JVSTMMemBackEnd.java

package pt.ist.fenixframework.backend.jvstmmem;

import pt.ist.fenixframework.DomainObject;
import pt.ist.fenixframework.DomainRoot;
import pt.ist.fenixframework.TransactionManager;
import pt.ist.fenixframework.backend.BackEnd;
import pt.ist.fenixframework.core.SharedIdentityMap;

public class JVSTMMemBackEnd implements BackEnd {
    protected static final String BACKEND_NAME = "jvstmmem";

    private final TransactionManager transactionManager;

    public JVSTMMemBackEnd() {
	transactionManager = new JVSTMMemTransactionManager();
    }

    @Override
    public <T extends DomainObject> T fromOid(Object oid) {
        return (T) SharedIdentityMap.getCache().lookup(oid);

    }
    
    @Override
    public <T extends DomainObject> T getDomainObject(String externalId) {
        return fromOid(Long.parseLong(externalId));
    }
    
    @Override
    public DomainRoot getDomainRoot() {
	DomainRoot root = fromOid(1L);
	if (root == null) {
	    root = new DomainRoot(); // which automatically caches this instance, but does not
	    // ensure that it is the first, as a concurrent request
	    // might create another
	    
	    // so we get it again from the cache before returning it
	    root = fromOid(1L);
	    assert root != null;
	}
	return root;
    }

    @Override
    public String getName() {
	return BACKEND_NAME;
    }

    @Override
    public TransactionManager getTransactionManager() {
	return transactionManager;
    }

    @Override
    public void shutdown() {
    }
}