Return a new instance of Driver from registry's GetDriver() function

README.md

@@ -1,3 +1,7 @@
+__[v3.0 in the making](https://github.com/mattes/migrate/tree/v3.0-prev)__
+
+---
+
 # migrate
 
 [![Build Status](https://travis-ci.org/mattes/migrate.svg?branch=master)](https://travis-ci.org/mattes/migrate)

driver/bash/bash.go

@@ -32,5 +32,5 @@ func (driver *Driver) Version() (uint64, error) {
 }
 
 func init() {
-	driver.RegisterDriver("bash", &Driver{})
+	driver.RegisterDriver("bash", Driver{})
 }

driver/cassandra/cassandra.go

@@ -14,44 +14,16 @@ import (
 	"github.com/mattes/migrate/migrate/direction"
 )
 
+// Driver implements migrate Driver interface
 type Driver struct {
 	session *gocql.Session
 }
 
 const (
-	tableName  = "schema_migrations"
-	versionRow = 1
+	tableName = "schema_migrations"
 )
 
-type counterStmt bool
-
-func (c counterStmt) Exec(session *gocql.Session) error {
-	var version int64
-	if err := session.Query("SELECT version FROM "+tableName+" WHERE versionRow = ?", versionRow).Scan(&version); err != nil {
-		return err
-	}
-
-	if bool(c) {
-		version++
-	} else {
-		version--
-	}
-
-	return session.Query("UPDATE "+tableName+" SET version = ? WHERE versionRow = ?", version, versionRow).Exec()
-}
-
-const (
-	up   counterStmt = true
-	down counterStmt = false
-)
-
-// Cassandra Driver URL format:
-// cassandra://host:port/keyspace?protocol=version&consistency=level
-//
-// Examples:
-// cassandra://localhost/SpaceOfKeys?protocol=4
-// cassandra://localhost/SpaceOfKeys?protocol=4&consistency=all
-// cassandra://localhost/SpaceOfKeys?consistency=quorum
+// Initialize will be called first
 func (driver *Driver) Initialize(rawurl string) error {
 	u, err := url.Parse(rawurl)
 	if err != nil {
@@ -68,7 +40,8 @@ func (driver *Driver) Initialize(rawurl string) error {
 	cluster.Timeout = 1 * time.Minute
 
 	if len(u.Query().Get("consistency")) > 0 {
-		consistency, err := parseConsistency(u.Query().Get("consistency"))
+		var consistency gocql.Consistency
+		consistency, err = parseConsistency(u.Query().Get("consistency"))
 		if err != nil {
 			return err
 		}
@@ -77,7 +50,8 @@ func (driver *Driver) Initialize(rawurl string) error {
 	}
 
 	if len(u.Query().Get("protocol")) > 0 {
-		protoversion, err := strconv.Atoi(u.Query().Get("protocol"))
+		var protoversion int
+		protoversion, err = strconv.Atoi(u.Query().Get("protocol"))
 		if err != nil {
 			return err
 		}
@@ -90,7 +64,7 @@ func (driver *Driver) Initialize(rawurl string) error {
 		password, passwordSet := u.User.Password()
 
 		if passwordSet == false {
-			return fmt.Errorf("Missing password. Please provide password.")
+			return fmt.Errorf("Missing password. Please provide password")
 		}
 
 		cluster.Authenticator = gocql.PasswordAuthenticator{
@@ -112,61 +86,71 @@ func (driver *Driver) Initialize(rawurl string) error {
 	return nil
 }
 
+// Close last function to be called. Closes cassandra session
 func (driver *Driver) Close() error {
 	driver.session.Close()
 	return nil
 }
 
 func (driver *Driver) ensureVersionTableExists() error {
-	err := driver.session.Query("CREATE TABLE IF NOT EXISTS " + tableName + " (version int, versionRow bigint primary key);").Exec()
+	err := driver.session.Query(fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s (id uuid primary key, version bigint)", tableName)).Exec()
 	if err != nil {
 		return err
 	}
 
-	_, err = driver.Version()
-	if err != nil {
-		if err.Error() == "not found" {
-			return driver.session.Query("UPDATE "+tableName+" SET version = ? WHERE versionRow = ?", 1, versionRow).Exec()
-		}
+	if _, err = driver.Version(); err != nil {
 		return err
 	}
 
 	return nil
 }
 
+// FilenameExtension return extension of migrations files
 func (driver *Driver) FilenameExtension() string {
 	return "cql"
 }
 
