Golang pipe.New函数代码示例

func ExamplePipe() {
	p := pipe.New()
	go func() { p <- "ping" }()
	msg := <-p
	fmt.Println(msg)
	// Output: ping
}

// Reset runs the down and up migration function
func Reset(pipe chan interface{}, url, migrationsPath string) {
	pipe1 := pipep.New()
	go Down(pipe1, url, migrationsPath)
	if ok := pipep.WaitAndRedirect(pipe1, pipe, handleInterrupts()); !ok {
		go pipep.Close(pipe, nil)
		return
	} else {
		go Up(pipe, url, migrationsPath)
	}
}

func main() {
	cfgPath := "lobster.cfg"
	if len(os.Args) >= 2 {
		cfgPath = os.Args[1]
	}
	lobster.Setup(cfgPath)
	url := "mysql://" + lobster.GetDatabaseString()
	pipe := pipep.New()
	go migrate.Up(pipe, url, "./db/migrations")
	hadError := false
	done := false
	for !done {
		select {
		case item, more := <-pipe:
			if !more {
				done = true
			} else {
				switch item.(type) {
				case string:
					fmt.Println(item.(string))
				case error:
					fmt.Printf("ERROR: %v\n", item)
					hadError = true
				case file.File:
					f := item.(file.File)
					if f.Direction == direction.Up {
						fmt.Print("> ")
					} else if f.Direction == direction.Down {
						fmt.Print("< ")
					}
					fmt.Println(f.FileName)
				default:
					fmt.Printf("%v", item)
				}
			}
		}
	}
	if !hadError {
		fmt.Println("database up to date")
	}
}

// Down rolls back all migrations
func Down(pipe chan interface{}, url, migrationsPath string) {
	d, files, version, err := initDriverAndReadMigrationFilesAndGetVersion(url, migrationsPath)
	if err != nil {
		go pipep.Close(pipe, err)
		return
	}

	applyMigrationFiles, err := files.ToFirstFrom(version)
	if err != nil {
		if err2 := d.Close(); err2 != nil {
			pipe <- err2
		}
		go pipep.Close(pipe, err)
		return
	}

	if len(applyMigrationFiles) > 0 {
		for _, f := range applyMigrationFiles {
			pipe1 := pipep.New()
			go d.Migrate(f, pipe1)
			if ok := pipep.WaitAndRedirect(pipe1, pipe, handleInterrupts()); !ok {
				break
			}
		}
		if err2 := d.Close(); err2 != nil {
			pipe <- err2
		}
		go pipep.Close(pipe, nil)
		return
	} else {
		if err2 := d.Close(); err2 != nil {
			pipe <- err2
		}
		go pipep.Close(pipe, nil)
		return
	}
}

func TestMigrate(t *testing.T) {
	var session *gocql.Session
	driverUrl := "cassandra://localhost/migratetest"

	// prepare a clean test database
	u, err := url.Parse(driverUrl)
	if err != nil {
		t.Fatal(err)
	}

	cluster := gocql.NewCluster(u.Host)
	cluster.Keyspace = u.Path[1:len(u.Path)]
	cluster.Consistency = gocql.All
	cluster.Timeout = 1 * time.Minute

	session, err = cluster.CreateSession()

	if err != nil {
		t.Fatal(err)
	}

	if err := session.Query(`DROP TABLE IF EXISTS yolo`).Exec(); err != nil {
		t.Fatal(err)
	}
	if err := session.Query(`DROP TABLE IF EXISTS ` + tableName).Exec(); err != nil {
		t.Fatal(err)
	}

	d := &Driver{}
	if err := d.Initialize(driverUrl); err != nil {
		t.Fatal(err)
	}

	files := []file.File{
		{
			Path:      "/foobar",
			FileName:  "001_foobar.up.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
                CREATE TABLE yolo (
                    id varint primary key,
                    msg text
                );

				CREATE INDEX ON yolo (msg);
            `),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.down.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Down,
			Content: []byte(`
                DROP TABLE yolo;
            `),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.up.sql",
			Version:   2,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
                CREATE TABLE error (
                    id THIS WILL CAUSE AN ERROR
                )
            `),
		},
	}

	pipe := pipep.New()
	go d.Migrate(files[0], pipe)
	errs := pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[1], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[2], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) == 0 {
		t.Error("Expected test case to fail")
	}

	if err := d.Close(); err != nil {
		t.Fatal(err)
	}

}

// TestMigrate runs some additional tests on Migrate().
// Basic testing is already done in migrate/migrate_test.go
func TestMigrate(t *testing.T) {
	driverUrl := "[email protected](127.0.0.1:3306)/migratetest"

