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package main
import (
"context"
"io/ioutil"
"net/http"
"os"
"github.com/jackc/pgx/v4"
"github.com/jackc/pgx/v4/log/log15adapter"
"github.com/jackc/pgx/v4/pgxpool"
log "gopkg.in/inconshreveable/log15.v2"
)
var db *pgxpool.Pool
func getUrlHandler(w http.ResponseWriter, req *http.Request) {
var url string
err := db.QueryRow(context.Background(), "select url from shortened_urls where id=$1", req.URL.Path).Scan(&url)
switch err {
case nil:
http.Redirect(w, req, url, http.StatusSeeOther)
case pgx.ErrNoRows:
http.NotFound(w, req)
default:
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
}
func putUrlHandler(w http.ResponseWriter, req *http.Request) {
id := req.URL.Path
var url string
if body, err := ioutil.ReadAll(req.Body); err == nil {
url = string(body)
} else {
http.Error(w, "Internal server error", http.StatusInternalServerError)
return
}
if _, err := db.Exec(context.Background(), `insert into shortened_urls(id, url) values ($1, $2)
on conflict (id) do update set url=excluded.url`, id, url); err == nil {
w.WriteHeader(http.StatusOK)
} else {
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
}
func deleteUrlHandler(w http.ResponseWriter, req *http.Request) {
if _, err := db.Exec(context.Background(), "delete from shortened_urls where id=$1", req.URL.Path); err == nil {
w.WriteHeader(http.StatusOK)
} else {
http.Error(w, "Internal server error", http.StatusInternalServerError)
}
}
func urlHandler(w http.ResponseWriter, req *http.Request) {
switch req.Method {
case "GET":
getUrlHandler(w, req)
case "PUT":
putUrlHandler(w, req)
case "DELETE":
deleteUrlHandler(w, req)
default:
w.Header().Add("Allow", "GET, PUT, DELETE")
w.WriteHeader(http.StatusMethodNotAllowed)
}
}
func main() {
logger := log15adapter.NewLogger(log.New("module", "pgx"))
poolConfig, err := pgxpool.ParseConfig(os.Getenv("DATABASE_URL"))
if err != nil {
log.Crit("Unable to parse DATABASE_URL", "error", err)
os.Exit(1)
}
poolConfig.ConnConfig.Logger = logger
db, err = pgxpool.ConnectConfig(context.Background(), poolConfig)
if err != nil {
log.Crit("Unable to create connection pool", "error", err)
os.Exit(1)
}
http.HandleFunc("/", urlHandler)
log.Info("Starting URL shortener on localhost:8080")
err = http.ListenAndServe("localhost:8080", nil)
if err != nil {
log.Crit("Unable to start web server", "error", err)
os.Exit(1)
}
}
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