-func (driver *Driver) version(d direction.Direction, invert bool) error {
-	var stmt counterStmt
-	switch d {
-	case direction.Up:
-		stmt = up
-	case direction.Down:
-		stmt = down
+func (driver *Driver) updateVersion(version uint64, dir direction.Direction) error {
+	var ids []string
+	var id string
+	var err error
+	iter := driver.session.Query(fmt.Sprintf("SELECT id FROM %s WHERE version >= ? ALLOW FILTERING", tableName), version).Iter()
+	for iter.Scan(&id) {
+		ids = append(ids, id)
+	}
+	if len(ids) > 0 {
+		err = driver.session.Query(fmt.Sprintf("DELETE FROM %s WHERE id IN ?", tableName), ids).Exec()
+		if err != nil {
+			return err
+		}
 	}
-	if invert {
-		stmt = !stmt
+	if dir == direction.Up {
+		return driver.session.Query(fmt.Sprintf("INSERT INTO %s (id, version) VALUES (uuid(), ?)", tableName), version).Exec()
 	}
-	return stmt.Exec(driver.session)
+	return nil
 }
 
+// Migrate run migration file. Restore previous version in case of fail
 func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
 	var err error
+	previousVersion, err := driver.Version()
+	if err != nil {
+		close(pipe)
+		return
+	}
 	defer func() {
 		if err != nil {
 			// Invert version direction if we couldn't apply the changes for some reason.
-			if err := driver.version(f.Direction, true); err != nil {
-				pipe <- err
+			if updErr := driver.updateVersion(previousVersion, direction.Up); updErr != nil {
+				pipe <- updErr
 			}
 			pipe <- err
 		}
 		close(pipe)
 	}()
 
 	pipe <- f
-	if err = driver.version(f.Direction, false); err != nil {
+	if err = driver.updateVersion(f.Version, f.Direction); err != nil {
 		return
 	}
 
@@ -186,14 +170,15 @@ func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
 	}
 }
 
+// Version return current version
 func (driver *Driver) Version() (uint64, error) {
 	var version int64
-	err := driver.session.Query("SELECT version FROM "+tableName+" WHERE versionRow = ?", versionRow).Scan(&version)
-	return uint64(version) - 1, err
+	err := driver.session.Query(fmt.Sprintf("SELECT max(version) FROM %s", tableName)).Scan(&version)
+	return uint64(version), err
 }
 
 func init() {
-	driver.RegisterDriver("cassandra", &Driver{})
+	driver.RegisterDriver("cassandra", Driver{})
 }
 
 // ParseConsistency wraps gocql.ParseConsistency to return an error

driver/cassandra/cassandra_test.go

@@ -21,10 +21,10 @@ func TestMigrate(t *testing.T) {
 
 	host := os.Getenv("CASSANDRA_PORT_9042_TCP_ADDR")
 	port := os.Getenv("CASSANDRA_PORT_9042_TCP_PORT")
-	driverUrl := "cassandra://" + host + ":" + port + "/system"
+	driverURL := "cassandra://" + host + ":" + port + "/system"
 
 	// prepare a clean test database
-	u, err := url.Parse(driverUrl)
+	u, err := url.Parse(driverURL)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -35,23 +35,25 @@ func TestMigrate(t *testing.T) {
 	cluster.Timeout = 1 * time.Minute
 
 	session, err = cluster.CreateSession()
-
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	if err := session.Query(`DROP KEYSPACE IF EXISTS migrate;`).Exec(); err != nil {
+	if err = session.Query(`DROP KEYSPACE IF EXISTS migrate;`).Exec(); 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 {
+	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"
+	if err != nil {
+		t.Fatal(err)
+	}
+	driverURL = "cassandra://" + host + ":" + port + "/migrate"
 
 	d := &Driver{}
-	if err := d.Initialize(driverUrl); err != nil {
+	if err := d.Initialize(driverURL); err != nil {
 		t.Fatal(err)
 	}
 

driver/crate/crate.go

@@ -13,7 +13,7 @@ import (
 )
 
 func init() {
-	driver.RegisterDriver("crate", &Driver{})
+	driver.RegisterDriver("crate", Driver{})
 }
 
 type Driver struct {
@@ -97,8 +97,8 @@ func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
 func splitContent(content string) []string {
 	lines := strings.Split(content, ";")
 	resultLines := make([]string, 0, len(lines))
-	for i, line := range lines {
-		line = strings.Replace(lines[i], ";", "", -1)
+	for i := range lines {
+		line := strings.Replace(lines[i], ";", "", -1)
 		line = strings.TrimSpace(line)
 		if line != "" {
 			resultLines = append(resultLines, line)