	// prepare clean database
	connection, err := sql.Open("mysql", driverUrl)
	if err != nil {
		t.Fatal(err)
	}

	if _, err := connection.Exec(`DROP TABLE IF EXISTS yolo, yolo1, ` + tableName); err != nil {
		t.Fatal(err)
	}

	d := &Driver{}
	if err := d.Initialize(driverUrl); err != nil {
		t.Fatal(err)
	}

	files := []file.File{
		{
			Path:      "/foobar",
			FileName:  "001_foobar.up.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
        CREATE TABLE yolo (
          id int(11) not null primary key auto_increment
        );

				CREATE TABLE yolo1 (
				  id int(11) not null primary key auto_increment
				);
      `),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.down.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Down,
			Content: []byte(`
        DROP TABLE yolo;
      `),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.up.sql",
			Version:   2,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`

      	// a comment
				CREATE TABLE error (
          id THIS WILL CAUSE AN ERROR
        );
      `),
		},
	}

	pipe := pipep.New()
	go d.Migrate(files[0], pipe)
	errs := pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[1], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[2], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) == 0 {
		t.Error("Expected test case to fail")
	}

	if err := d.Close(); err != nil {
		t.Fatal(err)
	}
}

func main() {
	flag.Usage = func() {
		helpCmd()
	}

	flag.Parse()
	command := flag.Arg(0)
	if *version {
		fmt.Println(Version)
		os.Exit(0)
	}

	if *migrationsPath == "" {
		*migrationsPath, _ = os.Getwd()
	}

	switch command {
	case "create":
		verifyMigrationsPath(*migrationsPath)
		name := flag.Arg(1)
		if name == "" {
			fmt.Println("Please specify name.")
			os.Exit(1)
		}

		migrationFile, err := migrate.Create(*url, *migrationsPath, name)
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		fmt.Printf("Version %v migration files created in %v:\n", migrationFile.Version, *migrationsPath)
		fmt.Println(migrationFile.UpFile.FileName)
		fmt.Println(migrationFile.DownFile.FileName)

	case "migrate":
		verifyMigrationsPath(*migrationsPath)
		relativeN := flag.Arg(1)
		relativeNInt, err := strconv.Atoi(relativeN)
		if err != nil {
			fmt.Println("Unable to parse param <n>.")
			os.Exit(1)
		}
		timerStart = time.Now()
		pipe := pipep.New()
		go migrate.Migrate(pipe, *url, *migrationsPath, relativeNInt)
		ok := writePipe(pipe)
		printTimer()
		if !ok {
			os.Exit(1)
		}

	case "goto":
		verifyMigrationsPath(*migrationsPath)
		toVersion := flag.Arg(1)
		toVersionInt, err := strconv.Atoi(toVersion)
		if err != nil || toVersionInt < 0 {
			fmt.Println("Unable to parse param <v>.")
			os.Exit(1)
		}

		currentVersion, err := migrate.Version(*url, *migrationsPath)
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		relativeNInt := toVersionInt - int(currentVersion)

		timerStart = time.Now()
		pipe := pipep.New()
		go migrate.Migrate(pipe, *url, *migrationsPath, relativeNInt)
		ok := writePipe(pipe)
		printTimer()
		if !ok {
			os.Exit(1)
		}

	case "up":
		verifyMigrationsPath(*migrationsPath)
		timerStart = time.Now()
		pipe := pipep.New()
		go migrate.Up(pipe, *url, *migrationsPath)
		ok := writePipe(pipe)
		printTimer()
		if !ok {
			os.Exit(1)
		}

	case "down":
		verifyMigrationsPath(*migrationsPath)
		timerStart = time.Now()
		pipe := pipep.New()
		go migrate.Down(pipe, *url, *migrationsPath)
		ok := writePipe(pipe)
		printTimer()
		if !ok {
			os.Exit(1)
		}

//.........这里部分代码省略.........

// TestMigrate runs some additional tests on Migrate().
// Basic testing is already done in migrate/migrate_test.go
func TestMigrate(t *testing.T) {
	driverUrl := "postgres://localhost/migratetest?sslmode=disable"

	// prepare clean database
	connection, err := sql.Open("postgres", driverUrl)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := connection.Exec(`
				DROP TABLE IF EXISTS yolo;
				DROP TABLE IF EXISTS ` + tableName + `;`); err != nil {
		t.Fatal(err)
	}

	d := &Driver{}
	if err := d.Initialize(driverUrl); err != nil {
		t.Fatal(err)
	}

	files := []file.File{
		{
			Path:      "/foobar",
			FileName:  "001_foobar.up.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
				CREATE TABLE yolo (
					id serial not null primary key
				);
			`),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.down.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Down,
			Content: []byte(`
				DROP TABLE yolo;
			`),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.up.sql",
			Version:   2,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
				CREATE TABLE error (
					id THIS WILL CAUSE AN ERROR
				)
			`),
		},
	}

	pipe := pipep.New()
	go d.Migrate(files[0], pipe)
	errs := pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[1], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[2], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) == 0 {
		t.Error("Expected test case to fail")
	}

	if err := d.Close(); err != nil {
		t.Fatal(err)
	}
}

// UpSync is synchronous version of Up
func UpSync(url, migrationsPath string) (err []error, ok bool) {
	pipe := pipep.New()
	go Up(pipe, url, migrationsPath)
	err = pipep.ReadErrors(pipe)
	return err, len(err) == 0
}

