Golang pgx.NewConnPool函數代碼示例

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 (s *S) SetUpSuite(c *C) {
	dbname := "controllertest"
	if err := pgtestutils.SetupPostgres(dbname); err != nil {
		c.Fatal(err)
	}

	pgxpool, err := pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     os.Getenv("PGHOST"),
			Database: dbname,
		},
	})
	if err != nil {
		c.Fatal(err)
	}
	db := postgres.New(pgxpool, nil)
	if err = migrateDB(db); err != nil {
		c.Fatal(err)
	}

	// reconnect with que statements prepared now that schema is migrated

	pgxpool, err = pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     "/var/run/postgresql",
			Database: dbname,
		},
		AfterConnect: schema.PrepareStatements,
	})
	if err != nil {
		c.Fatal(err)
	}
	db = postgres.New(pgxpool, nil)

	s.flac = newFakeLogAggregatorClient()
	s.cc = tu.NewFakeCluster()
	s.hc = handlerConfig{
		db:   db,
		cc:   s.cc,
		lc:   s.flac,
		rc:   newFakeRouter(),
		keys: []string{authKey},
	}
	handler := appHandler(s.hc)
	s.srv = httptest.NewServer(handler)
	client, err := controller.NewClient(s.srv.URL, authKey)
	c.Assert(err, IsNil)
	s.c = client
}

func TestOpenFromConnPool(t *testing.T) {
	connConfig := pgx.ConnConfig{
		Host:     "localhost",
		User:     "pgx_md5",
		Password: "secret",
		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 (s *S) SetUpSuite(c *C) {
	s.discoverd, s.cleanup = setup(c)

	dbname := "routertest"
	if err := pgtestutils.SetupPostgres(dbname); err != nil {
		c.Fatal(err)
	}

	dsn := fmt.Sprintf("dbname=%s", dbname)
	db, err := sql.Open("postgres", dsn)
	if err != nil {
		c.Fatal(err)
	}
	if err = migrateDB(db); err != nil {
		c.Fatal(err)
	}
	db.Close()
	pgxpool, err := pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     os.Getenv("PGHOST"),
			Database: dbname,
		},
	})
	if err != nil {
		c.Fatal(err)
	}
	s.pgx = pgxpool
	s.pgx.Exec(sqlCreateTruncateTables)
}

func TestPostgresFilesystem(t *testing.T) {
	dbname := "blobstoretest"
	if err := pgtestutils.SetupPostgres(dbname); err != nil {
		t.Fatal(err)
	}
	pgxpool, err := pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     os.Getenv("PGHOST"),
			Database: dbname,
		},
	})
	if err != nil {
		t.Fatal(err)
	}
	db := postgres.New(pgxpool, nil)
	defer db.Close()

	fs, err := NewPostgresFilesystem(db)
	if err != nil {
		t.Fatal(err)
	}
	testList(fs, t)
	testDelete(fs, t)
	testOffset(fs, t)
	testFilesystem(fs, true, t)
}

func main() {
	var err error
	connPoolConfig := pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     "127.0.0.1",
			User:     "jack",
			Password: "jack",
			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 openTestClientMaxConns(t testing.TB, maxConnections int) *Client {
	connPoolConfig := pgx.ConnPoolConfig{
		ConnConfig:     testConnConfig,
		MaxConnections: maxConnections,
		AfterConnect:   PrepareStatements,
	}
	pool, err := pgx.NewConnPool(connPoolConfig)
	if err != nil {
		t.Fatal(err)
	}
	return NewClient(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 setupTestDB(c *C, dbname string) *postgres.DB {
	if err := pgtestutils.SetupPostgres(dbname); err != nil {
		c.Fatal(err)
	}
	pgxpool, err := pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     os.Getenv("PGHOST"),
			Database: dbname,
		},
	})
	if err != nil {
		c.Fatal(err)
	}
	return postgres.New(pgxpool, nil)
}

func Open(conf *Conf, afterConn func(*pgx.Conn) error) (*DB, error) {
	connConfig := pgx.ConnConfig{
		Host:     fmt.Sprintf("leader.%s.discoverd", conf.Service),
		User:     conf.User,
		Database: conf.Database,
		Password: conf.Password,
		Dial:     dialer.Retry.Dial,
	}
	connPool, err := pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig:     connConfig,
		AfterConnect:   afterConn,
		MaxConnections: 20,
	})
	db := &DB{connPool, conf}
	return db, err
}

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() {
	log := logger.New("fn", "main")

	log.Info("creating controller client")
	client, err := controller.NewClient("", os.Getenv("AUTH_KEY"))
	if err != nil {
		log.Error("error creating controller client", "err", err)
		shutdown.Fatal()
	}

	log.Info("connecting to postgres")
	db := postgres.Wait("", "")

	log.Info("creating postgres connection pool")
	pgxpool, err := pgx.NewConnPool(pgx.ConnPoolConfig{
		ConnConfig: pgx.ConnConfig{
			Host:     os.Getenv("PGHOST"),
			User:     os.Getenv("PGUSER"),
			Password: os.Getenv("PGPASSWORD"),
			Database: os.Getenv("PGDATABASE"),
		},
		AfterConnect:   que.PrepareStatements,
		MaxConnections: workerCount,
	})
	if err != nil {
		log.Error("error creating postgres connection pool", "err", err)
		shutdown.Fatal()
	}
	shutdown.BeforeExit(func() { pgxpool.Close() })

	workers := que.NewWorkerPool(
		que.NewClient(pgxpool),
		que.WorkMap{
			"deployment":   deployment.JobHandler(db, client, logger),
			"app_deletion": app_deletion.JobHandler(db, client, logger),
		},
		workerCount,
	)
	workers.Interval = 5 * time.Second

	log.Info("starting workers", "count", workerCount, "interval", workers.Interval)
	workers.Start()
	shutdown.BeforeExit(func() { workers.Shutdown() })

	select {} // block and keep running
}

func (s *S) SetUpSuite(c *C) {
	s.discoverd, s.cleanup = setup(c)

	if err := pgtestutils.SetupPostgres(dbname); err != nil {
		c.Fatal(err)
	}
	pgxpool, err := pgx.NewConnPool(newPgxConnPoolConfig())
	if err != nil {
		c.Fatal(err)
	}
	db := postgres.New(pgxpool, nil)

	if err = migrateDB(db); err != nil {
		c.Fatal(err)
	}
	s.pgx = db.ConnPool
	s.pgx.Exec(sqlCreateTruncateTables)
}