driver/driver.go

@@ -43,7 +43,7 @@ func New(url string) (Driver, error) {
 
 	d := GetDriver(u.Scheme)
 	if d == nil {
-		return nil, fmt.Errorf("Driver '%s' not found.", u.Scheme)
+		return nil, fmt.Errorf("Driver '%s' not found", u.Scheme)
 	}
 	verifyFilenameExtension(u.Scheme, d)
 	if err := d.Initialize(url); err != nil {
@@ -53,6 +53,22 @@ func New(url string) (Driver, error) {
 	return d, nil
 }
 
+// FilenameExtensionFromURL return extension for migration files. Used for create migrations
+func FilenameExtensionFromURL(url string) (string, error) {
+	u, err := neturl.Parse(url)
+	if err != nil {
+		return "", err
+	}
+
+	d := GetDriver(u.Scheme)
+	if d == nil {
+		return "", fmt.Errorf("Driver '%s' not found", u.Scheme)
+	}
+	verifyFilenameExtension(u.Scheme, d)
+
+	return d.FilenameExtension(), nil
+}
+
 // verifyFilenameExtension panics if the driver's filename extension
 // is not correct or empty.
 func verifyFilenameExtension(driverName string, d Driver) {

driver/mongodb/example/mongodb_test.go

@@ -6,13 +6,14 @@ import (
 	"github.com/mattes/migrate/file"
 	"github.com/mattes/migrate/migrate/direction"
 
+	"os"
+	"reflect"
+	"time"
+
 	"github.com/mattes/migrate/driver"
 	"github.com/mattes/migrate/driver/mongodb"
 	"github.com/mattes/migrate/driver/mongodb/gomethods"
 	pipep "github.com/mattes/migrate/pipe"
-	"os"
-	"reflect"
-	"time"
 )
 
 type ExpectedMigrationResult struct {

driver/mongodb/example/sample_mongdb_migrator.go

@@ -1,11 +1,12 @@
 package example
 
 import (
+	"time"
+
 	"github.com/mattes/migrate/driver/mongodb/gomethods"
 	_ "github.com/mattes/migrate/driver/mongodb/gomethods"
 	"gopkg.in/mgo.v2"
 	"gopkg.in/mgo.v2/bson"
-	"time"
 
 	"github.com/mattes/migrate/driver/mongodb"
 )

driver/mongodb/gomethods/gomethods_migrator.go

@@ -3,11 +3,12 @@ package gomethods
 import (
 	"bufio"
 	"fmt"
-	"github.com/mattes/migrate/driver"
-	"github.com/mattes/migrate/file"
 	"os"
 	"path"
 	"strings"
+
+	"github.com/mattes/migrate/driver"
+	"github.com/mattes/migrate/file"
 )
 
 type MethodNotFoundError string

driver/mongodb/gomethods/gomethods_registry.go

@@ -2,8 +2,9 @@ package gomethods
 
 import (
 	"fmt"
-	"github.com/mattes/migrate/driver"
 	"sync"
+
+	"github.com/mattes/migrate/driver"
 )
 
 var methodsReceiversMu sync.Mutex

driver/mongodb/mongodb.go

@@ -2,14 +2,15 @@ package mongodb
 
 import (
 	"errors"
+	"reflect"
+	"strings"
+
 	"github.com/mattes/migrate/driver"
 	"github.com/mattes/migrate/driver/mongodb/gomethods"
 	"github.com/mattes/migrate/file"
 	"github.com/mattes/migrate/migrate/direction"
 	"gopkg.in/mgo.v2"
 	"gopkg.in/mgo.v2/bson"
-	"reflect"
-	"strings"
 )
 
 type UnregisteredMethodsReceiverError string
@@ -55,7 +56,7 @@ func (d *Driver) SetMethodsReceiver(r interface{}) error {
 }
 
 func init() {
-	driver.RegisterDriver("mongodb", &Driver{})
+	driver.RegisterDriver("mongodb", Driver{})
 }
 
 type DbMigration struct {

driver/mysql/mysql.go

@@ -181,5 +181,5 @@ func (driver *Driver) Version() (uint64, error) {
 }
 
 func init() {
-	driver.RegisterDriver("mysql", &Driver{})
+	driver.RegisterDriver("mysql", Driver{})
 }