func TestNewConnPool(t *testing.T) {
t.Parallel()
var numCallbacks int
afterConnect := func(c *pgx.Conn) error {
numCallbacks++
return nil
}
config := pgx.ConnPoolConfig{ConnConfig: *defaultConnConfig, MaxConnections: 2, AfterConnect: afterConnect}
pool, err := pgx.NewConnPool(config)
if err != nil {
t.Fatal("Unable to establish connection pool")
}
defer pool.Close()
// It initially connects once
stat := pool.Stat()
if stat.CurrentConnections != 1 {
t.Errorf("Expected 1 connection to be established immediately, but %v were", numCallbacks)
}
// Pool creation returns an error if any AfterConnect callback does
errAfterConnect := errors.New("Some error")
afterConnect = func(c *pgx.Conn) error {
return errAfterConnect
}
config = pgx.ConnPoolConfig{ConnConfig: *defaultConnConfig, MaxConnections: 2, AfterConnect: afterConnect}
pool, err = pgx.NewConnPool(config)
if err != errAfterConnect {
t.Errorf("Expected errAfterConnect but received unexpected: %v", err)
}
}
func TestOpenFromConnPool(t *testing.T) {
connConfig := pgx.ConnConfig{
Host: "localhost",
User: "******",
Password: "******",
Database: "pgx_test",
}
config := pgx.ConnPoolConfig{ConnConfig: connConfig}
pool, err := pgx.NewConnPool(config)
if err != nil {
t.Fatalf("Unable to create connection pool: %v", err)
}
defer pool.Close()
db, err := stdlib.OpenFromConnPool(pool)
if err != nil {
t.Fatalf("Unable to create connection pool: %v", err)
}
defer closeDB(t, db)
// Can get pgx.ConnPool from driver
driver := db.Driver().(*stdlib.Driver)
if driver.Pool == nil {
t.Fatal("Expected driver opened through OpenFromConnPool to have Pool, but it did not")
}
// Normal sql/database still works
var n int64
err = db.QueryRow("select 1").Scan(&n)
if err != nil {
t.Fatalf("db.QueryRow unexpectedly failed: %v", err)
}
}
func main() {
var err error
connPoolConfig := pgx.ConnPoolConfig{
ConnConfig: pgx.ConnConfig{
Host: "127.0.0.1",
User: "******",
Password: "******",
Database: "url_shortener",
Logger: log.New("module", "pgx"),
},
MaxConnections: 5,
AfterConnect: afterConnect,
}
pool, err = pgx.NewConnPool(connPoolConfig)
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)
}
}
func createConnPool(t *testing.T, maxConnections int) *pgx.ConnPool {
config := pgx.ConnPoolConfig{ConnConfig: *defaultConnConfig, MaxConnections: maxConnections}
pool, err := pgx.NewConnPool(config)
if err != nil {
t.Fatalf("Unable to create connection pool: %v", err)
}
return pool
}
func TestNewConnPoolMaxConnectionsCannotBeLessThan2(t *testing.T) {
t.Parallel()
config := pgx.ConnPoolConfig{ConnConfig: *defaultConnConfig, MaxConnections: 1}
pool, err := pgx.NewConnPool(config)
if err == nil {
pool.Close()
t.Fatal(`Expected NewConnPool to fail with "MaxConnections must be at least 2" error, but it succeeded`)
}
if err.Error() != "MaxConnections must be at least 2" {
t.Fatalf(`Expected NewConnPool to fail with "MaxConnections must be at least 2" error, but it failed with %v`, err)
}
}
func TestNewConnPoolDefaultsTo5MaxConnections(t *testing.T) {
t.Parallel()
config := pgx.ConnPoolConfig{ConnConfig: *defaultConnConfig}
pool, err := pgx.NewConnPool(config)
if err != nil {
t.Fatal("Unable to establish connection pool")
}
defer pool.Close()
if n := pool.Stat().MaxConnections; n != 5 {
t.Fatalf("Expected pool to default to 5 max connections, but it was %d", n)
}
}
func BenchmarkConnPool(b *testing.B) {
config := pgx.ConnPoolConfig{ConnConfig: *defaultConnConfig, MaxConnections: 5}
pool, err := pgx.NewConnPool(config)
if err != nil {
b.Fatalf("Unable to create connection pool: %v", err)
}
defer pool.Close()
b.ResetTimer()
for i := 0; i < b.N; i++ {
var conn *pgx.Conn
if conn, err = pool.Acquire(); err != nil {
b.Fatalf("Unable to acquire connection: %v", err)
}
pool.Release(conn)
}
}
func main() {
var err error
pool, err = pgx.NewConnPool(extractConfig())
if err != nil {
fmt.Fprintln(os.Stderr, "Unable to connect to database:", err)
os.Exit(1)
}
go listen()
fmt.Println(`Type a message and press enter.
This message should appear in any other chat instances connected to the same
database.
Type "exit" to quit.
`)
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
msg := scanner.Text()
if msg == "exit" {
os.Exit(0)
}
_, err = pool.Exec("select pg_notify('chat', $1)", msg)
if err != nil {
fmt.Fprintln(os.Stderr, "Error sending notification:", err)
os.Exit(1)
}
}
if err := scanner.Err(); err != nil {
fmt.Fprintln(os.Stderr, "Error scanning from stdin:", err)
os.Exit(1)
}
}