diff --git a/array_type.go b/array_type.go new file mode 100644 index 00000000..f25051d1 --- /dev/null +++ b/array_type.go @@ -0,0 +1,350 @@ +package pgtype + +import ( + "database/sql/driver" + "encoding/binary" + "reflect" + + "github.com/jackc/pgio" + errors "golang.org/x/xerrors" +) + +// ArrayType represents an array type. While it implements Value, this is only in service of its type conversion duties +// when registered as a data type in a ConnType. It should not be used directly as a Value. ArrayType is a convenience +// type for types that do not have an concrete array type. +type ArrayType struct { + elements []ValueTranscoder + dimensions []ArrayDimension + status Status + + typeName string + newElement func() ValueTranscoder +} + +func NewArrayType(typeName string, newElement func() ValueTranscoder) *ArrayType { + return &ArrayType{typeName: typeName, newElement: newElement} +} + +func (at *ArrayType) CloneTypeValue() Value { + return &ArrayType{ + elements: at.elements, + dimensions: at.dimensions, + status: at.status, + + typeName: at.typeName, + newElement: at.newElement, + } +} + +func (at *ArrayType) TypeName() string { + return at.typeName +} + +func (dst *ArrayType) setNil() { + dst.elements = nil + dst.dimensions = nil + dst.status = Null +} + +func (dst *ArrayType) Set(src interface{}) error { + // untyped nil and typed nil interfaces are different + if src == nil { + dst.setNil() + return nil + } + + sliceVal := reflect.ValueOf(src) + if sliceVal.Kind() != reflect.Slice { + return errors.Errorf("cannot set non-slice") + } + + if sliceVal.IsNil() { + dst.setNil() + return nil + } + + dst.elements = make([]ValueTranscoder, sliceVal.Len()) + for i := range dst.elements { + v := dst.newElement() + err := v.Set(sliceVal.Index(i).Interface()) + if err != nil { + return err + } + + dst.elements[i] = v + } + dst.dimensions = []ArrayDimension{{Length: int32(len(dst.elements)), LowerBound: 1}} + dst.status = Present + + return nil +} + +func (dst ArrayType) Get() interface{} { + switch dst.status { + case Present: + return dst.elements + case Null: + return nil + default: + return dst.status + } +} + +func (src *ArrayType) AssignTo(dst interface{}) error { + ptrSlice := reflect.ValueOf(dst) + if ptrSlice.Kind() != reflect.Ptr { + return errors.Errorf("cannot assign to non-pointer") + } + + sliceVal := ptrSlice.Elem() + sliceType := sliceVal.Type() + + if sliceType.Kind() != reflect.Slice { + return errors.Errorf("cannot assign to pointer to non-slice") + } + + switch src.status { + case Present: + slice := reflect.MakeSlice(sliceType, len(src.elements), len(src.elements)) + elemType := sliceType.Elem() + + for i := range src.elements { + ptrElem := reflect.New(elemType) + err := src.elements[i].AssignTo(ptrElem.Interface()) + if err != nil { + return err + } + + slice.Index(i).Set(ptrElem.Elem()) + } + + sliceVal.Set(slice) + return nil + case Null: + sliceVal.Set(reflect.Zero(sliceType)) + return nil + } + + return errors.Errorf("cannot decode %#v into %T", src, dst) +} + +func (dst *ArrayType) DecodeText(ci *ConnInfo, src []byte) error { + if src == nil { + dst.setNil() + return nil + } + + uta, err := ParseUntypedTextArray(string(src)) + if err != nil { + return err + } + + var elements []ValueTranscoder + + if len(uta.Elements) > 0 { + elements = make([]ValueTranscoder, len(uta.Elements)) + + for i, s := range uta.Elements { + elem := dst.newElement() + var elemSrc []byte + if s != "NULL" { + elemSrc = []byte(s) + } + err = elem.DecodeText(ci, elemSrc) + if err != nil { + return err + } + + elements[i] = elem + } + } + + dst.elements = elements + dst.dimensions = uta.Dimensions + dst.status = Present + + return nil +} + +func (dst *ArrayType) DecodeBinary(ci *ConnInfo, src []byte) error { + if src == nil { + dst.setNil() + return nil + } + + var arrayHeader ArrayHeader + rp, err := arrayHeader.DecodeBinary(ci, src) + if err != nil { + return err + } + + if len(arrayHeader.Dimensions) == 0 { + *dst = ArrayType{dimensions: arrayHeader.Dimensions, status: Present} + return nil + } + + elementCount := arrayHeader.Dimensions[0].Length + for _, d := range arrayHeader.Dimensions[1:] { + elementCount *= d.Length + } + + elements := make([]ValueTranscoder, elementCount) + + for i := range elements { + elem := dst.newElement() + elemLen := int(int32(binary.BigEndian.Uint32(src[rp:]))) + rp += 4 + var elemSrc []byte + if elemLen >= 0 { + elemSrc = src[rp : rp+elemLen] + rp += elemLen + } + err = elem.DecodeBinary(ci, elemSrc) + if err != nil { + return err + } + + elements[i] = elem + } + + dst.elements = elements + dst.dimensions = arrayHeader.Dimensions + dst.status = Present + + return nil +} + +func (src ArrayType) EncodeText(ci *ConnInfo, buf []byte) ([]byte, error) { + switch src.status { + case Null: + return nil, nil + case Undefined: + return nil, errUndefined + } + + if len(src.dimensions) == 0 { + return append(buf, '{', '}'), nil + } + + buf = EncodeTextArrayDimensions(buf, src.dimensions) + + // dimElemCounts is the multiples of elements that each array lies on. For + // example, a single dimension array of length 4 would have a dimElemCounts of + // [4]. A multi-dimensional array of lengths [3,5,2] would have a + // dimElemCounts of [30,10,2]. This is used to simplify when to render a '{' + // or '}'. + dimElemCounts := make([]int, len(src.dimensions)) + dimElemCounts[len(src.dimensions)-1] = int(src.dimensions[len(src.dimensions)-1].Length) + for i := len(src.dimensions) - 2; i > -1; i-- { + dimElemCounts[i] = int(src.dimensions[i].Length) * dimElemCounts[i+1] + } + + inElemBuf := make([]byte, 0, 32) + for i, elem := range src.elements { + if i > 0 { + buf = append(buf, ',') + } + + for _, dec := range dimElemCounts { + if i%dec == 0 { + buf = append(buf, '{') + } + } + + elemBuf, err := elem.EncodeText(ci, inElemBuf) + if err != nil { + return nil, err + } + if elemBuf == nil { + buf = append(buf, `NULL`...) + } else { + buf = append(buf, QuoteArrayElementIfNeeded(string(elemBuf))...) + } + + for _, dec := range dimElemCounts { + if (i+1)%dec == 0 { + buf = append(buf, '}') + } + } + } + + return buf, nil +} + +func (src ArrayType) EncodeBinary(ci *ConnInfo, buf []byte) ([]byte, error) { + switch src.status { + case Null: + return nil, nil + case Undefined: + return nil, errUndefined + } + + arrayHeader := ArrayHeader{ + Dimensions: src.dimensions, + } + + { + value := src.newElement() + if dt, ok := ci.DataTypeForValue(value); ok { + arrayHeader.ElementOID = int32(dt.OID) + } else { + return nil, errors.Errorf("unable to find oid for element type %v", value) + } + } + + for i := range src.elements { + if src.elements[i].Get() == nil { + arrayHeader.ContainsNull = true + break + } + } + + buf = arrayHeader.EncodeBinary(ci, buf) + + for i := range src.elements { + sp := len(buf) + buf = pgio.AppendInt32(buf, -1) + + elemBuf, err := src.elements[i].EncodeBinary(ci, buf) + if err != nil { + return nil, err + } + if elemBuf != nil { + buf = elemBuf + pgio.SetInt32(buf[sp:], int32(len(buf[sp:])-4)) + } + } + + return buf, nil +} + +// Scan implements the database/sql Scanner interface. +func (dst *ArrayType) Scan(src interface{}) error { + if src == nil { + return dst.DecodeText(nil, 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 errors.Errorf("cannot scan %T", src) +} + +// Value implements the database/sql/driver Valuer interface. +func (src ArrayType) Value() (driver.Value, error) { + buf, err := src.EncodeText(nil, nil) + if err != nil { + return nil, err + } + if buf == nil { + return nil, nil + } + + return string(buf), nil +} diff --git a/array_type_test.go b/array_type_test.go new file mode 100644 index 00000000..d0812a67 --- /dev/null +++ b/array_type_test.go @@ -0,0 +1,62 @@ +package pgtype_test + +import ( + "context" + "testing" + + "github.com/jackc/pgtype" + "github.com/jackc/pgtype/testutil" + "github.com/stretchr/testify/require" +) + +func TestArrayTypeValue(t *testing.T) { + arrayType := pgtype.NewArrayType("_text", func() pgtype.ValueTranscoder { return &pgtype.Text{} }) + + err := arrayType.Set(nil) + require.NoError(t, err) + + gotValue := arrayType.Get() + require.Nil(t, gotValue) + + slice := []string{"foo", "bar"} + err = arrayType.AssignTo(&slice) + require.NoError(t, err) + require.Nil(t, slice) + + err = arrayType.Set([]string{}) + require.NoError(t, err) + + gotValue = arrayType.Get() + require.Len(t, gotValue, 0) + + err = arrayType.AssignTo(&slice) + require.NoError(t, err) + require.EqualValues(t, []string{}, slice) + + err = arrayType.Set([]string{"baz", "quz"}) + require.NoError(t, err) + + gotValue = arrayType.Get() + require.Len(t, gotValue, 2) + + err = arrayType.AssignTo(&slice) + require.NoError(t, err) + require.EqualValues(t, []string{"baz", "quz"}, slice) +} + +func TestArrayTypeTranscode(t *testing.T) { + conn := testutil.MustConnectPgx(t) + defer testutil.MustCloseContext(t, conn) + + conn.ConnInfo().RegisterDataType(pgtype.DataType{ + Value: pgtype.NewArrayType("_text", func() pgtype.ValueTranscoder { return &pgtype.Text{} }), + Name: "_text", + OID: pgtype.TextArrayOID, + }) + + var dstStrings []string + err := conn.QueryRow(context.Background(), "select $1::text[]", []string{"red", "green", "blue"}).Scan(&dstStrings) + require.NoError(t, err) + + require.EqualValues(t, []string{"red", "green", "blue"}, dstStrings) +} diff --git a/pgtype.go b/pgtype.go index ed676929..7fee66b3 100644 --- a/pgtype.go +++ b/pgtype.go @@ -142,6 +142,15 @@ type TypeValue interface { TypeName() string } +// ValueTranscoder is a value that implements the text and binary encoding and decoding interfaces. +type ValueTranscoder interface { + Value + TextEncoder + BinaryEncoder + TextDecoder + BinaryDecoder +} + // ResultFormatPreferrer allows a type to specify its preferred result format instead of it being inferred from // whether it is also a BinaryDecoder. type ResultFormatPreferrer interface {