Move not null Oid to pgtype

In preparation to ConnInfo implementation.

oid.go

@@ -1,45 +1,57 @@
 package pgtype
 
 import (
+	"encoding/binary"
+	"fmt"
 	"io"
+	"strconv"
+
+	"github.com/jackc/pgx/pgio"
 )
 
 // Oid (Object Identifier Type) is, according to
 // https://www.postgresql.org/docs/current/static/datatype-oid.html, used
 // internally by PostgreSQL as a primary key for various system tables. It is
 // currently implemented as an unsigned four-byte integer. Its definition can be
-// found in src/include/postgres_ext.h in the PostgreSQL sources.
+// found in src/include/postgres_ext.h in the PostgreSQL sources. Because it is
-type Oid pguint32
+// so frequently required to be in a NOT NULL condition Oid cannot be NULL. To
-
+// allow for NULL Oids use OidValue.
-// Set converts from src to dst. Note that as Oid is not a general
+type Oid uint32
-// number type Set does not do automatic type conversion as other number
-// types do.
-func (dst *Oid) Set(src interface{}) error {
-	return (*pguint32)(dst).Set(src)
-}
-
-func (dst *Oid) Get() interface{} {
-	return (*pguint32)(dst).Get()
-}
-
-// AssignTo assigns from src to dst. Note that as Oid is not a general number
-// type AssignTo does not do automatic type conversion as other number types do.
-func (src *Oid) AssignTo(dst interface{}) error {
-	return (*pguint32)(src).AssignTo(dst)
-}
 
 func (dst *Oid) DecodeText(src []byte) error {
-	return (*pguint32)(dst).DecodeText(src)
+	if src == nil {
+		return fmt.Errorf("cannot decode nil into Oid")
+	}
+
+	n, err := strconv.ParseUint(string(src), 10, 32)
+	if err != nil {
+		return err
+	}
+
+	*dst = Oid(n)
+	return nil
 }
 
 func (dst *Oid) DecodeBinary(src []byte) error {
-	return (*pguint32)(dst).DecodeBinary(src)
+	if src == nil {
+		return fmt.Errorf("cannot decode nil into Oid")
+	}
+
+	if len(src) != 4 {
+		return fmt.Errorf("invalid length: %v", len(src))
+	}
+
+	n := binary.BigEndian.Uint32(src)
+	*dst = Oid(n)
+	return nil
 }
 
 func (src Oid) EncodeText(w io.Writer) (bool, error) {
-	return (pguint32)(src).EncodeText(w)
+	_, err := io.WriteString(w, strconv.FormatUint(uint64(src), 10))
+	return false, err
 }
 
 func (src Oid) EncodeBinary(w io.Writer) (bool, error) {
-	return (pguint32)(src).EncodeBinary(w)
+	_, err := pgio.WriteUint32(w, uint32(src))
+	return false, err
 }

oid_value.go

@@ -0,0 +1,45 @@
+package pgtype
+
+import (
+	"io"
+)
+
+// OidValue (Object Identifier Type) is, according to
+// https://www.postgresql.org/docs/current/static/datatype-OidValue.html, used
+// internally by PostgreSQL as a primary key for various system tables. It is
+// currently implemented as an unsigned four-byte integer. Its definition can be
+// found in src/include/postgres_ext.h in the PostgreSQL sources.
+type OidValue pguint32
+
+// Set converts from src to dst. Note that as OidValue is not a general
+// number type Set does not do automatic type conversion as other number
+// types do.
+func (dst *OidValue) Set(src interface{}) error {
+	return (*pguint32)(dst).Set(src)
+}
+
+func (dst *OidValue) Get() interface{} {
+	return (*pguint32)(dst).Get()
+}
+
+// AssignTo assigns from src to dst. Note that as OidValue is not a general number
+// type AssignTo does not do automatic type conversion as other number types do.
+func (src *OidValue) AssignTo(dst interface{}) error {
+	return (*pguint32)(src).AssignTo(dst)
+}
+
+func (dst *OidValue) DecodeText(src []byte) error {
+	return (*pguint32)(dst).DecodeText(src)
+}
+
+func (dst *OidValue) DecodeBinary(src []byte) error {
+	return (*pguint32)(dst).DecodeBinary(src)
+}
+
+func (src OidValue) EncodeText(w io.Writer) (bool, error) {
+	return (pguint32)(src).EncodeText(w)
+}
+
+func (src OidValue) EncodeBinary(w io.Writer) (bool, error) {
+	return (pguint32)(src).EncodeBinary(w)
+}

