1 // Go support for Protocol Buffers - Google's data interchange format
3 // Copyright 2011 The Go Authors. All rights reserved.
4 // https://github.com/golang/protobuf
6 // Redistribution and use in source and binary forms, with or without
7 // modification, are permitted provided that the following conditions are
10 // * Redistributions of source code must retain the above copyright
11 // notice, this list of conditions and the following disclaimer.
12 // * Redistributions in binary form must reproduce the above
13 // copyright notice, this list of conditions and the following disclaimer
14 // in the documentation and/or other materials provided with the
16 // * Neither the name of Google Inc. nor the names of its
17 // contributors may be used to endorse or promote products derived from
18 // this software without specific prior written permission.
20 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 // Protocol buffer comparison.
44 Equal returns true iff protocol buffers a and b are equal.
45 The arguments must both be pointers to protocol buffer structs.
47 Equality is defined in this way:
48 - Two messages are equal iff they are the same type,
49 corresponding fields are equal, unknown field sets
50 are equal, and extensions sets are equal.
51 - Two set scalar fields are equal iff their values are equal.
52 If the fields are of a floating-point type, remember that
53 NaN != x for all x, including NaN. If the message is defined
54 in a proto3 .proto file, fields are not "set"; specifically,
55 zero length proto3 "bytes" fields are equal (nil == {}).
56 - Two repeated fields are equal iff their lengths are the same,
57 and their corresponding elements are equal. Note a "bytes" field,
58 although represented by []byte, is not a repeated field and the
59 rule for the scalar fields described above applies.
60 - Two unset fields are equal.
61 - Two unknown field sets are equal if their current
62 encoded state is equal.
63 - Two extension sets are equal iff they have corresponding
64 elements that are pairwise equal.
65 - Two map fields are equal iff their lengths are the same,
66 and they contain the same set of elements. Zero-length map
68 - Every other combination of things are not equal.
70 The return value is undefined if a and b are not protocol buffers.
72 func Equal(a, b Message) bool {
73 if a == nil || b == nil {
76 v1, v2 := reflect.ValueOf(a), reflect.ValueOf(b)
77 if v1.Type() != v2.Type() {
80 if v1.Kind() == reflect.Ptr {
87 v1, v2 = v1.Elem(), v2.Elem()
89 if v1.Kind() != reflect.Struct {
92 return equalStruct(v1, v2)
95 // v1 and v2 are known to have the same type.
96 func equalStruct(v1, v2 reflect.Value) bool {
97 sprop := GetProperties(v1.Type())
98 for i := 0; i < v1.NumField(); i++ {
99 f := v1.Type().Field(i)
100 if strings.HasPrefix(f.Name, "XXX_") {
103 f1, f2 := v1.Field(i), v2.Field(i)
104 if f.Type.Kind() == reflect.Ptr {
105 if n1, n2 := f1.IsNil(), f2.IsNil(); n1 && n2 {
109 // set/unset mismatch
112 f1, f2 = f1.Elem(), f2.Elem()
114 if !equalAny(f1, f2, sprop.Prop[i]) {
119 if em1 := v1.FieldByName("XXX_InternalExtensions"); em1.IsValid() {
120 em2 := v2.FieldByName("XXX_InternalExtensions")
121 if !equalExtensions(v1.Type(), em1.Interface().(XXX_InternalExtensions), em2.Interface().(XXX_InternalExtensions)) {
126 if em1 := v1.FieldByName("XXX_extensions"); em1.IsValid() {
127 em2 := v2.FieldByName("XXX_extensions")
128 if !equalExtMap(v1.Type(), em1.Interface().(map[int32]Extension), em2.Interface().(map[int32]Extension)) {
133 uf := v1.FieldByName("XXX_unrecognized")
139 u2 := v2.FieldByName("XXX_unrecognized").Bytes()
140 return bytes.Equal(u1, u2)
143 // v1 and v2 are known to have the same type.
