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Diffstat (limited to 'vendor/sigs.k8s.io/structured-merge-diff/v4/value/map.go')
-rw-r--r-- | vendor/sigs.k8s.io/structured-merge-diff/v4/value/map.go | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/vendor/sigs.k8s.io/structured-merge-diff/v4/value/map.go b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/map.go new file mode 100644 index 000000000..168b9fa08 --- /dev/null +++ b/vendor/sigs.k8s.io/structured-merge-diff/v4/value/map.go @@ -0,0 +1,270 @@ +/* +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" +) + +// 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) + // GetUsing uses the provided allocator and returns the value for the given key, + // if present, or (nil, false) otherwise. + // The returned Value should be given back to the Allocator when no longer needed + // by calling Allocator.Free(Value). + GetUsing(a Allocator, 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 + // EqualsUsing uses the provided allocator and compares the two maps, and return true if + // they are the same, false otherwise. Implementations can use MapEqualsUsing as a general + // implementation for this methods. + EqualsUsing(a Allocator, 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 + // IterateUsing uses the provided allocator and runs the given function for each key/value + // in the map. Returning false in the closure prematurely stops the iteration. + IterateUsing(Allocator, func(key string, value Value) bool) bool + // Length returns the number of items in the map. + Length() int + // Empty returns true if the map is empty. + Empty() bool + // Zip iterates over the entries of two maps together. If both maps contain a value for a given key, fn is called + // with the values from both maps, otherwise it is called with the value of the map that contains the key and nil + // for the map that does not contain the key. Returning false in the closure prematurely stops the iteration. + Zip(other Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool + // ZipUsing uses the provided allocator and iterates over the entries of two maps together. If both maps + // contain a value for a given key, fn is called with the values from both maps, otherwise it is called with + // the value of the map that contains the key and nil for the map that does not contain the key. Returning + // false in the closure prematurely stops the iteration. + ZipUsing(a Allocator, other Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool +} + +// MapTraverseOrder defines the map traversal ordering available. +type MapTraverseOrder int + +const ( + // Unordered indicates that the map traversal has no ordering requirement. + Unordered = iota + // LexicalKeyOrder indicates that the map traversal is ordered by key, lexically. + LexicalKeyOrder +) + +// MapZip iterates over the entries of two maps together. If both maps contain a value for a given key, fn is called +// with the values from both maps, otherwise it is called with the value of the map that contains the key and nil +// for the other map. Returning false in the closure prematurely stops the iteration. +func MapZip(lhs, rhs Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool { + return MapZipUsing(HeapAllocator, lhs, rhs, order, fn) +} + +// MapZipUsing uses the provided allocator and iterates over the entries of two maps together. If both maps +// contain a value for a given key, fn is called with the values from both maps, otherwise it is called with +// the value of the map that contains the key and nil for the other map. Returning false in the closure +// prematurely stops the iteration. +func MapZipUsing(a Allocator, lhs, rhs Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool { + if lhs != nil { + return lhs.ZipUsing(a, rhs, order, fn) + } + if rhs != nil { + return rhs.ZipUsing(a, lhs, order, func(key string, rhs, lhs Value) bool { // arg positions of lhs and rhs deliberately swapped + return fn(key, lhs, rhs) + }) + } + return true +} + +// defaultMapZip provides a default implementation of Zip for implementations that do not need to provide +// their own optimized implementation. +func defaultMapZip(a Allocator, lhs, rhs Map, order MapTraverseOrder, fn func(key string, lhs, rhs Value) bool) bool { + switch order { + case Unordered: + return unorderedMapZip(a, lhs, rhs, fn) + case LexicalKeyOrder: + return lexicalKeyOrderedMapZip(a, lhs, rhs, fn) + default: + panic("Unsupported map order") + } +} + +func unorderedMapZip(a Allocator, lhs, rhs Map, fn func(key string, lhs, rhs Value) bool) bool { + if (lhs == nil || lhs.Empty()) && (rhs == nil || rhs.Empty()) { + return true + } + + if lhs != nil { + ok := lhs.IterateUsing(a, func(key string, lhsValue Value) bool { + var rhsValue Value + if rhs != nil { + if item, ok := rhs.GetUsing(a, key); ok { + rhsValue = item + defer a.Free(rhsValue) + } + } + return fn(key, lhsValue, rhsValue) + }) + if !ok { + return false + } + } + if rhs != nil { + return rhs.IterateUsing(a, func(key string, rhsValue Value) bool { + if lhs == nil || !lhs.Has(key) { + return fn(key, nil, rhsValue) + } + return true + }) + } + return true +} + +func lexicalKeyOrderedMapZip(a Allocator, lhs, rhs Map, fn func(key string, lhs, rhs Value) bool) bool { + var lhsLength, rhsLength int + var orderedLength int // rough estimate of length of union of map keys + if lhs != nil { + lhsLength = lhs.Length() + orderedLength = lhsLength + } + if rhs != nil { + rhsLength = rhs.Length() + if rhsLength > orderedLength { + orderedLength = rhsLength + } + } + if lhsLength == 0 && rhsLength == 0 { + return true + } + + ordered := make([]string, 0, orderedLength) + if lhs != nil { + lhs.IterateUsing(a, func(key string, _ Value) bool { + ordered = append(ordered, key) + return true + }) + } + if rhs != nil { + rhs.IterateUsing(a, func(key string, _ Value) bool { + if lhs == nil || !lhs.Has(key) { + ordered = append(ordered, key) + } + return true + }) + } + sort.Strings(ordered) + for _, key := range ordered { + var litem, ritem Value + if lhs != nil { + litem, _ = lhs.GetUsing(a, key) + } + if rhs != nil { + ritem, _ = rhs.GetUsing(a, key) + } + ok := fn(key, litem, ritem) + if litem != nil { + a.Free(litem) + } + if ritem != nil { + a.Free(ritem) + } + if !ok { + return false + } + } + return true +} + +// 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 { + return MapCompareUsing(HeapAllocator, lhs, rhs) +} + +// MapCompareUsing uses the provided allocator and compares two maps lexically. +func MapCompareUsing(a Allocator, lhs, rhs Map) int { + c := 0 + var llength, rlength int + if lhs != nil { + llength = lhs.Length() + } + if rhs != nil { + rlength = rhs.Length() + } + if llength == 0 && rlength == 0 { + return 0 + } + i := 0 + MapZipUsing(a, lhs, rhs, LexicalKeyOrder, func(key string, lhs, rhs Value) bool { + switch { + case i == llength: + c = -1 + case i == rlength: + c = 1 + case lhs == nil: + c = 1 + case rhs == nil: + c = -1 + default: + c = CompareUsing(a, lhs, rhs) + } + i++ + return c == 0 + }) + return c +} + +// 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. +// WARN: This is a naive implementation, calling lhs.Equals(rhs) is typically the most efficient. +func MapEquals(lhs, rhs Map) bool { + return MapEqualsUsing(HeapAllocator, lhs, rhs) +} + +// MapEqualsUsing uses the provided allocator and 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. +// WARN: This is a naive implementation, calling lhs.EqualsUsing(allocator, rhs) is typically the most efficient. +func MapEqualsUsing(a Allocator, lhs, rhs Map) bool { + if lhs == nil && rhs == nil { + return true + } + if lhs == nil || rhs == nil { + return false + } + if lhs.Length() != rhs.Length() { + return false + } + return MapZipUsing(a, lhs, rhs, Unordered, func(key string, lhs, rhs Value) bool { + if lhs == nil || rhs == nil { + return false + } + return EqualsUsing(a, lhs, rhs) + }) +} |