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authorWim <wim@42.be>2020-08-10 00:29:54 +0200
committerGitHub <noreply@github.com>2020-08-10 00:29:54 +0200
commit4e50fd864921c556988c919269448efdb90fa961 (patch)
treea3625f03f8de3c4f3841364000a4ea3aa42c1533 /vendor/google.golang.org/protobuf/proto/encode.go
parentdfdffa0027334e55ce213fc6eb62206dbf48baf6 (diff)
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Use mattermost v5 module (#1192)
Diffstat (limited to 'vendor/google.golang.org/protobuf/proto/encode.go')
-rw-r--r--vendor/google.golang.org/protobuf/proto/encode.go343
1 files changed, 343 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/proto/encode.go b/vendor/google.golang.org/protobuf/proto/encode.go
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+++ b/vendor/google.golang.org/protobuf/proto/encode.go
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+// 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 proto
+
+import (
+ "sort"
+
+ "google.golang.org/protobuf/encoding/protowire"
+ "google.golang.org/protobuf/internal/encoding/messageset"
+ "google.golang.org/protobuf/internal/fieldsort"
+ "google.golang.org/protobuf/internal/mapsort"
+ "google.golang.org/protobuf/internal/pragma"
+ "google.golang.org/protobuf/reflect/protoreflect"
+ "google.golang.org/protobuf/runtime/protoiface"
+)
+
+// MarshalOptions configures the marshaler.
+//
+// Example usage:
+// b, err := MarshalOptions{Deterministic: true}.Marshal(m)
+type MarshalOptions struct {
+ pragma.NoUnkeyedLiterals
+
+ // AllowPartial allows messages that have missing required fields to marshal
+ // without returning an error. If AllowPartial is false (the default),
+ // Marshal will return an error if there are any missing required fields.
+ AllowPartial bool
+
+ // Deterministic controls whether the same message will always be
+ // serialized to the same bytes within the same binary.
+ //
+ // Setting this option guarantees that repeated serialization of
+ // the same message will return the same bytes, and that different
+ // processes of the same binary (which may be executing on different
+ // machines) will serialize equal messages to the same bytes.
+ // It has no effect on the resulting size of the encoded message compared
+ // to a non-deterministic marshal.
+ //
+ // Note that the deterministic serialization is NOT canonical across
+ // languages. It is not guaranteed to remain stable over time. It is
+ // unstable across different builds with schema changes due to unknown
+ // fields. Users who need canonical serialization (e.g., persistent
+ // storage in a canonical form, fingerprinting, etc.) must define
+ // their own canonicalization specification and implement their own
+ // serializer rather than relying on this API.
+ //
+ // If deterministic serialization is requested, map entries will be
+ // sorted by keys in lexographical order. This is an implementation
+ // detail and subject to change.
+ Deterministic bool
+
+ // UseCachedSize indicates that the result of a previous Size call
+ // may be reused.
+ //
+ // Setting this option asserts that:
+ //
+ // 1. Size has previously been called on this message with identical
+ // options (except for UseCachedSize itself).
+ //
+ // 2. The message and all its submessages have not changed in any
+ // way since the Size call.
+ //
+ // If either of these invariants is violated,
+ // the results are undefined and may include panics or corrupted output.
+ //
+ // Implementations MAY take this option into account to provide
+ // better performance, but there is no guarantee that they will do so.
+ // There is absolutely no guarantee that Size followed by Marshal with
+ // UseCachedSize set will perform equivalently to Marshal alone.
+ UseCachedSize bool
+}
+
+// Marshal returns the wire-format encoding of m.
+func Marshal(m Message) ([]byte, error) {
+ // Treat nil message interface as an empty message; nothing to output.
+ if m == nil {
+ return nil, nil
+ }
+
+ out, err := MarshalOptions{}.marshal(nil, m.ProtoReflect())
+ if len(out.Buf) == 0 && err == nil {
+ out.Buf = emptyBytesForMessage(m)
+ }
+ return out.Buf, err
+}
+
+// Marshal returns the wire-format encoding of m.
+func (o MarshalOptions) Marshal(m Message) ([]byte, error) {
+ // Treat nil message interface as an empty message; nothing to output.
+ if m == nil {
+ return nil, nil
+ }
+
+ out, err := o.marshal(nil, m.ProtoReflect())
+ if len(out.Buf) == 0 && err == nil {
+ out.Buf = emptyBytesForMessage(m)
+ }
+ return out.Buf, err
+}
+
+// emptyBytesForMessage returns a nil buffer if and only if m is invalid,
+// otherwise it returns a non-nil empty buffer.
