Merge pull request #13426 from influxdata/sgc/feat/13369

Implementation of storage schema TagValues API

storage/engine_schema.go

@@ -1,50 +1,35 @@
 package storage
 
 import (
+	"context"
+
 	"github.com/influxdata/influxdb"
+	"github.com/influxdata/influxdb/tsdb/cursors"
 	"github.com/influxdata/influxql"
 )
 
-// StringIterator describes the behavior for enumerating a sequence of
-// string values.
-type StringIterator interface {
-	// Next advances the StringIterator to the next value. It returns false
-	// when there are no more values.
-	Next() bool
-
-	// Value returns the current value.
-	Value() string
-}
-
 // TagKeys returns an iterator where the values are tag keys for the bucket
 // matching the predicate within the time range (start, end].
-func (e *Engine) TagKeys(orgID, bucketID influxdb.ID, start, end int64, predicate influxql.Expr) StringIterator {
+func (e *Engine) TagKeys(ctx context.Context, orgID, bucketID influxdb.ID, start, end int64, predicate influxql.Expr) cursors.StringIterator {
 	// This method would be invoked when the consumer wants to get the following schema information for an arbitrary
 	// time range in a single bucket:
 	//
 	// * All tag keys;
 	// * All tag keys filtered by an arbitrary predicate, e.g., tag keys for a measurement or tag keys appearing alongside another tag key pair.
 	//
-	return nullStringIterator
+
+	return cursors.NewStringSliceIterator([]string{"\x00", "arch", "cluster_id", "datacenter", "hostname", "os", "rack", "region", "service", "service_environment", "service_version", "\xff"})
 }
 
 // TagValues returns an iterator which enumerates the values for the specific
 // tagKey in the given bucket matching the predicate within the
 // time range (start, end].
-func (e *Engine) TagValues(orgID, bucketID influxdb.ID, tagKey string, start, end int64, predicate influxql.Expr) StringIterator {
-	// This method would be invoked when the consumer wants to get the following schema information for an arbitrary
-	// time range in a single bucket:
-	//
-	// * All measurement names, i.e. tagKey == _measurement);
-	// * All field names for a specific measurement using a predicate
-	//     * i.e. tagKey is "_field", predicate _measurement == "<measurement>"
-	//
-	return nullStringIterator
+func (e *Engine) TagValues(ctx context.Context, orgID, bucketID influxdb.ID, tagKey string, start, end int64, predicate influxql.Expr) (cursors.StringIterator, error) {
+	e.mu.RLock()
+	defer e.mu.RUnlock()
+	if e.closing == nil {
+		return cursors.EmptyStringIterator, nil
+	}
+
+	return e.engine.TagValues(ctx, orgID, bucketID, tagKey, start, end, predicate)
 }
-
-var nullStringIterator StringIterator = &emptyStringIterator{}
-
-type emptyStringIterator struct{}
-
-func (*emptyStringIterator) Next() bool    { return false }
-func (*emptyStringIterator) Value() string { return "" }

storage/reads/merge.go

@@ -4,7 +4,6 @@ import (
 	"container/heap"
 
 	"github.com/influxdata/influxdb/models"
-	"github.com/influxdata/influxdb/storage"
 	"github.com/influxdata/influxdb/tsdb/cursors"
 )
 
@@ -123,12 +122,15 @@ func (h *resultSetHeap) Pop() interface{} {
 }
 
 type MergedStringIterator struct {
-	iterators    []storage.StringIterator
+	iterators    []cursors.StringIterator
 	uniqueValues map[string]struct{}
 	nextValue    string
 }
 
