protobuf-go/runtime/protoiface/methods.go
Damien Neil 4686e239b6 proto: add IsInitialized
Move all checks for required fields into a proto.IsInitialized function.

Initial testing makes me confident that we can provide a fast-path
implementation of IsInitialized which will perform more than
acceptably.  (In the degenerate-but-common case where a message
transitively contains no required fields, this check can be nearly
zero cost.)

Unifying checks into a single function provides consistent behavior
between the wire, text, and json codecs.

Performing the check after decoding eliminates the wire decoder bug
where a split message is incorrectly seen as missing required fields.

Performing the check after decoding also provides consistent and
arguably more correct behavior when the target message was partially
prepopulated.

Change-Id: I9478b7bebb263af00c0d9f66a1f26e31ff553522
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/170787
Reviewed-by: Herbie Ong <herbie@google.com>
2019-04-05 22:21:46 +00:00

73 lines
2.2 KiB
Go

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package protoiface
import (
"github.com/golang/protobuf/v2/internal/pragma"
"github.com/golang/protobuf/v2/reflect/protoreflect"
)
// Methoder is an optional interface implemented by generated messages to
// provide fast-path implementations of various operations.
type Methoder interface {
XXX_Methods() *Methods // may return nil
}
// Methods is a set of optional fast-path implementations of various operations.
type Methods struct {
// Flags indicate support for optional features.
Flags MethodFlag
// MarshalAppend appends the wire-format encoding of m to b, returning the result.
// It does not perform required field checks.
MarshalAppend func(b []byte, m protoreflect.ProtoMessage, opts MarshalOptions) ([]byte, error)
// Size returns the size in bytes of the wire-format encoding of m.
Size func(m protoreflect.ProtoMessage) int
// CachedSize returns the result of the last call to Size.
// It must not be called if the message has been changed since the last call to Size.
CachedSize func(m protoreflect.ProtoMessage) int
// Unmarshal parses the wire-format message in b and places the result in m.
// It does not reset m or perform required field checks.
Unmarshal func(b []byte, m protoreflect.ProtoMessage, opts UnmarshalOptions) error
// IsInitialized returns an error if any required fields in m are not set.
IsInitialized func(m protoreflect.ProtoMessage) error
pragma.NoUnkeyedLiterals
}
// MethodFlag indicates support for optional fast-path features.
type MethodFlag int64
const (
// MethodFlagDeterministicMarshal indicates support for deterministic marshaling.
MethodFlagDeterministicMarshal MethodFlag = 1 << iota
)
// MarshalOptions configure the marshaler.
//
// This type is identical to the one in package proto.
type MarshalOptions struct {
AllowPartial bool
Deterministic bool
Reflection bool
pragma.NoUnkeyedLiterals
}
// UnmarshalOptions configures the unmarshaler.
//
// This type is identical to the one in package proto.
type UnmarshalOptions struct {
AllowPartial bool
DiscardUnknown bool
Reflection bool
pragma.NoUnkeyedLiterals
}