FeatureTable.java :  » IDE-Eclipse » Eclipse-plug-in-development » org » eclipse » pde » internal » core » Java Open Source

/*******************************************************************************
 * Copyright (c) 2005 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.pde.internal.core;

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

import org.eclipse.pde.internal.core.ifeature.IFeature;
import org.eclipse.pde.internal.core.ifeature.IFeatureModel;

/**
 * Stores IFeatureModels. Models are indexed by id and id with version for fast
 * retrieval. Given id or version may have more than one corresponding model. A
 * model has only one id and version that can be null. When models changes, its
 * Idver stays unchanged until the models reinserted.
 */
class FeatureTable {
  public class Idver {
    private final String fId;

    private final String fVer;

    public Idver(String id, String version) {
      fId = id;
      fVer = version;
    }

    public String getId() {
      return fId;
    }

    public String getVer() {
      return fVer;
    }

    public int hashCode() {
      int code = 0;
      if (fId != null)
        code += fId.hashCode();
      if (fVer != null)
        code += fVer.hashCode();

      return code;
    }

    public boolean equals(Object obj) {
      if (this == obj)
        return true;
      if (!(obj instanceof Idver))
        return false;
      return equals(((Idver) obj).getId(), ((Idver) obj).getVer());
    }

    public boolean equals(String id, String version) {
      boolean sameId = fId == null && id == null || fId != null
          && fId.equals(id);
      boolean sameVer = fVer == null && version == null || fVer != null
          && fVer.equals(version);
      return sameId && sameVer;

    }

    public String toString() {
      return fId + "_" + fVer; //$NON-NLS-1$
    }
  }

  private static final IFeatureModel[] NO_MODELS = new IFeatureModel[0];

  /**
   * Map of IFeatureModel to Idver
   */
  private Map fModel2idver;

  /**
   * Map of Idver to ArrayList of IFeatureModel
   */
  private Map fIdver2models;

  /**
   * Map of Id to ArrayList of Idver
   */
  private Map fId2idvers;

  public FeatureTable() {

    fModel2idver = new HashMap();
    fIdver2models = new HashMap();
    fId2idvers = new HashMap();
  }

  public synchronized Idver get(IFeatureModel model) {
    return (Idver) fModel2idver.get(model);
  }

  /**
   * @param id
   * @param version
   * @return IFeatureModel[]
   */
  public synchronized IFeatureModel[] get(String id, String version) {
    return getImpl(new Idver(id, version));
  }

  /**
   * @param idver
   * @return IFeatureModel[]
   */
  public synchronized IFeatureModel[] get(Idver idver) {
    return getImpl(idver);
  }

  /**
   * @param idver
   * @return
   */
  private IFeatureModel[] getImpl(Idver idver) {
    ArrayList models = (ArrayList) fIdver2models.get(idver);
    if (models == null) {
      return NO_MODELS;
    }
    return (IFeatureModel[]) models
        .toArray(new IFeatureModel[models.size()]);
  }

  public synchronized IFeatureModel[] get(String id) {
    ArrayList idvers = (ArrayList) fId2idvers.get(id);
    if (idvers == null)
      return NO_MODELS;
    ArrayList allModels = new ArrayList();
    for (int i = 0; i < idvers.size(); i++) {
      Idver idver = (Idver) idvers.get(i);
      ArrayList models = (ArrayList) fIdver2models.get(idver);
      if (models == null) {
        continue;
      }
      allModels.addAll(models);
    }
    return (IFeatureModel[]) allModels.toArray(new IFeatureModel[allModels
        .size()]);
  }

  public synchronized IFeatureModel[] getAll() {
    return getAllImpl();
  }

  /**
   * @return
   */
  private IFeatureModel[] getAllImpl() {
    return (IFeatureModel[]) fModel2idver.keySet().toArray(
        new IFeatureModel[fModel2idver.size()]);
  }

  /**
   * Removes the model.
   * 
   * @return Idver if model existed and was removed, null otherwise
   */
  public synchronized Idver remove(IFeatureModel model) {
    return removeImpl(model);
  }

  /**
   * @param model
   * @return
   */
  private Idver removeImpl(IFeatureModel model) {
    Idver idver = (Idver) fModel2idver.remove(model);
    if (idver == null) {
      return null;
    }
    ArrayList models = (ArrayList) fIdver2models.get(idver);
    for (int i = 0; i < models.size(); i++) {
      if (models.get(i) == model) {
        models.remove(i);
        break;
      }
    }
    if (models.size() <= 0) {
      fIdver2models.remove(idver);

      ArrayList idvers = (ArrayList) fId2idvers.get(idver.getId());
      for (int i = 0; i < idvers.size(); i++) {
        if (idvers.get(i).equals(idver)) {
          idvers.remove(i);
          break;
        }
      }
      if (idvers.size() <= 0) {
        fId2idvers.remove(idver.getId());
      }
    }
    return idver;
  }

  /**
   * Adds the model. Updates the position of the model if already exist.
   * 
   * @return Idver used during insertion
   */
  public synchronized Idver add(IFeatureModel model) {
    removeImpl(model);

    IFeature feature = model.getFeature();
    String id = feature.getId();
    String ver = feature.getVersion();
    Idver idver = new Idver(id, ver);

    fModel2idver.put(model, idver);

    ArrayList models = (ArrayList) fIdver2models.get(idver);
    if (models == null) {
      models = new ArrayList(1);
      fIdver2models.put(idver, models);
    }
    models.add(model);

    ArrayList idvers = (ArrayList) fId2idvers.get(id);
    if (idvers == null) {
      idvers = new ArrayList(1);
      fId2idvers.put(id, idvers);
    }
    idvers.add(idver);

    return idver;
  }

  public synchronized String toString() {
    IFeatureModel[] models = getAllImpl();
    StringBuffer buf = new StringBuffer(30 * models.length);
    buf.append("["); //$NON-NLS-1$
    for (int i = 0; i < models.length; i++) {
      if (i > 0) {
        buf.append(",  "); //$NON-NLS-1$
      }
      buf.append(get(models[i]));
      buf.append("@"); //$NON-NLS-1$
      buf.append(models[i].getFeature().getId());
      buf.append("_"); //$NON-NLS-1$
      buf.append(models[i].getFeature().getVersion());
    }
    buf.append("]"); //$NON-NLS-1$
    return buf.toString();
  }

}