rexp.go

// Copyright 2015 go-swagger maintainers
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations untader the License.

package validate

import (
	re "regexp"
	"sync"
)

// Cache for compiled regular expressions
var (
	reDict = sync.Map{}
)

func compileRegexp(pattern string) (*re.Regexp, error) {
	// Save repeated regexp compilation
	if reg, ok := reDict.Load(pattern); ok {
		return reg.(*re.Regexp), nil
	}

	patternCompiled, err := re.Compile(pattern)
	if err == nil {
		reDict.Store(pattern, patternCompiled)
	}
	return patternCompiled, err
}

func mustCompileRegexp(pattern string) *re.Regexp {
	// Save repeated regexp compilation, with panic on error
	if reg, ok := reDict.Load(pattern); ok {
		return reg.(*re.Regexp)
	}

	patternCompiled := re.MustCompile(pattern)
	reDict.Store(pattern, patternCompiled)
	return patternCompiled
}