storageimplementation.java

lucene2.2.0版本

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.lucene.gdata.storage.lucenestorage;

import java.io.IOException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.lucene.gdata.data.GDataAccount;
import org.apache.lucene.gdata.data.ServerBaseEntry;
import org.apache.lucene.gdata.data.ServerBaseFeed;
import org.apache.lucene.gdata.server.registry.ComponentType;
import org.apache.lucene.gdata.server.registry.GDataServerRegistry;
import org.apache.lucene.gdata.storage.ModificationConflictException;
import org.apache.lucene.gdata.storage.ResourceNotFoundException;
import org.apache.lucene.gdata.storage.Storage;
import org.apache.lucene.gdata.storage.StorageController;
import org.apache.lucene.gdata.storage.StorageException;
import org.apache.lucene.gdata.storage.lucenestorage.StorageEntryWrapper.StorageOperation;
import org.apache.lucene.gdata.utils.ReferenceCounter;

import com.google.gdata.data.BaseEntry;
import com.google.gdata.data.BaseFeed;

/**
 * This is an implementation of the
 * {@link org.apache.lucene.gdata.storage.Storage} interface. The
 * StorageImplementation provides access to the
 * {@link org.apache.lucene.gdata.storage.lucenestorage.StorageQuery} and the
 * {@link org.apache.lucene.gdata.storage.lucenestorage.StorageModifier}. This
 * class will be instantiated per client request.
 * 
 * 
 * 
 * @author Simon Willnauer
 * 
 */
public class StorageImplementation implements Storage {
    private final StorageCoreController controller;

    private static final Log LOG = LogFactory
            .getLog(StorageImplementation.class);

    /**
     * Creates a new StorageImplementation
     * 
     * @throws StorageException -
     *             if the storage controller can not be obtained
     * 
     * 
     * 
     */
    public StorageImplementation() throws StorageException {
        this.controller = (StorageCoreController) GDataServerRegistry
                .getRegistry().lookup(StorageController.class,
                        ComponentType.STORAGECONTROLLER);
        if (this.controller == null)
            throw new StorageException("Can't get registered StorageController");
    }

    /**
     * @see org.apache.lucene.gdata.storage.Storage#storeEntry(org.apache.lucene.gdata.data.ServerBaseEntry)
     */
    public BaseEntry storeEntry(final ServerBaseEntry entry)
            throws StorageException {
        if (entry == null)
            throw new StorageException("entry is null");
        if(entry.getFeedId() == null)
            throw new StorageException("feed-id is null");
        if(entry.getVersion() != 1)
            throw new StorageException("entry version must be 1");
        if(entry.getServiceConfig() == null)
            throw new StorageException("ProvidedService must not be null");
        StorageModifier modifier = this.controller.getStorageModifier();
        String id = this.controller.releaseId();
        entry.setId(entry.getFeedId() + id);
        if (LOG.isInfoEnabled())
            LOG.info("Store entry " + id + " -- feed: " + entry.getFeedId());

        try {
            StorageEntryWrapper wrapper = new StorageEntryWrapper(entry,
                    StorageOperation.INSERT);
            modifier.insertEntry(wrapper);
        } catch (IOException e) {
            StorageException ex = new StorageException("Can't create Entry -- "
                    + e.getMessage(), e);
            ex.setStackTrace(e.getStackTrace());
            throw ex;

        }

        return entry.getEntry();
    }

    /**
     * @see org.apache.lucene.gdata.storage.Storage#deleteEntry(org.apache.lucene.gdata.data.ServerBaseEntry)
     */
    public void deleteEntry(final ServerBaseEntry entry)
            throws StorageException {

        if (entry == null)
            throw new StorageException("Entry is null");
        if(entry.getId() == null)
            throw new StorageException("Entry id is null");
        if(entry.getFeedId() == null)
            throw new StorageException("feed id is null");
        if (LOG.isInfoEnabled())
            LOG.info("delete entry " + entry.getId() + " -- feed: "
                    + entry.getFeedId());
        StorageModifier modifier = this.controller.getStorageModifier();
        ReferenceCounter<StorageQuery> query = this.controller.getStorageQuery();
        // try to set concurrency Lock
        String key = entry.getId();
        setLock(key);
        try{
        if(query.get().isEntryStored(entry.getId(),entry.getFeedId())){
            if(query.get().checkEntryVersion(entry.getId(),entry.getFeedId(),entry.getVersion())){
                modifier.deleteEntry(new StorageEntryWrapper(entry,StorageOperation.DELETE));
            }else
                throw new ModificationConflictException("The entry version does not match -- entry "+entry.getId()+" feed:"+entry.getFeedId()+" version: "+entry.getVersion());
        }
        else
            throw new ResourceNotFoundException("Entry for entry id: "+entry.getId()+" is not stored");
        }catch (IOException e) {
            throw new StorageException("Can not access storage");
        }finally{
            if(query != null)
                query.decrementRef();
            // release lock for concurrency
            releaseLock(key);
        }
    }

