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关于go:用-Go-写一个简单消息队列六服务器实现

本篇咱们实现音讯队列的收尾工作,将咱们的服务器搭建起来。咱们的构想是消费者通过 tcp 连贯到服务端,生产者则是通过 http 协定间接发送音讯。

监听消费者连贯

在 server 目录下新建一个 tcp.go 文件,用于监听消费者的 tcp 连贯,代码如下:

package server

import (
    "context"
    "log"
    "net"
)

func TcpServer(ctx context.Context, addr, port string) {
    fqAddress := addr + ":" + port
    listener, err := net.Listen("tcp", fqAddress)
    if err != nil {panic("tcp listen(" + fqAddress + ") failed")
    }
    log.Printf("listening for clients on %s", fqAddress)

    for {
        select {case <-ctx.Done():
            return
        default:
            conn, err := listener.Accept()
            if err != nil {panic("accept failed:" + err.Error())
            }
            client := NewClient(conn, conn.RemoteAddr().String())
            go client.Handle(ctx)
        }
    }
}

每当监听到 tcp 连贯,就新建一个 client 来解决,同时传入一个 context 不便对立进行退出治理。client 和 protocol 也都要同时加上对这个 context 的监听代码,具体可参考代码仓库。

HTTP Server

同样在 server 目录下新建一个 http.go 文件来编写 HTTP 服务器,咱们的 HTTP 服务器只提供三个办法:测试连贯、写入音讯和查看所有 topic,先来看一下这三个办法的代码:

http.go

package server

import (
    "context"
    "errors"
    "fmt"
    "github.com/yhao1206/SMQ/message"
    "github.com/yhao1206/SMQ/protocol"
    "io"
    "log"
    "net/http"
    "net/url"
    "strconv"
    "time"
)

type ReqParams struct {
    params url.Values
    body   []byte}

func NewReqParams(req *http.Request) (*ReqParams, error) {reqParams, err := url.ParseQuery(req.URL.RawQuery)
    if err != nil {return nil, err}

    data, err := io.ReadAll(req.Body)
    if err != nil {return nil, err}

    return &ReqParams{reqParams, data}, nil
}

func (r *ReqParams) Query(key string) (string, error) {keyData := r.params[key]
    if len(keyData) == 0 {return "", errors.New("key not in query params")
    }
    return keyData[0], nil
}

func pingHandler(w http.ResponseWriter, req *http.Request) {w.Header().Set("Content-Length", "2")
    io.WriteString(w, "OK")
}

func putHandler(w http.ResponseWriter, req *http.Request) {reqParams, err := NewReqParams(req)
    if err != nil {log.Printf("HTTP: error - %s", err.Error())
        return
    }

    topicName, err := reqParams.Query("topic")
    if err != nil {log.Printf("HTTP: error - %s", err.Error())
        return
    }

    conn := &FakeConn{}
    client := NewClient(conn, "HTTP")
    proto := &protocol.Protocol{}
    resp, err := proto.Execute(client, "PUB", topicName, string(reqParams.body))
    if err != nil {log.Printf("HTTP: error - %s", err.Error())
        return
    }

    w.Header().Set("Content-Length", strconv.Itoa(len(resp)))
    w.Write(resp)
}

func statsHandler(w http.ResponseWriter, req *http.Request) {
    for topicName, _ := range message.TopicMap {io.WriteString(w, fmt.Sprintf("%s\n", topicName))
    }
}

为了对立治理,咱们的 putHandler 办法没有间接操作 topic,而是包装了一个假的客户端向协定中发送 PUB 指令,由协定与 topic 进行交互。fake_conn 和 PUB 办法的代码如下:

server/fake_conn.go

package server

import ("io")

type FakeConn struct {io.ReadWriter}

func (c *FakeConn) Close() error {return nil}

----------

protocol/protocol.go

func (p *Protocol) PUB(client StatefulReadWriter, params []string) ([]byte, error) {
    var buf bytes.Buffer
    var err error

