diff options
Diffstat (limited to 'internal/impl/codec_message.go')
| -rw-r--r-- | internal/impl/codec_message.go | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/internal/impl/codec_message.go b/internal/impl/codec_message.go new file mode 100644 index 00000000..cd40527f --- /dev/null +++ b/internal/impl/codec_message.go @@ -0,0 +1,217 @@ +// 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 ( + "fmt" + "reflect" + "sort" + + "google.golang.org/protobuf/encoding/protowire" + "google.golang.org/protobuf/internal/encoding/messageset" + "google.golang.org/protobuf/internal/order" + 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 { + methods piface.Methods + + orderedCoderFields []*coderFieldInfo + denseCoderFields []*coderFieldInfo + coderFields map[protowire.Number]*coderFieldInfo + sizecacheOffset offset + unknownOffset offset + unknownPtrKind bool + extensionOffset offset + needsInitCheck bool + isMessageSet bool + numRequiredFields uint8 +} + +type coderFieldInfo struct { + funcs pointerCoderFuncs // fast-path per-field functions + mi *MessageInfo // field's message + ft reflect.Type + validation validationInfo // information used by message validation + 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) makeCoderMethods(t reflect.Type, si structInfo) { + mi.sizecacheOffset = invalidOffset + mi.unknownOffset = invalidOffset + mi.extensionOffset = invalidOffset + + if si.sizecacheOffset.IsValid() && si.sizecacheType == sizecacheType { + mi.sizecacheOffset = si.sizecacheOffset + } + if si.unknownOffset.IsValid() && (si.unknownType == unknownFieldsAType || si.unknownType == unknownFieldsBType) { + mi.unknownOffset = si.unknownOffset + mi.unknownPtrKind = si.unknownType.Kind() == reflect.Ptr + } + if si.extensionOffset.IsValid() && si.extensionType == extensionFieldsType { + mi.extensionOffset = si.extensionOffset + } + + mi.coderFields = make(map[protowire.Number]*coderFieldInfo) + fields := mi.Desc.Fields() + preallocFields := make([]coderFieldInfo, fields.Len()) + for i := 0; i < fields.Len(); i++ { + fd := fields.Get(i) + + fs := si.fieldsByNumber[fd.Number()] + isOneof := fd.ContainingOneof() != nil && !fd.ContainingOneof().IsSynthetic() + if isOneof { + fs = si.oneofsByName[fd.ContainingOneof().Name()] + } + ft := fs.Type + var wiretag uint64 + if !fd.IsPacked() { + wiretag = protowire.EncodeTag(fd.Number(), wireTypes[fd.Kind()]) + } else { + wiretag = protowire.EncodeTag(fd.Number(), protowire.BytesType) + } + var fieldOffset offset + var funcs pointerCoderFuncs + var childMessage *MessageInfo + switch { + case ft == nil: + // This never occurs for generated message types. + // It implies that a hand-crafted type has missing Go fields + // for specific protobuf message fields. + funcs = pointerCoderFuncs{ + size: func(p pointer, f *coderFieldInfo, opts marshalOptions) int { + return 0 + }, + marshal: func(b []byte, p pointer, f *coderFieldInfo, opts marshalOptions) ([]byte, error) { + return nil, nil + }, + unmarshal: func(b []byte, p pointer, wtyp protowire.Type, f *coderFieldInfo, opts unmarshalOptions) (unmarshalOutput, error) { + panic("missing Go struct field for " + string(fd.FullName())) + }, + isInit: func(p pointer, f *coderFieldInfo) error { + panic("missing Go struct field for " + string(fd.FullName())) + }, + merge: func(dst, src pointer, f *coderFieldInfo, opts mergeOptions) { + panic("missing