Add support for record array

Like Record itself, it only implements BinaryDecoder,
doesn't implement BinaryEncoder, and has no support for the text
protocol.
non-blocking
WGH 2022-03-28 05:06:16 +03:00 committed by Jack Christensen
parent 3e230ba731
commit ccb207cba5
3 changed files with 424 additions and 0 deletions

318
record_array.go Normal file
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@ -0,0 +1,318 @@
// Code generated by erb. DO NOT EDIT.
package pgtype
import (
"encoding/binary"
"fmt"
"reflect"
)
type RecordArray struct {
Elements []Record
Dimensions []ArrayDimension
Status Status
}
func (dst *RecordArray) Set(src interface{}) error {
// untyped nil and typed nil interfaces are different
if src == nil {
*dst = RecordArray{Status: Null}
return nil
}
if value, ok := src.(interface{ Get() interface{} }); ok {
value2 := value.Get()
if value2 != value {
return dst.Set(value2)
}
}
// Attempt to match to select common types:
switch value := src.(type) {
case [][]Value:
if value == nil {
*dst = RecordArray{Status: Null}
} else if len(value) == 0 {
*dst = RecordArray{Status: Present}
} else {
elements := make([]Record, len(value))
for i := range value {
if err := elements[i].Set(value[i]); err != nil {
return err
}
}
*dst = RecordArray{
Elements: elements,
Dimensions: []ArrayDimension{{Length: int32(len(elements)), LowerBound: 1}},
Status: Present,
}
}
case []Record:
if value == nil {
*dst = RecordArray{Status: Null}
} else if len(value) == 0 {
*dst = RecordArray{Status: Present}
} else {
*dst = RecordArray{
Elements: value,
Dimensions: []ArrayDimension{{Length: int32(len(value)), LowerBound: 1}},
Status: Present,
}
}
default:
// Fallback to reflection if an optimised match was not found.
// The reflection is necessary for arrays and multidimensional slices,
// but it comes with a 20-50% performance penalty for large arrays/slices
reflectedValue := reflect.ValueOf(src)
if !reflectedValue.IsValid() || reflectedValue.IsZero() {
*dst = RecordArray{Status: Null}
return nil
}
dimensions, elementsLength, ok := findDimensionsFromValue(reflectedValue, nil, 0)
if !ok {
return fmt.Errorf("cannot find dimensions of %v for RecordArray", src)
}
if elementsLength == 0 {
*dst = RecordArray{Status: Present}
return nil
}
if len(dimensions) == 0 {
if originalSrc, ok := underlyingSliceType(src); ok {
return dst.Set(originalSrc)
}
return fmt.Errorf("cannot convert %v to RecordArray", src)
}
*dst = RecordArray{
Elements: make([]Record, elementsLength),
Dimensions: dimensions,
Status: Present,
}
elementCount, err := dst.setRecursive(reflectedValue, 0, 0)
if err != nil {
// Maybe the target was one dimension too far, try again:
if len(dst.Dimensions) > 1 {
dst.Dimensions = dst.Dimensions[:len(dst.Dimensions)-1]
elementsLength = 0
for _, dim := range dst.Dimensions {
if elementsLength == 0 {
elementsLength = int(dim.Length)
} else {
elementsLength *= int(dim.Length)
}
}
dst.Elements = make([]Record, elementsLength)
elementCount, err = dst.setRecursive(reflectedValue, 0, 0)
if err != nil {
return err
}
} else {
return err
}
}
if elementCount != len(dst.Elements) {
return fmt.Errorf("cannot convert %v to RecordArray, expected %d dst.Elements, but got %d instead", src, len(dst.Elements), elementCount)
}
}
return nil
}
func (dst *RecordArray) setRecursive(value reflect.Value, index, dimension int) (int, error) {
switch value.Kind() {
case reflect.Array:
fallthrough
case reflect.Slice:
if len(dst.Dimensions) == dimension {
break
}
valueLen := value.Len()
if int32(valueLen) != dst.Dimensions[dimension].Length {
return 0, fmt.Errorf("multidimensional arrays must have array expressions with matching dimensions")
}
for i := 0; i < valueLen; i++ {
var err error
index, err = dst.setRecursive(value.Index(i), index, dimension+1)
if err != nil {
return 0, err
}
}
return index, nil
}
if !value.CanInterface() {
return 0, fmt.Errorf("cannot convert all values to RecordArray")
}
if err := dst.Elements[index].Set(value.Interface()); err != nil {
return 0, fmt.Errorf("%v in RecordArray", err)
}
index++
return index, nil
}
func (dst RecordArray) Get() interface{} {
switch dst.Status {
case Present:
return dst
case Null:
return nil
default:
return dst.Status
}
}
func (src *RecordArray) AssignTo(dst interface{}) error {
switch src.Status {
case Present:
if len(src.Dimensions) <= 1 {
// Attempt to match to select common types:
switch v := dst.(type) {
case *[][]Value:
*v = make([][]Value, len(src.Elements))
for i := range src.Elements {
if err := src.Elements[i].AssignTo(&((*v)[i])); err != nil {
return err
}
}
return nil
}
}
// Try to convert to something AssignTo can use directly.
