proto/equal.go - third_party/golang/protobuf - Git at Google

 // Go support for Protocol Buffers - Google's data interchange format
 //
 // Copyright 2011 The Go Authors.  All rights reserved.
 // https://github.com/golang/protobuf
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // Protocol buffer comparison.

 package proto

 import (
 	"bytes"
 	"log"
 	"reflect"
 	"strings"
 )

 /*
 Equal returns true iff protocol buffers a and b are equal.
 The arguments must both be pointers to protocol buffer structs.

 Equality is defined in this way:
   - Two messages are equal iff they are the same type,
     corresponding fields are equal, unknown field sets
     are equal, and extensions sets are equal.
   - Two set scalar fields are equal iff their values are equal.
     If the fields are of a floating-point type, remember that
     NaN != x for all x, including NaN. If the message is defined
     in a proto3 .proto file, fields are not "set"; specifically,
     zero length proto3 "bytes" fields are equal (nil == {}).
   - Two repeated fields are equal iff their lengths are the same,
     and their corresponding elements are equal (a "bytes" field,
     although represented by []byte, is not a repeated field)
   - Two unset fields are equal.
   - Two unknown field sets are equal if their current
     encoded state is equal.
   - Two extension sets are equal iff they have corresponding
     elements that are pairwise equal.
   - Every other combination of things are not equal.

 The return value is undefined if a and b are not protocol buffers.
 */
 func Equal(a, b Message) bool {
 	if a == nil || b == nil {
 		return a == b
 	}
 	v1, v2 := reflect.ValueOf(a), reflect.ValueOf(b)
 	if v1.Type() != v2.Type() {
 		return false
 	}
 	if v1.Kind() == reflect.Ptr {
 		if v1.IsNil() {
 			return v2.IsNil()
 		}
 		if v2.IsNil() {
 			return false
 		}
 		v1, v2 = v1.Elem(), v2.Elem()
 	}
 	if v1.Kind() != reflect.Struct {
 		return false
 	}
 	return equalStruct(v1, v2)
 }

 // v1 and v2 are known to have the same type.
 func equalStruct(v1, v2 reflect.Value) bool {
 	sprop := GetProperties(v1.Type())
 	for i := 0; i < v1.NumField(); i++ {
 		f := v1.Type().Field(i)
 		if strings.HasPrefix(f.Name, "XXX_") {
 			continue
 		}
 		f1, f2 := v1.Field(i), v2.Field(i)
 		if f.Type.Kind() == reflect.Ptr {
 			if n1, n2 := f1.IsNil(), f2.IsNil(); n1 && n2 {
 				// both unset
 				continue
 			} else if n1 != n2 {
 				// set/unset mismatch
 				return false
 			}
 			b1, ok := f1.Interface().(raw)
 			if ok {
 				b2 := f2.Interface().(raw)
 				// RawMessage
 				if !bytes.Equal(b1.Bytes(), b2.Bytes()) {
 					return false
 				}
 				continue
 			}
 			f1, f2 = f1.Elem(), f2.Elem()
 		}
 		if !equalAny(f1, f2, sprop.Prop[i]) {
 			return false
 		}
 	}

 	if em1 := v1.FieldByName("XXX_extensions"); em1.IsValid() {
 		em2 := v2.FieldByName("XXX_extensions")
 		if !equalExtensions(v1.Type(), em1.Interface().(map[int32]Extension), em2.Interface().(map[int32]Extension)) {
 			return false
 		}
 	}

 	uf := v1.FieldByName("XXX_unrecognized")
 	if !uf.IsValid() {
 		return true
 	}

 	u1 := uf.Bytes()
 	u2 := v2.FieldByName("XXX_unrecognized").Bytes()
 	if !bytes.Equal(u1, u2) {
 		return false
 	}

 	return true
 }

 // v1 and v2 are known to have the same type.
 // prop may be nil.
 func equalAny(v1, v2 reflect.Value, prop *Properties) bool {
 	if v1.Type() == protoMessageType {
 		m1, _ := v1.Interface().(Message)
 		m2, _ := v2.Interface().(Message)
 		return Equal(m1, m2)
 	}
 	switch v1.Kind() {
 	case reflect.Bool:
 		return v1.Bool() == v2.Bool()
 	case reflect.Float32, reflect.Float64:
 		return v1.Float() == v2.Float()
 	case reflect.Int32, reflect.Int64:
 		return v1.Int() == v2.Int()
 	case reflect.Interface:
 		// Probably a oneof field; compare the inner values.
 		n1, n2 := v1.IsNil(), v2.IsNil()
 		if n1 || n2 {
 			return n1 == n2
 		}
 		e1, e2 := v1.Elem(), v2.Elem()
 		if e1.Type() != e2.Type() {
 			return false
 		}
 		return equalAny(e1, e2, nil)
 	case reflect.Map:
 		if v1.Len() != v2.Len() {
 			return false
 		}
 		for _, key := range v1.MapKeys() {
 			val2 := v2.MapIndex(key)
 			if !val2.IsValid() {
 				// This key was not found in the second map.
 				return false
 			}
 			if !equalAny(v1.MapIndex(key), val2, nil) {
 				return false
 			}
 		}
 		return true
 	case reflect.Ptr:
 		return equalAny(v1.Elem(), v2.Elem(), prop)
 	case reflect.Slice:
 		if v1.Type().Elem().Kind() == reflect.Uint8 {
 			// short circuit: []byte

