golang代码片段(摘抄)
以下是从golang并发编程实战2中摘抄过来的代码片段,主要是实现一个简单的tcp socket通讯(客户端发送一个数字,服务端计算该数字的立方根然后返回),写的不错,用到了go的并发以及看下郝林大神是如何处理socket通讯的。具体代码记录如下,多看多学习多共勉:
package main import ( "net" "strings" "fmt" "time" "io" "bytes" "strconv" "math" "math/rand" "sync" ) const ( SERVER_NETWORK = "tcp" SERVER_ADDRESS = "127.0.0.1:8085" DELIMITER = '\t' ) var wg sync.WaitGroup func main() { wg.Add(2) go serverGo() time.Sleep(500 * time.Millisecond) go clientGo(1) wg.Wait() } func serverGo() { defer wg.Done() listener, err := net.Listen(SERVER_NETWORK, SERVER_ADDRESS) if err != nil { printServerLog("Listen Error: %s", err) return } defer listener.Close() printServerLog("Got listener for the server.(local address: %s)", listener.Addr()) for { conn, err := listener.Accept() if err != nil { printServerLog("Accept Error: %s", err) } printServerLog("Established a connection with a client application,(remote address: %s)", conn.RemoteAddr()) go handleConn(conn) } } func printLog(role string, sn int, format string, args ...interface{}) { if !strings.HasSuffix(format, "\n") { format += "\n" } fmt.Printf("%s[%d]: %s", role, sn, fmt.Sprintf(format, args...)) } func printServerLog(format string, args ...interface{}) { printLog("Server", 0, format, args...) } func printClientLog(sn int, format string, args ...interface{}) { printLog("Cient", sn, format, args...) } func handleConn(conn net.Conn) { defer conn.Close() for { conn.SetDeadline(time.Now().Add(10 * time.Second)) // set read timeline 10s strReq, err := read(conn) if err != nil { if err == io.EOF { printServerLog("The connection is closed by another side.") } else { printServerLog("Read Error: %s", err) } break } printServerLog("Received request: %s", strReq) intReq, err := strToInt32(strReq) if err != nil { n, err := write(conn, err.Error()) printServerLog("Sent error message (written %d bytes): %s", n, err) continue } floatResp := cbrt(intReq) respMsg := fmt.Sprintf("The cube root of %d is %f.", intReq, floatResp) n, err := write(conn, respMsg) if err != nil { printServerLog("Sent response message (written %d bytes: %s).", n, respMsg) } } } func read(conn net.Conn) (string, error){ readBytes := make([]byte, 1) var buffer bytes.Buffer for { _, err := conn.Read(readBytes) if err != nil { return "", err } readByte := readBytes[0] if readByte == DELIMITER { break } buffer.WriteByte(readByte) } return buffer.String(), nil } func strToInt32(str string) (int32, error){ i32, err := strconv.ParseInt(str, 10 ,32) return int32(i32), err } func write(conn net.Conn, content string) (int, error) { var buffer bytes.Buffer buffer.WriteString(content) buffer.WriteByte(DELIMITER) return conn.Write(buffer.Bytes()) } func cbrt(intReq int32) float64 { return math.Cbrt(float64(intReq)) } func clientGo(id int) { defer wg.Done() conn, err := net.DialTimeout(SERVER_NETWORK, SERVER_ADDRESS, 2 * time.Second) if err != nil { printClientLog(id, "Dial Error: %s", err) return } defer conn.Close() printClientLog(id, "Connected to server.(remote address: %s,local address: %s)", conn.RemoteAddr(), conn.LocalAddr()) time.Sleep(200 * time.Millisecond) requestNumber := 5 conn.SetDeadline(time.Now().Add(5 * time.Millisecond)) for i := 0; i< requestNumber; i++ { req := rand.Int31() n, err := write(conn, fmt.Sprintf("%d", req)) if err != nil { printClientLog(id, "Write Error: %s", err) continue } printClientLog(id, "Sent request (written %d bytes)", n) } for j := 0; j< requestNumber; j++ { strResp, err := read(conn) if err != nil { if err == io.EOF { printClientLog(id, "The connection is closed by another side.") }else{ printClientLog(id, "Read Error: %s", err) } break } printClientLog(id, "Received response: %s", strResp) } }
执行效果:
作者:程序员小波与Bug
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