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		u := *p.Apply(mi.unknownOffset).Bytes()
83		size += len(u)
84	}
85	if mi.sizecacheOffset.IsValid() {
86		if size > math.MaxInt32 {
87			// The size is too large for the int32 sizecache field.
88			// We will need to recompute the size when encoding;
89			// unfortunately expensive, but better than invalid output.
90			atomic.StoreInt32(p.Apply(mi.sizecacheOffset).Int32(), -1)
91		} else {
92			atomic.StoreInt32(p.Apply(mi.sizecacheOffset).Int32(), int32(size))
93		}
94	}
95	return size
96}
97
98// marshal is protoreflect.Methods.Marshal.
99func (mi *MessageInfo) marshal(in piface.MarshalInput) (out piface.MarshalOutput, err error) {
100	var p pointer
101	if ms, ok := in.Message.(*messageState); ok {
102		p = ms.pointer()
103	} else {
104		p = in.Message.(*messageReflectWrapper).pointer()
105	}
106	b, err := mi.marshalAppendPointer(in.Buf, p, marshalOptions{
107		flags: in.Flags,
108	})
109	return piface.MarshalOutput{Buf: b}, err
110}
111
112func (mi *MessageInfo) marshalAppendPointer(b []byte, p pointer, opts marshalOptions) ([]byte, error) {
113	mi.init()
114	if p.IsNil() {
115		return b, nil
116	}
117	if flags.ProtoLegacy && mi.isMessageSet {
118		return marshalMessageSet(mi, b, p, opts)
119	}
120	var err error
121	// The old marshaler encodes extensions at beginning.
122	if mi.extensionOffset.IsValid() {
123		e := p.Apply(mi.extensionOffset).Extensions()
124		// TODO: Special handling for MessageSet?
125		b, err = mi.appendExtensions(b, e, opts)
126		if err != nil {
127			return b, err
128		}
129	}
130	for _, f := range mi.orderedCoderFields {
131		if f.funcs.marshal == nil {
132			continue
133		}
134		fptr := p.Apply(f.offset)
135		if f.isPointer && fptr.Elem().IsNil() {
136			continue
137		}
138		b, err = f.funcs.marshal(b, fptr, f, opts)
139		if err != nil {
140			return b, err
141		}
142	}
143	if mi.unknownOffset.IsValid() && !mi.isMessageSet {
144		u := *p.Apply(mi.unknownOffset).Bytes()
145		b = append(b, u...)
146	}
147	return b, nil
148}
149
150func (mi *MessageInfo) sizeExtensions(ext *map[int32]ExtensionField, opts marshalOptions) (n int) {
151	if ext == nil {
152		return 0
153	}
154	for _, x := range *ext {
155		xi := getExtensionFieldInfo(x.Type())
156		if xi.funcs.size == nil {
157			continue
158		}
159		n += xi.funcs.size(x.Value(), xi.tagsize, opts)
160	}
161	return n
162}
163
164func (mi *MessageInfo) appendExtensions(b []byte, ext *map[int32]ExtensionField, opts marshalOptions) ([]byte, error) {
165	if ext == nil {
166		return b, nil
167	}
168
169	switch len(*ext) {
170	case 0:
171		return b, nil
172	case 1:
173		// Fast-path for one extension: Don't bother sorting the keys.
174		var err error
175		for _, x := range *ext {
176			xi := getExtensionFieldInfo(x.Type())
177			b, err = xi.funcs.marshal(b, x.Value(), xi.wiretag, opts)
178		}
179		return b, err
180	default:
181		// Sort the keys to provide a deterministic encoding.
182		// Not sure this is required, but the old code does it.
183		keys := make([]int, 0, len(*ext))
184		for k := range *ext {
185			keys = append(keys, int(k))
186		}
187		sort.Ints(keys)
188		var err error
189		for _, k := range keys {
190			x := (*ext)[int32(k)]
191			xi := getExtensionFieldInfo(x.Type())
192			b, err = xi.funcs.marshal(b, x.Value(), xi.wiretag, opts)
193			if err != nil {
194				return b, err
195			}
196		}
197		return b, nil
198	}
199}
200