Add status to pgtype.Bool

conn.go

@@ -279,13 +279,12 @@ func (c *Conn) connect(config ConnConfig, network, address string, tlsConfig *tl
 	c.doneChan = make(chan struct{})
 	c.closedChan = make(chan error)
 
-	b := pgtype.Bool(false)
 	i2 := pgtype.Int2(0)
 	i4 := pgtype.Int4(0)
 	i8 := pgtype.Int8(0)
 
 	c.oidPgtypeValues = map[OID]pgtype.Value{
-		BoolOID: &b,
+		BoolOID: &pgtype.Bool{},
 		DateOID: &pgtype.Date{},
 		Int2OID: &i2,
 		Int4OID: &i4,
@@ -978,6 +977,10 @@ func (c *Conn) sendPreparedQuery(ps *PreparedStatement, arguments ...interface{}
 		switch arg := arguments[i].(type) {
 		case Encoder:
 			wbuf.WriteInt16(arg.FormatCode())
+		case pgtype.BinaryEncoder:
+			wbuf.WriteInt16(BinaryFormatCode)
+		case pgtype.TextEncoder:
+			wbuf.WriteInt16(TextFormatCode)
 		case string, *string:
 			wbuf.WriteInt16(TextFormatCode)
 		default:

pgtype/bool.go

@@ -8,20 +8,23 @@ import (
 	"github.com/jackc/pgx/pgio"
 )
 
-type Bool bool
+type Bool struct {
+	Bool   bool
+	Status Status
+}
 
 func (b *Bool) ConvertFrom(src interface{}) error {
 	switch value := src.(type) {
 	case Bool:
 		*b = value
 	case bool:
-		*b = Bool(value)
+		*b = Bool{Bool: value, Status: Present}
 	case string:
 		bb, err := strconv.ParseBool(value)
 		if err != nil {
 			return err
 		}
-		*b = Bool(bb)
+		*b = Bool{Bool: bb, Status: Present}
 	default:
 		if originalSrc, ok := underlyingBoolType(src); ok {
 			return b.ConvertFrom(originalSrc)
@@ -42,6 +45,11 @@ func (b *Bool) DecodeText(r io.Reader) error {
 		return err
 	}
 
+	if size == -1 {
+		*b = Bool{Status: Null}
+		return nil
+	}
+
 	if size != 1 {
 		return fmt.Errorf("invalid length for bool: %v", size)
 	}
@@ -51,7 +59,7 @@ func (b *Bool) DecodeText(r io.Reader) error {
 		return err
 	}
 
-	*b = Bool(byt == 't')
+	*b = Bool{Bool: byt == 't', Status: Present}
 	return nil
 }
 
@@ -61,6 +69,11 @@ func (b *Bool) DecodeBinary(r io.Reader) error {
 		return err
 	}
 
+	if size == -1 {
+		*b = Bool{Status: Null}
+		return nil
+	}
+
 	if size != 1 {
 		return fmt.Errorf("invalid length for bool: %v", size)
 	}
@@ -70,18 +83,22 @@ func (b *Bool) DecodeBinary(r io.Reader) error {
 		return err
 	}
 
-	*b = Bool(byt == 1)
+	*b = Bool{Bool: byt == 1, Status: Present}
 	return nil
 }
 
 func (b Bool) EncodeText(w io.Writer) error {
+	if done, err := encodeNotPresent(w, b.Status); done {
+		return err
+	}
+
 	_, err := pgio.WriteInt32(w, 1)
 	if err != nil {
 		return nil
 	}
 
 	var buf []byte
-	if b {
+	if b.Bool {
 		buf = []byte{'t'}
 	} else {
 		buf = []byte{'f'}
@@ -92,13 +109,17 @@ func (b Bool) EncodeText(w io.Writer) error {
 }
 
 func (b Bool) EncodeBinary(w io.Writer) error {
+	if done, err := encodeNotPresent(w, b.Status); done {
+		return err
+	}
+
 	_, err := pgio.WriteInt32(w, 1)
 	if err != nil {
 		return nil
 	}
 
 	var buf []byte
-	if b {
+	if b.Bool {
 		buf = []byte{1}
 	} else {
 		buf = []byte{0}

pgtype/bool_test.go

@@ -1,11 +1,9 @@
 package pgtype_test
 
 import (
-	"bytes"
 	"testing"
 
