tree 5750d45ae06f9836b101eddacc8c6ccfbbcd3baf
parent 69839c78c3baff8f1fb37f37b24127ecae185e03
author Joe Tsai <joetsai@digital-static.net> 1585077733 -0700
committer Joe Tsai <joetsai@digital-static.net> 1591737714 +0000

all: implement first-class WKT support

This CL introduces generation of specialized APIs directly into the
generated packages for certain well-known types. This follows the pattern
set forth by the other language implementations that have specialized
generated support for certain well-known types.

Overview of new API:
  package anypb
    func MarshalFrom(*Any, proto.Message, proto.MarshalOptions) error
    func UnmarshalTo(*Any, proto.Message, proto.UnmarshalOptions) error
    func UnmarshalNew(*Any, proto.UnmarshalOptions) (proto.Message, error)
    func (*Any) MessageIs(proto.Message) bool
    func (*Any) MessageName() protoreflect.FullName
    func (*Any) MarshalFrom(proto.Message) error
    func (*Any) UnmarshalTo(proto.Message) error
    func (*Any) UnmarshalNew() (proto.Message, error)

  package timestamppb
    func Now() *Timestamp
    func New(time.Time) *Timestamp
    func (*Timestamp) AsTime() time.Time
    func (*Timestamp) IsValid() bool
    func (*Timestamp) CheckValid() error

  package durationpb
    func New(time.Duration) *Duration
    func (*Duration) AsDuration() time.Duration
    func (*Duration) IsValid() bool
    func (*Duration) CheckValid() error

  package structpb
    func NewStruct(map[string]interface{}) (*Struct, error)
    func (*Struct) AsMap() map[string]interface{}
    func (*Struct) MarshalJSON() ([]byte, error)
    func (*Struct) UnmarshalJSON(b []byte) error

    func NewList([]interface{}) (*ListValue, error)
    func (*ListValue) AsSlice() []interface{}
    func (*ListValue) MarshalJSON() ([]byte, error)
    func (*ListValue) UnmarshalJSON(b []byte) error

    func NewValue(interface{}) (*Value, error)
    func NewNullValue() *Value
    func NewBoolValue(bool) *Value
    func NewNumberValue(float64) *Value
    func NewStringValue(string) *Value
    func NewStructValue(*Struct) *Value
    func NewListValue(*ListValue) *Value
    func (*Value) AsInterface() interface{}
    func (*Value) MarshalJSON() ([]byte, error)
    func (*Value) UnmarshalJSON(b []byte) error

  package fieldmaskpb
    func New(proto.Message, ...string) (*FieldMask, error)
    func Union(*FieldMask, *FieldMask, ...*FieldMask) *FieldMask
    func Intersect(*FieldMask, *FieldMask, ...*FieldMask) *FieldMask
    func (*FieldMask) IsValid(proto.Message) bool
    func (*FieldMask) Append(proto.Message, ...string) error
    func (*FieldMask) Normalize()

  package wrapperspb
    func Bool(bool) *BoolValue
    func Int32(int32) *Int32Value
    func Int64(int64) *Int64Value
    func UInt32(uint32) *UInt32Value
    func UInt64(uint64) *UInt64Value
    func Float(float32) *FloatValue
    func Double(float64) *DoubleValue
    func String(string) *StringValue
    func Bytes([]byte) *BytesValue

This functionality expands upon and supersedes the
older github.com/golang/protobuf/ptypes package,
which provided helpers for Any, Timestamp, and Duration.

Comparison with older ptypes package:

* ptypes.AnyMessageName is replaced by anypb.Any.MessageName.
  The former returned an error for malformed type URLs,
  while the latter simply returns an empty string.

* ptypes.Is is replaced by anypb.Any.MessageIs.

* ptypes.Empty has no direct replacement as it is equivalent to:
	mt, err := protoregistry.GlobalTypes.FindMessageByURL(any.GetTypeUrl())
	if err != nil {
		return nil, err
	}
	return mt.New().Interface(), nil
  Analysis of user code revealed that this function is seldom used.

* ptypes.MarshalAny is replaced by anypb.Any.MarshalFrom.
  The former creates a new Any message and returns it,
  while the latter is a method that modifies the receiver.

* ptypes.UnmarshalAny is replaced by anypb.Any.UnmarshalTo.

* ptypes.DynamicAny is loosely replaced by anypb.Any.UnmarshalNew.
  The DynamicAny type is a custom proto.Message that is special
  to ptypes.UnmarshalAny where it would allocate a new message
  and store it into the DynamicAny instance. The UnmarshalNew method
  accomplishes the equivalent functionality in a more direct fashion.

* ptypes.TimestampNow is replaced by timestamppb.Now.

* ptypes.TimestampProto is replaced by timestamppb.New.
  The former returned an error if the timestamp was outside the
  10000-year range recommended by timestamp.proto,
  while the latter always succeeded. To preserve the behavior of
  the former validation check, the replacement can additionally
  call the timestamppb.Timestamp.CheckValid method.

* ptypes.Timestamp is replaced by timestamppb.Timestamp.AsTime.
  The former returned an error if the timestamp was outside the
  10000-year range recommended by timestamp.proto,
  while the latter always succeeded. To preserve the behavior of
  the former validation check, the replacement can additionally
  call the timestamppb.Timestamp.CheckValid method.

* ptypes.TimestampString has no direct replacement as it is equivalent to:
	ts.AsTime().Format(time.RFC3339Nano)

* ptypes.DurationProto is replaced by durationpb.New.

* ptypes.Duration is replaced by durationpb.Duration.AsDuration.
  The former returned an error if the duration would overflow
  when converting to a time.Duration, while the latter uses
  saturation arithmetic (similiar to the time package itself).
  Underflow resulted in time.Duration(math.MinInt64), while
  overflow resulted in time.Duration(math.MaxInt64).
  To preserve the behavior of former validation checks,
  the replacement can call the durationpb.Duration.CheckValid method
  and check whether the duration is fixed to one of the overflow values.

Change-Id: Ia996b1037a1fcafced7c7e10e9408ef7fa22863a
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/225298
Reviewed-by: Damien Neil <dneil@google.com>