metamorphic: add CockroachKeyFormat

Add a new KeyFormat that uses the cockroach encoding of KV pairs in the
metamorphic test, expanding test coverage to cover the cockroachkvs package.

Fixes cockroachdb#4167.

cockroachkvs/cockroachkvs.go

@@ -196,6 +196,26 @@ func EncodeTimestamp(key []byte, walltime uint64, logical uint32) []byte {
 	return key
 }
 
+// NewTimestampSuffix allocates and encodes a new suffix byte slice encoding the
+// provided timestamp.
+func NewTimestampSuffix(wallTime uint64, logical uint32) []byte {
+	switch {
+	case wallTime == 0 && logical == 0:
+		return nil
+	case logical == 0:
+		v := make([]byte, suffixLenWithWall)
+		binary.BigEndian.PutUint64(v, wallTime)
+		v[suffixLenWithWall-1] = suffixLenWithWall
+		return v
+	default:
+		v := make([]byte, suffixLenWithLogical)
+		binary.BigEndian.PutUint64(v, wallTime)
+		binary.BigEndian.PutUint32(v[8:], logical)
+		v[suffixLenWithLogical-1] = suffixLenWithLogical
+		return v
+	}
+}
+
 // DecodeMVCCTimestampSuffix decodes an MVCC timestamp from its Pebble representation,
 // including the length suffix.
 func DecodeMVCCTimestampSuffix(encodedTS []byte) (wallTime uint64, logical uint32, err error) {
@@ -1059,6 +1079,11 @@ func (fk formatKey) Format(f fmt.State, c rune) {
 	formatKeySuffix(fk[i:]).Format(f, c)
 }
 
+// FormatKeySuffix returns a formatter for the user key suffix.
+func FormatKeySuffix(suffix []byte) fmt.Formatter {
+	return formatKeySuffix(suffix)
+}
+
 type formatKeySuffix []byte
 
 func (fk formatKeySuffix) Format(f fmt.State, c rune) {

internal/metamorphic/meta_test.go

@@ -51,19 +51,28 @@ var runOnceFlags, runFlags = metaflags.InitAllFlags()
 // be customized via the --inner-binary flag (used for code coverage
 // instrumentation).
 func TestMeta(t *testing.T) {
-	runTestMeta(t, false /* multiInstance */)
+	runTestMeta(t)
 }
 
 func TestMetaTwoInstance(t *testing.T) {
-	runTestMeta(t, true /* multiInstance */)
+	runTestMeta(t, metamorphic.MultiInstance(2))
 }
 
-func runTestMeta(t *testing.T, multiInstance bool) {
+func TestMetaCockroachKVs(t *testing.T) {
+	runTestMeta(t, metamorphic.CockroachKeyFormat)
+}
+
+type option interface {
+	metamorphic.RunOnceOption
+	metamorphic.RunOption
+}
+
+func runTestMeta(t *testing.T, addtlOptions ...option) {
 	switch {
 	case runOnceFlags.Compare != "":
 		onceOpts := runOnceFlags.MakeRunOnceOptions()
-		if multiInstance {
-			onceOpts = append(onceOpts, metamorphic.MultiInstance(2))
+		for _, opt := range addtlOptions {
+			onceOpts = append(onceOpts, opt)
 		}
 		testRootDir, runSubdirs := runOnceFlags.ParseCompare()
 		if runOnceFlags.TryToReduce {
@@ -78,8 +87,8 @@ func runTestMeta(t *testing.T, multiInstance bool) {
 		// runOptions() below) or the user specified it manually in order to re-run
 		// a test.
 		onceOpts := runOnceFlags.MakeRunOnceOptions()
-		if multiInstance {
-			onceOpts = append(onceOpts, metamorphic.MultiInstance(2))
+		for _, opt := range addtlOptions {
+			onceOpts = append(onceOpts, opt)
 		}
 		if runOnceFlags.TryToReduce {
 			tryToReduce(t, runOnceFlags.Dir, runOnceFlags.RunDir, runOnceFlags.ReduceAttempts)
@@ -90,8 +99,8 @@ func runTestMeta(t *testing.T, multiInstance bool) {
 
 	default:
 		opts := runFlags.MakeRunOptions()
-		if multiInstance {
-			opts = append(opts, metamorphic.MultiInstance(2))
+		for _, opt := range addtlOptions {
+			opts = append(opts, opt)
 		}
 		metamorphic.RunAndCompare(t, runFlags.Dir, opts...)
 	}

internal/metamorphic/metaflags/meta_flags.go

@@ -60,7 +60,8 @@ func (c *CommonFlags) KeyFormat() metamorphic.KeyFormat {
 
 // KeyFormats is a map of available key formats.
 var KeyFormats = map[string]metamorphic.KeyFormat{
-	"testkeys": metamorphic.TestkeysKeyFormat,
+	"testkeys":     metamorphic.TestkeysKeyFormat,
+	"cockroachkvs": metamorphic.CockroachKeyFormat,
 }
 
 func initCommonFlags() *CommonFlags {