使用golang统计代码行数
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2022-04-18 18:29:39
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有关golang的介绍请参考我的另一篇博文.
本文通过递归遍历src目录, 统计代码行数. 涉及到的知识点有:
1. 目录遍历.
2. 读取文件.
3. 使用channel进行goroutine间的通信.
4. 使用sync包进行传统的共享内存方式的同步.
5. 错误处理.
6. defer语句的使用.
在程序中有详细的注释:
// a simple go program for computing total line of souce files stored in one dir package main import ( "fmt" "bufio" "os" "sync" "strings" ) var ( linesum int mutex *sync.Mutex = new(sync.Mutex) ) var ( // the dir where souce file stored rootPath string = "/home/xing/Dropbox/source/go/src" // exclude these sub dirs nodirs [5]string = [...]string{"/bitbucket.org", "/github.com", "/goplayer", "/uniqush", "/code.google.com"} // the suffix name you care suffixname string = ".go" ) func main() { argsLen := len(os.Args) if argsLen == 2 { rootPath = os.Args[1] } else if argsLen == 3 { rootPath = os.Args[1] suffixname = os.Args[2] } // sync chan using for waiting done := make(chan bool) go codeLineSum(rootPath, done) <-done fmt.Println("total line:", linesum) } // compute souce file line number func codeLineSum(root string, done chan bool) { var goes int // children goroutines number godone := make(chan bool) // sync chan using for waiting all his children goroutines finished isDstDir := checkDir(root) defer func() { if pan := recover(); pan != nil { fmt.Printf("root: %s, panic:%#v\n", root, pan) } // waiting for his children done for i := 0; i < goes; i++ { <-godone } // this goroutine done, notify his parent done <- true }() if !isDstDir { return } rootfi, err := os.Lstat(root) checkerr(err) rootdir, err := os.Open(root) checkerr(err) defer rootdir.Close() if rootfi.IsDir() { fis, err := rootdir.Readdir(0) checkerr(err) for _, fi := range fis { if strings.HasPrefix(fi.Name(), ".") { continue } goes++ if fi.IsDir() { go codeLineSum(root+"/"+fi.Name(), godone) } else { go readfile(root+"/"+fi.Name(), godone) } } } else { goes = 1 // if rootfi is a file, current goroutine has only one child go readfile(root, godone) } } func readfile(filename string, done chan bool) { var line int isDstFile := strings.HasSuffix(filename, suffixname) defer func() { if pan := recover(); pan != nil { fmt.Printf("filename: %s, panic:%#v\n", filename, pan) } if isDstFile { addLineNum(line) fmt.Printf("file %s complete, line = %d\n", filename, line) } // this goroutine done, notify his parent done <- true }() if !isDstFile { return } file, err := os.Open(filename) checkerr(err) defer file.Close() reader := bufio.NewReader(file) for { _, isPrefix, err := reader.ReadLine() if err != nil { break } if !isPrefix { line++ } } } // check whether this dir is the dest dir func checkDir(dirpath string) bool { // 判断该文件夹是否在被排除的范围之内 for _, dir := range nodirs { if rootPath+dir == dirpath { return false } } return true } func addLineNum(num int) { // 获取锁 mutex.Lock() // defer语句在函数返回时调用, 确保锁被释放 defer mutex.Unlock() linesum += num } // if error happened, throw a panic, and the panic will be recover in defer function func checkerr(err error) { if err != nil { // 在发生错误时调用panic, 程序将立即停止正常执行, 开始沿调用栈往上抛, 直到遇到recover // 对于java程序员, 可以将panic类比为exception, 而recover则是try...catch panic(err.Error()) } }
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