 			// Edge case: if this is in a proto3 message, a zero length
 			// bytes field is considered the zero value.
 			if prop != nil && prop.proto3 && v1.Len() == 0 && v2.Len() == 0 {
 				return true
 			}
 			if v1.IsNil() != v2.IsNil() {
 				return false
 			}
 			return bytes.Equal(v1.Interface().([]byte), v2.Interface().([]byte))
 		}

 		if v1.Len() != v2.Len() {
 			return false
 		}
 		for i := 0; i < v1.Len(); i++ {
 			if !equalAny(v1.Index(i), v2.Index(i), prop) {
 				return false
 			}
 		}
 		return true
 	case reflect.String:
 		return v1.Interface().(string) == v2.Interface().(string)
 	case reflect.Struct:
 		return equalStruct(v1, v2)
 	case reflect.Uint32, reflect.Uint64:
 		return v1.Uint() == v2.Uint()
 	}

 	// unknown type, so not a protocol buffer
 	log.Printf("proto: don't know how to compare %v", v1)
 	return false
 }

 // base is the struct type that the extensions are based on.
 // em1 and em2 are extension maps.
 func equalExtensions(base reflect.Type, em1, em2 map[int32]Extension) bool {
 	if len(em1) != len(em2) {
 		return false
 	}

 	for extNum, e1 := range em1 {
 		e2, ok := em2[extNum]
 		if !ok {
 			return false
 		}

 		m1, m2 := e1.value, e2.value

 		if m1 != nil && m2 != nil {
 			// Both are unencoded.
 			if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
 				return false
 			}
 			continue
 		}

 		// At least one is encoded. To do a semantically correct comparison
 		// we need to unmarshal them first.
 		var desc *ExtensionDesc
 		if m := extensionMaps[base]; m != nil {
 			desc = m[extNum]
 		}
 		if desc == nil {
 			log.Printf("proto: don't know how to compare extension %d of %v", extNum, base)
 			continue
 		}
 		var err error
 		if m1 == nil {
 			m1, err = decodeExtension(e1.enc, desc)
 		}
 		if m2 == nil && err == nil {
 			m2, err = decodeExtension(e2.enc, desc)
 		}
 		if err != nil {
 			// The encoded form is invalid.
 			log.Printf("proto: badly encoded extension %d of %v: %v", extNum, base, err)
 			return false
 		}
 		if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
 			return false
 		}
 	}

 	return true
 }
	// Go support for Protocol Buffers - Google's data interchange format
	//
	// Copyright 2011 The Go Authors. All rights reserved.
	// https://github.com/golang/protobuf
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	// Protocol buffer comparison.

	package proto

	import (
	"bytes"
	"log"
	"reflect"
	"strings"
	)

	/*
	Equal returns true iff protocol buffers a and b are equal.
	The arguments must both be pointers to protocol buffer structs.

	Equality is defined in this way:
	- Two messages are equal iff they are the same type,
	corresponding fields are equal, unknown field sets
	are equal, and extensions sets are equal.
	- Two set scalar fields are equal iff their values are equal.
	If the fields are of a floating-point type, remember that
	NaN != x for all x, including NaN. If the message is defined
	in a proto3 .proto file, fields are not "set"; specifically,
	zero length proto3 "bytes" fields are equal (nil == {}).
	- Two repeated fields are equal iff their lengths are the same,
	and their corresponding elements are equal (a "bytes" field,
	although represented by []byte, is not a repeated field)
	- Two unset fields are equal.
	- Two unknown field sets are equal if their current
	encoded state is equal.
	- Two extension sets are equal iff they have corresponding
	elements that are pairwise equal.
	- Every other combination of things are not equal.

	The return value is undefined if a and b are not protocol buffers.
	*/
	func Equal(a, b Message) bool {
	if a == nil \|\| b == nil {
	return a == b
	}
	v1, v2 := reflect.ValueOf(a), reflect.ValueOf(b)
	if v1.Type() != v2.Type() {
	return false
	}
	if v1.Kind() == reflect.Ptr {
	if v1.IsNil() {
	return v2.IsNil()
	}
	if v2.IsNil() {
	return false
	}
	v1, v2 = v1.Elem(), v2.Elem()
	}
	if v1.Kind() != reflect.Struct {
	return false
	}
	return equalStruct(v1, v2)
	}