+//
+// This is to assist the edge-case where user-code does the following:
+// m1.OptionalBytes, _ = proto.Marshal(m2)
+// where they expect the proto2 "optional_bytes" field to be populated
+// if any only if m2 is a valid message.
+func emptyBytesForMessage(m Message) []byte {
+ if m == nil || !m.ProtoReflect().IsValid() {
+ return nil
+ }
+ return emptyBuf[:]
+}
+
+// MarshalAppend appends the wire-format encoding of m to b,
+// returning the result.
+func (o MarshalOptions) MarshalAppend(b []byte, m Message) ([]byte, error) {
+ // Treat nil message interface as an empty message; nothing to append.
+ if m == nil {
+ return b, nil
+ }
+
+ out, err := o.marshal(b, m.ProtoReflect())
+ return out.Buf, err
+}
+
+// MarshalState returns the wire-format encoding of a message.
+//
+// This method permits fine-grained control over the marshaler.
+// Most users should use Marshal instead.
+func (o MarshalOptions) MarshalState(in protoiface.MarshalInput) (protoiface.MarshalOutput, error) {
+ return o.marshal(in.Buf, in.Message)
+}
+
+func (o MarshalOptions) marshal(b []byte, m protoreflect.Message) (out protoiface.MarshalOutput, err error) {
+ allowPartial := o.AllowPartial
+ o.AllowPartial = true
+ if methods := protoMethods(m); methods != nil && methods.Marshal != nil &&
+ !(o.Deterministic && methods.Flags&protoiface.SupportMarshalDeterministic == 0) {
+ in := protoiface.MarshalInput{
+ Message: m,
+ Buf: b,
+ }
+ if o.Deterministic {
+ in.Flags |= protoiface.MarshalDeterministic
+ }
+ if o.UseCachedSize {
+ in.Flags |= protoiface.MarshalUseCachedSize
+ }
+ if methods.Size != nil {
+ sout := methods.Size(protoiface.SizeInput{
+ Message: m,
+ Flags: in.Flags,
+ })
+ if cap(b) < len(b)+sout.Size {
+ in.Buf = make([]byte, len(b), growcap(cap(b), len(b)+sout.Size))
+ copy(in.Buf, b)
+ }
+ in.Flags |= protoiface.MarshalUseCachedSize
+ }
+ out, err = methods.Marshal(in)
+ } else {
+ out.Buf, err = o.marshalMessageSlow(b, m)
+ }
+ if err != nil {
+ return out, err
+ }
+ if allowPartial {
+ return out, nil
+ }
+ return out, checkInitialized(m)
+}
+
+func (o MarshalOptions) marshalMessage(b []byte, m protoreflect.Message) ([]byte, error) {
+ out, err := o.marshal(b, m)
+ return out.Buf, err
+}
+
+// growcap scales up the capacity of a slice.
+//
+// Given a slice with a current capacity of oldcap and a desired
+// capacity of wantcap, growcap returns a new capacity >= wantcap.
+//
+// The algorithm is mostly identical to the one used by append as of Go 1.14.
+func growcap(oldcap, wantcap int) (newcap int) {
+ if wantcap > oldcap*2 {
+ newcap = wantcap
+ } else if oldcap < 1024 {
+ // The Go 1.14 runtime takes this case when len(s) < 1024,
+ // not when cap(s) < 1024. The difference doesn't seem
+ // significant here.
+ newcap = oldcap * 2
+ } else {
+ newcap = oldcap
+ for 0 < newcap && newcap < wantcap {
+ newcap += newcap / 4
+ }
+ if newcap <= 0 {
+ newcap = wantcap
+ }
+ }
+ return newcap
+}
+
+func (o MarshalOptions) marshalMessageSlow(b []byte, m protoreflect.Message) ([]byte, error) {
+ if messageset.IsMessageSet(m.Descriptor()) {
+ return marshalMessageSet(b, m, o)
+ }
+ // There are many choices for what order we visit fields in. The default one here
+ // is chosen for reasonable efficiency and simplicity given the protoreflect API.
+ // It is not deterministic, since Message.Range does not return fields in any
+ // defined order.
+ //
+ // When using deterministic serialization, we sort the known fields.
+ var err error
+ o.rangeFields(m, func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
+ b, err = o.marshalField(b, fd, v)
+ return err == nil
+ })
+ if err != nil {
+ return b, err
+ }
+ b = append(b, m.GetUnknown()...)
