make projection a pointer

Signed-off-by: yeya24 <[email protected]>

Author: yeya24

logicalplan/logical_nodes.go

@@ -73,7 +73,7 @@ type VectorSelector struct {
 	Filters         []*labels.Matcher
 	BatchSize       int64
 	SelectTimestamp bool
-	Projection      Projection
+	Projection      *Projection
 	// When set, histogram iterators can return objects which only have their
 	// CounterResetHint, Count and Sum values populated. Histogram buckets and spans
 	// will not be used during query evaluation.
@@ -87,8 +87,11 @@ func (f *VectorSelector) Clone() Node {
 
 	clone.Filters = shallowCloneSlice(f.Filters)
 	clone.LabelMatchers = shallowCloneSlice(f.LabelMatchers)
-	clone.Projection.Labels = shallowCloneSlice(f.Projection.Labels)
-	clone.Projection.Include = f.Projection.Include
+	if f.Projection != nil {
+		clone.Projection = &Projection{}
+		clone.Projection.Labels = shallowCloneSlice(f.Projection.Labels)
+		clone.Projection.Include = f.Projection.Include
+	}
 
 	if f.VectorSelector.Timestamp != nil {
 		ts := *f.VectorSelector.Timestamp

logicalplan/plan_test.go

@@ -40,12 +40,14 @@ func renderExprTree(expr Node) string {
 		if t.BatchSize > 0 {
 			base += fmt.Sprintf("[batch=%d]", t.BatchSize)
 		}
-		if t.Projection.Labels != nil {
-			sort.Strings(t.Projection.Labels)
-			if t.Projection.Include {
-				base += fmt.Sprintf("[projection=include(%s)]", strings.Join(t.Projection.Labels, ","))
-			} else {
-				base += fmt.Sprintf("[projection=exclude(%s)]", strings.Join(t.Projection.Labels, ","))
+		if t.Projection != nil {
+			if t.Projection.Labels != nil {
+				sort.Strings(t.Projection.Labels)
+				if t.Projection.Include {
+					base += fmt.Sprintf("[projection=include(%s)]", strings.Join(t.Projection.Labels, ","))
+				} else {
+					base += fmt.Sprintf("[projection=exclude(%s)]", strings.Join(t.Projection.Labels, ","))
+				}
 			}
 		}
 		if len(t.Filters) > 0 {

logicalplan/projection_pushdown.go

@@ -23,14 +23,17 @@ func (p ProjectionPushdown) pushProjection(node *Node, requiredLabels map[string
 	case *VectorSelector:
 		// Apply projection if we have required labels
 		if requiredLabels != nil {
-			projection := Projection{
+			projection := &Projection{
 				Labels:  make([]string, 0, len(requiredLabels)),
 				Include: !isWithout,
 			}
 			for lbl := range requiredLabels {
 				projection.Labels = append(projection.Labels, lbl)
 			}
 			n.Projection = projection
+		} else {
+			// Set dummy projection.
+			n.Projection = &Projection{}
 		}
 
 	case *Aggregation:

storage/prometheus/scanners.go

@@ -54,8 +54,10 @@ func (p Scanners) NewVectorSelector(
 	logicalNode logicalplan.VectorSelector,
 ) (model.VectorOperator, error) {
 	// Update hints with projection information if available
-	hints.Grouping = logicalNode.Projection.Labels
-	hints.By = logicalNode.Projection.Include
+	if logicalNode.Projection != nil {
+		hints.Grouping = logicalNode.Projection.Labels
+		hints.By = logicalNode.Projection.Include
+	}
 
 	selector := p.selectors.GetFilteredSelector(hints.Start, hints.End, opts.Step.Milliseconds(), logicalNode.VectorSelector.LabelMatchers, logicalNode.Filters, hints)
 	if logicalNode.DecodeNativeHistogramStats {
@@ -125,8 +127,10 @@ func (p Scanners) NewMatrixSelector(
 	}
 
 	vs := logicalNode.VectorSelector
-	hints.Grouping = vs.Projection.Labels
-	hints.By = vs.Projection.Include
+	if vs.Projection != nil {
+		hints.Grouping = vs.Projection.Labels
+		hints.By = vs.Projection.Include
+	}
 
 	selector := p.selectors.GetFilteredSelector(hints.Start, hints.End, opts.Step.Milliseconds(), vs.LabelMatchers, vs.Filters, hints)
 	if logicalNode.VectorSelector.DecodeNativeHistogramStats {