byteswith output unaffected by buffer

grafana · Oct 27, 2020 · 7ec0fb0 · 7ec0fb0
1 parent 48fa77f
commit 7ec0fb0
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Showing 3 changed files with 14 additions and 1 deletion.
diff --git a/pkg/chunkenc/memchunk.go b/pkg/chunkenc/memchunk.go
@@ -252,7 +252,7 @@ func (c *MemChunk) BytesWith(b []byte) ([]byte, error) {
 	}
 	crc32Hash := newCRC32()
 
-	buf := bytes.NewBuffer(b)
+	buf := bytes.NewBuffer(b[:0])
 	offset := 0
 
 	eb := encbuf{b: make([]byte, 0, 1<<10)}

diff --git a/pkg/chunkenc/memchunk_test.go b/pkg/chunkenc/memchunk_test.go
@@ -767,3 +767,13 @@ func TestMemchunkLongLine(t *testing.T) {
 		})
 	}
 }
+
+// Ensure passing a reusable []byte doesn't affect output
+func TestBytesWith(t *testing.T) {
+	exp, err := NewMemChunk(EncNone, testBlockSize, testTargetSize).BytesWith(nil)
+	require.Nil(t, err)
+	out, err := NewMemChunk(EncNone, testBlockSize, testTargetSize).BytesWith([]byte{1, 2, 3})
+	require.Nil(t, err)
+
+	require.Equal(t, exp, out)
+}
diff --git a/pkg/ingester/checkpoint.pb.go b/pkg/ingester/checkpoint.pb.go