Go struct field for " + string(fd.FullName())) + }, + } + case isOneof: + fieldOffset = offsetOf(fs, mi.Exporter) + case fd.IsWeak(): + fieldOffset = si.weakOffset + funcs = makeWeakMessageFieldCoder(fd) + default: + fieldOffset = offsetOf(fs, mi.Exporter) + childMessage, funcs = fieldCoder(fd, ft) + } + cf := &preallocFields[i] + *cf = coderFieldInfo{ + num: fd.Number(), + offset: fieldOffset, + wiretag: wiretag, + ft: ft, + tagsize: protowire.SizeVarint(wiretag), + funcs: funcs, + mi: childMessage, + validation: newFieldValidationInfo(mi, si, fd, ft), + isPointer: fd.Cardinality() == pref.Repeated || fd.HasPresence(), + isRequired: fd.Cardinality() == pref.Required, + } + mi.orderedCoderFields = append(mi.orderedCoderFields, cf) + mi.coderFields[cf.num] = cf + } + for i, oneofs := 0, mi.Desc.Oneofs(); i < oneofs.Len(); i++ { + if od := oneofs.Get(i); !od.IsSynthetic() { + mi.initOneofFieldCoders(od, si) + } + } + if messageset.IsMessageSet(mi.Desc) { + if !mi.extensionOffset.IsValid() { + panic(fmt.Sprintf("%v: MessageSet with no extensions field", mi.Desc.FullName())) + } + if !mi.unknownOffset.IsValid() { + panic(fmt.Sprintf("%v: MessageSet with no unknown field", mi.Desc.FullName())) + } + mi.isMessageSet = true + } + sort.Slice(mi.orderedCoderFields, func(i, j int) bool { + return mi.orderedCoderFields[i].num < mi.orderedCoderFields[j].num + }) + + var maxDense pref.FieldNumber + for _, cf := range mi.orderedCoderFields { + if cf.num >= 16 && cf.num >= 2*maxDense { + break + } + maxDense = cf.num + } + mi.denseCoderFields = make([]*coderFieldInfo, maxDense+1) + for _, cf := range mi.orderedCoderFields { + if int(cf.num) >= len(mi.denseCoderFields) { + break + } + mi.denseCoderFields[cf.num] = cf + } + + // To preserve compatibility with historic wire output, marshal oneofs last. + if mi.Desc.Oneofs().Len() > 0 { + sort.Slice(mi.orderedCoderFields, func(i, j int) bool { + fi := fields.ByNumber(mi.orderedCoderFields[i].num) + fj := fields.ByNumber(mi.orderedCoderFields[j].num) + return order.LegacyFieldOrder(fi, fj) + }) + } + + mi.needsInitCheck = needsInitCheck(mi.Desc) + if mi.methods.Marshal == nil && mi.methods.Size == nil { + mi.methods.Flags |= piface.SupportMarshalDeterministic + mi.methods.Marshal = mi.marshal + mi.methods.Size = mi.size + } + if mi.methods.Unmarshal == nil { + mi.methods.Flags |= piface.SupportUnmarshalDiscardUnknown + mi.methods.Unmarshal = mi.unmarshal + } + if mi.methods.CheckInitialized == nil { + mi.methods.CheckInitialized = mi.checkInitialized + } + if mi.methods.Merge == nil { + mi.methods.Merge = mi.merge + } +} + +// getUnknownBytes returns a *[]byte for the unknown fields. +// It is the caller's responsibility to check whether the pointer is nil. +// This function is specially designed to be inlineable. +func (mi *MessageInfo) getUnknownBytes(p pointer) *[]byte { + if mi.unknownPtrKind { + return *p.Apply(mi.unknownOffset).BytesPtr() + } else { + return p.Apply(mi.unknownOffset).Bytes() + } +} + +// mutableUnknownBytes returns a *[]byte for the unknown fields. +// The returned pointer is guaranteed to not be nil. +func (mi *MessageInfo) mutableUnknownBytes(p pointer) *[]byte { + if mi.unknownPtrKind { + bp := p.Apply(mi.unknownOffset).BytesPtr() + if *bp == nil { + *bp = new([]byte) + } + return *bp + } else { + return p.Apply(mi.unknownOffset).Bytes() + } +} |