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49 lines
1.3 KiB
Go
49 lines
1.3 KiB
Go
// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
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//
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// This Source Code Form is subject to the terms of the MIT License.
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// If a copy of the MIT was not distributed with this file,
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// You can obtain one at https://github.com/gogf/gf.
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package gregex
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import (
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"regexp"
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"sync"
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)
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var (
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regexMu = sync.RWMutex{}
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// Cache for regex object.
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// Note that:
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// 1. It uses sync.RWMutex ensuring the concurrent safety.
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// 2. There's no expiring logic for this map.
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regexMap = make(map[string]*regexp.Regexp)
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)
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// getRegexp returns *regexp.Regexp object with given <pattern>.
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// It uses cache to enhance the performance for compiling regular expression pattern,
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// which means, it will return the same *regexp.Regexp object with the same regular
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// expression pattern.
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//
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// It is concurrent-safe for multiple goroutines.
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func getRegexp(pattern string) (regex *regexp.Regexp, err error) {
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// Retrieve the regular expression object using reading lock.
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regexMu.RLock()
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regex = regexMap[pattern]
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regexMu.RUnlock()
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if regex != nil {
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return
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}
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// If it does not exist in the cache,
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// it compiles the pattern and creates one.
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regex, err = regexp.Compile(pattern)
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if err != nil {
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return
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}
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// Cache the result object using writing lock.
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regexMu.Lock()
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regexMap[pattern] = regex
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regexMu.Unlock()
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return
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}
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