// Copyright (c) 2015-2021 MinIO, Inc.//// This file is part of MinIO Object Storage stack//// This program is free software: you can redistribute it and/or modify// it under the terms of the GNU Affero General Public License as published by// the Free Software Foundation, either version 3 of the License, or// (at your option) any later version.//// This program is distributed in the hope that it will be useful// but WITHOUT ANY WARRANTY; without even the implied warranty of// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the// GNU Affero General Public License for more details.//// You should have received a copy of the GNU Affero General Public License// along with this program.  If not, see <http://www.gnu.org/licenses/>. package event import (	"strings" 	"github.com/minio/pkg/wildcard") // NewPattern - create new pattern for prefix/suffix.func NewPattern(prefix, suffix string) (pattern string) {	if prefix != "" {		if !strings.HasSuffix(prefix, "*") {			prefix += "*"		} 		pattern = prefix	} 	if suffix != "" {		if !strings.HasPrefix(suffix, "*") {			suffix = "*" + suffix		} 		pattern += suffix	} 	pattern = strings.ReplaceAll(pattern, "**", "*") 	return pattern} // Rules - event rulestype Rules map[string]TargetIDSet // Add - adds pattern and target ID.func (rules Rules) Add(pattern string, targetID TargetID) {	rules[pattern] = NewTargetIDSet(targetID).Union(rules[pattern])} // MatchSimple - returns true one of the matching object name in rules.func (rules Rules) MatchSimple(objectName string) bool {	for pattern := range rules {		if wildcard.MatchSimple(pattern, objectName) {			return true		}	}	return false} // Match - returns TargetIDSet matching object name in rules.func (rules Rules) Match(objectName string) TargetIDSet {	targetIDs := NewTargetIDSet() 	for pattern, targetIDSet := range rules {		if wildcard.MatchSimple(pattern, objectName) {			targetIDs = targetIDs.Union(targetIDSet)		}	} 	return targetIDs} // Clone - returns copy of this rules.func (rules Rules) Clone() Rules {	rulesCopy := make(Rules) 	for pattern, targetIDSet := range rules {		rulesCopy[pattern] = targetIDSet.Clone()	} 	return rulesCopy} // Union - returns union with given rules as new rules.func (rules Rules) Union(rules2 Rules) Rules {	nrules := rules.Clone() 	for pattern, targetIDSet := range rules2 {		nrules[pattern] = nrules[pattern].Union(targetIDSet)	} 	return nrules} // Difference - returns diffrence with given rules as new rules.func (rules Rules) Difference(rules2 Rules) Rules {	nrules := make(Rules) 	for pattern, targetIDSet := range rules {		if nv := targetIDSet.Difference(rules2[pattern]); len(nv) > 0 {			nrules[pattern] = nv		}	} 	return nrules}