| // 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. |
| // TODO: MessageSet. |
| |
| 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. |
| - 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 { |
| 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) { |
| 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. |
| func equalAny(v1, v2 reflect.Value) 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.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) { |
| return false |
| } |
| } |
| return true |
| case reflect.Ptr: |
| return equalAny(v1.Elem(), v2.Elem()) |
| case reflect.Slice: |
| if v1.Type().Elem().Kind() == reflect.Uint8 { |
| // short circuit: []byte |
| 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)) { |
| 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)) { |
| 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)) { |
| return false |
| } |
| } |
| |
| return true |
| } |