diff options
Diffstat (limited to 'vendor/k8s.io/apimachinery/third_party/forked/golang/reflect/deep_equal.go')
-rw-r--r-- | vendor/k8s.io/apimachinery/third_party/forked/golang/reflect/deep_equal.go | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/third_party/forked/golang/reflect/deep_equal.go b/vendor/k8s.io/apimachinery/third_party/forked/golang/reflect/deep_equal.go new file mode 100644 index 000000000..9e45dbe1d --- /dev/null +++ b/vendor/k8s.io/apimachinery/third_party/forked/golang/reflect/deep_equal.go @@ -0,0 +1,388 @@ +// Copyright 2009 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 reflect is a fork of go's standard library reflection package, which +// allows for deep equal with equality functions defined. +package reflect + +import ( + "fmt" + "reflect" + "strings" +) + +// Equalities is a map from type to a function comparing two values of +// that type. +type Equalities map[reflect.Type]reflect.Value + +// For convenience, panics on errrors +func EqualitiesOrDie(funcs ...interface{}) Equalities { + e := Equalities{} + if err := e.AddFuncs(funcs...); err != nil { + panic(err) + } + return e +} + +// AddFuncs is a shortcut for multiple calls to AddFunc. +func (e Equalities) AddFuncs(funcs ...interface{}) error { + for _, f := range funcs { + if err := e.AddFunc(f); err != nil { + return err + } + } + return nil +} + +// AddFunc uses func as an equality function: it must take +// two parameters of the same type, and return a boolean. +func (e Equalities) AddFunc(eqFunc interface{}) error { + fv := reflect.ValueOf(eqFunc) + ft := fv.Type() + if ft.Kind() != reflect.Func { + return fmt.Errorf("expected func, got: %v", ft) + } + if ft.NumIn() != 2 { + return fmt.Errorf("expected three 'in' params, got: %v", ft) + } + if ft.NumOut() != 1 { + return fmt.Errorf("expected one 'out' param, got: %v", ft) + } + if ft.In(0) != ft.In(1) { + return fmt.Errorf("expected arg 1 and 2 to have same type, but got %v", ft) + } + var forReturnType bool + boolType := reflect.TypeOf(forReturnType) + if ft.Out(0) != boolType { + return fmt.Errorf("expected bool return, got: %v", ft) + } + e[ft.In(0)] = fv + return nil +} + +// Below here is forked from go's reflect/deepequal.go + +// During deepValueEqual, must keep track of checks that are +// in progress. The comparison algorithm assumes that all +// checks in progress are true when it reencounters them. +// Visited comparisons are stored in a map indexed by visit. +type visit struct { + a1 uintptr + a2 uintptr + typ reflect.Type +} + +// unexportedTypePanic is thrown when you use this DeepEqual on something that has an +// unexported type. It indicates a programmer error, so should not occur at runtime, +// which is why it's not public and thus impossible to catch. +type unexportedTypePanic []reflect.Type + +func (u unexportedTypePanic) Error() string { return u.String() } +func (u unexportedTypePanic) String() string { + strs := make([]string, len(u)) + for i, t := range u { + strs[i] = fmt.Sprintf("%v", t) + } + return "an unexported field was encountered, nested like this: " + strings.Join(strs, " -> ") +} + +func makeUsefulPanic(v reflect.Value) { + if x := recover(); x != nil { + if u, ok := x.(unexportedTypePanic); ok { + u = append(unexportedTypePanic{v.Type()}, u...) + x = u + } + panic(x) + } +} + +// Tests for deep equality using reflected types. The map argument tracks +// comparisons that have already been seen, which allows short circuiting on +// recursive types. +func (e Equalities) deepValueEqual(v1, v2 reflect.Value, visited map[visit]bool, depth int) bool { + defer makeUsefulPanic(v1) + + if !v1.IsValid() || !v2.IsValid() { + return v1.IsValid() == v2.IsValid() + } + if v1.Type() != v2.Type() { + return false + } + if fv, ok := e[v1.Type()]; ok { + return fv.Call([]reflect.Value{v1, v2})[0].Bool() + } + + hard := func(k reflect.Kind) bool { + switch k { + case reflect.Array, reflect.Map, reflect.Slice, reflect.Struct: + return true + } + return false + } + + if v1.CanAddr() && v2.CanAddr() && hard(v1.Kind()) { + addr1 := v1.UnsafeAddr() + addr2 := v2.UnsafeAddr() + if addr1 > addr2 { + // Canonicalize order to reduce number of entries in visited. + addr1, addr2 = addr2, addr1 + } + + // Short circuit if references are identical ... + if addr1 == addr2 { + return true + } + + // ... or already seen + typ := v1.Type() + v := visit{addr1, addr2, typ} + if visited[v] { + return true + } + + // Remember for later. + visited[v] = true + } + + switch v1.Kind() { + case reflect.Array: + // We don't need to check length here because length is part of + // an array's type, which has already been filtered for. + for i := 0; i < v1.Len(); i++ { + if !e.deepValueEqual(v1.Index(i), v2.Index(i), visited, depth+1) { + return false + } + } + return true + case reflect.Slice: + if (v1.IsNil() || v1.Len() == 0) != (v2.IsNil() || v2.Len() == 0) { + return false + } + if v1.IsNil() || v1.Len() == 0 { + return true + } + if v1.Len() != v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for i := 0; i < v1.Len(); i++ { + if !e.deepValueEqual(v1.Index(i), v2.Index(i), visited, depth+1) { + return