Golang进阶笔记#
性能分析#
import (
"net/http"
_ "net/http/pprof"
)
go func() {
log.Println(http.ListenAndServe("localhost:6060", nil))
}()将以上代码插入程序中 启动之后执行
go tool pprof http://localhost:6060/debug/pprof/profile?seconds=30具体使用方法可以help
如果使用top的话就可以查看方法占用了
(pprof) top
Showing nodes accounting for 29.59s, 98.60% of 30.01s total Dropped 35 nodes (cum <= 0.15s)
flat flat% sum% cum cum%
28.98s 96.57% 96.57% 28.98s 96.57% time.Now
0.24s 0.8% 97.37% 0.51s 1.70% runtime.selectgo
0.16s 0.53% 97.90% 0.16s 0.53% memeqbody
0.13s 0.43% 98.33% 0.29s 0.97% runtime.mapaccess2_faststr
0.08s 0.27% 98.60% 29.95s 99.80% example.com//pts/services/monitor.Run如以上就是说monitor.Run方法中使用了select, 然后其中的time.Now被疯狂执行.
路径问题#
test_test.go#
package main
import "testing"
func TestHelloWorld(t *testing.T) {
// t.Fatal("not implemented")
path := getCurrentPath()
t.Log("getCurrentPath: ", path)
}test.go#
package main
import (
"fmt"
"log"
"os"
"path"
"path/filepath"
"runtime"
"strings"
)
func main() {
fmt.Println("getTmpDir（当前系统临时目录） = ", getTmpDir())
fmt.Println("getCurrentAbPathByExecutable（仅支持go build） = ", getCurrentAbPathByExecutable())
fmt.Println("getCurrentAbPathByCaller（仅支持go run） = ", getCurrentAbPathByCaller())
fmt.Println("getCurrentAbPath（最终方案-全兼容） = ", getCurrentAbPath())
fmt.Println("getCurrentPath（runtime.Caller1） = ", getCurrentPath())
}
// 最终方案-全兼容
func getCurrentAbPath() string {
dir := getCurrentAbPathByExecutable()
if strings.Contains(dir, getTmpDir()) {
return getCurrentAbPathByCaller()
}
return dir
}
func getCurrentPath() string {
_, filename, _, _ := runtime.Caller(1)
return path.Dir(filename)
}
// 获取系统临时目录，兼容go run
func getTmpDir() string {
dir := os.Getenv("TEMP")
if dir == "" {
dir = os.Getenv("TMP")
}
res, _ := filepath.EvalSymlinks(dir)
return res
}
// 获取当前执行文件绝对路径
func getCurrentAbPathByExecutable() string {
exePath, err := os.Executable()
if err != nil {
log.Fatal(err)
}
res, _ := filepath.EvalSymlinks(filepath.Dir(exePath))
return res
}
// 获取当前执行文件绝对路径（go run）
func getCurrentAbPathByCaller() string {
var abPath string
_, filename, _, ok := runtime.Caller(0)
if ok {
abPath = path.Dir(filename)
}
return abPath
}输出#
ian@ianDebian:~$ ./test
getTmpDir（当前系统临时目录） = .
getCurrentAbPathByExecutable（仅支持go build） = /home/ian
getCurrentAbPathByCaller（仅支持go run） = /home/ian
getCurrentAbPath（最终方案-全兼容） = /home/ian
getCurrentPath（runtime.Caller1） = /home/ian
ian@ianDebian:~$
ian@ianDebian:~$ go run test.go
getTmpDir（当前系统临时目录） = .
getCurrentAbPathByExecutable（仅支持go build） = /tmp/go-build3048077768/b001/exe
getCurrentAbPathByCaller（仅支持go run） = /home/ian
getCurrentAbPath（最终方案-全兼容） = /tmp/go-build3048077768/b001/exe
getCurrentPath（runtime.Caller1） = /home/ian
ian@ianDebian:~$
ian@ianDebian:~$ go test test_test.go test.go -v
=== RUN TestHelloWorld
test_test.go:8: getCurrentPath: /home/ian
--- PASS: TestHelloWorld (0.00s)
PASS
ok command-line-arguments 0.002sGolang 私有仓库#
xxx替换为具体地址