mirror of https://github.com/jackc/pgx.git
74 lines
1.5 KiB
Go
74 lines
1.5 KiB
Go
package main
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import (
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"bufio"
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"context"
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"fmt"
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"os"
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"github.com/jackc/pgx/v5/pgxpool"
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)
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var pool *pgxpool.Pool
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func main() {
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var err error
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pool, err = pgxpool.New(context.Background(), os.Getenv("DATABASE_URL"))
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if err != nil {
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fmt.Fprintln(os.Stderr, "Unable to connect to database:", err)
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os.Exit(1)
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}
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go listen()
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fmt.Println(`Type a message and press enter.
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This message should appear in any other chat instances connected to the same
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database.
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Type "exit" to quit.`)
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scanner := bufio.NewScanner(os.Stdin)
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for scanner.Scan() {
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msg := scanner.Text()
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if msg == "exit" {
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os.Exit(0)
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}
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_, err = pool.Exec(context.Background(), "select pg_notify('chat', $1)", msg)
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if err != nil {
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fmt.Fprintln(os.Stderr, "Error sending notification:", err)
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os.Exit(1)
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}
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}
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if err := scanner.Err(); err != nil {
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fmt.Fprintln(os.Stderr, "Error scanning from stdin:", err)
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os.Exit(1)
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}
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}
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func listen() {
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conn, err := pool.Acquire(context.Background())
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if err != nil {
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fmt.Fprintln(os.Stderr, "Error acquiring connection:", err)
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os.Exit(1)
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}
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defer conn.Release()
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_, err = conn.Exec(context.Background(), "listen chat")
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if err != nil {
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fmt.Fprintln(os.Stderr, "Error listening to chat channel:", err)
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os.Exit(1)
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}
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for {
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notification, err := conn.Conn().WaitForNotification(context.Background())
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if err != nil {
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fmt.Fprintln(os.Stderr, "Error waiting for notification:", err)
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os.Exit(1)
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}
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fmt.Println("PID:", notification.PID, "Channel:", notification.Channel, "Payload:", notification.Payload)
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}
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}
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