servicer.go

package migrator

// DatabaseServicer represents a service that runs the migrations.
type DatabaseServicer interface {
	// BeginTransaction creates a transaction in the implementing database
	// servicer.
	BeginTransaction() error

	// CommitTransaction ends the created transaction providing there is one
	// and commits it to the database.
	CommitTransaction() error

	// RanMigrations retrieves all previously ran migrations.
	RanMigrations() ([]RanMigration, error)

	// RemoveMigrationHistory removes the specified migration from the
	// history table.
	RemoveMigrationHistory(m Migration) error

	// RollbackTransaction ends the created transaction providing there is one
	// and rolls it back, ensuring there are no changes to the database made.
	RollbackTransaction() error

	// RollbackMigration rolls back the specified migration and removes it
	// from the RanMigrations table.
	RollbackMigration(m Migration) error

	// RunMigration runs the specified migration against the current database.
	RunMigration(m Migration) error

	// TryCreateHistoryTable creates the migration history table if it does
	// not already exist. The boolean return value indicates whether or not
	// the table had to be created.
	TryCreateHistoryTable() (bool, error)

	// WriteMigrationHistory writes that a migration has been ran into the
	// migration history table.
	WriteMigrationHistory(m Migration) error
}

// LogServicer abstracts common logging functions so we do not have to
// call the log.Logger implementation directly.
type LogServicer interface {
	// Printf formats a string with a set of parameters before printing it to
	// the output.
	Printf(format string, v ...interface{})
}