Convert box to Codec

2022-01-03 20:27:35 -06:00
parent 4b1121c2a9
commit 298a5f0dca
4 changed files with 194 additions and 135 deletions
@@ -11,32 +11,189 @@ import (
 	"github.com/jackc/pgio"
 )

+type BoxScanner interface {
+	ScanBox(v Box) error
+}
+
+type BoxValuer interface {
+	BoxValue() (Box, error)
+}
+
 type Box struct {
 	P     [2]Vec2
 	Valid bool
 }

-func (dst *Box) Set(src interface{}) error {
-	return fmt.Errorf("cannot convert %v to Box", src)
+func (b *Box) ScanBox(v Box) error {
+	*b = v
+	return nil
 }

-func (dst Box) Get() interface{} {
-	if !dst.Valid {
-		return nil
-	}
-	return dst
+func (b Box) BoxValue() (Box, error) {
+	return b, nil
 }

-func (src *Box) AssignTo(dst interface{}) error {
-	return fmt.Errorf("cannot assign %v to %T", src, dst)
-}
-
-func (dst *Box) DecodeText(ci *ConnInfo, src []byte) error {
+// Scan implements the database/sql Scanner interface.
+func (dst *Box) Scan(src interface{}) error {
 	if src == nil {
 		*dst = Box{}
 		return nil
 	}

+	switch src := src.(type) {
+	case string:
+		return scanPlanTextAnyToBoxScanner{}.Scan(nil, 0, TextFormatCode, []byte(src), dst)
+	}
+
+	return fmt.Errorf("cannot scan %T", src)
+}
+
+// Value implements the database/sql/driver Valuer interface.
+func (src Box) Value() (driver.Value, error) {
+	buf, err := BoxCodec{}.Encode(nil, 0, TextFormatCode, src, nil)
+	if err != nil {
+		return nil, err
+	}
+	return string(buf), err
+}
+
+type BoxCodec struct{}
+
+func (BoxCodec) FormatSupported(format int16) bool {
+	return format == TextFormatCode || format == BinaryFormatCode
+}
+
+func (BoxCodec) PreferredFormat() int16 {
+	return BinaryFormatCode
+}
+
+func (BoxCodec) Encode(ci *ConnInfo, oid uint32, format int16, value interface{}, buf []byte) (newBuf []byte, err error) {
+	if value == nil {
+		return nil, nil
+	}
+
+	var box Box
+	if v, ok := value.(BoxValuer); ok {
+		b, err := v.BoxValue()
+		if err != nil {
+			return nil, err
+		}
+		box = b
+	} else {
+		return nil, fmt.Errorf("cannot convert %v to box: %v", value, err)
+	}
+
+	if !box.Valid {
+		return nil, nil
+	}
+
+	switch format {
+	case BinaryFormatCode:
+		buf = pgio.AppendUint64(buf, math.Float64bits(box.P[0].X))
+		buf = pgio.AppendUint64(buf, math.Float64bits(box.P[0].Y))
+		buf = pgio.AppendUint64(buf, math.Float64bits(box.P[1].X))
+		buf = pgio.AppendUint64(buf, math.Float64bits(box.P[1].Y))
+		return buf, nil
+	case TextFormatCode:
+		buf = append(buf, fmt.Sprintf(`(%s,%s),(%s,%s)`,
+			strconv.FormatFloat(box.P[0].X, 'f', -1, 64),
+			strconv.FormatFloat(box.P[0].Y, 'f', -1, 64),
+			strconv.FormatFloat(box.P[1].X, 'f', -1, 64),
+			strconv.FormatFloat(box.P[1].Y, 'f', -1, 64),
+		)...)
+		return buf, nil
+	default:
+		return nil, fmt.Errorf("unknown format code: %v", format)
+	}
+}
+
+func (BoxCodec) PlanScan(ci *ConnInfo, oid uint32, format int16, target interface{}, actualTarget bool) ScanPlan {
+
+	switch format {
+	case BinaryFormatCode:
+		switch target.(type) {
+		case BoxScanner:
+			return scanPlanBinaryBoxToBoxScanner{}
+		}
+	case TextFormatCode:
+		switch target.(type) {
+		case BoxScanner:
+			return scanPlanTextAnyToBoxScanner{}
+		}
+	}
+
+	return nil
+}
+
+func (c BoxCodec) DecodeDatabaseSQLValue(ci *ConnInfo, oid uint32, format int16, src []byte) (driver.Value, error) {
+	if format == TextFormatCode {
+		return string(src), nil
+	} else {
+		box, err := c.DecodeValue(ci, oid, format, src)
+		if err != nil {
+			return nil, err
+		}
+		buf, err := c.Encode(ci, oid, TextFormatCode, box, nil)
+		if err != nil {
+			return nil, err
+		}
+		return string(buf), nil
+	}
+}
+
+func (c BoxCodec) DecodeValue(ci *ConnInfo, oid uint32, format int16, src []byte) (interface{}, error) {
+	if src == nil {
+		return nil, nil
+	}
+
+	var box Box
+	scanPlan := c.PlanScan(ci, oid, format, &box, true)
+	if scanPlan == nil {
+		return nil, fmt.Errorf("PlanScan did not find a plan")
+	}
+	err := scanPlan.Scan(ci, oid, format, src, &box)
+	if err != nil {
+		return nil, err
+	}
+	return box, nil
+}
+
+type scanPlanBinaryBoxToBoxScanner struct{}
+
+func (scanPlanBinaryBoxToBoxScanner) Scan(ci *ConnInfo, oid uint32, formatCode int16, src []byte, dst interface{}) error {
+	scanner := (dst).(BoxScanner)
+
+	if src == nil {
+		return scanner.ScanBox(Box{})
+	}
+
+	if len(src) != 32 {
+		return fmt.Errorf("invalid length for Box: %v", len(src))
+	}
+
+	x1 := binary.BigEndian.Uint64(src)
+	y1 := binary.BigEndian.Uint64(src[8:])
+	x2 := binary.BigEndian.Uint64(src[16:])
+	y2 := binary.BigEndian.Uint64(src[24:])
+
+	return scanner.ScanBox(Box{
+		P: [2]Vec2{
+			{math.Float64frombits(x1), math.Float64frombits(y1)},
+			{math.Float64frombits(x2), math.Float64frombits(y2)},
+		},
+		Valid: true,
+	})
+}
+
+type scanPlanTextAnyToBoxScanner struct{}
+
+func (scanPlanTextAnyToBoxScanner) Scan(ci *ConnInfo, oid uint32, formatCode int16, src []byte, dst interface{}) error {
+	scanner := (dst).(BoxScanner)
+
+	if src == nil {
+		return scanner.ScanBox(Box{})
+	}
+
 	if len(src) < 11 {
 		return fmt.Errorf("invalid length for Box: %v", len(src))
 	}
@@ -74,82 +231,5 @@ func (dst *Box) DecodeText(ci *ConnInfo, src []byte) error {
 		return err
 	}

