Add text to pgtype

2017-03-04 21:20:56 -06:00
parent b1fc8109db
commit fa57904d6b
25 changed files with 768 additions and 149 deletions
@@ -0,0 +1,115 @@
+package pgtype
+
+import (
+	"fmt"
+	"io"
+	"reflect"
+
+	"github.com/jackc/pgx/pgio"
+)
+
+type Text struct {
+	String string
+	Status Status
+}
+
+func (dst *Text) ConvertFrom(src interface{}) error {
+	switch value := src.(type) {
+	case Text:
+		*dst = value
+	case string:
+		*dst = Text{String: value, Status: Present}
+	case *string:
+		if value == nil {
+			*dst = Text{Status: Null}
+		} else {
+			*dst = Text{String: *value, Status: Present}
+		}
+	default:
+		if originalSrc, ok := underlyingStringType(src); ok {
+			return dst.ConvertFrom(originalSrc)
+		}
+		return fmt.Errorf("cannot convert %v to Text", value)
+	}
+
+	return nil
+}
+
+func (src *Text) AssignTo(dst interface{}) error {
+	switch v := dst.(type) {
+	case *string:
+		if src.Status != Present {
+			return fmt.Errorf("cannot assign %v to %T", src, dst)
+		}
+		*v = src.String
+	default:
+		if v := reflect.ValueOf(dst); v.Kind() == reflect.Ptr {
+			el := v.Elem()
+			switch el.Kind() {
+			// if dst is a pointer to pointer, strip the pointer and try again
+			case reflect.Ptr:
+				if src.Status == Null {
+					el.Set(reflect.Zero(el.Type()))
+					return nil
+				}
+				if el.IsNil() {
+					// allocate destination
+					el.Set(reflect.New(el.Type().Elem()))
+				}
+				return src.AssignTo(el.Interface())
+			case reflect.String:
+				if src.Status != Present {
+					return fmt.Errorf("cannot assign %v to %T", src, dst)
+				}
+				el.SetString(src.String)
+				return nil
+			}
+		}
+		return fmt.Errorf("cannot decode %v into %T", src, dst)
+	}
+
+	return nil
+}
+
+func (dst *Text) DecodeText(r io.Reader) error {
+	size, err := pgio.ReadInt32(r)
+	if err != nil {
+		return err
+	}
+
+	if size == -1 {
+		*dst = Text{Status: Null}
+		return nil
+	}
+
+	buf := make([]byte, int(size))
+	_, err = r.Read(buf)
+	if err != nil {
+		return err
+	}
+
+	*dst = Text{String: string(buf), Status: Present}
+	return nil
+}
+
+func (dst *Text) DecodeBinary(r io.Reader) error {
+	return dst.DecodeText(r)
+}
+
+func (src Text) EncodeText(w io.Writer) error {
+	if done, err := encodeNotPresent(w, src.Status); done {
+		return err
+	}
+
+	_, err := pgio.WriteInt32(w, int32(len(src.String)))
+	if err != nil {
+		return nil
+	}
+
+	_, err = io.WriteString(w, src.String)
+	return err
+}
+
+func (src Text) EncodeBinary(w io.Writer) error {
+	return src.EncodeText(w)
+}