 	"github.com/jackc/pgx"
-	"github.com/jackc/pgx/pgio"
 	"github.com/jackc/pgx/pgtype"
 )
 
@@ -21,64 +19,33 @@ func TestBoolTranscode(t *testing.T) {
 	tests := []struct {
 		result pgtype.Bool
 	}{
-		{result: pgtype.Bool(false)},
+		{result: pgtype.Bool{Bool: false, Status: pgtype.Present}},
-		{result: pgtype.Bool(true)},
+		{result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
+		{result: pgtype.Bool{Bool: false, Status: pgtype.Null}},
 	}
 
-	ps.FieldDescriptions[0].FormatCode = pgx.TextFormatCode
+	formats := []struct {
+		name       string
+		formatCode int16
+	}{
+		{name: "TextFormat", formatCode: pgx.TextFormatCode},
+		{name: "BinaryFormat", formatCode: pgx.BinaryFormatCode},
+	}
+
+	for _, fc := range formats {
+		ps.FieldDescriptions[0].FormatCode = fc.formatCode
+
 		for i, tt := range tests {
-		inputBuf := &bytes.Buffer{}
-		err = tt.result.EncodeText(inputBuf)
-		if err != nil {
-			t.Errorf("TextFormat %d: %v", i, err)
-		}
-
-		var s string
-		err := conn.QueryRow("test", string(inputBuf.Bytes()[4:])).Scan(&s)
-		if err != nil {
-			t.Errorf("TextFormat %d: %v", i, err)
-		}
-
-		outputBuf := &bytes.Buffer{}
-		pgio.WriteInt32(outputBuf, int32(len(s)))
-		outputBuf.WriteString(s)
 			var r pgtype.Bool
-		err = r.DecodeText(outputBuf)
+			err := conn.QueryRow("test", tt.result).Scan(&r)
 			if err != nil {
-			t.Errorf("TextFormat %d: %v", i, err)
+				t.Errorf("%v %d: %v", fc.name, i, err)
 			}
 
 			if r != tt.result {
-			t.Errorf("TextFormat %d: expected %v, got %v", i, tt.result, r)
+				t.Errorf("%v %d: expected %v, got %v", fc.name, i, tt.result, r)
 			}
 		}
-
-	ps.FieldDescriptions[0].FormatCode = pgx.BinaryFormatCode
-	for i, tt := range tests {
-		inputBuf := &bytes.Buffer{}
-		err = tt.result.EncodeBinary(inputBuf)
-		if err != nil {
-			t.Errorf("BinaryFormat %d: %v", i, err)
-		}
-
-		var buf []byte
-		err := conn.QueryRow("test", inputBuf.Bytes()[4:]).Scan(&buf)
-		if err != nil {
-			t.Errorf("BinaryFormat %d: %v", i, err)
-		}
-
-		outputBuf := &bytes.Buffer{}
-		pgio.WriteInt32(outputBuf, int32(len(buf)))
-		outputBuf.Write(buf)
-		var r pgtype.Bool
-		err = r.DecodeBinary(outputBuf)
-		if err != nil {
-			t.Errorf("BinaryFormat %d: %v", i, err)
-		}
-
-		if r != tt.result {
-			t.Errorf("BinaryFormat %d: expected %v, got %v", i, tt.result, r)
-		}
 	}
 }
 
@@ -89,12 +56,12 @@ func TestBoolConvertFrom(t *testing.T) {
 		source interface{}
 		result pgtype.Bool
 	}{
-		{source: true, result: pgtype.Bool(true)},
+		{source: true, result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
-		{source: false, result: pgtype.Bool(false)},
+		{source: false, result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
-		{source: "true", result: pgtype.Bool(true)},
+		{source: "true", result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
-		{source: "false", result: pgtype.Bool(false)},
+		{source: "false", result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
-		{source: "t", result: pgtype.Bool(true)},
+		{source: "t", result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
-		{source: "f", result: pgtype.Bool(false)},
+		{source: "f", result: pgtype.Bool{Bool: true, Status: pgtype.Present}},
 	}
 
