BindingsCache.java

/*
 * Copyright 2000-2009 JetBrains s.r.o.
 *
 * Licensed 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.
 */

/*
 * @author: Eugene Zhuravlev
 * Date: Jul 4, 2003
 * Time: 7:39:27 PM
 */
package com.intellij.uiDesigner.make;

import com.intellij.compiler.impl.StateCache;
import com.intellij.openapi.compiler.CompilerPaths;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.fileEditor.FileDocumentManager;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.io.FileUtil;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.uiDesigner.compiler.Utils;
import com.intellij.uiDesigner.lw.LwRootContainer;
import org.jetbrains.annotations.NonNls;

import java.io.*;

final class BindingsCache {
  private static final Logger LOG = Logger.getInstance("#com.intellij.uiDesigner.make.BindingsCache");
  @NonNls
  private static final String BINDINGS_FILE_NAME = "formbinding.dat";
  private StateCache<MyState> myCache;

  public BindingsCache(final Project project) {
    final File cacheStoreDirectory = CompilerPaths.getCacheStoreDirectory(project);
    try {
      if (cacheStoreDirectory != null) {
        FileUtil.createParentDirs(cacheStoreDirectory);
        myCache = createCache(cacheStoreDirectory);
      }
      else {
        myCache = null;
      }
    }
    catch (IOException e) {
      LOG.info(e);
      for (File file : cacheStoreDirectory.listFiles()) {
        if (file.getName().startsWith(BINDINGS_FILE_NAME)) {
          FileUtil.delete(file);
        }
      }
      try {
        myCache = createCache(cacheStoreDirectory);
      }
      catch (IOException e1) {
        LOG.info(e1);
        myCache = null;
      }
    }
  }

  private static StateCache<MyState> createCache(final File cacheStoreDirectory) throws IOException {
    return new StateCache<MyState>(new File(cacheStoreDirectory, BINDINGS_FILE_NAME)) {
      public MyState read(final DataInput stream) throws IOException {
        return new MyState(stream.readLong(), stream.readUTF());
      }

      public void write(final MyState myState, final DataOutput out) throws IOException {
        out.writeLong(myState.getFormTimeStamp());
        out.writeUTF(myState.getClassName());
      }
    };
  }

  public String getBoundClassName(final VirtualFile formFile) throws Exception {
    String classToBind = getSavedBinding(formFile);
    if (classToBind == null) {
      final Document doc = FileDocumentManager.getInstance().getDocument(formFile);
      final LwRootContainer rootContainer = Utils.getRootContainer(doc.getText(), null);
      classToBind = rootContainer.getClassToBind();
    }
    if (classToBind != null) {
      updateCache(formFile, classToBind);
    }
    return classToBind;
  }

  private String getSavedBinding(final VirtualFile formFile) {
    if (myCache != null) {
      try {
        final String formUrl = formFile.getUrl();
        final MyState state = myCache.getState(formUrl);
        if (state != null) {
          if (formFile.getTimeStamp() == state.getFormTimeStamp()) {
            return state.getClassName();
          }
        }
      }
      catch (IOException e) {
        myCache.wipe();
      }
    }
    return null;
  }
    
  private void updateCache(final VirtualFile formFile, final String classToBind) {
    if (myCache != null) {
      final String url = formFile.getUrl();
      final MyState state = new MyState(formFile.getTimeStamp(), classToBind);
      try {
        myCache.update(url, state);
      }
      catch (IOException e) {
        LOG.info(e);
        myCache.wipe();
        try {
          myCache.update(url, state);
        }
        catch (IOException ignored) {
        }
      }
    }
  }

  public void close() {
    try {
      myCache.close();
    }
    catch (IOException e) {
      LOG.info(e);
    }
  }

  private static final class MyState implements Serializable{
    private final long myFormTimeStamp;
    private final String myClassName;

    public MyState(final long formTimeStamp, final String className){
      myFormTimeStamp = formTimeStamp;
      myClassName = className;
    }

    public long getFormTimeStamp(){
      return myFormTimeStamp;
    }

    public String getClassName(){
      return myClassName;
    }
  }
}