Subversion Repositories SmartDukaan

package in.shop2020.storage.bdb;

import in.shop2020.metamodel.core.Entity;

import in.shop2020.metamodel.core.EntityState;

import in.shop2020.util.Utils;

import java.util.Collection;

import java.util.Map;

import com.sleepycat.collections.TransactionRunner;

import com.sleepycat.collections.TransactionWorker;

import com.sleepycat.je.DatabaseException;

/**

 * Entry point for storing everything in berkley database. Singleton class which initialises the berkley database.

 * @author rajveer

 *

 */

public class StorageManager {

    private final ContentDatabase db;

    private final ContentViews views;

    private final TransactionRunner txnRunner;

    private static StorageManager storageUtils;

    private static final String homeDir =  Utils.BERKELEY_DB_PATH;

    static{

		synchronized(StorageManager.class){

			storageUtils = new StorageManager(homeDir);

		}

	}

    /**

     * Run the sample program.

     */

    public static void main(String[] args) {

        System.out.println("\nRunning sample: " + StorageManager.class);

        try {

        	Collection<Entity> entities=  StorageManager.getStorageManager().getEntitisByCategory(10002);

        	for(Entity entity: entities){

        		System.out.println(entity.getID());

        	}

        	//StorageManager.getStorageManager().printEntitis(10002);

        } catch (Exception e) {

            // If an exception reaches this point, the last transaction did not

            // complete.  If the exception is RunRecoveryException, follow

            // the Berkeley DB recovery procedures before running again.

            e.printStackTrace();

        } finally {

        	StorageManager.getStorageManager().close();

        }

    }

    /**

     * get storage manager

     * @return StorageManager

     */

    public static StorageManager getStorageManager(){

		return storageUtils;

    }

    /**

     * Open the database and views.

     */

    private StorageManager(String homeDir)

        throws DatabaseException {

    	db = new ContentDatabase(homeDir);

        views = new ContentViews(db);

        txnRunner = new TransactionRunner(db.getEnvironment());

    }

    /**

     * Close the database cleanly.

     */

    public void close() throws DatabaseException {

        db.close();

    }

    /**

     * Get the entities for a given category

     * @param categoryId

     * @return Collection<Entity>

     */

    @SuppressWarnings("unchecked")

	public Collection<Entity> getEntitisByCategory(long categoryId){

    	return views.getEntityByCategoryMap().duplicates(categoryId);

    }

    /**

     * get metadata for all entities

     * @return

     */

    @SuppressWarnings("unchecked")

	public Map<Long, EntityState> getEntitiesMetadata(){

    	return views.getEntityMetadataMap();

    }

    /**

     * Get metadata for an given entity.

     * @param entityId

     * @return

     */

    public EntityState getEntityMetadata(long entityId){

    	return (EntityState) views.getEntityMetadataMap().get(entityId);

    }

    /**

     * update metadata for an given entity

     * @param entityMetadata

     */

    @SuppressWarnings("unchecked")

	public void updateEntityMetadata(EntityState entityMetadata){

    	Map states = views.getEntityMetadataMap();

    	states.put(new Long(entityMetadata.getID()), entityMetadata);

    }

    /**

     * Create an entity in database. This is done in transaction.

     * @param entity

     * @param entityMetadata

     * @throws Exception

     */

    public void createEntity(Entity entity, EntityState entityMetadata) throws Exception{

    	txnRunner.run(new StoreEntity(entity, entityMetadata));

    }

    /**

     * Delete an entity from database. This is done in transaction.

     * @param entityId

     * @throws Exception

     */

    public void deleteEntity(long entityId) throws Exception{

    	txnRunner.run(new DeleteEntity(entityId));

    }

    /**

     * Get entity for given id.

     * @param entityId

     * @return

     * @throws Exception

     */

    public Entity getEntity(long entityId) throws Exception{

    	return (Entity)views.getEntityMap().get(new Long(entityId));

    }

    /**

     * Update an existing entity

     * @param entity

     * @throws Exception

     */

    public void updateEntity(Entity entity) throws Exception{

    	Map entities = views.getEntityMap();

		entities.put(new Long(entity.getID()), entity);

    }

    /**

     * Get all entities.

     * @return

     * @throws Exception

     */

    @SuppressWarnings("unchecked")

	public Map<Long, Entity> getEntities() throws Exception{

    	return views.getEntityMap();

    }

    /**

     * Get dataobject. Generic method which will return the object with the name.

     * @param dataObjectName

     * @return

     * @throws Exception

     */

    public Object getDataObject(String dataObjectName) throws Exception{

    	return views.getDataObjectMap().get(dataObjectName);

    }

    /**

     * Store data object

     * @param dataObjectName

     * @param dataObject

     * @throws Exception

     */

    public void storeDataObject(String dataObjectName, Object dataObject) throws Exception{

    	Map dataObjects = views.getDataObjectMap();

    	dataObjects.put(dataObjectName, dataObject);

    }

    /**

     * Delete dataobject

     * @param dataObjectName

     * @throws Exception

     */

    public void deleteDataObject(String dataObjectName) throws Exception{

    	views.getDataObjectMap().remove(dataObjectName);

    }

    /**

     * Class extending TransactionWorker used for deleting entity.

     * @author rajveer

     *

     */

    private class DeleteEntity implements TransactionWorker{

    	long entityId;

    	public DeleteEntity(long entityId) {

			this.entityId = entityId;

		}

		@Override

		public void doWork() throws Exception {

			views.getEntityMap().remove(new Long(entityId));

        	views.getEntityMetadataMap().remove(entityId);

		}

    }

    /**

     * Class extending TransactionWorker used for creating entity.

     * @author rajveer

     *

     */

    private class StoreEntity implements TransactionWorker{

    	Entity entity;

    	EntityState entityMetadata; 

    	public StoreEntity(Entity entity, EntityState entityMetadata) {

			this.entity = entity;

			this.entityMetadata = entityMetadata;

			//System.out.println(entity);

		}

		@Override

		public void doWork() throws Exception {

	    	Map entities = views.getEntityMap();

	    	entities.put(new Long(entity.getID()), entity);

	    	Map states = views.getEntityMetadataMap();

        	states.put(new Long(entityMetadata.getID()), entityMetadata);

		}

    }

}