open-nomad/vendor/github.com/gogo/protobuf/proto/equal.go
Seth Hoenig 435c0d9fc8 deps: Switch to Go modules for dependency management
This PR switches the Nomad repository from using govendor to Go modules
for managing dependencies. Aspects of the Nomad workflow remain pretty
much the same. The usual Makefile targets should continue to work as
they always did. The API submodule simply defers to the parent Nomad
version on the repository, keeping the semantics of API versioning that
currently exists.
2020-06-02 14:30:36 -05:00

301 lines
8.7 KiB
Go

// 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. Note a "bytes" field,
although represented by []byte, is not a repeated field and the
rule for the scalar fields described above applies.
- 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.
- Two map fields are equal iff their lengths are the same,
and they contain the same set of elements. Zero-length map
fields are 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
}
f1, f2 = f1.Elem(), f2.Elem()
}
if !equalAny(f1, f2, sprop.Prop[i]) {
return false
}
}
if em1 := v1.FieldByName("XXX_InternalExtensions"); em1.IsValid() {
em2 := v2.FieldByName("XXX_InternalExtensions")
if !equalExtensions(v1.Type(), em1.Interface().(XXX_InternalExtensions), em2.Interface().(XXX_InternalExtensions)) {
return false
}
}
if em1 := v1.FieldByName("XXX_extensions"); em1.IsValid() {
em2 := v2.FieldByName("XXX_extensions")
if !equalExtMap(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()
return bytes.Equal(u1, u2)
}
// 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:
// Maps may have nil values in them, so check for nil.
if v1.IsNil() && v2.IsNil() {
return true
}
if v1.IsNil() != v2.IsNil() {
return false
}
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.
// x1 and x2 are InternalExtensions.
func equalExtensions(base reflect.Type, x1, x2 XXX_InternalExtensions) bool {
em1, _ := x1.extensionsRead()
em2, _ := x2.extensionsRead()
return equalExtMap(base, em1, em2)
}
func equalExtMap(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 have only encoded form.
if bytes.Equal(e1.enc, e2.enc) {
continue
}
// The bytes are different, but the extensions might still be
// equal. We need to decode them to compare.
}
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 {
// If both have only encoded form and the bytes are the same,
// it is handled above. We get here when the bytes are different.
// We don't know how to decode it, so just compare them as byte
// slices.
log.Printf("proto: don't know how to compare extension %d of %v", extNum, base)
return false
}
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
}