forked from mattes/migrate
/
cassandra.go
103 lines (83 loc) · 2.24 KB
/
cassandra.go
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// Package cassandra implements the Driver interface.
package cassandra
import (
"net/url"
"time"
"github.com/gocql/gocql"
"github.com/mattes/migrate/file"
"github.com/mattes/migrate/migrate/direction"
)
type Driver struct {
session *gocql.Session
}
const tableName = "schema_migrations"
const versionRow = 1
// Cassandra Driver URL format:
// cassandra://host:port/keyspace
//
// Example:
// cassandra://localhost/SpaceOfKeys
func (driver *Driver) Initialize(rawurl string) error {
u, err := url.Parse(rawurl)
cluster := gocql.NewCluster(u.Host)
cluster.Keyspace = u.Path[1:len(u.Path)]
cluster.Consistency = gocql.All
cluster.Timeout = 1 * time.Minute
driver.session, err = cluster.CreateSession()
if err != nil {
return err
}
if err := driver.ensureVersionTableExists(); err != nil {
return err
}
return nil
}
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 counter, versionRow bigint primary key);").Exec()
if err != nil {
return err
}
_, err = driver.Version()
if err != nil {
driver.session.Query("UPDATE "+tableName+" SET version = version + 1 where versionRow = ?", versionRow).Exec()
}
return nil
}
func (driver *Driver) FilenameExtension() string {
return "cql"
}
func (driver *Driver) Migrate(f file.File, pipe chan interface{}) {
defer close(pipe)
pipe <- f
if f.Direction == direction.Up {
err := driver.session.Query("UPDATE "+tableName+" SET version = version + 1 where versionRow = ?", versionRow).Exec()
if err != nil {
pipe <- err
return
}
} else if f.Direction == direction.Down {
err := driver.session.Query("UPDATE "+tableName+" SET version = version - 1 where versionRow = ?", versionRow).Exec()
if err != nil {
pipe <- err
return
}
}
if err := f.ReadContent(); err != nil {
pipe <- err
return
}
err := driver.session.Query(string(f.Content)).Exec()
if err != nil {
pipe <- err
return
}
}
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
}