owobot/internal/cache/regex.go

50 lines
1.2 KiB
Go

/*
* owobot - Your server's guardian and entertainer
* Copyright (C) 2023 owobot Contributors
*
* 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 <https://www.gnu.org/licenses/>.
*/
package cache
import (
"regexp"
"sync"
)
var (
regexMtx = sync.RWMutex{}
regexes = map[string]*regexp.Regexp{}
)
func Regex(regex string) (*regexp.Regexp, error) {
regexMtx.RLock()
if re, ok := regexes[regex]; ok {
regexMtx.RUnlock()
return re, nil
}
regexMtx.RUnlock()
re, err := regexp.Compile(regex)
if err != nil {
return nil, err
}
regexMtx.Lock()
regexes[regex] = re
regexMtx.Unlock()
return re, nil
}