minio/pkg/wildcard/match.go

// 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 wildcard

// MatchSimple - finds whether the text matches/satisfies the pattern string.
// supports only '*' wildcard in the pattern.
// considers a file system path as a flat name space.
func MatchSimple(pattern, name string) bool {
	if pattern == "" {
		return name == pattern
	}
	if pattern == "*" {
		return true
	}
	// Does only wildcard '*' match.
	return deepMatchRune([]rune(name), []rune(pattern), true)
}

// Match -  finds whether the text matches/satisfies the pattern string.
// supports  '*' and '?' wildcards in the pattern string.
// unlike path.Match(), considers a path as a flat name space while matching the pattern.
// The difference is illustrated in the example here https://play.golang.org/p/Ega9qgD4Qz .
func Match(pattern, name string) (matched bool) {
	if pattern == "" {
		return name == pattern
	}
	if pattern == "*" {
		return true
	}
	// Does extended wildcard '*' and '?' match.
	return deepMatchRune([]rune(name), []rune(pattern), false)
}

func deepMatchRune(str, pattern []rune, simple bool) bool {
	for len(pattern) > 0 {
		switch pattern[0] {
		default:
			if len(str) == 0 || str[0] != pattern[0] {
				return false
			}
		case '?':
			if len(str) == 0 && !simple {
				return false
			}
		case '*':
			return deepMatchRune(str, pattern[1:], simple) ||
				(len(str) > 0 && deepMatchRune(str[1:], pattern, simple))
		}
		str = str[1:]
		pattern = pattern[1:]
	}
	return len(str) == 0 && len(pattern) == 0
}