    //  fake clients don't get to ClientInit
    if client.GetState() != -1 {return nil, ClientErrInvalid}

    if len(params) < 3 {return nil, ClientErrInvalid}

    topicName := params[1]
    body := []byte(params[2])

    _, err = buf.Write(<-util.UuidChan)
    if err != nil {return nil, err}

    _, err = buf.Write(body)
    if err != nil {return nil, err}

    topic := message.GetTopic(topicName)
    topic.PutMessage(message.NewMessage(buf.Bytes()))

    return []byte("OK"), nil
}

再来就是启动一个 http server:

http.go

func HttpServer(ctx context.Context, address string, port string, endChan chan struct{}) {http.HandleFunc("/ping", pingHandler)
    http.HandleFunc("/put", putHandler)
    http.HandleFunc("/stats", statsHandler)

    fqAddress := address + ":" + port
    httpServer := http.Server{Addr: fqAddress,}

    go func() {log.Printf("listening for http requests on %s", fqAddress)
        err := http.ListenAndServe(fqAddress, nil)
        if err != nil {log.Fatal("http.ListenAndServe:", err)
        }
    }()

    <-ctx.Done()
    log.Printf("HTTP server on %s is shutdowning...", fqAddress)
    timeoutCtx, fn := context.WithTimeout(context.Background(), 10*time.Second)
    defer fn()
    if err := httpServer.Shutdown(timeoutCtx); err != nil {log.Printf("HTTP server shutdown error: %v", err)
    }
    close(endChan)
}

作为参数传入的 context 也是为了对立退出治理,当监听到退出信号(<-ctx.Done())后,咱们再生成一个带超时工夫的 context,让 http server 有足够的工夫实现清理工作,实现优雅退出。退出之后敞开 endChan,调用方能够依据从 endChan 接管到数据判断优雅退出已实现。

main 函数

终于到了最初一步,就是实现咱们的 main 函数,将咱们的服务都启动起来。在我的项目根目录下创立 smq.go 文件,写入以下代码:

package main

import (
    "context"
    "flag"
    "github.com/yhao1206/SMQ/message"
    "github.com/yhao1206/SMQ/server"
    "github.com/yhao1206/SMQ/util"
    "os"
    "os/signal"
    "strconv"
)

var bindAddress = flag.String("address", "","address to bind to")
var webPort = flag.Int("web-port", 5150, "port to listen on for HTTP connections")
var tcpPort = flag.Int("tcp-port", 5151, "port to listen on for TCP connections")
var memQueueSize = flag.Int("mem-queue-size", 10000, "number of messages to keep in memory (per topic)")

func main() {flag.Parse()

    endChan := make(chan struct{})
    signalChan := make(chan os.Signal, 1)
    signal.Notify(signalChan, os.Interrupt)

    ctx, fn := context.WithCancel(context.Background())
    go func() {
        <-signalChan
        fn()}()

    go message.TopicFactory(ctx, *memQueueSize)
    go util.UuidFactory(ctx)
    go server.TcpServer(ctx, *bindAddress, strconv.Itoa(*tcpPort))
    server.HttpServer(ctx, *bindAddress, strconv.Itoa(*webPort), endChan)

    for _, topic := range message.TopicMap {topic.Close()
    }

    <-endChan
}

第一步按照常规都是解析命令行参数,让用户能够自主管制监听端口和内存队列的大小。

第二步是监听中断信号,接管到信号后通过 context 的个性向所有的后盾服务发送退出信号,而后敞开所有的 topic,期待 http server 退出实现即可。简略两步,咱们的音讯队列零碎就搭建起来了。

