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Diffstat (limited to 'vendor/google.golang.org/protobuf/proto/equal.go')
-rw-r--r-- | vendor/google.golang.org/protobuf/proto/equal.go | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/proto/equal.go b/vendor/google.golang.org/protobuf/proto/equal.go new file mode 100644 index 00000000..10902bd8 --- /dev/null +++ b/vendor/google.golang.org/protobuf/proto/equal.go @@ -0,0 +1,154 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package proto + +import ( + "bytes" + "math" + "reflect" + + "google.golang.org/protobuf/encoding/protowire" + pref "google.golang.org/protobuf/reflect/protoreflect" +) + +// Equal reports whether two messages are equal. +// If two messages marshal to the same bytes under deterministic serialization, +// then Equal is guaranteed to report true. +// +// Two messages are equal if they belong to the same message descriptor, +// have the same set of populated known and extension field values, +// and the same set of unknown fields values. If either of the top-level +// messages are invalid, then Equal reports true only if both are invalid. +// +// Scalar values are compared with the equivalent of the == operator in Go, +// except bytes values which are compared using bytes.Equal and +// floating point values which specially treat NaNs as equal. +// Message values are compared by recursively calling Equal. +// Lists are equal if each element value is also equal. +// Maps are equal if they have the same set of keys, where the pair of values +// for each key is also equal. +func Equal(x, y Message) bool { + if x == nil || y == nil { + return x == nil && y == nil + } + mx := x.ProtoReflect() + my := y.ProtoReflect() + if mx.IsValid() != my.IsValid() { + return false + } + return equalMessage(mx, my) +} + +// equalMessage compares two messages. +func equalMessage(mx, my pref.Message) bool { + if mx.Descriptor() != my.Descriptor() { + return false + } + + nx := 0 + equal := true + mx.Range(func(fd pref.FieldDescriptor, vx pref.Value) bool { + nx++ + vy := my.Get(fd) + equal = my.Has(fd) && equalField(fd, vx, vy) + return equal + }) + if !equal { + return false + } + ny := 0 + my.Range(func(fd pref.FieldDescriptor, vx pref.Value) bool { + ny++ + return true + }) + if nx != ny { + return false + } + + return equalUnknown(mx.GetUnknown(), my.GetUnknown()) +} + +// equalField compares two fields. +func equalField(fd pref.FieldDescriptor, x, y pref.Value) bool { + switch { + case fd.IsList(): + return equalList(fd, x.List(), y.List()) + case fd.IsMap(): + return equalMap(fd, x.Map(), y.Map()) + default: + return equalValue(fd, x, y) + } +} + +// equalMap compares two maps. +func equalMap(fd pref.FieldDescriptor, x, y pref.Map) bool { + if x.Len() != y.Len() { + return false + } + equal := true + x.Range(func(k pref.MapKey, vx pref.Value) bool { + vy := y.Get(k) + equal = y.Has(k) && equalValue(fd.MapValue(), vx, vy) + return equal + }) + return equal +} + +// equalList compares two lists. +func equalList(fd pref.FieldDescriptor, x, y pref.List) bool { + if x.Len() != y.Len() { + return false + } + for i := x.Len() - 1; i >= 0; i-- { + if !equalValue(fd, x.Get(i), y.Get(i)) { + return false + } + } + return true +} + +// equalValue compares two singular values. +func equalValue(fd pref.FieldDescriptor, x, y pref.Value) bool { + switch { + case fd.Message() != nil: + return equalMessage(x.Message(), y.Message()) + case fd.Kind() == pref.BytesKind: + return bytes.Equal(x.Bytes(), y.Bytes()) + case fd.Kind() == pref.FloatKind, fd.Kind() == pref.DoubleKind: + fx := x.Float() + fy := y.Float() + if math.IsNaN(fx) || math.IsNaN(fy) { + return math.IsNaN(fx) && math.IsNaN(fy) + } + return fx == fy + default: + return x.Interface() == y.Interface() + } +} + +// equalUnknown compares unknown fields by direct comparison on the raw bytes +// of each individual field number. +func equalUnknown(x, y pref.RawFields) bool { + if len(x) != len(y) { + return false + } + if bytes.Equal([]byte(x), []byte(y)) { + return true + } + + mx := make(map[pref.FieldNumber]pref.RawFields) + my := make(map[pref.FieldNumber]pref.RawFields) + for len(x) > 0 { + fnum, _, n := protowire.ConsumeField(x) + mx[fnum] = append(mx[fnum], x[:n]...) + x = x[n:] + } + for len(y) > 0 { + fnum, _, n := protowire.ConsumeField(y) + my[fnum] = append(my[fnum], y[:n]...) + y = y[n:] + } + return reflect.DeepEqual(mx, my) +} |