[common] Extract some key encoding / decoding into separate module.

sources/lib/common/keys.go

@@ -0,0 +1,120 @@
+
+
+package common
+
+
+import "encoding/binary"
+import "fmt"
+
+
+
+
+func PrepareKeyToString (_namespace string, _key uint64) (string, error) {
+	if _key_0, _error := PrepareKey (_namespace, _key); _error == nil {
+		return EncodeKeyToString (_namespace, _key_0)
+	} else {
+		return "", _error
+	}
+}
+
+
+
+
+func EncodeKeyToString (_namespace string, _key uint64) (string, error) {
+	var _buffer [8]byte
+	if _error := EncodeKeyToBytes_0 (_namespace, _key, _buffer[:]); _error == nil {
+		return string (_buffer[:]), nil
+	} else {
+		return "", _error
+	}
+}
+
+
+func EncodeKeyToBytes (_namespace string, _key uint64) ([]byte, error) {
+	_buffer := make ([]byte, 8)
+	_error := EncodeKeyToBytes_0 (_namespace, _key, _buffer)
+	return _buffer, _error
+}
+
+
+func EncodeKeyToBytes_0 (_namespace string, _key uint64, _buffer []byte) (error) {
+	if len (_buffer) != 8 {
+		return fmt.Errorf ("[890eef13]  invalid key buffer length!")
+	}
+	_prefix := keyNamespacePrefix (_namespace)
+	if _prefix == 0 {
+		return fmt.Errorf ("[feece73b]  invalid key namespace `%s`!", _namespace)
+	}
+	if (_key << 8) == 0 {
+		return fmt.Errorf ("[c8fa7817]  invalid key zero!")
+	}
+	_keyPrefix := byte (_key >> 56)
+	if _keyPrefix != _prefix {
+		return fmt.Errorf ("[85a5c362]  invalid key prefix `%0x` for `%d`!", _key, _keyPrefix)
+	}
+	binary.BigEndian.PutUint64 (_buffer, _key)
+	return nil
+}
+
+
+
+
+func PrepareKey (_namespace string, _key uint64) (uint64, error) {
+	if _key == 0 {
+		return 0, fmt.Errorf ("[355f64d0]  invalid key zero!")
+	}
+	if _key >= (1 << 24) {
+		return 0, fmt.Errorf ("[aba09b4d]  invalid key value `%d`!", _key)
+	}
+	_prefix := keyNamespacePrefix (_namespace)
+	if _prefix == 0 {
+		return 0, fmt.Errorf ("[feece73b]  invalid key namespace `%s`!", _namespace)
+	}
+	_keyString := fmt.Sprintf ("%08x", _key)
+	_keyBytes := []byte (_keyString)
+	_keyBytes[0] = _prefix
+	_keyValue := binary.BigEndian.Uint64 (_keyBytes)
+	return _keyValue, nil
+}
+
+
+
+
+func keyNamespacePrefix (_namespace string) (byte) {
+	switch _namespace {
+		case NamespaceFilesContent : return 'f'
+		case NamespaceFilesIndex : return 'F'
+		case NamespaceFoldersContent : return 'l'
+		case NamespaceFoldersIndex : return 'L'
+		case NamespaceDataContent : return 'd'
+		case NamespaceDataMetadata : return 'm'
+		default : return '0'
+	}
+}
+
+
+
+
+func EncodeKeysPairToString (_namespace1 string, _key1 uint64, _namespace2 string, _key2 uint64) (string, error) {
+	var _buffer [16]byte
+	if _error := EncodeKeyToBytes_0 (_namespace1, _key1, _buffer[0:8]); _error != nil {
+		return "", _error
+	}
+	if _error := EncodeKeyToBytes_0 (_namespace2, _key2, _buffer[8:16]); _error != nil {
+		return "", _error
+	}
+	return string (_buffer[:]), nil
+}
+
+
+
+
+func DecodeKeysPair (_buffer []byte) (uint64, uint64, error) {
+	if len (_buffer) != 16 {
+		return 0, 0, fmt.Errorf ("[dd6ba461]  invalid key buffer length!")
+	}
+	_key1 := binary.BigEndian.Uint64 (_buffer[0:8])
+	_key2 := binary.BigEndian.Uint64 (_buffer[8:16])
+	return _key1, _key2, nil
+}
+

sources/lib/common/namespaces.go

@@ -5,14 +5,14 @@ package common
 
 
 
-const NamespaceSchemaVersion = "s"
+const NamespaceSchemaVersion = "schema"
-const CurrentSchemaVersion = "2021a"
+const CurrentSchemaVersion = "kawipiko-2021b"
 
-const NamespaceFilesContent = "f"
+const NamespaceFilesContent = "files-content"
-const NamespaceFilesIndex = "fi"
+const NamespaceFilesIndex = "files-index"
-const NamespaceFoldersContent = "l"
+const NamespaceFoldersContent = "folders-content"
-const NamespaceFoldersIndex = "li"
+const NamespaceFoldersIndex = "folders-index"
 
-const NamespaceDataContent = "c"
+const NamespaceDataContent = "resource-data"
-const NamespaceDataMetadata = "m"
+const NamespaceDataMetadata = "resource-metadata"