测试

咱们当初来测试一下咱们的音讯队列,为了不便测试,这边提供了一个简略的消费者连贯库:

client/conn.go

package client

import (
    "bytes"
    "encoding/binary"
    "fmt"
    "github.com/yhao1206/SMQ/message"
    "io"
    "net"
    "strconv"
)

type Client struct {conn io.ReadWriteCloser}

type Command struct {name   []byte
    params [][]byte
}

type Response struct {
    FrameType int32
    Data      interface{}}

func NewClient(conn net.Conn) *Client {return &Client{conn}
}

func (c *Client) Connect(address string, port int) error {fqAddress := address + ":" + strconv.Itoa(port)
    conn, err := net.Dial("tcp", fqAddress)
    if err != nil {return err}
    c.conn = conn
    return nil
}

func (c *Client) Version(version string) error {_, err := c.conn.Write([]byte(version))
    return err
}

func (c *Client) Subscribe(topic string, channel string) *Command {params := make([][]byte, 2)
    params[0] = []byte(topic)
    params[1] = []byte(channel)
    return &Command{[]byte("SUB"), params}
}

func (c *Client) Ready(count int) *Command {params := make([][]byte, 1)
    params[0] = []byte(strconv.Itoa(count))
    return &Command{[]byte("RDY"), params}
}

func (c *Client) Finish(uuid string) *Command {params := make([][]byte, 1)
    params[0] = []byte(uuid)
    return &Command{[]byte("FIN"), params}
}

func (c *Client) Requeue(uuid string) *Command {params := make([][]byte, 1)
    params[0] = []byte(uuid)
    return &Command{[]byte("REQ"), params}
}

func (c *Client) Get() *Command {return &Command{[]byte("GET"), nil}
}

func (c *Client) WriteCommand(cmd *Command) error {if len(cmd.params) > 0 {_, err := fmt.Fprintf(c.conn, "%s %s\n", cmd.name, string(bytes.Join(cmd.params, []byte(" "))))
        if err != nil {return err}
    } else {_, err := fmt.Fprintf(c.conn, "%s\n", cmd.name)
        if err != nil {return err}
    }
    return nil
}

func (c *Client) ReadResponse() (*message.Message, error) {err := c.WriteCommand(c.Get())
    if err != nil {return nil, err}

    var msgSize int32
    err = binary.Read(c.conn, binary.BigEndian, &msgSize)
    if err != nil {return nil, err}

    buf := make([]byte, msgSize)
    _, err = c.conn.Read(buf)
    if err != nil {return nil, err}

    msg := message.NewMessage(buf)

    return msg, nil
}

新建 examples/cousumer/consumer.go 文件,写下咱们的消费者测试代码:

examples/cousumer/consumer.go

package main

import (
    "github.com/yhao1206/SMQ/client"
    "github.com/yhao1206/SMQ/util"
    "log"
)

func main() {consumeClient := client.NewClient(nil)
    err := consumeClient.Connect("127.0.0.1", 5151)
    if err != nil {log.Fatal(err)
    }
    consumeClient.WriteCommand(consumeClient.Subscribe("test", "ch"))

    for {msg, err := consumeClient.ReadResponse()
        if err != nil {log.Fatal(err)
        }
        log.Printf("%s - %s", util.UuidToStr(msg.Uuid()), msg.Body())
        consumeClient.WriteCommand(consumeClient.Finish(util.UuidToStr(msg.Uuid())))
    }
}

启动服务端:go run smq.go,输入如下:

服务已胜利启动。

再启动咱们的测试消费者:go run ./examples/consumer/consumer.go,此时服务端多了几行输入:

能够看出咱们的消费者已胜利连贯到服务器并执行了订阅申请,相应的 topic 也曾经创立结束。

通过 curl 客户端(shell 或者 postman 等)发送 curl 命令来公布一条音讯:

curl --location --request POST '127.0.0.1:5150/put?topic=test' --header 'Content-Type: text/plain' --data-raw 'hello'

服务端输入日志:

查看一下消费者客户端的输入:

能够看到咱们的消费者胜利拉取到了生产者的音讯。

到这里咱们整个系列就全副完结了,欢送大家提出贵重的意见。


我的项目地址:https://github.com/yhao1206/SMQ
相干浏览:

  • 用 Go 写一个简略音讯队列(一):定义音讯和根底工具
  • 用 Go 写一个简略音讯队列(二):客户端解决和 channel 设计
  • 用 Go 写一个简略音讯队列(三):减少实现确认和重入队列性能
  • 用 Go 写一个简略音讯队列(四):topic 设计
  • 用 Go 写一个简略音讯队列(五):协定与后盾队列实现
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