73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
// Solution to part 3 of the Whispering Gophers code lab.
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//
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// This program listens on the host and port specified by the -listen flag.
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// For each incoming connection, it launches a goroutine that reads and decodes
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// JSON-encoded messages from the connection and prints them to standard
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// output.
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//
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// You can test this program by running it in one terminal:
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// $ part3 -listen=localhost:8000
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// And running part2 in another terminal:
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// $ part2 -dial=localhost:8000
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// Lines typed in the second terminal should appear as JSON objects in the
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// first terminal.
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//
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package main
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import (
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"encoding/json"
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"flag"
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"fmt"
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"io"
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"log"
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"net"
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)
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var listenAddr = flag.String("listen", "localhost:8000", "host:port to listen on")
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type Message struct {
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Body string
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}
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func main() {
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flag.Parse()
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// TODO: Create a net.Listener listening from the address in the "listen" flag.
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l, err := net.Listen("tcp", *listenAddr)
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if err != nil {
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log.Fatal(err)
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}
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for {
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// TODO: Accept a new connection from the listener.
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c, err := l.Accept()
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if err != nil {
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log.Fatal(err)
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}
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go serve(c)
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}
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}
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func serve(c net.Conn) {
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// TODO: Use defer to Close the connection when this function returns.
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defer c.Close()
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// TODO: Create a new json.Decoder reading from the connection.
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e := json.NewDecoder(c)
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for {
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// TODO: Create an empty message.
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m := Message{}
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// TODO: Decode a new message into the variable you just created.
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err := e.Decode(&m)
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switch err {
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case nil:
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// TODO: Print the message to the standard output.
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fmt.Printf("%+v\n", m)
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case io.EOF:
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log.Println("End of input")
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return
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default:
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log.Fatal(err)
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}
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}
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}
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