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1// Copyright 2019 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package impl
6
7import (
8	"math"
9	"sort"
10	"sync/atomic"
11
12	"google.golang.org/protobuf/internal/flags"
13	proto "google.golang.org/protobuf/proto"
14	piface "google.golang.org/protobuf/runtime/protoiface"
15)
16
17type marshalOptions struct {
18	flags piface.MarshalInputFlags
19}
20
21func (o marshalOptions) Options() proto.MarshalOptions {
22	return proto.MarshalOptions{
23		AllowPartial:  true,
24		Deterministic: o.Deterministic(),
25		UseCachedSize: o.UseCachedSize(),
26	}
27}
28
29func (o marshalOptions) Deterministic() bool { return o.flags&piface.MarshalDeterministic != 0 }
30func (o marshalOptions) UseCachedSize() bool { return o.flags&piface.MarshalUseCachedSize != 0 }
31
32// size is protoreflect.Methods.Size.
33func (mi *MessageInfo) size(in piface.SizeInput) piface.SizeOutput {
34	var p pointer
35	if ms, ok := in.Message.(*messageState); ok {
36		p = ms.pointer()
37	} else {
38		p = in.Message.(*messageReflectWrapper).pointer()
39	}
40	size := mi.sizePointer(p, marshalOptions{
41		flags: in.Flags,
42	})
43	return piface.SizeOutput{Size: size}
44}
45
46func (mi *MessageInfo) sizePointer(p pointer, opts marshalOptions) (size int) {
47	mi.init()
48	if p.IsNil() {
49		return 0
50	}
51	if opts.UseCachedSize() && mi.sizecacheOffset.IsValid() {
52		if size := atomic.LoadInt32(p.Apply(mi.sizecacheOffset).Int32()); size >= 0 {
53			return int(size)
54		}
55	}
56	return mi.sizePointerSlow(p, opts)
57}
58
59func (mi *MessageInfo) sizePointerSlow(p pointer, opts marshalOptions) (size int) {
60	if flags.ProtoLegacy && mi.isMessageSet {
61		size = sizeMessageSet(mi, p, opts)
62		if mi.sizecacheOffset.IsValid() {
63			atomic.StoreInt32(p.Apply(mi.sizecacheOffset).Int32(), int32(size))
64		}
65		return size
66	}
67	if mi.extensionOffset.IsValid() {
68		e := p.Apply(mi.extensionOffset).Extensions()
69		size += mi.sizeExtensions(e, opts)
70	}
71	for _, f := range mi.orderedCoderFields {
72		if f.funcs.size == nil {
73			continue
74		}
75		fptr := p.Apply(f.offset)
76		if f.isPointer && fptr.Elem().IsNil() {
77			continue
78		}
79		size += f.funcs.size(fptr, f, opts)
80	}
81	if mi.unknownOffset.IsValid() {
82		if u := mi.getUnknownBytes(p); u != nil {
83			size += len(*u)
84		}
85	}
86	if mi.sizecacheOffset.IsValid() {
87		if size > math.MaxInt32 {
88			// The size is too large for the int32 sizecache field.
89			// We will need to recompute the size when encoding;
90			// unfortunately expensive, but better than invalid output.
91			atomic.StoreInt32(p.Apply(mi.sizecacheOffset).Int32(), -1)
92		} else {
93			atomic.StoreInt32(p.Apply(mi.sizecacheOffset).Int32(), int32(size))
94		}
95	}
96	return size
97}
98
99// marshal is protoreflect.Methods.Marshal.
100func (mi *MessageInfo) marshal(in piface.MarshalInput) (out piface.MarshalOutput, err error) {
101	var p pointer
102	if ms, ok := in.Message.(*messageState); ok {
103		p = ms.pointer()
104	} else {
105		p = in.Message.(*messageReflectWrapper).pointer()
106	}
107	b, err := mi.marshalAppendPointer(in.Buf, p, marshalOptions{
108		flags: in.Flags,
109	})
110	return piface.MarshalOutput{Buf: b}, err
111}
112
113func (mi *MessageInfo) marshalAppendPointer(b []byte, p pointer, opts marshalOptions) ([]byte, error) {
114	mi.init()
115	if p.IsNil() {
116		return b, nil
117	}
118	if flags.ProtoLegacy && mi.isMessageSet {
119		return marshalMessageSet(mi, b, p, opts)
120	}
121	var err error
122	// The old marshaler encodes extensions at beginning.
123	if mi.extensionOffset.IsValid() {
124		e := p.Apply(mi.extensionOffset).Extensions()
125		// TODO: Special handling for MessageSet?
126		b, err = mi.appendExtensions(b, e, opts)
127		if err != nil {
128			return b, err
129		}
130	}
131	for _, f := range mi.orderedCoderFields {
132		if f.funcs.marshal == nil {
133			continue
134		}
135		fptr := p.Apply(f.offset)
136		if f.isPointer && fptr.Elem().IsNil() {
137			continue
138		}
139		b, err = f.funcs.marshal(b, fptr, f, opts)
140		if err != nil {
141			return b, err
142		}
143	}
144	if mi.unknownOffset.IsValid() && !mi.isMessageSet {
145		if u := mi.getUnknownBytes(p); u != nil {
146			b = append(b, (*u)...)
147		}
148	}
149	return b, nil
150}
151
152func (mi *MessageInfo) sizeExtensions(ext *map[int32]ExtensionField, opts marshalOptions) (n int) {
153	if ext == nil {
154		return 0
155	}
156	for _, x := range *ext {
157		xi := getExtensionFieldInfo(x.Type())
158		if xi.funcs.size == nil {
159			continue
160		}
161		n += xi.funcs.size(x.Value(), xi.tagsize, opts)
162	}
163	return n
164}
165
166func (mi *MessageInfo) appendExtensions(b []byte, ext *map[int32]ExtensionField, opts marshalOptions) ([]byte, error) {
167	if ext == nil {
168		return b, nil
169	}
170
171	switch len(*ext) {
172	case 0:
173		return b, nil
174	case 1:
175		// Fast-path for one extension: Don't bother sorting the keys.
176		var err error
177		for _, x := range *ext {
178			xi := getExtensionFieldInfo(x.Type())
179			b, err = xi.funcs.marshal(b, x.Value(), xi.wiretag, opts)
180		}
181		return b, err
182	default:
183		// Sort the keys to provide a deterministic encoding.
184		// Not sure this is required, but the old code does it.
185		keys := make([]int, 0, len(*ext))
186		for k := range *ext {
187			keys = append(keys, int(k))
188		}
189		sort.Ints(keys)
190		var err error
191		for _, k := range keys {
192			x := (*ext)[int32(k)]
193			xi := getExtensionFieldInfo(x.Type())
194			b, err = xi.funcs.marshal(b, x.Value(), xi.wiretag, opts)
195			if err != nil {
196				return b, err
197			}
198		}
199		return b, nil
200	}
201}
202