-func NewMergedStringIterator(iterators []storage.StringIterator) *MergedStringIterator {
+// API compatibility
+var _ cursors.StringIterator = (*MergedStringIterator)(nil)
+
+func NewMergedStringIterator(iterators []cursors.StringIterator) *MergedStringIterator {
 	return &MergedStringIterator{
 		iterators:    iterators,
 		uniqueValues: make(map[string]struct{}),
@@ -161,3 +163,7 @@ func (mr *MergedStringIterator) Next() bool {
 func (mr *MergedStringIterator) Value() string {
 	return mr.nextValue
 }
+
+func (mr *MergedStringIterator) Stats() cursors.CursorStats {
+	return cursors.CursorStats{}
+}

storage/reads/merge_test.go

@@ -6,9 +6,9 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
-	"github.com/influxdata/influxdb/storage"
 	"github.com/influxdata/influxdb/storage/reads"
 	"github.com/influxdata/influxdb/storage/reads/datatypes"
+	"github.com/influxdata/influxdb/tsdb/cursors"
 )
 
 func newStreamSeries(v ...string) *sliceStreamReader {
@@ -109,19 +109,19 @@ series: _m=m0,tag0=val03
 func TestNewMergedStringIterator(t *testing.T) {
 	tests := []struct {
 		name           string
-		iterators      []storage.StringIterator
+		iterators      []cursors.StringIterator
 		expectedValues []string
 	}{
 		{
 			name: "simple",
-			iterators: []storage.StringIterator{
+			iterators: []cursors.StringIterator{
 				newMockStringIterator("foo", "bar"),
 			},
 			expectedValues: []string{"foo", "bar"},
 		},
 		{
 			name: "duplicates",
-			iterators: []storage.StringIterator{
+			iterators: []cursors.StringIterator{
 				newMockStringIterator("foo"),
 				newMockStringIterator("bar", "bar"),
 				newMockStringIterator("foo"),

storage/reads/store.go

@@ -5,7 +5,6 @@ import (
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/influxdata/influxdb/models"
-	"github.com/influxdata/influxdb/storage"
 	"github.com/influxdata/influxdb/storage/reads/datatypes"
 	"github.com/influxdata/influxdb/tsdb/cursors"
 )
@@ -79,6 +78,6 @@ type Store interface {
 	ReadFilter(ctx context.Context, req *datatypes.ReadFilterRequest) (ResultSet, error)
 	GroupRead(ctx context.Context, req *datatypes.ReadRequest) (GroupResultSet, error)
 	GetSource(orgID, bucketID uint64) proto.Message
-	TagKeys(ctx context.Context, req *datatypes.TagKeysRequest) (storage.StringIterator, error)
-	TagValues(ctx context.Context, req *datatypes.TagValuesRequest) (storage.StringIterator, error)
+	TagKeys(ctx context.Context, req *datatypes.TagKeysRequest) (cursors.StringIterator, error)
+	TagValues(ctx context.Context, req *datatypes.TagValuesRequest) (cursors.StringIterator, error)
 }

storage/reads/string_iterator_reader.go

@@ -2,6 +2,7 @@ package reads
 
 import (
 	"github.com/influxdata/influxdb/storage/reads/datatypes"
+	"github.com/influxdata/influxdb/tsdb/cursors"
 )
 
 type StringValuesStreamReader interface {
@@ -16,6 +17,9 @@ type StringIteratorStreamReader struct {
 	err error
 }
 
+// API compatibility
+var _ cursors.StringIterator = (*StringIteratorStreamReader)(nil)
+
 func NewStringIteratorStreamReader(stream StringValuesStreamReader) *StringIteratorStreamReader {
 	return &StringIteratorStreamReader{
 		stream: stream,
@@ -53,3 +57,7 @@ func (r *StringIteratorStreamReader) Value() string {
 	// Better than panic.
 	return ""
 }
+
+func (r *StringIteratorStreamReader) Stats() cursors.CursorStats {
+	return cursors.CursorStats{}
+}

storage/reads/string_iterator_reader_test.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/influxdata/influxdb/storage/reads"
 	"github.com/influxdata/influxdb/storage/reads/datatypes"
+	"github.com/influxdata/influxdb/tsdb/cursors"
 )
 
 type mockStringIterator struct {
@@ -37,6 +38,10 @@ func (si *mockStringIterator) Value() string {
 	return ""
 }
 
