public void GetMigrationsTo(long timestamp, Predicate<IMigrationMetadata> migrationSelector,
out IEnumerable<ApplicableMigration> applicableMigrations, out IEnumerable<IMigrationMetadata> unidentifiedMigrations)
{
IEnumerable<ImportedMigration> moduleMigrations = _importedMigrations.Where(m => migrationSelector(m.Metadata));
var comparer = new MigrationMetadataComparer();
var applicableUpMigrations = new List<ApplicableMigration>(
moduleMigrations.Where(m => m.Metadata.Timestamp <= timestamp &&
!_executedMigrations.Any(x => comparer.Equals(x, m.Metadata)))
.OrderBy(m => m.Metadata.Timestamp)
.Select(m => new ApplicableMigration(m, MigrationDirection.Up)));
var applicableDownMigrations = new List<ApplicableMigration>(
moduleMigrations.Where(m => m.Metadata.Timestamp > timestamp &&
_executedMigrations.Any(x => comparer.Equals(x, m.Metadata)))
.OrderByDescending(m => m.Metadata.Timestamp)
.Select(m => new ApplicableMigration(m, MigrationDirection.Down)));
if (applicableDownMigrations.Any(m => !(m.Migration.Implementation is IReversibleMigration)))
{
throw new IrreversibleMigrationException();
}
int countUp = applicableUpMigrations.Count;
int countDown = applicableDownMigrations.Count;
Log.Info("Found {0} (up: {1}, down: {2}) applicable migration(s)", countUp + countDown, countUp, countDown);
applicableMigrations = applicableDownMigrations.Concat(applicableUpMigrations); // order matters!
unidentifiedMigrations = new List<IMigrationMetadata>(
from m in _executedMigrations
where !_importedMigrations.Any(a => a.Metadata.ModuleName == m.ModuleName &&
a.Metadata.Timestamp == m.Timestamp)
orderby m.Timestamp
select m);
if (unidentifiedMigrations.Any())
{
Log.Warning("Found {0} migration(s) that were executed in the database but are not contained in the application.", unidentifiedMigrations.Count());
}
}
private bool IsApplicable(IMigrationMetadata migration)
{
var comparer = new MigrationMetadataComparer();
return _applicableMigrations.Select(m => m.Migration.Metadata).Contains(migration, comparer);
}
