Merge pull request #153 from ClickHouse/fix/proto-enum-and-low-cardin…

…ality-idempotent-prepare fix(proto): make Prepare for ColEnum and ColLowCardinality[T] idempotent
ClickHouse · Jul 8, 2022 · c39560e · c39560e
2 parents 4a4267f + 2eb44c7
commit c39560e
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Showing 3 changed files with 5 additions and 10 deletions.
diff --git a/otel_test.go b/otel_test.go
@@ -24,7 +24,7 @@ func (m MapPair[V]) Append(k []string, v []V) {
 
 func NewMapPair[X comparable](v proto.ColumnOf[X]) MapPair[X] {
 	return MapPair[X]{
-		Keys:   new(proto.ColStr).Array(),
+		Keys:   new(proto.ColStr).LowCardinality().Array(),
 		Values: proto.NewArray(v),
 	}
 }
@@ -169,12 +169,6 @@ func BenchmarkOTEL(b *testing.B) {
 			buf.Reset()
 			buf.PutString("")
 
-			// Important!
-			// Simulating "Reset" to new values.
-			v := data.SevText.Values
-			data.SevText.Reset()
-			data.SevText.Values = v
-
 			if err := block.EncodeBlock(buf, proto.Version, input); err != nil {
 				b.Fatal(err)
 			}

diff --git a/proto/col_enum.go b/proto/col_enum.go
@@ -142,9 +142,8 @@ func (e *ColEnum) Reset() {
 }
 
 func (e *ColEnum) Prepare() error {
-	if e.raw().Rows() != 0 {
-		return errors.New("already prepared")
-	}
+	e.raw8 = e.raw8[:0]
+	e.raw16 = e.raw16[:0]
 	for _, v := range e.Values {
 		raw, ok := e.strToRaw[v]
 		if !ok {

diff --git a/proto/col_low_cardinality.go b/proto/col_low_cardinality.go
@@ -91,6 +91,7 @@ const sharedDictionariesWithAdditionalKeys keySerializationVersion = 1
 //
 // For example, ["Eko", "Eko", "Amadela", "Amadela", "Amadela", "Amadela"] can
 // be encoded as:
+//
 //	Index: ["Eko", "Amadela"] (String)
 //	Keys:  [0, 0, 1, 1, 1, 1] (UInt8)
 //
@@ -249,6 +250,7 @@ type cardinalityKeyValue interface {
 }
 
 func fillKeys[K cardinalityKeyValue](values []int, keys []K) []K {
+	keys = keys[:0]
 	for _, v := range values {
 		keys = append(keys, K(v))
 	}