+func (si *mockStringIterator) Stats() cursors.CursorStats {
+	return cursors.CursorStats{}
+}
+
 type mockStringValuesStreamReader struct {
 	responses []*datatypes.StringValuesResponse
 }

storage/reads/string_iterator_writer.go

@@ -1,8 +1,8 @@
 package reads
 
 import (
-	"github.com/influxdata/influxdb/storage"
 	"github.com/influxdata/influxdb/storage/reads/datatypes"
+	"github.com/influxdata/influxdb/tsdb/cursors"
 )
 
 type StringIteratorStream interface {
@@ -37,7 +37,7 @@ func (w *StringIteratorWriter) WrittenN() int {
 	return w.vc
 }
 
-func (w *StringIteratorWriter) WriteStringIterator(si storage.StringIterator) error {
+func (w *StringIteratorWriter) WriteStringIterator(si cursors.StringIterator) error {
 	for si.Next() {
 		v := si.Value()
 		if v == "" {

storage/readservice/store.go

@@ -13,6 +13,7 @@ import (
 	"github.com/influxdata/influxdb/storage"
 	"github.com/influxdata/influxdb/storage/reads"
 	"github.com/influxdata/influxdb/storage/reads/datatypes"
+	"github.com/influxdata/influxdb/tsdb/cursors"
 	"github.com/influxdata/influxql"
 )
 
@@ -133,7 +134,7 @@ func (s *store) GroupRead(ctx context.Context, req *datatypes.ReadRequest) (read
 	return reads.NewGroupResultSet(ctx, req, newCursor), nil
 }
 
-func (s *store) TagKeys(ctx context.Context, req *datatypes.TagKeysRequest) (storage.StringIterator, error) {
+func (s *store) TagKeys(ctx context.Context, req *datatypes.TagKeysRequest) (cursors.StringIterator, error) {
 	span, _ := tracing.StartSpanFromContext(ctx)
 	defer span.Finish()
 
@@ -169,12 +170,12 @@ func (s *store) TagKeys(ctx context.Context, req *datatypes.TagKeysRequest) (sto
 	if err != nil {
 		return nil, err
 	}
-	si := s.engine.TagKeys(influxdb.ID(readSource.OrganizationID), influxdb.ID(readSource.BucketID), req.Range.Start, req.Range.End, expr)
+	si := s.engine.TagKeys(ctx, influxdb.ID(readSource.OrganizationID), influxdb.ID(readSource.BucketID), req.Range.Start, req.Range.End, expr)
 
 	return si, nil
 }
 
-func (s *store) TagValues(ctx context.Context, req *datatypes.TagValuesRequest) (storage.StringIterator, error) {
+func (s *store) TagValues(ctx context.Context, req *datatypes.TagValuesRequest) (cursors.StringIterator, error) {
 	span, _ := tracing.StartSpanFromContext(ctx)
 	defer span.Finish()
 
@@ -214,9 +215,7 @@ func (s *store) TagValues(ctx context.Context, req *datatypes.TagValuesRequest)
 	if err != nil {
 		return nil, err
 	}
-	si := s.engine.TagValues(influxdb.ID(readSource.OrganizationID), influxdb.ID(readSource.BucketID), req.TagKey, req.Range.Start, req.Range.End, expr)
-
-	return si, nil
+	return s.engine.TagValues(ctx, influxdb.ID(readSource.OrganizationID), influxdb.ID(readSource.BucketID), req.TagKey, req.Range.Start, req.Range.End, expr)
 }
 
 // this is easier than fooling around with .proto files.

tsdb/cursor.go

@@ -7,11 +7,12 @@ import "github.com/influxdata/influxdb/tsdb/cursors"
 // talk about consuming data.
 
 type (
-	IntegerArray  = cursors.IntegerArray
-	FloatArray    = cursors.FloatArray
-	UnsignedArray = cursors.UnsignedArray
-	StringArray   = cursors.StringArray
-	BooleanArray  = cursors.BooleanArray
+	IntegerArray   = cursors.IntegerArray
+	FloatArray     = cursors.FloatArray
+	UnsignedArray  = cursors.UnsignedArray
+	StringArray    = cursors.StringArray
+	BooleanArray   = cursors.BooleanArray
+	TimestampArray = cursors.TimestampArray
 
 	IntegerArrayCursor  = cursors.IntegerArrayCursor
 	FloatArrayCursor    = cursors.FloatArrayCursor