feat(aa-log): add some util functions.

pkg/util/slice.go

@@ -0,0 +1,81 @@
+// apparmor.d - Full set of apparmor profiles
+// Copyright (C) 2023-2024 Alexandre Pujol <alexandre@pujol.io>
+// SPDX-License-Identifier: GPL-2.0-only
+
+package util
+
+// RemoveDuplicate filter out all duplicates from a slice. Also filter out empty element.
+func RemoveDuplicate[T comparable](inlist []T) []T {
+	var empty T
+	list := []T{}
+	seen := map[T]bool{}
+	seen[empty] = true
+	for _, item := range inlist {
+		if _, ok := seen[item]; !ok {
+			seen[item] = true
+			list = append(list, item)
+		}
+	}
+	return list
+}
+
+// Intersect returns the intersection between two collections.
+// From https://github.com/samber/lo
+func Intersect[T comparable](list1 []T, list2 []T) []T {
+	result := []T{}
+	seen := map[T]struct{}{}
+
+	for _, elem := range list1 {
+		seen[elem] = struct{}{}
+	}
+
+	for _, elem := range list2 {
+		if _, ok := seen[elem]; ok {
+			result = append(result, elem)
+		}
+	}
+
+	return result
+}
+
+// Flatten returns an array a single level deep.
+// From https://github.com/samber/lo
+func Flatten[T comparable](collection [][]T) []T {
+	totalLen := 0
+	for i := range collection {
+		totalLen += len(collection[i])
+	}
+
+	result := make([]T, 0, totalLen)
+	for i := range collection {
+		result = append(result, collection[i]...)
+	}
+
+	return result
+}
+
+// Invert creates a map composed of the inverted keys and values. If map
+// contains duplicate values, subsequent values overwrite property assignments
+// of previous values.
+// Play: https://go.dev/play/p/rFQ4rak6iA1
+func Invert[K comparable, V comparable](in map[K]V) map[V]K {
+	out := make(map[V]K, len(in))
+
+	for k := range in {
+		out[in[k]] = k
+	}
+
+	return out
+}
+
+func InvertFlatten[V comparable](in map[V][]V) map[V]V {
+	out := make(map[V]V, len(in))
+
+	for k := range in {
+		for _, v := range in[k] {
+			out[v] = k
+		}
+	}
+
+	return out
+}