Merge pull request #8893 from benbjohnson/handle-nil-measurement-iterator

Handle nil MeasurementIterator.

CHANGELOG.md

@@ -43,6 +43,7 @@
 - [#8995](https://github.com/influxdata/influxdb/pull/8995): Sort & validate TSI key value insertion.
 - [#8968](https://github.com/influxdata/influxdb/issues/8968): Make client errors more helpful on downstream errs. Thanks @darkliquid!
 - [#8984](https://github.com/influxdata/influxdb/pull/8984): EXACT and estimated CARDINALITY queries.
+- [#8893](https://github.com/influxdata/influxdb/pull/8893): Handle nil MeasurementIterator.
 
 ### Bugfixes
 

cmd/influx_inspect/dumptsi/dumptsi.go

@@ -229,7 +229,7 @@ func (cmd *Command) printMeasurements(fs *tsi1.FileSet) error {
 	fmt.Fprintln(tw, "Measurement\t")
 
 	// Iterate over each series.
-	itr := fs.MeasurementIterator()
+	if itr := fs.MeasurementIterator(); itr != nil {
 		for e := itr.Next(); e != nil; e = itr.Next() {
 			if cmd.measurementFilter != nil && !cmd.measurementFilter.Match(e.Name()) {
 				continue
@@ -244,6 +244,7 @@ func (cmd *Command) printMeasurements(fs *tsi1.FileSet) error {
 				return err
 			}
 		}
+	}
 
 	fmt.Fprint(cmd.Stdout, "\n\n")
 
@@ -364,7 +365,8 @@ func (cmd *Command) printIndexFileSummary(f *tsi1.IndexFile) error {
 	var measurementN, measurementSeriesN, measurementSeriesSize uint64
 	var keyN uint64
 	var valueN, valueSeriesN, valueSeriesSize uint64
-	mitr := f.MeasurementIterator()
+
+	if mitr := f.MeasurementIterator(); mitr != nil {
 		for me, _ := mitr.Next().(*tsi1.MeasurementBlockElem); me != nil; me, _ = mitr.Next().(*tsi1.MeasurementBlockElem) {
 			kitr := f.TagKeyIterator(me.Name())
 			for ke, _ := kitr.Next().(*tsi1.TagBlockKeyElem); ke != nil; ke, _ = kitr.Next().(*tsi1.TagBlockKeyElem) {
@@ -380,6 +382,7 @@ func (cmd *Command) printIndexFileSummary(f *tsi1.IndexFile) error {
 			measurementSeriesN += uint64(me.SeriesN())
 			measurementSeriesSize += uint64(len(me.SeriesData()))
 		}
+	}
 
 	// Write stats.
 	tw := tabwriter.NewWriter(cmd.Stdout, 8, 8, 1, '\t', 0)

tsdb/index/tsi1/file_set.go

@@ -528,9 +528,13 @@ func (fs *FileSet) MeasurementNamesByExpr(expr influxql.Expr) ([][]byte, error)
 		return fs.measurementNamesByExpr(expr)
 	}
 
+	itr := fs.MeasurementIterator()
+	if itr == nil {
+		return nil, nil
+	}
+
 	// Iterate over all measurements if no condition exists.
 	var names [][]byte
-	itr := fs.MeasurementIterator()
 	for e := itr.Next(); e != nil; e = itr.Next() {
 		names = append(names, e.Name())
 	}
@@ -605,8 +609,12 @@ func (fs *FileSet) measurementNamesByExpr(expr influxql.Expr) ([][]byte, error)
 
 // measurementNamesByNameFilter returns matching measurement names in sorted order.
 func (fs *FileSet) measurementNamesByNameFilter(op influxql.Token, val string, regex *regexp.Regexp) [][]byte {
-	var names [][]byte
 	itr := fs.MeasurementIterator()
+	if itr == nil {
+		return nil
+	}
+
+	var names [][]byte
 	for e := itr.Next(); e != nil; e = itr.Next() {
 		var matched bool
 		switch op {
@@ -632,6 +640,10 @@ func (fs *FileSet) measurementNamesByTagFilter(op influxql.Token, key, val strin
 	var names [][]byte
 
 	mitr := fs.MeasurementIterator()
+	if mitr == nil {
+		return nil
+	}
+
 	for me := mitr.Next(); me != nil; me = mitr.Next() {
 		// If the operator is non-regex, only check the specified value.
 		var tagMatch bool

tsdb/index/tsi1/index.go

@@ -415,6 +415,10 @@ func (i *Index) MeasurementNamesByRegex(re *regexp.Regexp) ([][]byte, error) {
 	defer fs.Release()
 
 	itr := fs.MeasurementIterator()
+	if itr == nil {
+		return nil, nil
+	}
+
 	var a [][]byte
 	for e := itr.Next(); e != nil; e = itr.Next() {
 		if re.Match(e.Name()) {
@@ -1200,6 +1204,10 @@ func (itr *seriesPointIterator) Next() (*query.FloatPoint, error) {
 		// Create new series iterator, if necessary.
 		// Exit if there are no measurements remaining.
 		if itr.sitr == nil {
+			if itr.mitr == nil {
+				return nil, nil
+			}
+
 			m := itr.mitr.Next()
 			if m == nil {
 				return nil, nil

tsdb/index/tsi1/index_files.go

@@ -51,6 +51,10 @@ func (p IndexFiles) Files() []File {
 // MeasurementNames returns a sorted list of all measurement names for all files.
 func (p *IndexFiles) MeasurementNames() [][]byte {
 	itr := p.MeasurementIterator()
+	if itr == nil {
+		return nil
+	}
+
 	var names [][]byte
 	for e := itr.Next(); e != nil; e = itr.Next() {
 		names = append(names, bytesutil.Clone(e.Name()))
@@ -219,6 +223,10 @@ func (p IndexFiles) writeSeriesBlockTo(w io.Writer, m, k uint64, info *indexComp
 
 func (p IndexFiles) writeTagsetsTo(w io.Writer, info *indexCompactInfo, n *int64) error {
 	mitr := p.MeasurementIterator()
+	if mitr == nil {
+		return nil
+	}
+
 	for m := mitr.Next(); m != nil; m = mitr.Next() {
 		if err := p.writeTagsetTo(w, m.Name(), info, n); err != nil {
 			return err
@@ -290,6 +298,7 @@ func (p IndexFiles) writeMeasurementBlockTo(w io.Writer, info *indexCompactInfo,
 
 	// Add measurement data & compute sketches.
 	mitr := p.MeasurementIterator()
+	if mitr != nil {
 		for m := mitr.Next(); m != nil; m = mitr.Next() {
 			name := m.Name()
 
@@ -309,6 +318,7 @@ func (p IndexFiles) writeMeasurementBlockTo(w io.Writer, info *indexCompactInfo,
 			pos := info.tagSets[string(name)]
 			mw.Add(name, m.Deleted(), pos.offset, pos.size, seriesIDs)
 		}
+	}
 
 	// Flush data to writer.
 	nn, err := mw.WriteTo(w)