Update Structured Merge Diff to V3

vendor/sigs.k8s.io/structured-merge-diff/v3/value/map.go

@@ -0,0 +1,113 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package value
+
+import (
+	"sort"
+	"strings"
+)
+
+// Map represents a Map or go structure.
+type Map interface {
+	// Set changes or set the value of the given key.
+	Set(key string, val Value)
+	// Get returns the value for the given key, if present, or (nil, false) otherwise.
+	Get(key string) (Value, bool)
+	// Has returns true if the key is present, or false otherwise.
+	Has(key string) bool
+	// Delete removes the key from the map.
+	Delete(key string)
+	// Equals compares the two maps, and return true if they are the same, false otherwise.
+	// Implementations can use MapEquals as a general implementation for this methods.
+	Equals(other Map) bool
+	// Iterate runs the given function for each key/value in the
+	// map. Returning false in the closure prematurely stops the
+	// iteration.
+	Iterate(func(key string, value Value) bool) bool
+	// Length returns the number of items in the map.
+	Length() int
+}
+
+// MapLess compares two maps lexically.
+func MapLess(lhs, rhs Map) bool {
+	return MapCompare(lhs, rhs) == -1
+}
+
+// MapCompare compares two maps lexically.
+func MapCompare(lhs, rhs Map) int {
+	lorder := make([]string, 0, lhs.Length())
+	lhs.Iterate(func(key string, _ Value) bool {
+		lorder = append(lorder, key)
+		return true
+	})
+	sort.Strings(lorder)
+	rorder := make([]string, 0, rhs.Length())
+	rhs.Iterate(func(key string, _ Value) bool {
+		rorder = append(rorder, key)
+		return true
+	})
+	sort.Strings(rorder)
+
+	i := 0
+	for {
+		if i >= len(lorder) && i >= len(rorder) {
+			// Maps are the same length and all items are equal.
+			return 0
+		}
+		if i >= len(lorder) {
+			// LHS is shorter.
+			return -1
+		}
+		if i >= len(rorder) {
+			// RHS is shorter.
+			return 1
+		}
+		if c := strings.Compare(lorder[i], rorder[i]); c != 0 {
+			return c
+		}
+		litem, _ := lhs.Get(lorder[i])
+		ritem, _ := rhs.Get(rorder[i])
+		if c := Compare(litem, ritem); c != 0 {
+			return c
+		}
+		litem.Recycle()
+		ritem.Recycle()
+		// The items are equal; continue.
+		i++
+	}
+}
+
+// MapEquals returns true if lhs == rhs, false otherwise. This function
+// acts on generic types and should not be used by callers, but can help
+// implement Map.Equals.
+func MapEquals(lhs, rhs Map) bool {
+	if lhs.Length() != rhs.Length() {
+		return false
+	}
+	return lhs.Iterate(func(k string, v Value) bool {
+		vo, ok := rhs.Get(k)
+		if !ok {
+			return false
+		}
+		if !Equals(v, vo) {
+			vo.Recycle()
+			return false
+		}
+		vo.Recycle()
+		return true
+	})
+}