Added bson encode and decode functions for KeyRange Arrays.

go/vt/key/key.go

@@ -164,6 +164,17 @@ func (kr *KeyRange) MarshalBson(buf *bytes2.ChunkedWriter) {
 	lenWriter.RecordLen()
 }
 
+func EncodeKeyRanges(buf *bytes2.ChunkedWriter, keyName string, keyranges []KeyRange) {
+	bson.EncodePrefix(buf, bson.Array, keyName)
+	lenWriter := bson.NewLenWriter(buf)
+	for i, kr := range keyranges {
+		bson.EncodePrefix(buf, bson.Object, bson.Itoa(i))
+		kr.MarshalBson(buf)
+	}
+	buf.WriteByte(0)
+	lenWriter.RecordLen()
+}
+
 func (kr *KeyRange) UnmarshalBson(buf *bytes.Buffer) {
 	bson.Next(buf, 4)
 
@@ -182,6 +193,29 @@ func (kr *KeyRange) UnmarshalBson(buf *bytes.Buffer) {
 	}
 }
 
+func DecodeKeyRanges(buf *bytes.Buffer, kind byte) (keyranges []KeyRange) {
+	switch kind {
+	case bson.Array:
+		// valid
+	case bson.Null:
+		return nil
+	default:
+		panic(bson.NewBsonError("Unexpected data type %v for Keyranges", kind))
+	}
+
+	bson.Next(buf, 4)
+	keyranges = make([]KeyRange, 0, 10)
+	kind = bson.NextByte(buf)
+	var kr KeyRange
+	for i := 0; kind != bson.EOO; i++ {
+		bson.ExpectIndex(buf, i)
+		kr.UnmarshalBson(buf)
+		keyranges = append(keyranges, kr)
+		kind = bson.NextByte(buf)
+	}
+	return keyranges
+}
+
 // KeyRangesIntersect returns true if some Keyspace values exist in both ranges.
 //
 // See: http://stackoverflow.com/questions/4879315/what-is-a-tidy-algorithm-to-find-overlapping-intervals