chain: define "extractSpecificTimeKey"

Signed-off-by: Gyuho Lee <[email protected]>

Author: gyuho

chain/storage.go

@@ -96,17 +96,6 @@ func PrefixValueKey(rprefix ids.ShortID, key []byte) (k []byte) {
 	return k
 }
 
-// [expiry/pruningPrefix] + [delimiter] + [timestamp] + [delimiter] + [rawPrefix]
-func specificTimeKey(p byte, t int64, rprefix ids.ShortID) (k []byte) {
-	k = make([]byte, 2+8+1+shortIDLen)
-	k[0] = p
-	k[1] = parser.Delimiter
-	binary.LittleEndian.PutUint64(k[2:], uint64(t))
-	k[2+8] = parser.Delimiter
-	copy(k[2+8+1:], rprefix[:])
-	return k
-}
-
 // [expiry/pruningPrefix] + [delimiter] + [timestamp] + [delimiter]
 func RangeTimeKey(p byte, t int64) (k []byte) {
 	k = make([]byte, 2+8+1)
@@ -127,6 +116,31 @@ func PrefixPruningKey(expired int64, rprefix ids.ShortID) (k []byte) {
 	return specificTimeKey(pruningPrefix, expired, rprefix)
 }
 
+const specificTimeKeyLen = 2 + 8 + 1 + shortIDLen
+
+// [expiry/pruningPrefix] + [delimiter] + [timestamp] + [delimiter] + [rawPrefix]
+func specificTimeKey(p byte, t int64, rprefix ids.ShortID) (k []byte) {
+	k = make([]byte, specificTimeKeyLen)
+	k[0] = p
+	k[1] = parser.Delimiter
+	binary.LittleEndian.PutUint64(k[2:], uint64(t))
+	k[2+8] = parser.Delimiter
+	copy(k[2+8+1:], rprefix[:])
+	return k
+}
+
+var ErrInvalidKeyFormat = errors.New("invalid key format")
+
+// extracts expiry/pruning timstamp and raw prefix
+func extractSpecificTimeKey(k []byte) (timestamp int64, rprefix ids.ShortID, err error) {
+	if len(k) != specificTimeKeyLen {
+		return -1, ids.ShortEmpty, ErrInvalidKeyFormat
+	}
+	timestamp = int64(binary.LittleEndian.Uint64(k[2 : 2+8]))
+	rprefix, err = ids.ToShortID(k[2+8+1:])
+	return timestamp, rprefix, err
+}
+
 func GetPrefixInfo(db database.KeyValueReader, prefix []byte) (*PrefixInfo, bool, error) {
 	// TODO: add caching (will need some expiry when keys cleared)
 	// [infoPrefix] + [delimiter] + [prefix]
@@ -215,8 +229,7 @@ func ExpireNext(db database.Database, parent int64, current int64) (err error) {
 		if err := db.Delete(k); err != nil {
 			return err
 		}
-		expired := int64(binary.LittleEndian.Uint64(curKey[2 : 2+8]))
-		rpfx, err := ids.ToShortID(curKey[2+8+1:])
+		expired, rpfx, err := extractSpecificTimeKey(curKey)
 		if err != nil {
 			return err
 		}
@@ -246,7 +259,7 @@ func PruneNext(db database.Database, limit int) (err error) {
 		if bytes.Compare(curKey, endKey) > 0 { // curKey > endKey; end search
 			break
 		}
-		rpfx, err := ids.ToShortID(curKey[2+8+1:])
+		_, rpfx, err := extractSpecificTimeKey(curKey)
 		if err != nil {
 			return err
 		}

chain/storage_test.go

@@ -277,3 +277,22 @@ func TestRange(t *testing.T) {
 		}
 	}
 }
+
+func TestSpecificTimeKey(t *testing.T) {
+	rpfx0 := ids.ShortID{'k'}
+	k := PrefixExpiryKey(100, rpfx0)
+	ts, rpfx, err := extractSpecificTimeKey(k)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ts != 100 {
+		t.Fatalf("unexpected timestamp %d, expected 100", ts)
+	}
+	if rpfx != rpfx0 {
+		t.Fatalf("unexpected rawPrefix %v, expected %v", rpfx, rpfx0)
+	}
+
+	if _, _, err = extractSpecificTimeKey(k[:10]); !errors.Is(err, ErrInvalidKeyFormat) {
+		t.Fatalf("unexpected error %v, expected %v", err, ErrInvalidKeyFormat)
+	}
+}