	// v1 and v2 are known to have the same type.
	func equalStruct(v1, v2 reflect.Value) bool {
	sprop := GetProperties(v1.Type())
	for i := 0; i < v1.NumField(); i++ {
	f := v1.Type().Field(i)
	if strings.HasPrefix(f.Name, "XXX_") {
	continue
	}
	f1, f2 := v1.Field(i), v2.Field(i)
	if f.Type.Kind() == reflect.Ptr {
	if n1, n2 := f1.IsNil(), f2.IsNil(); n1 && n2 {
	// both unset
	continue
	} else if n1 != n2 {
	// set/unset mismatch
	return false
	}
	b1, ok := f1.Interface().(raw)
	if ok {
	b2 := f2.Interface().(raw)
	// RawMessage
	if !bytes.Equal(b1.Bytes(), b2.Bytes()) {
	return false
	}
	continue
	}
	f1, f2 = f1.Elem(), f2.Elem()
	}
	if !equalAny(f1, f2, sprop.Prop[i]) {
	return false
	}
	}

	if em1 := v1.FieldByName("XXX_extensions"); em1.IsValid() {
	em2 := v2.FieldByName("XXX_extensions")
	if !equalExtensions(v1.Type(), em1.Interface().(map[int32]Extension), em2.Interface().(map[int32]Extension)) {
	return false
	}
	}

	uf := v1.FieldByName("XXX_unrecognized")
	if !uf.IsValid() {
	return true
	}

	u1 := uf.Bytes()
	u2 := v2.FieldByName("XXX_unrecognized").Bytes()
	if !bytes.Equal(u1, u2) {
	return false
	}

	return true
	}

	// v1 and v2 are known to have the same type.
	// prop may be nil.
	func equalAny(v1, v2 reflect.Value, prop *Properties) bool {
	if v1.Type() == protoMessageType {
	m1, _ := v1.Interface().(Message)
	m2, _ := v2.Interface().(Message)
	return Equal(m1, m2)
	}
	switch v1.Kind() {
	case reflect.Bool:
	return v1.Bool() == v2.Bool()
	case reflect.Float32, reflect.Float64:
	return v1.Float() == v2.Float()
	case reflect.Int32, reflect.Int64:
	return v1.Int() == v2.Int()
	case reflect.Interface:
	// Probably a oneof field; compare the inner values.
	n1, n2 := v1.IsNil(), v2.IsNil()
	if n1 \|\| n2 {
	return n1 == n2
	}
	e1, e2 := v1.Elem(), v2.Elem()
	if e1.Type() != e2.Type() {
	return false
	}
	return equalAny(e1, e2, nil)
	case reflect.Map:
	if v1.Len() != v2.Len() {
	return false
	}
	for _, key := range v1.MapKeys() {
	val2 := v2.MapIndex(key)
	if !val2.IsValid() {
	// This key was not found in the second map.
	return false
	}
	if !equalAny(v1.MapIndex(key), val2, nil) {
	return false
	}
	}
	return true
	case reflect.Ptr:
	return equalAny(v1.Elem(), v2.Elem(), prop)
	case reflect.Slice:
	if v1.Type().Elem().Kind() == reflect.Uint8 {
	// short circuit: []byte

	// Edge case: if this is in a proto3 message, a zero length
	// bytes field is considered the zero value.
	if prop != nil && prop.proto3 && v1.Len() == 0 && v2.Len() == 0 {
	return true
	}
	if v1.IsNil() != v2.IsNil() {
	return false
	}
	return bytes.Equal(v1.Interface().([]byte), v2.Interface().([]byte))
	}

	if v1.Len() != v2.Len() {
	return false
	}
	for i := 0; i < v1.Len(); i++ {
	if !equalAny(v1.Index(i), v2.Index(i), prop) {
	return false
	}
	}
	return true
	case reflect.String:
	return v1.Interface().(string) == v2.Interface().(string)
	case reflect.Struct:
	return equalStruct(v1, v2)
	case reflect.Uint32, reflect.Uint64:
	return v1.Uint() == v2.Uint()
	}

	// unknown type, so not a protocol buffer
	log.Printf("proto: don't know how to compare %v", v1)
	return false
	}

	// base is the struct type that the extensions are based on.
	// em1 and em2 are extension maps.
	func equalExtensions(base reflect.Type, em1, em2 map[int32]Extension) bool {
	if len(em1) != len(em2) {
	return false
	}

	for extNum, e1 := range em1 {
	e2, ok := em2[extNum]
	if !ok {
	return false
	}

	m1, m2 := e1.value, e2.value

	if m1 != nil && m2 != nil {
	// Both are unencoded.
	if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
	return false
	}
	continue
	}

	// At least one is encoded. To do a semantically correct comparison
	// we need to unmarshal them first.
	var desc *ExtensionDesc
	if m := extensionMaps[base]; m != nil {
	desc = m[extNum]
	}
	if desc == nil {
	log.Printf("proto: don't know how to compare extension %d of %v", extNum, base)
	continue
	}
	var err error
	if m1 == nil {
	m1, err = decodeExtension(e1.enc, desc)
	}
	if m2 == nil && err == nil {
	m2, err = decodeExtension(e2.enc, desc)
	}
	if err != nil {
	// The encoded form is invalid.
	log.Printf("proto: badly encoded extension %d of %v: %v", extNum, base, err)
	return false
	}
	if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
	return false
	}
	}

	return true
	}