if nextDst, retry := GetAssignToDstType(dst); retry {
return src.AssignTo(nextDst)
}
// Fallback to reflection if an optimised match was not found.
// The reflection is necessary for arrays and multidimensional slices,
// but it comes with a 20-50% performance penalty for large arrays/slices
value := reflect.ValueOf(dst)
if value.Kind() == reflect.Ptr {
value = value.Elem()
}
switch value.Kind() {
case reflect.Array, reflect.Slice:
default:
return fmt.Errorf("cannot assign %T to %T", src, dst)
}
if len(src.Elements) == 0 {
if value.Kind() == reflect.Slice {
value.Set(reflect.MakeSlice(value.Type(), 0, 0))
return nil
}
}
elementCount, err := src.assignToRecursive(value, 0, 0)
if err != nil {
return err
}
if elementCount != len(src.Elements) {
return fmt.Errorf("cannot assign %v, needed to assign %d elements, but only assigned %d", dst, len(src.Elements), elementCount)
}
return nil
case Null:
return NullAssignTo(dst)
}
return fmt.Errorf("cannot decode %#v into %T", src, dst)
}
func (src *RecordArray) assignToRecursive(value reflect.Value, index, dimension int) (int, error) {
switch kind := value.Kind(); kind {
case reflect.Array:
fallthrough
case reflect.Slice:
if len(src.Dimensions) == dimension {
break
}
length := int(src.Dimensions[dimension].Length)
if reflect.Array == kind {
typ := value.Type()
if typ.Len() != length {
return 0, fmt.Errorf("expected size %d array, but %s has size %d array", length, typ, typ.Len())
}
value.Set(reflect.New(typ).Elem())
} else {
value.Set(reflect.MakeSlice(value.Type(), length, length))
}
var err error
for i := 0; i < length; i++ {
index, err = src.assignToRecursive(value.Index(i), index, dimension+1)
if err != nil {
return 0, err
}
}
return index, nil
}
if len(src.Dimensions) != dimension {
return 0, fmt.Errorf("incorrect dimensions, expected %d, found %d", len(src.Dimensions), dimension)
}
if !value.CanAddr() {
return 0, fmt.Errorf("cannot assign all values from RecordArray")
}
addr := value.Addr()
if !addr.CanInterface() {
return 0, fmt.Errorf("cannot assign all values from RecordArray")
}
if err := src.Elements[index].AssignTo(addr.Interface()); err != nil {
return 0, err
}
index++
return index, nil
}
func (dst *RecordArray) DecodeBinary(ci *ConnInfo, src []byte) error {
if src == nil {
*dst = RecordArray{Status: Null}
return nil
}
var arrayHeader ArrayHeader
rp, err := arrayHeader.DecodeBinary(ci, src)
if err != nil {
return err
}
if len(arrayHeader.Dimensions) == 0 {
*dst = RecordArray{Dimensions: arrayHeader.Dimensions, Status: Present}
return nil
}
elementCount := arrayHeader.Dimensions[0].Length
for _, d := range arrayHeader.Dimensions[1:] {
elementCount *= d.Length
}
elements := make([]Record, elementCount)
for i := range elements {
elemLen := int(int32(binary.BigEndian.Uint32(src[rp:])))
rp += 4
var elemSrc []byte
if elemLen >= 0 {
elemSrc = src[rp : rp+elemLen]
rp += elemLen
}
err = elements[i].DecodeBinary(ci, elemSrc)
if err != nil {
return err
}
}