// NewPipe is a convenience function for pipe.New().
// This is helpful if the user just wants to import this package and nothing else.
func NewPipe() chan interface{} {
	return pipep.New()
}

// MigrateSync is synchronous version of Migrate
func MigrateSync(url, migrationsPath string, relativeN int) (err []error, ok bool) {
	pipe := pipep.New()
	go Migrate(pipe, url, migrationsPath, relativeN)
	err = pipep.ReadErrors(pipe)
	return err, len(err) == 0
}

// TestMigrate runs some additional tests on Migrate()
// Basic testing is already done in migrate/migrate_test.go
func TestMigrate(t *testing.T) {
	driverFile := ":memory:"
	driverUrl := "sqlite3://" + driverFile

	// prepare clean database
	connection, err := sql.Open("sqlite3", driverFile)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := connection.Exec(`
							DROP TABLE IF EXISTS yolo;
							DROP TABLE IF EXISTS ` + tableName + `;`); err != nil {
		t.Fatal(err)
	}

	d := &Driver{}
	if err := d.Initialize(driverUrl); err != nil {
		t.Fatal(err)
	}

	files := []file.File{
		{
			Path:      "/foobar",
			FileName:  "001_foobar.up.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
				CREATE TABLE yolo (
					id INTEGER PRIMARY KEY AUTOINCREMENT
				);
			`),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.down.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Down,
			Content: []byte(`
				DROP TABLE yolo;
			`),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.up.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Down,
			Content: []byte(`
				CREATE TABLE error (
					THIS; WILL CAUSE; AN ERROR;
				)
			`),
		},
	}

	pipe := pipep.New()
	go d.Migrate(files[0], pipe)
	errs := pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[1], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[2], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) == 0 {
		t.Error("Expected test case to fail")
	}

	if err := d.Close(); err != nil {
		t.Fatal(err)
	}
}

func TestMigrate(t *testing.T) {
	var session *gocql.Session

	host := os.Getenv("CASSANDRA_PORT_9042_TCP_ADDR")
	port := os.Getenv("CASSANDRA_PORT_9042_TCP_PORT")
	driverUrl := "cassandra://" + host + ":" + port + "/system"

	// prepare a clean test database
	u, err := url.Parse(driverUrl)
	if err != nil {
		t.Fatal(err)
	}

	cluster := gocql.NewCluster(u.Host)
	cluster.Keyspace = u.Path[1:len(u.Path)]
	cluster.Consistency = gocql.All
	cluster.Timeout = 1 * time.Minute

	session, err = cluster.CreateSession()

	if err != nil {
		t.Fatal(err)
	}

	if err := session.Query(`CREATE KEYSPACE IF NOT EXISTS migrate WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor': 1};`).Exec(); err != nil {
		t.Fatal(err)
	}
	cluster.Keyspace = "migrate"
	session, err = cluster.CreateSession()
	driverUrl = "cassandra://" + host + ":" + port + "/migrate"

	d := &Driver{}
	if err := d.Initialize(driverUrl); err != nil {
		t.Fatal(err)
	}

	files := []file.File{
		{
			Path:      "/foobar",
			FileName:  "001_foobar.up.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
                CREATE TABLE yolo (
                    id varint primary key,
                    msg text
                );

				CREATE INDEX ON yolo (msg);
            `),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.down.sql",
			Version:   1,
			Name:      "foobar",
			Direction: direction.Down,
			Content: []byte(`
                DROP TABLE yolo;
            `),
		},
		{
			Path:      "/foobar",
			FileName:  "002_foobar.up.sql",
			Version:   2,
			Name:      "foobar",
			Direction: direction.Up,
			Content: []byte(`
                CREATE TABLE error (
                    id THIS WILL CAUSE AN ERROR
                )
            `),
		},
	}

	pipe := pipep.New()
	go d.Migrate(files[0], pipe)
	errs := pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[1], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) > 0 {
		t.Fatal(errs)
	}

	pipe = pipep.New()
	go d.Migrate(files[2], pipe)
	errs = pipep.ReadErrors(pipe)
	if len(errs) == 0 {
		t.Error("Expected test case to fail")
	}

	if err := d.Close(); err != nil {
		t.Fatal(err)
	}
//.........这里部分代码省略.........