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timestamp.go
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timestamp.go
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package pgtype
import (
"database/sql/driver"
"encoding/binary"
"time"
"github.com/pkg/errors"
"github.com/ronaldslc/pgx/pgio"
)
const pgTimestampFormat = "2006-01-02 15:04:05.999999999"
// Timestamp represents the PostgreSQL timestamp type. The PostgreSQL
// timestamp does not have a time zone. This presents a problem when
// translating to and from time.Time which requires a time zone. It is highly
// recommended to use timestamptz whenever possible. Timestamp methods either
// convert to UTC or return an error on non-UTC times.
type Timestamp struct {
Time time.Time // Time must always be in UTC.
Status Status
InfinityModifier InfinityModifier
}
// Set converts src into a Timestamp and stores in dst. If src is a
// time.Time in a non-UTC time zone, the time zone is discarded.
func (dst *Timestamp) Set(src interface{}) error {
if src == nil {
*dst = Timestamp{Status: Null}
return nil
}
switch value := src.(type) {
case time.Time:
*dst = Timestamp{Time: time.Date(value.Year(), value.Month(), value.Day(), value.Hour(), value.Minute(), value.Second(), value.Nanosecond(), time.UTC), Status: Present}
default:
if originalSrc, ok := underlyingTimeType(src); ok {
return dst.Set(originalSrc)
}
return errors.Errorf("cannot convert %v to Timestamp", value)
}
return nil
}
func (dst *Timestamp) Get() interface{} {
switch dst.Status {
case Present:
if dst.InfinityModifier != None {
return dst.InfinityModifier
}
return dst.Time
case Null:
return nil
default:
return dst.Status
}
}
func (src *Timestamp) AssignTo(dst interface{}) error {
switch src.Status {
case Present:
switch v := dst.(type) {
case *time.Time:
if src.InfinityModifier != None {
return errors.Errorf("cannot assign %v to %T", src, dst)
}
*v = src.Time
return nil
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)
}
// DecodeText decodes from src into dst. The decoded time is considered to
// be in UTC.
func (dst *Timestamp) DecodeText(ci *ConnInfo, src []byte) error {
if src == nil {
*dst = Timestamp{Status: Null}
return nil
}
sbuf := string(src)
switch sbuf {
case "infinity":
*dst = Timestamp{Status: Present, InfinityModifier: Infinity}
case "-infinity":
*dst = Timestamp{Status: Present, InfinityModifier: -Infinity}
default:
tim, err := time.Parse(pgTimestampFormat, sbuf)
if err != nil {
return err
}
*dst = Timestamp{Time: tim, Status: Present}
}
return nil
}
// DecodeBinary decodes from src into dst. The decoded time is considered to
// be in UTC.
func (dst *Timestamp) DecodeBinary(ci *ConnInfo, src []byte) error {
if src == nil {
*dst = Timestamp{Status: Null}
return nil
}
if len(src) != 8 {
return errors.Errorf("invalid length for timestamp: %v", len(src))
}
microsecSinceY2K := int64(binary.BigEndian.Uint64(src))
switch microsecSinceY2K {
case infinityMicrosecondOffset:
*dst = Timestamp{Status: Present, InfinityModifier: Infinity}
case negativeInfinityMicrosecondOffset:
*dst = Timestamp{Status: Present, InfinityModifier: -Infinity}
default:
microsecSinceUnixEpoch := microsecFromUnixEpochToY2K + microsecSinceY2K
tim := time.Unix(microsecSinceUnixEpoch/1000000, (microsecSinceUnixEpoch%1000000)*1000).UTC()
*dst = Timestamp{Time: tim, Status: Present}
}
return nil
}
// EncodeText writes the text encoding of src into w. If src.Time is not in
// the UTC time zone it returns an error.
func (src *Timestamp) EncodeText(ci *ConnInfo, buf []byte) ([]byte, error) {
switch src.Status {
case Null:
return nil, nil
case Undefined:
return nil, errUndefined
}
if src.Time.Location() != time.UTC {
return nil, errors.Errorf("cannot encode non-UTC time into timestamp")
}
var s string
switch src.InfinityModifier {
case None:
s = src.Time.Format(pgTimestampFormat)
case Infinity:
s = "infinity"
case NegativeInfinity:
s = "-infinity"
}
return append(buf, s...), nil
}
// EncodeBinary writes the binary encoding of src into w. If src.Time is not in
// the UTC time zone it returns an error.
func (src *Timestamp) EncodeBinary(ci *ConnInfo, buf []byte) ([]byte, error) {
switch src.Status {
case Null:
return nil, nil
case Undefined:
return nil, errUndefined
}
if src.Time.Location() != time.UTC {
return nil, errors.Errorf("cannot encode non-UTC time into timestamp")
}
var microsecSinceY2K int64
switch src.InfinityModifier {
case None:
microsecSinceUnixEpoch := src.Time.Unix()*1000000 + int64(src.Time.Nanosecond())/1000
microsecSinceY2K = microsecSinceUnixEpoch - microsecFromUnixEpochToY2K
case Infinity:
microsecSinceY2K = infinityMicrosecondOffset
case NegativeInfinity:
microsecSinceY2K = negativeInfinityMicrosecondOffset
}
return pgio.AppendInt64(buf, microsecSinceY2K), nil
}
// Scan implements the database/sql Scanner interface.
func (dst *Timestamp) Scan(src interface{}) error {
if src == nil {
*dst = Timestamp{Status: Null}
return 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)
case time.Time:
*dst = Timestamp{Time: src, Status: Present}
return nil
}
return errors.Errorf("cannot scan %T", src)
}
// Value implements the database/sql/driver Valuer interface.
func (src *Timestamp) Value() (driver.Value, error) {
switch src.Status {
case Present:
if src.InfinityModifier != None {
return src.InfinityModifier.String(), nil
}
return src.Time, nil
case Null:
return nil, nil
default:
return nil, errUndefined
}
}