    /**
     * @see org.apache.lucene.gdata.storage.Storage#updateEntry(org.apache.lucene.gdata.data.ServerBaseEntry)
     */
    public BaseEntry updateEntry(ServerBaseEntry entry) throws StorageException {

        if (entry == null)
            throw new StorageException("entry is null");
        if(entry.getId() == null)
            throw new StorageException("entry id is null");
        if(entry.getServiceConfig() == null)
            throw new StorageException("service config is not set -- null");
        if(entry.getFeedId() == null)
            throw new StorageException("feed id is null");
        if (LOG.isInfoEnabled())
            LOG.info("update entry " + entry.getId() + " -- feed: "
                    + entry.getFeedId());
        StorageModifier modifier = this.controller.getStorageModifier();
        ReferenceCounter<StorageQuery> query = this.controller.getStorageQuery();
        // try to set concurrency Lock
        String key = entry.getId();
        setLock(key);
        try {
            
            
            if(query.get().isEntryStored(entry.getId(),entry.getFeedId())){
                
                if(query.get().checkEntryVersion(entry.getId(),entry.getFeedId(),entry.getVersion())){
                    entry.setVersion(entry.getVersion()+1);
                    StorageEntryWrapper wrapper = new StorageEntryWrapper(entry,
                            StorageOperation.UPDATE);  
                    modifier.updateEntry(wrapper);
                }else
                    throw new ModificationConflictException("The entry version does not match -- entry "+entry.getId()+" feed:"+entry.getFeedId()+" version: "+entry.getVersion());
              
            }else
                throw new ResourceNotFoundException("Entry for entry id: "+entry.getId()+" is not stored");
            
        } catch (IOException e) {
            LOG.error("Can't update entry for feedID: " + entry.getFeedId()
                    + "; entryId: " + entry.getId() + " -- " + e.getMessage(),
                    e);
            StorageException ex = new StorageException("Can't update Entry -- "
                    + e.getMessage(), e);
            ex.setStackTrace(e.getStackTrace());
            throw ex;

        }

        finally{
            if(query != null)
                query.decrementRef();
            // release lock for concurrency
            releaseLock(key);
        }

        return entry.getEntry();

    }
    private void setLock(String key) throws ModificationConflictException{
        if(!this.controller.getLock().setLock(key))
            throw new ModificationConflictException("Can not set lock for entry -- "+key);
            
    }
    
    private void releaseLock(String key) throws StorageException{
        if(!this.controller.getLock().releaseLock(key))
            throw new StorageException("Can not release lock for key: "+key);
    }

    /**
     * @see org.apache.lucene.gdata.storage.Storage#getFeed(org.apache.lucene.gdata.data.ServerBaseFeed)
     */
    @SuppressWarnings("unchecked")
    public BaseFeed getFeed(final ServerBaseFeed feed) throws StorageException {

        if (feed == null)
            throw new StorageException("feed is null");
        if (LOG.isInfoEnabled())
            LOG.info("get feed: " + feed.getId() + " start-index: "
                    + feed.getStartIndex() + " resultCount: "
                    + feed.getItemsPerPage());
        ReferenceCounter<StorageQuery> query = null;
        try {
            query = this.controller.getStorageQuery();
            BaseFeed retVal = query.get().getLatestFeedQuery(feed.getId(),
                    feed.getItemsPerPage(), feed.getStartIndex(),
                    feed.getServiceConfig());
            return retVal;
        } catch (Exception e) {
            LOG.error("Can't get latest feed for feedID: " + feed.getId()
                    + " -- " + e.getMessage(), e);
            StorageException ex = new StorageException("Can't create Entry -- "
                    + e.getMessage(), e);
            ex.setStackTrace(e.getStackTrace());
            throw ex;

        } finally {
            if (query != null)
                query.decrementRef();
        }

    }

    /**
     * @see org.apache.lucene.gdata.storage.Storage#getEntry(org.apache.lucene.gdata.data.ServerBaseEntry)
     */
    public BaseEntry getEntry(final ServerBaseEntry entry)
            throws StorageException {

        if (entry == null)
            throw new StorageException("No entry  specified -- is null");
        if (LOG.isInfoEnabled())
            LOG.info("get entry " + entry.getId() + " -- feed: "
                    + entry.getFeedId());
        ReferenceCounter<StorageQuery> query = null;
        try {
            query = this.controller.getStorageQuery();
            BaseEntry retVal = query.get().singleEntryQuery(entry.getId(),
                    entry.getFeedId(), entry.getServiceConfig());
            if(retVal == null)
                throw new ResourceNotFoundException("can not get entry for entry ID "+entry.getId());
            return retVal;
        } catch (Exception e) {
            LOG.error("Can't get entry for feedID: " + entry.getFeedId()
                    + "; entryId: " + entry.getId() + " -- " + e.getMessage(),
                    e);
            StorageException ex = new StorageException("Can't create Entry -- "
                    + e.getMessage(), e);
            ex.setStackTrace(e.getStackTrace());
            throw ex;

        } finally {
            if (query != null)
                query.decrementRef();
        }

    }

    /**
     * @see org.apache.lucene.gdata.storage.Storage#close()