-	*dst = Box{P: [2]Vec2{{x1, y1}, {x2, y2}}, Valid: true}
-	return nil
-}
-
-func (dst *Box) DecodeBinary(ci *ConnInfo, src []byte) error {
-	if src == nil {
-		*dst = Box{}
-		return nil
-	}
-
-	if len(src) != 32 {
-		return fmt.Errorf("invalid length for Box: %v", len(src))
-	}
-
-	x1 := binary.BigEndian.Uint64(src)
-	y1 := binary.BigEndian.Uint64(src[8:])
-	x2 := binary.BigEndian.Uint64(src[16:])
-	y2 := binary.BigEndian.Uint64(src[24:])
-
-	*dst = Box{
-		P: [2]Vec2{
-			{math.Float64frombits(x1), math.Float64frombits(y1)},
-			{math.Float64frombits(x2), math.Float64frombits(y2)},
-		},
-		Valid: true,
-	}
-	return nil
-}
-
-func (src Box) EncodeText(ci *ConnInfo, buf []byte) ([]byte, error) {
-	if !src.Valid {
-		return nil, nil
-	}
-
-	buf = append(buf, fmt.Sprintf(`(%s,%s),(%s,%s)`,
-		strconv.FormatFloat(src.P[0].X, 'f', -1, 64),
-		strconv.FormatFloat(src.P[0].Y, 'f', -1, 64),
-		strconv.FormatFloat(src.P[1].X, 'f', -1, 64),
-		strconv.FormatFloat(src.P[1].Y, 'f', -1, 64),
-	)...)
-	return buf, nil
-}
-
-func (src Box) EncodeBinary(ci *ConnInfo, buf []byte) ([]byte, error) {
-	if !src.Valid {
-		return nil, nil
-	}
-
-	buf = pgio.AppendUint64(buf, math.Float64bits(src.P[0].X))
-	buf = pgio.AppendUint64(buf, math.Float64bits(src.P[0].Y))
-	buf = pgio.AppendUint64(buf, math.Float64bits(src.P[1].X))
-	buf = pgio.AppendUint64(buf, math.Float64bits(src.P[1].Y))
-
-	return buf, nil
-}
-
-// Scan implements the database/sql Scanner interface.
-func (dst *Box) Scan(src interface{}) error {
-	if src == nil {
-		*dst = Box{}
-		return nil
-	}
-
-	switch src := src.(type) {
-	case string:
-		return dst.DecodeText(nil, []byte(src))
-	case []byte:
-		srcCopy := make([]byte, len(src))
-		copy(srcCopy, src)
-		return dst.DecodeText(nil, srcCopy)
-	}
-
-	return fmt.Errorf("cannot scan %T", src)
-}
-
-// Value implements the database/sql/driver Valuer interface.
-func (src Box) Value() (driver.Value, error) {
-	return EncodeValueText(src)
+	return scanner.ScanBox(Box{P: [2]Vec2{{x1, y1}, {x2, y2}}, Valid: true})
 }