Add pgx.Oid serialization

conn.go

@@ -471,7 +471,7 @@ func (c *Conn) sendPreparedQuery(ps *PreparedStatement, arguments ...interface{}
 			wbuf.WriteInt16(TextFormatCode)
 		default:
 			switch oid {
-			case BoolOid, ByteaOid, Int2Oid, Int4Oid, Int8Oid, Float4Oid, Float8Oid, TimestampTzOid, Int2ArrayOid, Int4ArrayOid, Int8ArrayOid, Float4ArrayOid, Float8ArrayOid, TextArrayOid, VarcharArrayOid:
+			case BoolOid, ByteaOid, Int2Oid, Int4Oid, Int8Oid, Float4Oid, Float8Oid, TimestampTzOid, Int2ArrayOid, Int4ArrayOid, Int8ArrayOid, Float4ArrayOid, Float8ArrayOid, TextArrayOid, VarcharArrayOid, OidOid:
 				wbuf.WriteInt16(BinaryFormatCode)
 			default:
 				wbuf.WriteInt16(TextFormatCode)
@@ -529,6 +529,8 @@ func (c *Conn) sendPreparedQuery(ps *PreparedStatement, arguments ...interface{}
 				err = encodeTextArray(wbuf, arguments[i], TextOid)
 			case VarcharArrayOid:
 				err = encodeTextArray(wbuf, arguments[i], VarcharOid)
+			case OidOid:
+				err = encodeOid(wbuf, arguments[i])
 			default:
 				return SerializationError(fmt.Sprintf("Cannot encode %T into oid %v - %T must implement Encoder or be converted to a string", arg, oid, arg))
 			}

query.go

@@ -208,6 +208,8 @@ func (rows *Rows) Scan(dest ...interface{}) (err error) {
 			*d = decodeInt2(vr)
 		case *int32:
 			*d = decodeInt4(vr)
+		case *Oid:
+			*d = decodeOid(vr)
 		case *string:
 			*d = decodeText(vr)
 		case *float32:

query_test.go

@@ -332,6 +332,7 @@ func TestQueryRowCoreTypes(t *testing.T) {
 		f64 float64
 		b   bool
 		t   time.Time
+		oid pgx.Oid
 	}
 
 	var actual, zero allTypes
@@ -352,6 +353,7 @@ func TestQueryRowCoreTypes(t *testing.T) {
 		{"select $1::timestamptz", []interface{}{time.Unix(123, 5000)}, []interface{}{&actual.t}, allTypes{t: time.Unix(123, 5000)}},
 		{"select $1::timestamp", []interface{}{time.Date(2010, 1, 2, 3, 4, 5, 0, time.Local)}, []interface{}{&actual.t}, allTypes{t: time.Date(2010, 1, 2, 3, 4, 5, 0, time.Local)}},
 		{"select $1::date", []interface{}{time.Date(1987, 1, 2, 0, 0, 0, 0, time.Local)}, []interface{}{&actual.t}, allTypes{t: time.Date(1987, 1, 2, 0, 0, 0, 0, time.Local)}},
+		{"select $1::oid", []interface{}{pgx.Oid(42)}, []interface{}{&actual.oid}, allTypes{oid: 42}},
 	}
 
 	for i, tt := range tests {

values.go

@@ -17,6 +17,7 @@ const (
 	Int2Oid         = 21
 	Int4Oid         = 23
 	TextOid         = 25
+	OidOid          = 26
 	Float4Oid       = 700
 	Float8Oid       = 701
 	Int2ArrayOid    = 1005
@@ -58,6 +59,7 @@ func init() {
 	DefaultOidFormats[Float8ArrayOid] = BinaryFormatCode
 	DefaultOidFormats[TextArrayOid] = BinaryFormatCode
 	DefaultOidFormats[VarcharArrayOid] = BinaryFormatCode
+	DefaultOidFormats[OidOid] = BinaryFormatCode
 }
 
 type SerializationError string
@@ -680,6 +682,49 @@ func encodeInt4(w *WriteBuf, value interface{}) error {
 	return nil
 }
 
+func decodeOid(vr *ValueReader) Oid {
+	if vr.Len() == -1 {
+		vr.Fatal(ProtocolError("Cannot decode null into Oid"))
+		return 0
+	}
+
+	if vr.Type().DataType != OidOid {
+		vr.Fatal(ProtocolError(fmt.Sprintf("Expected type oid %v but received type oid %v", OidOid, vr.Type().DataType)))
+		return 0
+	}
+
+	switch vr.Type().FormatCode {
+	case TextFormatCode:
+		s := vr.ReadString(vr.Len())
+		n, err := strconv.ParseInt(s, 10, 32)
+		if err != nil {
+			vr.Fatal(ProtocolError(fmt.Sprintf("Received invalid Oid: %v", s)))
+		}
+		return Oid(n)
+	case BinaryFormatCode:
+		if vr.Len() != 4 {
+			vr.Fatal(ProtocolError(fmt.Sprintf("Received an invalid size for an Oid: %d", vr.Len())))
+			return 0
+		}
+		return Oid(vr.ReadInt32())
+	default:
+		vr.Fatal(ProtocolError(fmt.Sprintf("Unknown field description format code: %v", vr.Type().FormatCode)))
+		return Oid(0)
+	}
+}
+
+func encodeOid(w *WriteBuf, value interface{}) error {
+	v, ok := value.(Oid)
+	if !ok {
+		return fmt.Errorf("Expected Oid, received %T", value)
+	}
+
+	w.WriteInt32(4)
+	w.WriteInt32(int32(v))
+
+	return nil
+}
+
 func decodeFloat4(vr *ValueReader) float32 {
 	if vr.Len() == -1 {
 		vr.Fatal(ProtocolError("Cannot decode null into float32"))