keys: pretty print WAG node keys

Epic: none
Release note: none

Author: pav-kv

pkg/keys/keys.go

@@ -150,6 +150,22 @@ func StoreWAGNodeKey(index uint64) roachpb.Key {
 	return MakeStoreKey(localStoreWAGNodeSuffix, encoding.EncodeUint64Ascending(nil, index))
 }
 
+// DecodeWAGNodeKey returns the index of the WAG node from its key.
+func DecodeWAGNodeKey(key roachpb.Key) (uint64, error) {
+	suffix, detail, err := DecodeStoreKey(key)
+	if err != nil {
+		return 0, err
+	}
+	if !suffix.Equal(localStoreWAGNodeSuffix) {
+		return 0, errors.Errorf("key with suffix %q != %q", suffix, localStoreWAGNodeSuffix)
+	}
+	detail, index, err := encoding.DecodeUint64Ascending(detail)
+	if len(detail) != 0 {
+		return 0, errors.Errorf("invalid key has trailing garbage: %q", detail)
+	}
+	return index, err
+}
+
 // StoreCachedSettingsKey returns a store-local key for store's cached settings.
 func StoreCachedSettingsKey(settingKey roachpb.Key) roachpb.Key {
 	return MakeStoreKey(localStoreCachedSettingsSuffix, encoding.EncodeBytesAscending(nil, settingKey))

pkg/keys/printer.go

@@ -146,6 +146,7 @@ var constSubKeyDict = []struct {
 	{"/clusterVersion", localStoreClusterVersionSuffix},
 	{"/nodeTombstone", localStoreNodeTombstoneSuffix},
 	{"/cachedSettings", localStoreCachedSettingsSuffix},
+	{"/wag", localStoreWAGNodeSuffix},
 	{"/lossOfQuorumRecovery/applied", localStoreUnsafeReplicaRecoverySuffix},
 	{"/lossOfQuorumRecovery/status", localStoreLossOfQuorumRecoveryStatusSuffix},
 	{"/lossOfQuorumRecovery/cleanup", localStoreLossOfQuorumRecoveryCleanupActionsSuffix},
@@ -167,10 +168,19 @@ func cachedSettingsKeyPrint(buf *redact.StringBuilder, key roachpb.Key) {
 	buf.Print(settingKey.String())
 }
 
+func wagNodeKeyPrint(buf *redact.StringBuilder, key roachpb.Key) {
+	index, err := DecodeWAGNodeKey(key)
+	if err != nil {
+		buf.Printf("<invalid: %s>", err)
+	}
+	buf.Printf("%d", index)
+}
+
 func localStoreKeyPrint(buf *redact.StringBuilder, _ []encoding.Direction, key roachpb.Key) {
 	for _, v := range constSubKeyDict {
 		if bytes.HasPrefix(key, v.key) {
 			buf.Print(v.name)
+			// TODO(pav-kv): make this switch more efficient with a lookup.
 			if v.key.Equal(localStoreNodeTombstoneSuffix) {
 				buf.SafeRune('/')
 				nodeTombstoneKeyPrint(
@@ -186,6 +196,9 @@ func localStoreKeyPrint(buf *redact.StringBuilder, _ []encoding.Direction, key r
 				lossOfQuorumRecoveryEntryKeyPrint(
 					buf, append(roachpb.Key(nil), append(LocalStorePrefix, key...)...),
 				)
+			} else if v.key.Equal(localStoreWAGNodeSuffix) {
+				buf.SafeRune('/')
+				wagNodeKeyPrint(buf, append(append(roachpb.Key(nil), LocalStorePrefix...), key...))
 			}
 			return
 		}

pkg/kv/kvserver/kvstorage/wag/testdata/TestWrite.txt

@@ -1,9 +1,9 @@
 echo
 ----
 >> create
-Put: 0,0 /Local/Store"wagn\x00\x00\x00\x00\x00\x00\x00\x01" (0x01737761676e000000000000000100): "\n\x04\b{\x10\x04\x10\x01\x1a(\n&\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x01\x12state-machine-key\x00\x05state"
+Put: 0,0 /Local/Store/wag/1 (0x01737761676e000000000000000100): "\n\x04\b{\x10\x04\x10\x01\x1a(\n&\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x01\x12state-machine-key\x00\x05state"
 >> init
-Put: 0,0 /Local/Store"wagn\x00\x00\x00\x00\x00\x00\x00\x02" (0x01737761676e000000000000000200): "\n\x06\b{\x10\x04 \n\x10\x02\x1a\x18\x12\x16\n\ttmp/1.sst\n\ttmp/2.sst"
+Put: 0,0 /Local/Store/wag/2 (0x01737761676e000000000000000200): "\n\x06\b{\x10\x04 \n\x10\x02\x1a\x18\x12\x16\n\ttmp/1.sst\n\ttmp/2.sst"
 >> split
-Put: 0,0 /Local/Store"wagn\x00\x00\x00\x00\x00\x00\x00\x03" (0x01737761676e000000000000000300): "\n\a\b{\x10\x04 \xc7\x01\x10\x03\x1a\x00"
-Put: 0,0 /Local/Store"wagn\x00\x00\x00\x00\x00\x00\x00\x04" (0x01737761676e000000000000000400): "\n\a\b{\x10\x04 \xc8\x01\x10\x04\x1a6\n4\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x01\blhs-key\x00\tlhs-state\x01\brhs-key\x00\trhs-state \xb7\x04"
+Put: 0,0 /Local/Store/wag/3 (0x01737761676e000000000000000300): "\n\a\b{\x10\x04 \xc7\x01\x10\x03\x1a\x00"
+Put: 0,0 /Local/Store/wag/4 (0x01737761676e000000000000000400): "\n\a\b{\x10\x04 \xc8\x01\x10\x04\x1a6\n4\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x01\blhs-key\x00\tlhs-state\x01\brhs-key\x00\trhs-state \xb7\x04"