results or exit if closing.
select {
case <-closing:
return influxql.ErrQueryInterrupted
case results <- result:
}
emitted = true
}
// Emit write count if an INTO statement.
if stmt.Target != nil {
results <- &influxql.Result{
StatementID: statementID,
Series: []*models.Row{{
Name: "result",
Columns: []string{"time", "written"},
Values: [][]interface{}{{time.Unix(0, 0).UTC(), writeN}},
}},
}
return nil
}
// Always emit at least one result.
if !emitted {
results <- &influxql.Result{
StatementID: statementID,
Series: make([]*models.Row, 0),
}
}
return nil
}