 	for i, tt := range successfulTests {

pgtype/pgtype.go

@@ -1,7 +1,18 @@
 package pgtype
 
 import (
+	"errors"
 	"io"
+
+	"github.com/jackc/pgx/pgio"
+)
+
+type Status byte
+
+const (
+	Undefined Status = iota
+	Null
+	Present
 )
 
 type Value interface {
@@ -24,3 +35,16 @@ type BinaryEncoder interface {
 type TextEncoder interface {
 	EncodeText(w io.Writer) error
 }
+
+var errUndefined = errors.New("cannot encode status undefined")
+
+func encodeNotPresent(w io.Writer, status Status) (done bool, err error) {
+	switch status {
+	case Undefined:
+		return true, errUndefined
+	case Null:
+		_, err = pgio.WriteInt32(w, -1)
+		return true, err
+	}
+	return false, nil
+}

query.go

@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"golang.org/x/net/context"
 	"time"
+
+	"github.com/jackc/pgx/pgtype"
 )
 
 // Row is a convenience wrapper over Rows that is returned by QueryRow.
@@ -228,6 +230,18 @@ func (rows *Rows) Scan(dest ...interface{}) (err error) {
 			if err != nil {
 				rows.Fatal(scanArgError{col: i, err: err})
 			}
+		} else if s, ok := d.(pgtype.BinaryDecoder); ok && vr.Type().FormatCode == BinaryFormatCode {
+			vr.err = errRewoundLen
+			err = s.DecodeBinary(&valueReader2{vr})
+			if err != nil {
+				rows.Fatal(scanArgError{col: i, err: err})
+			}
+		} else if s, ok := d.(pgtype.TextDecoder); ok && vr.Type().FormatCode == TextFormatCode {
+			vr.err = errRewoundLen
+			err = s.DecodeText(&valueReader2{vr})
+			if err != nil {
+				rows.Fatal(scanArgError{col: i, err: err})
+			}
 		} else if s, ok := d.(sql.Scanner); ok {
 			var val interface{}
 			if 0 <= vr.Len() {

values.go

@@ -1026,6 +1026,10 @@ func Encode(wbuf *WriteBuf, oid OID, arg interface{}) error {
 	switch arg := arg.(type) {
 	case Encoder:
 		return arg.Encode(wbuf, oid)
+	case pgtype.BinaryEncoder:
+		return arg.EncodeBinary(wbuf)
+	case pgtype.TextEncoder:
+		return arg.EncodeText(wbuf)
 	case driver.Valuer:
 		v, err := arg.Value()
 		if err != nil {
@@ -1398,21 +1402,11 @@ func Decode(vr *ValueReader, d interface{}) error {
 }
 
 func decodeBool(vr *ValueReader) bool {
-	if vr.Len() == -1 {
-		vr.Fatal(ProtocolError("Cannot decode null into bool"))
-		return false
-	}
-
 	if vr.Type().DataType != BoolOID {
 		vr.Fatal(ProtocolError(fmt.Sprintf("Cannot decode oid %v into bool", vr.Type().DataType)))
 		return false
 	}
 
-	if vr.Type().FormatCode != BinaryFormatCode {
-		vr.Fatal(ProtocolError(fmt.Sprintf("Unknown field description format code: %v", vr.Type().FormatCode)))
-		return false
-	}
-
 	vr.err = errRewoundLen
 
 	var b pgtype.Bool
@@ -1432,7 +1426,12 @@ func decodeBool(vr *ValueReader) bool {
 		return false
 	}
 
-	return bool(b)
+	if b.Status != pgtype.Present {
+		vr.Fatal(fmt.Errorf("Cannot decode null into bool"))
+		return false
+	}
+
+	return b.Bool
 }
 
 func encodeBool(w *WriteBuf, oid OID, value bool) error {
@@ -1440,7 +1439,7 @@ func encodeBool(w *WriteBuf, oid OID, value bool) error {
 		return fmt.Errorf("cannot encode Go %s into oid %d", "bool", oid)
 	}
 
-	b := pgtype.Bool(value)
+	b := pgtype.Bool{Bool: value, Status: pgtype.Present}
 	return b.EncodeBinary(w)
 }