internal/impl: refactor fast-path
Move data used by the fast-path implementations into a substructure of
MessageInfo and initialize it separately.
Change-Id: Ib855ee8ea5cb0379528b52ba0e191319aa5e2dff
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184077
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/internal/impl/codec_message.go b/internal/impl/codec_message.go
new file mode 100644
index 0000000..204049d
--- /dev/null
+++ b/internal/impl/codec_message.go
@@ -0,0 +1,101 @@
+// 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 impl
+
+import (
+ "reflect"
+ "sort"
+
+ "google.golang.org/protobuf/internal/encoding/wire"
+ pref "google.golang.org/protobuf/reflect/protoreflect"
+ piface "google.golang.org/protobuf/runtime/protoiface"
+)
+
+// coderMessageInfo contains per-message information used by the fast-path functions.
+// This is a different type from MessageInfo to keep MessageInfo as general-purpose as
+// possible.
+type coderMessageInfo struct {
+ orderedCoderFields []*coderFieldInfo
+ sizecacheOffset offset
+ extensionOffset offset
+ unknownOffset offset
+ needsInitCheck bool
+}
+
+type coderFieldInfo struct {
+ funcs pointerCoderFuncs // fast-path per-field functions
+ num pref.FieldNumber // field number
+ offset offset // struct field offset
+ wiretag uint64 // field tag (number + wire type)
+ tagsize int // size of the varint-encoded tag
+ isPointer bool // true if IsNil may be called on the struct field
+ isRequired bool // true if field is required
+}
+
+func (mi *MessageInfo) makeMethods(t reflect.Type, si structInfo) {
+ mi.sizecacheOffset = invalidOffset
+ if fx, _ := t.FieldByName("XXX_sizecache"); fx.Type == sizecacheType {
+ mi.sizecacheOffset = offsetOf(fx)
+ }
+ mi.unknownOffset = invalidOffset
+ if fx, _ := t.FieldByName("XXX_unrecognized"); fx.Type == unknownFieldsType {
+ mi.unknownOffset = offsetOf(fx)
+ }
+ mi.extensionOffset = invalidOffset
+ if fx, _ := t.FieldByName("XXX_InternalExtensions"); fx.Type == extensionFieldsType {
+ mi.extensionOffset = offsetOf(fx)
+ } else if fx, _ = t.FieldByName("XXX_extensions"); fx.Type == extensionFieldsType {
+ mi.extensionOffset = offsetOf(fx)
+ }
+
+ for i := 0; i < mi.PBType.Descriptor().Fields().Len(); i++ {
+ fd := mi.PBType.Descriptor().Fields().Get(i)
+ if fd.ContainingOneof() != nil {
+ continue
+ }
+
+ fs := si.fieldsByNumber[fd.Number()]
+ ft := fs.Type
+ var wiretag uint64
+ if !fd.IsPacked() {
+ wiretag = wire.EncodeTag(fd.Number(), wireTypes[fd.Kind()])
+ } else {
+ wiretag = wire.EncodeTag(fd.Number(), wire.BytesType)
+ }
+ mi.orderedCoderFields = append(mi.orderedCoderFields, &coderFieldInfo{
+ num: fd.Number(),
+ offset: offsetOf(fs),
+ wiretag: wiretag,
+ tagsize: wire.SizeVarint(wiretag),
+ funcs: fieldCoder(fd, ft),
+ isPointer: (fd.Cardinality() == pref.Repeated ||
+ fd.Kind() == pref.MessageKind ||
+ fd.Kind() == pref.GroupKind ||
+ fd.Syntax() != pref.Proto3),
+ isRequired: fd.Cardinality() == pref.Required,
+ })
+ }
+ for i := 0; i < mi.PBType.Descriptor().Oneofs().Len(); i++ {
+ od := mi.PBType.Descriptor().Oneofs().Get(i)
+ fs := si.oneofsByName[od.Name()]
+ mi.orderedCoderFields = append(mi.orderedCoderFields, &coderFieldInfo{
+ num: od.Fields().Get(0).Number(),
+ offset: offsetOf(fs),
+ funcs: makeOneofFieldCoder(fs, od, si.fieldsByNumber, si.oneofWrappersByNumber),
+ isPointer: true,
+ })
+ }
+ sort.Slice(mi.orderedCoderFields, func(i, j int) bool {
+ return mi.orderedCoderFields[i].num < mi.orderedCoderFields[j].num
+ })
+
+ mi.needsInitCheck = needsInitCheck(mi.PBType)
+ mi.methods = piface.Methods{
+ Flags: piface.MethodFlagDeterministicMarshal,
+ MarshalAppend: mi.marshalAppend,
+ Size: mi.size,
+ IsInitialized: mi.isInitialized,
+ }
+}