145 func equalAny(v1, v2 reflect.Value, prop *Properties) bool {
146 if v1.Type() == protoMessageType {
147 m1, _ := v1.Interface().(Message)
148 m2, _ := v2.Interface().(Message)
153 return v1.Bool() == v2.Bool()
154 case reflect.Float32, reflect.Float64:
155 return v1.Float() == v2.Float()
156 case reflect.Int32, reflect.Int64:
157 return v1.Int() == v2.Int()
158 case reflect.Interface:
159 // Probably a oneof field; compare the inner values.
160 n1, n2 := v1.IsNil(), v2.IsNil()
164 e1, e2 := v1.Elem(), v2.Elem()
165 if e1.Type() != e2.Type() {
168 return equalAny(e1, e2, nil)
170 if v1.Len() != v2.Len() {
173 for _, key := range v1.MapKeys() {
174 val2 := v2.MapIndex(key)
176 // This key was not found in the second map.
179 if !equalAny(v1.MapIndex(key), val2, nil) {
185 // Maps may have nil values in them, so check for nil.
186 if v1.IsNil() && v2.IsNil() {
189 if v1.IsNil() != v2.IsNil() {
192 return equalAny(v1.Elem(), v2.Elem(), prop)
194 if v1.Type().Elem().Kind() == reflect.Uint8 {
195 // short circuit: []byte
197 // Edge case: if this is in a proto3 message, a zero length
198 // bytes field is considered the zero value.
199 if prop != nil && prop.proto3 && v1.Len() == 0 && v2.Len() == 0 {
202 if v1.IsNil() != v2.IsNil() {
205 return bytes.Equal(v1.Interface().([]byte), v2.Interface().([]byte))
208 if v1.Len() != v2.Len() {
211 for i := 0; i < v1.Len(); i++ {
212 if !equalAny(v1.Index(i), v2.Index(i), prop) {
218 return v1.Interface().(string) == v2.Interface().(string)
220 return equalStruct(v1, v2)
221 case reflect.Uint32, reflect.Uint64:
222 return v1.Uint() == v2.Uint()
225 // unknown type, so not a protocol buffer
226 log.Printf("proto: don't know how to compare %v", v1)
230 // base is the struct type that the extensions are based on.
231 // x1 and x2 are InternalExtensions.
232 func equalExtensions(base reflect.Type, x1, x2 XXX_InternalExtensions) bool {
233 em1, _ := x1.extensionsRead()
234 em2, _ := x2.extensionsRead()
235 return equalExtMap(base, em1, em2)
238 func equalExtMap(base reflect.Type, em1, em2 map[int32]Extension) bool {
239 if len(em1) != len(em2) {
243 for extNum, e1 := range em1 {
244 e2, ok := em2[extNum]
249 m1 := extensionAsLegacyType(e1.value)
250 m2 := extensionAsLegacyType(e2.value)
252 if m1 == nil && m2 == nil {
253 // Both have only encoded form.
254 if bytes.Equal(e1.enc, e2.enc) {
257 // The bytes are different, but the extensions might still be
258 // equal. We need to decode them to compare.
261 if m1 != nil && m2 != nil {
262 // Both are unencoded.
263 if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
269 // At least one is encoded. To do a semantically correct comparison
270 // we need to unmarshal them first.
271 var desc *ExtensionDesc
272 if m := extensionMaps[base]; m != nil {
276 // If both have only encoded form and the bytes are the same,
277 // it is handled above. We get here when the bytes are different.
278 // We don't know how to decode it, so just compare them as byte
280 log.Printf("proto: don't know how to compare extension %d of %v", extNum, base)
285 m1, err = decodeExtension(e1.enc, desc)
287 if m2 == nil && err == nil {
288 m2, err = decodeExtension(e2.enc, desc)
291 // The encoded form is invalid.
292 log.Printf("proto: badly encoded extension %d of %v: %v", extNum, base, err)
295 if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {