pgx/pgtype/typed_array.go.erb

package pgtype

import (
	"bytes"
	"fmt"
	"io"

	"github.com/jackc/pgx/pgio"
)

type <%= pgtype_array_type %> struct {
	Elements   []<%= pgtype_element_type %>
	Dimensions []ArrayDimension
	Status     Status
}

func (dst *<%= pgtype_array_type %>) Set(src interface{}) error {
	// untyped nil and typed nil interfaces are different
	if src == nil {
		*dst = <%= pgtype_array_type %>{Status: Null}
		return nil
	}

	switch value := src.(type) {
	<% go_array_types.split(",").each do |t| %>
	case <%= t %>:
		if value == nil {
			*dst = <%= pgtype_array_type %>{Status: Null}
		} else if len(value) == 0 {
			*dst = <%= pgtype_array_type %>{Status: Present}
		} else {
			elements := make([]<%= pgtype_element_type %>, len(value))
			for i := range value {
				if err := elements[i].Set(value[i]); err != nil {
					return err
				}
			}
			*dst = <%= pgtype_array_type %>{
				Elements:   elements,
				Dimensions: []ArrayDimension{{Length: int32(len(elements)), LowerBound: 1}},
				Status:     Present,
			}
		}
	<% end %>
	default:
		if originalSrc, ok := underlyingSliceType(src); ok {
			return dst.Set(originalSrc)
		}
		return errors.Errorf("cannot convert %v to <%= pgtype_array_type %>", value)
	}

	return nil
}

func (dst *<%= pgtype_array_type %>) Get() interface{} {
	switch dst.Status {
	case Present:
		return dst
	case Null:
		return nil
	default:
		return dst.Status
	}
}

func (src *<%= pgtype_array_type %>) AssignTo(dst interface{}) error {
	switch src.Status {
	case Present:
		switch v := dst.(type) {
		<% go_array_types.split(",").each do |t| %>
		case *<%= t %>:
			*v = make(<%= t %>, len(src.Elements))
			for i := range src.Elements {
				if err := src.Elements[i].AssignTo(&((*v)[i])); err != nil {
					return err
				}
			}
			return nil
		<% end %>
		default:
			if nextDst, retry := GetAssignToDstType(dst); retry {
				return src.AssignTo(nextDst)
			}
		}
	case Null:
		return NullAssignTo(dst)
	}

	return errors.Errorf("cannot decode %#v into %T", src, dst)
}

func (dst *<%= pgtype_array_type %>) DecodeText(ci *ConnInfo, src []byte) error {
	if src == nil {
		*dst = <%= pgtype_array_type %>{Status: Null}
		return nil
	}

	uta, err := ParseUntypedTextArray(string(src))
	if err != nil {
		return err
	}

	var elements []<%= pgtype_element_type %>

	if len(uta.Elements) > 0 {
		elements = make([]<%= pgtype_element_type %>, len(uta.Elements))

		for i, s := range uta.Elements {
			var elem <%= pgtype_element_type %>
			var elemSrc []byte
			if s != "NULL" {
				elemSrc = []byte(s)
			}
			err = elem.DecodeText(ci, elemSrc)
			if err != nil {
				return err
			}

			elements[i] = elem
		}
	}

	*dst = <%= pgtype_array_type %>{Elements: elements, Dimensions: uta.Dimensions, Status: Present}

	return nil
}

<% if binary_format == "true" %>
func (dst *<%= pgtype_array_type %>) DecodeBinary(ci *ConnInfo, src []byte) error {
	if src == nil {
		*dst = <%= pgtype_array_type %>{Status: Null}
		return nil
	}

	var arrayHeader ArrayHeader
	rp, err := arrayHeader.DecodeBinary(ci, src)
	if err != nil {
		return err
	}

	if len(arrayHeader.Dimensions) == 0 {
		*dst = <%= pgtype_array_type %>{Dimensions: arrayHeader.Dimensions, Status: Present}
		return nil
	}

	elementCount := arrayHeader.Dimensions[0].Length
	for _, d := range arrayHeader.Dimensions[1:] {
		elementCount *= d.Length
	}

	elements := make([]<%= pgtype_element_type %>, 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 = <%= pgtype_array_type %>{Elements: elements, Dimensions: arrayHeader.Dimensions, Status: Present}
	return nil
}
<% end %>

func (src *<%= pgtype_array_type %>) 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, `<%= text_null %>`...)
		} else {
			buf = append(buf, QuoteArrayElementIfNeeded(string(elemBuf))...)
		}

		for _, dec := range dimElemCounts {
			if (i+1)%dec == 0 {
				buf = append(buf, '}')
			}
		}
	}

	return buf, nil
}

<% if binary_format == "true" %>
	func (src *<%= pgtype_array_type %>) 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,
		}

		if dt, ok := ci.DataTypeForName("<%= element_type_name %>"); ok {
			arrayHeader.ElementOID = int32(dt.OID)
		} else {
			return nil, errors.Errorf("unable to find oid for type name %v", "<%= element_type_name %>")
		}

		for i := range src.Elements {
			if src.Elements[i].Status == Null {
				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
	}
<% end %>

// Scan implements the database/sql Scanner interface.
func (dst *<%= pgtype_array_type %>) 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 *<%= pgtype_array_type %>) 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
}