false + } + } + return true + case reflect.Interface: + if v1.IsNil() || v2.IsNil() { + return v1.IsNil() == v2.IsNil() + } + return e.deepValueEqual(v1.Elem(), v2.Elem(), visited, depth+1) + case reflect.Ptr: + return e.deepValueEqual(v1.Elem(), v2.Elem(), visited, depth+1) + case reflect.Struct: + for i, n := 0, v1.NumField(); i < n; i++ { + if !e.deepValueEqual(v1.Field(i), v2.Field(i), visited, depth+1) { + return false + } + } + return true + case reflect.Map: + if (v1.IsNil() || v1.Len() == 0) != (v2.IsNil() || v2.Len() == 0) { + return false + } + if v1.IsNil() || v1.Len() == 0 { + return true + } + if v1.Len() != v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for _, k := range v1.MapKeys() { + if !e.deepValueEqual(v1.MapIndex(k), v2.MapIndex(k), visited, depth+1) { + return false + } + } + return true + case reflect.Func: + if v1.IsNil() && v2.IsNil() { + return true + } + // Can't do better than this: + return false + default: + // Normal equality suffices + if !v1.CanInterface() || !v2.CanInterface() { + panic(unexportedTypePanic{}) + } + return v1.Interface() == v2.Interface() + } +} + +// DeepEqual is like reflect.DeepEqual, but focused on semantic equality +// instead of memory equality. +// +// It will use e's equality functions if it finds types that match. +// +// An empty slice *is* equal to a nil slice for our purposes; same for maps. +// +// Unexported field members cannot be compared and will cause an imformative panic; you must add an Equality +// function for these types. +func (e Equalities) DeepEqual(a1, a2 interface{}) bool { + if a1 == nil || a2 == nil { + return a1 == a2 + } + v1 := reflect.ValueOf(a1) + v2 := reflect.ValueOf(a2) + if v1.Type() != v2.Type() { + return false + } + return e.deepValueEqual(v1, v2, make(map[visit]bool), 0) +} + +func (e Equalities) deepValueDerive(v1, v2 reflect.Value, visited map[visit]bool, depth int) bool { + defer makeUsefulPanic(v1) + + if !v1.IsValid() || !v2.IsValid() { + return v1.IsValid() == v2.IsValid() + } + if v1.Type() != v2.Type() { + return false + } + if fv, ok := e[v1.Type()]; ok { + return fv.Call([]reflect.Value{v1, v2})[0].Bool() + } + + hard := func(k reflect.Kind) bool { + switch k { + case reflect.Array, reflect.Map, reflect.Slice, reflect.Struct: + return true + } + return false + } + + if v1.CanAddr() && v2.CanAddr() && hard(v1.Kind()) { + addr1 := v1.UnsafeAddr() + addr2 := v2.UnsafeAddr() + if addr1 > addr2 { + // Canonicalize order to reduce number of entries in visited. + addr1, addr2 = addr2, addr1 + } + + // Short circuit if references are identical ... + if addr1 == addr2 { + return true + } + + // ... or already seen + typ := v1.Type() + v := visit{addr1, addr2, typ} + if visited[v] { + return true + } + + // Remember for later. + visited[v] = true + } + + switch v1.Kind() { + case reflect.Array: + // We don't need to check length here because length is part of + // an array's type, which has already been filtered for. + for i := 0; i < v1.Len(); i++ { + if !e.deepValueDerive(v1.Index(i), v2.Index(i), visited, depth+1) { + return false + } + } + return true + case reflect.Slice: + if v1.IsNil() || v1.Len() == 0 { + return true + } + if v1.Len() > v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for i := 0; i < v1.Len(); i++ { + if !e.deepValueDerive(v1.Index(i), v2.Index(i), visited, depth+1) { + return false + } + } + return true + case reflect.String: + if v1.Len() == 0 { + return true + } + if v1.Len() > v2.Len() { + return false + } + return v1.String() == v2.String() + case reflect.Interface: + if v1.IsNil() { + return true + } + return e.deepValueDerive(v1.Elem(), v2.Elem(), visited, depth+1) + case reflect.Ptr: + if v1.IsNil() { + return true + } + return e.deepValueDerive(v1.Elem(), v2.Elem(), visited, depth+1) + case reflect.Struct: + for i, n := 0, v1.NumField(); i < n; i++ { + if !e.deepValueDerive(v1.Field(i), v2.Field(i), visited, depth+1) { + return false + } + } + return true + case reflect.Map: + if v1.IsNil() || v1.Len() == 0 { + return true + } + if v1.Len() > v2.Len() { + return false + } + if v1.Pointer() == v2.Pointer() { + return true + } + for _, k := range v1.MapKeys() { + if !e.deepValueDerive(v1.MapIndex(k), v2.MapIndex(k), visited, depth+1) { + return false + } + } + return true + case reflect.Func: + if v1.IsNil() && v2.IsNil() { + return true + } + // Can't do better than this: + return false + default: + // Normal equality suffices + if !v1.CanInterface() || !v2.CanInterface() { + panic(unexportedTypePanic{}) + } + return v1.Interface() == v2.Interface() + } +} + +// DeepDerivative is similar to DeepEqual except that unset fields in a1 are +// ignored (not compared). This allows us to focus on the fields that matter to +// the semantic comparison. +// +// The unset fields include a nil pointer and an empty string. +func (e Equalities) DeepDerivative(a1, a2 interface{}) bool { + if a1 == nil { + return true + } + v1 := reflect.ValueOf(a1) + v2 := reflect.ValueOf(a2) + if v1.Type() != v2.Type() { + return false + } + return e.deepValueDerive(v1, v2, make(map[visit]bool), 0) +} |