+ return b, nil
+}
+
+// rangeFields visits fields in a defined order when deterministic serialization is enabled.
+func (o MarshalOptions) rangeFields(m protoreflect.Message, f func(protoreflect.FieldDescriptor, protoreflect.Value) bool) {
+ if !o.Deterministic {
+ m.Range(f)
+ return
+ }
+ var fds []protoreflect.FieldDescriptor
+ m.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
+ fds = append(fds, fd)
+ return true
+ })
+ sort.Slice(fds, func(a, b int) bool {
+ return fieldsort.Less(fds[a], fds[b])
+ })
+ for _, fd := range fds {
+ if !f(fd, m.Get(fd)) {
+ break
+ }
+ }
+}
+
+func (o MarshalOptions) marshalField(b []byte, fd protoreflect.FieldDescriptor, value protoreflect.Value) ([]byte, error) {
+ switch {
+ case fd.IsList():
+ return o.marshalList(b, fd, value.List())
+ case fd.IsMap():
+ return o.marshalMap(b, fd, value.Map())
+ default:
+ b = protowire.AppendTag(b, fd.Number(), wireTypes[fd.Kind()])
+ return o.marshalSingular(b, fd, value)
+ }
+}
+
+func (o MarshalOptions) marshalList(b []byte, fd protoreflect.FieldDescriptor, list protoreflect.List) ([]byte, error) {
+ if fd.IsPacked() && list.Len() > 0 {
+ b = protowire.AppendTag(b, fd.Number(), protowire.BytesType)
+ b, pos := appendSpeculativeLength(b)
+ for i, llen := 0, list.Len(); i < llen; i++ {
+ var err error
+ b, err = o.marshalSingular(b, fd, list.Get(i))
+ if err != nil {
+ return b, err
+ }
+ }
+ b = finishSpeculativeLength(b, pos)
+ return b, nil
+ }
+
+ kind := fd.Kind()
+ for i, llen := 0, list.Len(); i < llen; i++ {
+ var err error
+ b = protowire.AppendTag(b, fd.Number(), wireTypes[kind])
+ b, err = o.marshalSingular(b, fd, list.Get(i))
+ if err != nil {
+ return b, err
+ }
+ }
+ return b, nil
+}
+
+func (o MarshalOptions) marshalMap(b []byte, fd protoreflect.FieldDescriptor, mapv protoreflect.Map) ([]byte, error) {
+ keyf := fd.MapKey()
+ valf := fd.MapValue()
+ var err error
+ o.rangeMap(mapv, keyf.Kind(), func(key protoreflect.MapKey, value protoreflect.Value) bool {
+ b = protowire.AppendTag(b, fd.Number(), protowire.BytesType)
+ var pos int
+ b, pos = appendSpeculativeLength(b)
+
+ b, err = o.marshalField(b, keyf, key.Value())
+ if err != nil {
+ return false
+ }
+ b, err = o.marshalField(b, valf, value)
+ if err != nil {
+ return false
+ }
+ b = finishSpeculativeLength(b, pos)
+ return true
+ })
+ return b, err
+}
+
+func (o MarshalOptions) rangeMap(mapv protoreflect.Map, kind protoreflect.Kind, f func(protoreflect.MapKey, protoreflect.Value) bool) {
+ if !o.Deterministic {
+ mapv.Range(f)
+ return
+ }
+ mapsort.Range(mapv, kind, f)
+}
+
+// When encoding length-prefixed fields, we speculatively set aside some number of bytes
+// for the length, encode the data, and then encode the length (shifting the data if necessary
+// to make room).
+const speculativeLength = 1
+
+func appendSpeculativeLength(b []byte) ([]byte, int) {
+ pos := len(b)
+ b = append(b, "\x00\x00\x00\x00"[:speculativeLength]...)
+ return b, pos
+}
+
+func finishSpeculativeLength(b []byte, pos int) []byte {
+ mlen := len(b) - pos - speculativeLength
+ msiz := protowire.SizeVarint(uint64(mlen))
+ if msiz != speculativeLength {
+ for i := 0; i < msiz-speculativeLength; i++ {
+ b = append(b, 0)
+ }
+ copy(b[pos+msiz:], b[pos+speculativeLength:])
+ b = b[:pos+msiz+mlen]
+ }
+ protowire.AppendVarint(b[:pos], uint64(mlen))
+ return b
+}