vendor/google.golang.org/protobuf/reflect/protoreflect/value_equal.go
changeset 274 cea6d2f4f728
equal deleted inserted replaced
273:63ec80976891 274:cea6d2f4f728
       
     1 // Copyright 2022 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 
       
     5 package protoreflect
       
     6 
       
     7 import (
       
     8 	"bytes"
       
     9 	"fmt"
       
    10 	"math"
       
    11 	"reflect"
       
    12 
       
    13 	"google.golang.org/protobuf/encoding/protowire"
       
    14 )
       
    15 
       
    16 // Equal reports whether v1 and v2 are recursively equal.
       
    17 //
       
    18 //   - Values of different types are always unequal.
       
    19 //
       
    20 //   - Bytes values are equal if they contain identical bytes.
       
    21 //     Empty bytes (regardless of nil-ness) are considered equal.
       
    22 //
       
    23 //   - Floating point values are equal if they contain the same value.
       
    24 //     Unlike the == operator, a NaN is equal to another NaN.
       
    25 //
       
    26 //   - Enums are equal if they contain the same number.
       
    27 //     Since Value does not contain an enum descriptor,
       
    28 //     enum values do not consider the type of the enum.
       
    29 //
       
    30 //   - Other scalar values are equal if they contain the same value.
       
    31 //
       
    32 //   - Message values are equal if they belong to the same message descriptor,
       
    33 //     have the same set of populated known and extension field values,
       
    34 //     and the same set of unknown fields values.
       
    35 //
       
    36 //   - Lists are equal if they are the same length and
       
    37 //     each corresponding element is equal.
       
    38 //
       
    39 //   - Maps are equal if they have the same set of keys and
       
    40 //     the corresponding value for each key is equal.
       
    41 func (v1 Value) Equal(v2 Value) bool {
       
    42 	return equalValue(v1, v2)
       
    43 }
       
    44 
       
    45 func equalValue(x, y Value) bool {
       
    46 	eqType := x.typ == y.typ
       
    47 	switch x.typ {
       
    48 	case nilType:
       
    49 		return eqType
       
    50 	case boolType:
       
    51 		return eqType && x.Bool() == y.Bool()
       
    52 	case int32Type, int64Type:
       
    53 		return eqType && x.Int() == y.Int()
       
    54 	case uint32Type, uint64Type:
       
    55 		return eqType && x.Uint() == y.Uint()
       
    56 	case float32Type, float64Type:
       
    57 		return eqType && equalFloat(x.Float(), y.Float())
       
    58 	case stringType:
       
    59 		return eqType && x.String() == y.String()
       
    60 	case bytesType:
       
    61 		return eqType && bytes.Equal(x.Bytes(), y.Bytes())
       
    62 	case enumType:
       
    63 		return eqType && x.Enum() == y.Enum()
       
    64 	default:
       
    65 		switch x := x.Interface().(type) {
       
    66 		case Message:
       
    67 			y, ok := y.Interface().(Message)
       
    68 			return ok && equalMessage(x, y)
       
    69 		case List:
       
    70 			y, ok := y.Interface().(List)
       
    71 			return ok && equalList(x, y)
       
    72 		case Map:
       
    73 			y, ok := y.Interface().(Map)
       
    74 			return ok && equalMap(x, y)
       
    75 		default:
       
    76 			panic(fmt.Sprintf("unknown type: %T", x))
       
    77 		}
       
    78 	}
       
    79 }
       
    80 
       
    81 // equalFloat compares two floats, where NaNs are treated as equal.
       
    82 func equalFloat(x, y float64) bool {
       
    83 	if math.IsNaN(x) || math.IsNaN(y) {
       
    84 		return math.IsNaN(x) && math.IsNaN(y)
       
    85 	}
       
    86 	return x == y
       
    87 }
       
    88 
       
    89 // equalMessage compares two messages.
       
    90 func equalMessage(mx, my Message) bool {
       
    91 	if mx.Descriptor() != my.Descriptor() {
       
    92 		return false
       
    93 	}
       
    94 
       
    95 	nx := 0
       
    96 	equal := true
       
    97 	mx.Range(func(fd FieldDescriptor, vx Value) bool {
       
    98 		nx++
       
    99 		vy := my.Get(fd)
       
   100 		equal = my.Has(fd) && equalValue(vx, vy)
       
   101 		return equal
       
   102 	})
       
   103 	if !equal {
       
   104 		return false
       
   105 	}
       
   106 	ny := 0
       
   107 	my.Range(func(fd FieldDescriptor, vx Value) bool {
       
   108 		ny++
       
   109 		return true
       
   110 	})
       
   111 	if nx != ny {
       
   112 		return false
       
   113 	}
       
   114 
       
   115 	return equalUnknown(mx.GetUnknown(), my.GetUnknown())
       
   116 }
       
   117 
       
   118 // equalList compares two lists.
       
   119 func equalList(x, y List) bool {
       
   120 	if x.Len() != y.Len() {
       
   121 		return false
       
   122 	}
       
   123 	for i := x.Len() - 1; i >= 0; i-- {
       
   124 		if !equalValue(x.Get(i), y.Get(i)) {
       
   125 			return false
       
   126 		}
       
   127 	}
       
   128 	return true
       
   129 }
       
   130 
       
   131 // equalMap compares two maps.
       
   132 func equalMap(x, y Map) bool {
       
   133 	if x.Len() != y.Len() {
       
   134 		return false
       
   135 	}
       
   136 	equal := true
       
   137 	x.Range(func(k MapKey, vx Value) bool {
       
   138 		vy := y.Get(k)
       
   139 		equal = y.Has(k) && equalValue(vx, vy)
       
   140 		return equal
       
   141 	})
       
   142 	return equal
       
   143 }
       
   144 
       
   145 // equalUnknown compares unknown fields by direct comparison on the raw bytes
       
   146 // of each individual field number.
       
   147 func equalUnknown(x, y RawFields) bool {
       
   148 	if len(x) != len(y) {
       
   149 		return false
       
   150 	}
       
   151 	if bytes.Equal([]byte(x), []byte(y)) {
       
   152 		return true
       
   153 	}
       
   154 
       
   155 	mx := make(map[FieldNumber]RawFields)
       
   156 	my := make(map[FieldNumber]RawFields)
       
   157 	for len(x) > 0 {
       
   158 		fnum, _, n := protowire.ConsumeField(x)
       
   159 		mx[fnum] = append(mx[fnum], x[:n]...)
       
   160 		x = x[n:]
       
   161 	}
       
   162 	for len(y) > 0 {
       
   163 		fnum, _, n := protowire.ConsumeField(y)
       
   164 		my[fnum] = append(my[fnum], y[:n]...)
       
   165 		y = y[n:]
       
   166 	}
       
   167 	return reflect.DeepEqual(mx, my)
       
   168 }