package liquibase.diff;
import liquibase.database.Database;
import liquibase.diff.compare.CompareControl;
import liquibase.exception.DatabaseException;
import liquibase.exception.LiquibaseException;
import liquibase.exception.UnexpectedLiquibaseException;
import liquibase.servicelocator.ServiceLocator;
import liquibase.snapshot.*;
import java.util.*;
public class DiffGeneratorFactory {
private static DiffGeneratorFactory instance;
private List<DiffGenerator> implementedGenerators = new ArrayList<DiffGenerator>();
protected DiffGeneratorFactory() {
try {
Class[] classes = ServiceLocator.getInstance().findClasses(DiffGenerator.class);
//noinspection unchecked
for (Class<? extends DiffGenerator> clazz : classes) {
register(clazz.getConstructor().newInstance());
}
} catch (Exception e) {
throw new RuntimeException(e);
}
}
public static DiffGeneratorFactory getInstance() {
if (instance == null) {
instance = new DiffGeneratorFactory();
}
return instance;
}
public void register(DiffGenerator generator) {
implementedGenerators.add(0, generator);
}
public DiffGenerator getGenerator(Database referenceDatabase, Database comparisonDatabase) {
SortedSet<DiffGenerator> foundGenerators = new TreeSet<DiffGenerator>(new Comparator<DiffGenerator>() {
@Override
public int compare(DiffGenerator o1, DiffGenerator o2) {
return -1 * new Integer(o1.getPriority()).compareTo(o2.getPriority());
}
});
for (DiffGenerator diffGenerator : implementedGenerators) {
if (diffGenerator.supports(referenceDatabase, comparisonDatabase)) {
foundGenerators.add(diffGenerator);
}
}
if (foundGenerators.size() == 0) {
throw new UnexpectedLiquibaseException("Cannot find DiffGenerator for "+referenceDatabase.getShortName()+", "+comparisonDatabase.getShortName());
}
try {
return foundGenerators.iterator().next().getClass().newInstance();
} catch (Exception e) {
throw new UnexpectedLiquibaseException(e);
}
}
public DiffResult compare(Database referenceDatabase, Database comparisonDatabase, CompareControl compareControl) throws LiquibaseException {
return compare(referenceDatabase, comparisonDatabase, new SnapshotControl(referenceDatabase), new SnapshotControl(comparisonDatabase), compareControl);
}
public DiffResult compare(Database referenceDatabase, Database comparisonDatabase, SnapshotControl referenceSnapshotControl, SnapshotControl comparisonSnapshotControl, CompareControl compareControl) throws LiquibaseException {
DatabaseSnapshot referenceSnapshot = SnapshotGeneratorFactory.getInstance().createSnapshot(referenceDatabase.getDefaultSchema(), referenceDatabase, referenceSnapshotControl);
DatabaseSnapshot comparisonSnapshot = null;
if (comparisonDatabase == null) {
comparisonSnapshot = new EmptyDatabaseSnapshot(referenceDatabase);
} else {
comparisonSnapshot = SnapshotGeneratorFactory.getInstance().createSnapshot(comparisonDatabase.getDefaultSchema(), comparisonDatabase, comparisonSnapshotControl);
}
return getGenerator(referenceDatabase, comparisonDatabase).compare(referenceSnapshot, comparisonSnapshot, compareControl);
}
public DiffResult compare(DatabaseSnapshot referenceSnapshot, DatabaseSnapshot comparisonSnapshot, CompareControl compareControl) throws DatabaseException {
Database referenceDatabase = referenceSnapshot.getDatabase();
Database comparisonDatabase;
if (comparisonSnapshot == null) {
comparisonDatabase = referenceSnapshot.getDatabase();
try {
comparisonSnapshot = new EmptyDatabaseSnapshot(referenceDatabase, referenceSnapshot.getSnapshotControl());
} catch (InvalidExampleException e) {
throw new UnexpectedLiquibaseException(e);
}
} else {
comparisonDatabase = comparisonSnapshot.getDatabase();
}
return getGenerator(referenceDatabase, comparisonDatabase).compare(referenceSnapshot, comparisonSnapshot, compareControl);
}
}