oid_value_test.go

@@ -7,23 +7,23 @@ import (
 	"github.com/jackc/pgx/pgtype"
 )
 
-func TestOidTranscode(t *testing.T) {
+func TestOidValueTranscode(t *testing.T) {
 	testSuccessfulTranscode(t, "oid", []interface{}{
-		pgtype.Oid{Uint: 42, Status: pgtype.Present},
+		pgtype.OidValue{Uint: 42, Status: pgtype.Present},
-		pgtype.Oid{Status: pgtype.Null},
+		pgtype.OidValue{Status: pgtype.Null},
 	})
 }
 
-func TestOidSet(t *testing.T) {
+func TestOidValueSet(t *testing.T) {
 	successfulTests := []struct {
 		source interface{}
-		result pgtype.Oid
+		result pgtype.OidValue
 	}{
-		{source: uint32(1), result: pgtype.Oid{Uint: 1, Status: pgtype.Present}},
+		{source: uint32(1), result: pgtype.OidValue{Uint: 1, Status: pgtype.Present}},
 	}
 
 	for i, tt := range successfulTests {
-		var r pgtype.Oid
+		var r pgtype.OidValue
 		err := r.Set(tt.source)
 		if err != nil {
 			t.Errorf("%d: %v", i, err)
@@ -35,17 +35,17 @@ func TestOidSet(t *testing.T) {
 	}
 }
 
-func TestOidAssignTo(t *testing.T) {
+func TestOidValueAssignTo(t *testing.T) {
 	var ui32 uint32
 	var pui32 *uint32
 
 	simpleTests := []struct {
-		src      pgtype.Oid
+		src      pgtype.OidValue
 		dst      interface{}
 		expected interface{}
 	}{
-		{src: pgtype.Oid{Uint: 42, Status: pgtype.Present}, dst: &ui32, expected: uint32(42)},
+		{src: pgtype.OidValue{Uint: 42, Status: pgtype.Present}, dst: &ui32, expected: uint32(42)},
-		{src: pgtype.Oid{Status: pgtype.Null}, dst: &pui32, expected: ((*uint32)(nil))},
+		{src: pgtype.OidValue{Status: pgtype.Null}, dst: &pui32, expected: ((*uint32)(nil))},
 	}
 
 	for i, tt := range simpleTests {
@@ -60,11 +60,11 @@ func TestOidAssignTo(t *testing.T) {
 	}
 
 	pointerAllocTests := []struct {
-		src      pgtype.Oid
+		src      pgtype.OidValue
 		dst      interface{}
 		expected interface{}
 	}{
-		{src: pgtype.Oid{Uint: 42, Status: pgtype.Present}, dst: &pui32, expected: uint32(42)},
+		{src: pgtype.OidValue{Uint: 42, Status: pgtype.Present}, dst: &pui32, expected: uint32(42)},
 	}
 
 	for i, tt := range pointerAllocTests {
@@ -79,10 +79,10 @@ func TestOidAssignTo(t *testing.T) {
 	}
 
 	errorTests := []struct {
-		src pgtype.Oid
+		src pgtype.OidValue
 		dst interface{}
 	}{
-		{src: pgtype.Oid{Status: pgtype.Null}, dst: &ui32},
+		{src: pgtype.OidValue{Status: pgtype.Null}, dst: &ui32},
 	}
 
 	for i, tt := range errorTests {