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author | Wim <wim@42.be> | 2020-08-10 00:29:54 +0200 |
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committer | GitHub <noreply@github.com> | 2020-08-10 00:29:54 +0200 |
commit | 4e50fd864921c556988c919269448efdb90fa961 (patch) | |
tree | a3625f03f8de3c4f3841364000a4ea3aa42c1533 /vendor/google.golang.org/protobuf/proto/merge.go | |
parent | dfdffa0027334e55ce213fc6eb62206dbf48baf6 (diff) | |
download | matterbridge-msglm-4e50fd864921c556988c919269448efdb90fa961.tar.gz matterbridge-msglm-4e50fd864921c556988c919269448efdb90fa961.tar.bz2 matterbridge-msglm-4e50fd864921c556988c919269448efdb90fa961.zip |
Use mattermost v5 module (#1192)
Diffstat (limited to 'vendor/google.golang.org/protobuf/proto/merge.go')
-rw-r--r-- | vendor/google.golang.org/protobuf/proto/merge.go | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/proto/merge.go b/vendor/google.golang.org/protobuf/proto/merge.go new file mode 100644 index 00000000..d761ab33 --- /dev/null +++ b/vendor/google.golang.org/protobuf/proto/merge.go @@ -0,0 +1,139 @@ +// 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 ( + "fmt" + + "google.golang.org/protobuf/reflect/protoreflect" + "google.golang.org/protobuf/runtime/protoiface" +) + +// Merge merges src into dst, which must be a message with the same descriptor. +// +// Populated scalar fields in src are copied to dst, while populated +// singular messages in src are merged into dst by recursively calling Merge. +// The elements of every list field in src is appended to the corresponded +// list fields in dst. The entries of every map field in src is copied into +// the corresponding map field in dst, possibly replacing existing entries. +// The unknown fields of src are appended to the unknown fields of dst. +// +// It is semantically equivalent to unmarshaling the encoded form of src +// into dst with the UnmarshalOptions.Merge option specified. +func Merge(dst, src Message) { + // TODO: Should nil src be treated as semantically equivalent to a + // untyped, read-only, empty message? What about a nil dst? + + dstMsg, srcMsg := dst.ProtoReflect(), src.ProtoReflect() + if dstMsg.Descriptor() != srcMsg.Descriptor() { + if got, want := dstMsg.Descriptor().FullName(), srcMsg.Descriptor().FullName(); got != want { + panic(fmt.Sprintf("descriptor mismatch: %v != %v", got, want)) + } + panic("descriptor mismatch") + } + mergeOptions{}.mergeMessage(dstMsg, srcMsg) +} + +// Clone returns a deep copy of m. +// If the top-level message is invalid, it returns an invalid message as well. +func Clone(m Message) Message { + // NOTE: Most usages of Clone assume the following properties: + // t := reflect.TypeOf(m) + // t == reflect.TypeOf(m.ProtoReflect().New().Interface()) + // t == reflect.TypeOf(m.ProtoReflect().Type().Zero().Interface()) + // + // Embedding protobuf messages breaks this since the parent type will have + // a forwarded ProtoReflect method, but the Interface method will return + // the underlying embedded message type. + if m == nil { + return nil + } + src := m.ProtoReflect() + if !src.IsValid() { + return src.Type().Zero().Interface() + } + dst := src.New() + mergeOptions{}.mergeMessage(dst, src) + return dst.Interface() +} + +// mergeOptions provides a namespace for merge functions, and can be +// exported in the future if we add user-visible merge options. +type mergeOptions struct{} + +func (o mergeOptions) mergeMessage(dst, src protoreflect.Message) { + methods := protoMethods(dst) + if methods != nil && methods.Merge != nil { + in := protoiface.MergeInput{ + Destination: dst, + Source: src, + } + out := methods.Merge(in) + if out.Flags&protoiface.MergeComplete != 0 { + return + } + } + + if !dst.IsValid() { + panic(fmt.Sprintf("cannot merge into invalid %v message", dst.Descriptor().FullName())) + } + + src.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool { + switch { + case fd.IsList(): + o.mergeList(dst.Mutable(fd).List(), v.List(), fd) + case fd.IsMap(): + o.mergeMap(dst.Mutable(fd).Map(), v.Map(), fd.MapValue()) + case fd.Message() != nil: + o.mergeMessage(dst.Mutable(fd).Message(), v.Message()) + case fd.Kind() == protoreflect.BytesKind: + dst.Set(fd, o.cloneBytes(v)) + default: + dst.Set(fd, v) + } + return true + }) + + if len(src.GetUnknown()) > 0 { + dst.SetUnknown(append(dst.GetUnknown(), src.GetUnknown()...)) + } +} + +func (o mergeOptions) mergeList(dst, src protoreflect.List, fd protoreflect.FieldDescriptor) { + // Merge semantics appends to the end of the existing list. + for i, n := 0, src.Len(); i < n; i++ { + switch v := src.Get(i); { + case fd.Message() != nil: + dstv := dst.NewElement() + o.mergeMessage(dstv.Message(), v.Message()) + dst.Append(dstv) + case fd.Kind() == protoreflect.BytesKind: + dst.Append(o.cloneBytes(v)) + default: + dst.Append(v) + } + } +} + +func (o mergeOptions) mergeMap(dst, src protoreflect.Map, fd protoreflect.FieldDescriptor) { + // Merge semantics replaces, rather than merges into existing entries. + src.Range(func(k protoreflect.MapKey, v protoreflect.Value) bool { + switch { + case fd.Message() != nil: + dstv := dst.NewValue() + o.mergeMessage(dstv.Message(), v.Message()) + dst.Set(k, dstv) + case fd.Kind() == protoreflect.BytesKind: + dst.Set(k, o.cloneBytes(v)) + default: + dst.Set(k, v) + } + return true + }) +} + +func (o mergeOptions) cloneBytes(v protoreflect.Value) protoreflect.Value { + return protoreflect.ValueOfBytes(append([]byte{}, v.Bytes()...)) +} |