*dst = RecordArray{Elements: elements, Dimensions: arrayHeader.Dimensions, Status: Present}
return nil
}

104
record_array_test.go Normal file
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@ -0,0 +1,104 @@
package pgtype_test
import (
"context"
"fmt"
"testing"
"github.com/stretchr/testify/require"
"github.com/jackc/pgtype"
"github.com/jackc/pgtype/testutil"
"github.com/jackc/pgx/v4"
)
var recordArrayTests = []struct {
sql string
expected pgtype.RecordArray
}{
{
sql: `select array_agg((x::int4, x+100::int8)) from generate_series(0, 1) x;`,
expected: pgtype.RecordArray{
Dimensions: []pgtype.ArrayDimension{
{LowerBound: 1, Length: 2},
},
Elements: []pgtype.Record{
{
Fields: []pgtype.Value{
&pgtype.Int4{Int: 0, Status: pgtype.Present},
&pgtype.Int8{Int: 100, Status: pgtype.Present},
},
Status: pgtype.Present,
},
{
Fields: []pgtype.Value{
&pgtype.Int4{Int: 1, Status: pgtype.Present},
&pgtype.Int8{Int: 101, Status: pgtype.Present},
},
Status: pgtype.Present,
},
},
Status: pgtype.Present,
},
},
}
func TestRecordArrayTranscode(t *testing.T) {
conn := testutil.MustConnectPgx(t)
defer testutil.MustCloseContext(t, conn)
for i, tt := range recordArrayTests {
psName := fmt.Sprintf("test%d", i)
_, err := conn.Prepare(context.Background(), psName, tt.sql)
require.NoError(t, err)
t.Run(tt.sql, func(t *testing.T) {
var result pgtype.RecordArray
err := conn.QueryRow(context.Background(), psName, pgx.QueryResultFormats{pgx.BinaryFormatCode}).Scan(&result)
require.NoError(t, err)
require.Equal(t, tt.expected, result)
})
}
}
func TestRecordArrayAssignTo(t *testing.T) {
src := pgtype.RecordArray{
Dimensions: []pgtype.ArrayDimension{
{LowerBound: 1, Length: 2},
},
Elements: []pgtype.Record{
{
Fields: []pgtype.Value{
&pgtype.Int4{Int: 0, Status: pgtype.Present},
&pgtype.Int8{Int: 100, Status: pgtype.Present},
},
Status: pgtype.Present,
},
{
Fields: []pgtype.Value{
&pgtype.Int4{Int: 1, Status: pgtype.Present},
&pgtype.Int8{Int: 101, Status: pgtype.Present},
},
Status: pgtype.Present,
},
},
Status: pgtype.Present,
}
dst := [][]pgtype.Value{}
err := src.AssignTo(&dst)
require.NoError(t, err)
expected := [][]pgtype.Value{
{
&pgtype.Int4{Int: 0, Status: pgtype.Present},
&pgtype.Int8{Int: 100, Status: pgtype.Present},
},
{
&pgtype.Int4{Int: 1, Status: pgtype.Present},
&pgtype.Int8{Int: 101, Status: pgtype.Present},
},
}
require.Equal(t, expected, dst)
}

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@ -25,4 +25,6 @@ erb pgtype_array_type=JSONBArray pgtype_element_type=JSONB go_array_types=[]stri
# While the binary format is theoretically possible it is only practical to use the text format.
erb pgtype_array_type=EnumArray pgtype_element_type=GenericText go_array_types=[]string,[]*string binary_format=false typed_array.go.erb > enum_array.go
erb pgtype_array_type=RecordArray pgtype_element_type=Record go_array_types=[][]Value element_type_name=record text_null=NULL encode_binary=false text_format=false typed_array.go.erb > record_array.go
goimports -w *_array.go