| /* |
| * Copyright (c) 2015 Eike Stepper (Berlin, Germany) 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: |
| * Eike Stepper - initial API and implementation |
| */ |
| package org.eclipse.userstorage.internal; |
| |
| import org.eclipse.userstorage.IStorageService; |
| import org.eclipse.userstorage.internal.util.IOUtil.EndOfFileAware; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| /** |
| * @author Eike Stepper |
| */ |
| public abstract class InternalStorageCache |
| { |
| private IStorageService service; |
| |
| public InternalStorageCache() |
| { |
| } |
| |
| public IStorageService getService() |
| { |
| return service; |
| } |
| |
| void setService(IStorageService service) |
| { |
| IStorageService oldService = this.service; |
| this.service = service; |
| |
| if (service != oldService) |
| { |
| storageChanged(oldService, service); |
| } |
| } |
| |
| protected abstract void storageChanged(IStorageService oldService, IStorageService newService); |
| |
| void internalLoadProperties(String applicationToken, String key, Map<String, String> properties) throws IOException |
| { |
| loadProperties(applicationToken, key, properties); |
| } |
| |
| void internalSaveProperties(String applicationToken, String key, Map<String, String> properties) throws IOException |
| { |
| saveProperties(applicationToken, key, properties); |
| } |
| |
| InputStream internalGetInputStream(String applicationToken, String key) throws IOException |
| { |
| return getInputStream(applicationToken, key); |
| } |
| |
| OutputStream internalGetOutputStream(final String applicationToken, final String key, final Map<String, String> properties) throws IOException |
| { |
| return new TransactionalOutputStream(applicationToken, key, properties); |
| } |
| |
| void internalDelete(String applicationToken, String key) throws IOException |
| { |
| delete(applicationToken, key); |
| } |
| |
| public abstract Iterator<String> getKeys(String applicationToken) throws IOException; |
| |
| protected abstract void loadProperties(String applicationToken, String key, Map<String, String> properties) throws IOException; |
| |
| protected abstract void saveProperties(String applicationToken, String key, Map<String, String> properties) throws IOException; |
| |
| protected abstract InputStream getInputStream(String applicationToken, String key) throws IOException; |
| |
| protected abstract OutputStream getOutputStream(String applicationToken, String key) throws IOException; |
| |
| protected abstract void delete(String applicationToken, String key) throws IOException; |
| |
| /** |
| * @author Eike Stepper |
| */ |
| private final class TransactionalOutputStream extends OutputStream implements EndOfFileAware |
| { |
| private final String applicationToken; |
| |
| private final String key; |
| |
| private final Map<String, String> properties; |
| |
| private OutputStream output; |
| |
| private boolean fullyWritten; |
| |
| private TransactionalOutputStream(String applicationToken, String key, Map<String, String> properties) |
| { |
| this.applicationToken = applicationToken; |
| this.key = key; |
| this.properties = properties; |
| } |
| |
| private void init() throws IOException |
| { |
| if (output == null) |
| { |
| saveProperties(applicationToken, key, Blob.NO_PROPERTIES); |
| output = getOutputStream(applicationToken, key); |
| } |
| } |
| |
| @Override |
| public void write(int b) throws IOException |
| { |
| init(); |
| output.write(b); |
| } |
| |
| @Override |
| public void write(byte[] b) throws IOException |
| { |
| init(); |
| output.write(b); |
| } |
| |
| @Override |
| public void write(byte[] b, int off, int len) throws IOException |
| { |
| init(); |
| output.write(b, off, len); |
| } |
| |
| @Override |
| public void reachedEndOfFile() |
| { |
| fullyWritten = true; |
| } |
| |
| @Override |
| public void close() throws IOException |
| { |
| if (output != null) |
| { |
| try |
| { |
| if (fullyWritten) |
| { |
| saveProperties(applicationToken, key, properties); |
| } |
| } |
| finally |
| { |
| output.close(); |
| output = null; |
| } |
| } |
| } |
| } |
| } |