Serge Bazanski | cc25bdf | 2018-10-25 14:02:58 +0200 | [diff] [blame] | 1 | // Copyright 2015 go-swagger maintainers |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package validate |
| 16 | |
| 17 | import ( |
| 18 | re "regexp" |
| 19 | "sync" |
| 20 | "sync/atomic" |
| 21 | ) |
| 22 | |
| 23 | // Cache for compiled regular expressions |
| 24 | var ( |
| 25 | cacheMutex = &sync.Mutex{} |
| 26 | reDict = atomic.Value{} //map[string]*re.Regexp |
| 27 | ) |
| 28 | |
| 29 | func compileRegexp(pattern string) (*re.Regexp, error) { |
| 30 | if cache, ok := reDict.Load().(map[string]*re.Regexp); ok { |
| 31 | if r := cache[pattern]; r != nil { |
| 32 | return r, nil |
| 33 | } |
| 34 | } |
| 35 | |
| 36 | r, err := re.Compile(pattern) |
| 37 | if err != nil { |
| 38 | return nil, err |
| 39 | } |
| 40 | cacheRegexp(r) |
| 41 | return r, nil |
| 42 | } |
| 43 | |
| 44 | func mustCompileRegexp(pattern string) *re.Regexp { |
| 45 | if cache, ok := reDict.Load().(map[string]*re.Regexp); ok { |
| 46 | if r := cache[pattern]; r != nil { |
| 47 | return r |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | r := re.MustCompile(pattern) |
| 52 | cacheRegexp(r) |
| 53 | return r |
| 54 | } |
| 55 | |
| 56 | func cacheRegexp(r *re.Regexp) { |
| 57 | cacheMutex.Lock() |
| 58 | defer cacheMutex.Unlock() |
| 59 | |
| 60 | if cache, ok := reDict.Load().(map[string]*re.Regexp); !ok || cache[r.String()] == nil { |
| 61 | newCache := map[string]*re.Regexp{ |
| 62 | r.String(): r, |
| 63 | } |
| 64 | |
| 65 | for k, v := range cache { |
| 66 | newCache[k] = v |
| 67 | } |
| 68 | |
| 69 | reDict.Store(newCache) |
| 70 | } |
| 71 | } |