ResourceCache.java

/*******************************************************************************
 * Copyright (c) 2011 Gerd Wuetherich (gerd@gerd-wuetherich.de).
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Gerd Wuetherich (gerd@gerd-wuetherich.de) - initial API and implementation
 ******************************************************************************/
package org.bundlemaker.core.internal.parser;

import java.util.HashMap;
import java.util.Map;

import org.bundlemaker.core.common.FlyWeightStringCache;
import org.bundlemaker.core.internal.resource.Resource;
import org.bundlemaker.core.project.IProjectContentResource;
import org.bundlemaker.core.spi.parser.IParsableResource;
import org.bundlemaker.core.spi.store.IPersistentDependencyStore;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;

/**
 * <p>
 * </p>
 * 
 * @author Gerd Wütherich (gerd@gerd-wuetherich.de)
 */
public class ResourceCache {

  /** the element map */
  private Map<IProjectContentResource, Resource> _storedResourcesMap;

  /** the element map */
  private Map<IProjectContentResource, Resource> _newResourceMap;

  /** the dependency store */
  private IPersistentDependencyStore             _dependencyStore;

  /** - */
  private FlyWeightStringCache                   _flyWeightStringCache;

  /**
   * <p>
   * Creates a new instance of type {@link ResourceCache}.
   * </p>
   * 
   * @param dependencyStore
   */
  @SuppressWarnings("rawtypes")
  public ResourceCache(IPersistentDependencyStore dependencyStore) {

    Assert.isNotNull(dependencyStore);

    // set the dependency store
    _dependencyStore = dependencyStore;

    //
    _storedResourcesMap = new HashMap<IProjectContentResource, Resource>();

    // set the element map
    _newResourceMap = new HashMap<IProjectContentResource, Resource>();

    //
    _flyWeightStringCache = new FlyWeightStringCache();
  }

  /**
   * <p>
   * Creates a new instance of type {@link ResourceCache}.
   * </p>
   */
  // just for test
  public ResourceCache() {

    //
    _storedResourcesMap = new HashMap<IProjectContentResource, Resource>();

    // set the element map
    _newResourceMap = new HashMap<IProjectContentResource, Resource>();

    //
    _flyWeightStringCache = new FlyWeightStringCache();
  }

  /**
   * <p>
   * </p>
   */
  public synchronized void clear() throws CoreException {

    // clear the map
    _newResourceMap.clear();
  }

  /**
   * <p>
   * </p>
   * 
   * @throws CoreException
   */
  public synchronized void commit(IProgressMonitor progressMonitor) throws CoreException {

    Assert.isNotNull(_dependencyStore, "Dependency store must not be null.");

    //
    if (progressMonitor != null) {
      progressMonitor.beginTask("Writing to disc...", _newResourceMap.values().size());
    }

    // update all
    for (Resource modifiableResource : _newResourceMap.values()) {

      //
      if (modifiableResource.isAnalyzeReferences()) {
        _dependencyStore.updateResource(modifiableResource);
      }

      //
      if (progressMonitor != null) {
        progressMonitor.worked(1);
      }
    }

    // commit the store
    _dependencyStore.commit();

    //
    if (progressMonitor != null) {
      progressMonitor.done();
    }
  }

  public synchronized IParsableResource getOrCreateResource(IProjectContentResource resourceKey) {

    //
    Resource resource = _storedResourcesMap.get(resourceKey);

    // return result if != null
    if (resource != null) {
      return resource;
    }

    //
    resource = _newResourceMap.get(resourceKey);

    // return result if != null
    if (resource != null) {
      return resource;
    }

    // create a new one if necessary
    resource = new Resource(resourceKey.getProjectContentEntryId().toString(), resourceKey.getRoot(),
        resourceKey.getPath(), getFlyWeightCache());
    resource.setAnalyzeReferences(resourceKey.isAnalyzeReferences());

    // store the Resource
    _newResourceMap.put(resource, resource);

    // return the result
    return resource;
  }

  @Deprecated
  public Map<IProjectContentResource, Resource> getResourceMap() {
    return _newResourceMap;
  }

  /**
   * <p>
   * </p>
   * 
   * @return
   */
  public FlyWeightStringCache getFlyWeightCache() {
    return _flyWeightStringCache;
  }

  /**
   * <p>
   * </p>
   * 
   * @param key
   * @param resource
   */
  public void addToStoredResourcesMap(IProjectContentResource key, Resource resource) {
    _storedResourcesMap.put(key, resource);
  }

  public Map<IProjectContentResource, Resource> getCombinedMap() {

    Map<IProjectContentResource, Resource> result = new HashMap<IProjectContentResource, Resource>();

    result.putAll(_storedResourcesMap);
    result.putAll(_newResourceMap);

    return result;
  }
}