Removed chunk.metadataInIndex because unused (#1836)

Signed-off-by: Marco Pracucci <[email protected]>

Author: pracucci

pkg/chunk/chunk.go

@@ -57,10 +57,6 @@ type Chunk struct {
 	Encoding prom_chunk.Encoding `json:"encoding"`
 	Data     prom_chunk.Chunk    `json:"-"`
 
-	// This flag is used for very old chunks, where the metadata is read out
-	// of the index.
-	metadataInIndex bool
-
 	// The encoded version of the chunk, held so we don't need to re-encode it
 	encoded []byte
 }
@@ -258,17 +254,6 @@ func NewDecodeContext() *DecodeContext {
 // Decode the chunk from the given buffer, and confirm the chunk is the one we
 // expected.
 func (c *Chunk) Decode(decodeContext *DecodeContext, input []byte) error {
-	// Legacy chunks were written with metadata in the index.
-	if c.metadataInIndex {
-		var err error
-		c.Data, err = prom_chunk.NewForEncoding(prom_chunk.DoubleDelta)
-		if err != nil {
-			return err
-		}
-		c.encoded = input
-		return errors.Wrap(c.Data.UnmarshalFromBuf(input), "when unmarshalling legacy chunk")
-	}
-
 	// First, calculate the checksum of the chunk and confirm it matches
 	// what we expected.
 	if c.ChecksumSet && c.Checksum != crc32.Checksum(input, castagnoliTable) {

pkg/chunk/chunk_store.go

@@ -206,7 +206,7 @@ func (c *store) LabelValuesForMetricName(ctx context.Context, userID string, fro
 
 	var result UniqueStrings
 	for _, entry := range entries {
-		_, labelValue, _, _, err := parseChunkTimeRangeValue(entry.RangeValue, entry.Value)
+		_, labelValue, _, err := parseChunkTimeRangeValue(entry.RangeValue, entry.Value)
 		if err != nil {
 			return nil, err
 		}
@@ -461,7 +461,7 @@ func (c *store) lookupEntriesByQueries(ctx context.Context, queries []IndexQuery
 func (c *store) parseIndexEntries(ctx context.Context, entries []IndexEntry, matcher *labels.Matcher) ([]string, error) {
 	result := make([]string, 0, len(entries))
 	for _, entry := range entries {
-		chunkKey, labelValue, _, _, err := parseChunkTimeRangeValue(entry.RangeValue, entry.Value)
+		chunkKey, labelValue, _, err := parseChunkTimeRangeValue(entry.RangeValue, entry.Value)
 		if err != nil {
 			return nil, err
 		}

pkg/chunk/schema_test.go

@@ -325,7 +325,7 @@ func TestSchemaRangeKey(t *testing.T) {
 					_, err := parseMetricNameRangeValue(entry.RangeValue, entry.Value)
 					require.NoError(t, err)
 				case ChunkTimeRangeValue:
-					_, _, _, _, err := parseChunkTimeRangeValue(entry.RangeValue, entry.Value)
+					_, _, _, err := parseChunkTimeRangeValue(entry.RangeValue, entry.Value)
 					require.NoError(t, err)
 				case SeriesRangeValue:
 					_, err := parseSeriesRangeValue(entry.RangeValue, entry.Value)

pkg/chunk/schema_util.go

@@ -164,11 +164,10 @@ func parseSeriesRangeValue(rangeValue []byte, value []byte) (model.Metric, error
 	}
 }
 
-// parseChunkTimeRangeValue returns the chunkKey, labelValue and metadataInIndex
-// for chunk time range values.
+// parseChunkTimeRangeValue returns the chunkID and labelValue for chunk time
+// range values.
 func parseChunkTimeRangeValue(rangeValue []byte, value []byte) (
-	chunkID string, labelValue model.LabelValue, metadataInIndex bool,
-	isSeriesID bool, err error,
+	chunkID string, labelValue model.LabelValue, isSeriesID bool, err error,
 ) {
 	components := decodeRangeKey(rangeValue)
 
@@ -182,7 +181,6 @@ func parseChunkTimeRangeValue(rangeValue []byte, value []byte) (
 	case len(components) == 3:
 		chunkID = string(components[2])
 		labelValue = model.LabelValue(components[1])
-		metadataInIndex = true
 		return
 
 	// v3 schema had four components - label name, label value, chunk ID and version.

pkg/chunk/schema_util_test.go

@@ -92,7 +92,7 @@ func TestParseChunkTimeRangeValue(t *testing.T) {
 		{[]byte("a1b2c3d4\x00Y29kZQ\x002:1484661279394:1484664879394\x004\x00"),
 			"code", "2:1484661279394:1484664879394"},
 	} {
-		chunkID, labelValue, _, _, err := parseChunkTimeRangeValue(c.encoded, nil)
+		chunkID, labelValue, _, err := parseChunkTimeRangeValue(c.encoded, nil)
 		require.NoError(t, err)
 		assert.Equal(t, model.LabelValue(c.value), labelValue)
 		assert.Equal(t, c.chunkID, chunkID)