update/org.eclipse.update.core/src/org/eclipse/update/core/FeatureContentProvider.java

package org.eclipse.update.core;
/*
 * (c) Copyright IBM Corp. 2000, 2002.
 * All Rights Reserved.
 */

import java.io.*;
import java.net.URL;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.update.core.model.*;
import org.eclipse.update.internal.core.Policy;
import org.eclipse.update.internal.core.UpdateManagerPlugin;

/**
 * Base implementation of a feature content provider.
 * This class provides a set of helper methods useful for implementing
 * feature content providers. In particular, methods dealing with
 * downloading and caching of feature files. 
 * <p>
 * This class must be subclassed by clients.
 * </p> 
 * @see org.eclipse.update.core.IFeatureContentProvider
 * @since 2.0
 */
public abstract class FeatureContentProvider
	implements IFeatureContentProvider {

	private URL base;
	private IFeature feature;
	private File tmpDir; // local work area for each provider
	public static final String JAR_EXTENSION = ".jar"; //$NON-NLS-1$	
	
	// lock
	private final static Object lock = new Object();

	/**
	 * Feature content provider constructor
	 * 
	 * @param base feature URL. The interpretation of this URL 
	 * is specific to each content provider.
	 * @since 2.0
	 */
	public FeatureContentProvider(URL base) {
		this.base = base;
		this.feature = null;
	}

	/**
	 * Returns the feature url. 
	 * @see IFeatureContentProvider#getURL()
	 */
	public URL getURL() {
		return base;
	}

	/**
	 * Returns the feature associated with this content provider.
	 * @see IFeatureContentProvider#getFeature()
	 */
	public IFeature getFeature() {
		return feature;
	}

	/**
	 * Sets the feature associated with this content provider.
	 * @see IFeatureContentProvider#setFeature(IFeature)
	 */
	public void setFeature(IFeature feature) {
		this.feature = feature;
	}

	/**
	 * Returns the specified reference as a local file system reference.
	 * If required, the file represented by the specified content
	 * reference is first downloaded to the local system
	 * 
	 * @param ref content reference
	 * @param monitor progress monitor, can be <code>null</code>
	 * @exception IOException
	 * @exception CoreException
	 * @since 2.0
	 */
	public ContentReference asLocalReference(
		ContentReference ref,
		InstallMonitor monitor)
		throws IOException,CoreException {

		// check to see if this is already a local reference
		if (ref.isLocalReference())
			return ref;

		// check to see if we already have a local file for this reference
		String key = ref.toString();
		
		// need to synch as another thread my have created the file but
		// is still copying into it
		File localFile=null;
		synchronized(lock){
			localFile = Utilities.lookupLocalFile(key);
			if (localFile != null)
				return ref.createContentReference(ref.getIdentifier(), localFile);
		
			// 
			// download the referenced file into local temporary area
			InputStream is = null;
			OutputStream os = null;
			localFile = Utilities.createLocalFile(getWorkingDirectory(), key, null /*name*/);			
			boolean sucess = false;
			try {
				if (monitor != null) {
					monitor.saveState();
					monitor.setTaskName(Policy.bind("FeatureContentProvider.Downloading"));
					//$NON-NLS-1$
					monitor.subTask(ref.getIdentifier() + " "); //$NON-NLS-1$
					monitor.setTotalCount(ref.getInputSize());
					monitor.showCopyDetails(true);
				}
				is = ref.getInputStream();
				os = new FileOutputStream(localFile);
				Utilities.copy(is, os, monitor);
				sucess = true;
			} catch (CoreException e) {
				Utilities.removeLocalFile(key);
				throw e;
			} catch (Exception e){
				Utilities.removeLocalFile(key);
				UpdateManagerPlugin.warn("Unable to create file "+localFile);
				throw Utilities.newCoreException(Policy.bind("FeatureContentProvider.UnableToCreate",new Object[]{ref}),e);				
			} finally {
				//Do not close IS if user cancel,
				//closing IS will read the entire Stream until the end
				if (sucess && is != null)
					try {
						is.close();
					} catch (IOException e) {
					}
				if (os != null)
					try {
						os.close();
					} catch (IOException e) {
					}
				if (monitor != null)
					monitor.restoreState();
			}
		}// end lock
	
		return ref.createContentReference(ref.getIdentifier(), localFile);
	}

	/**
	 * Returns the specified reference as a local file.
	 * If required, the file represented by the specified content
	 * reference is first downloaded to the local system
	 * 
	 * @param ref content reference
	 * @param monitor progress monitor, can be <code>null</code>
	 * @exception IOException	
	 * @exception CoreException  
	 * @since 2.0
	 */
	public File asLocalFile(ContentReference ref, InstallMonitor monitor)
		throws IOException,CoreException {
		File file = ref.asFile();
		if (file != null)
			return file;

		ContentReference localRef = asLocalReference(ref, monitor);
		file = localRef.asFile();
		return file;
	}

	/**
	 * Returns working directory for this content provider
	 * 
	 * @return working directory
	 * @exception IOException
	 * @since 2.0
	 */
	protected File getWorkingDirectory() throws IOException {
		if (tmpDir == null)
			tmpDir = Utilities.createWorkingDirectory();
		return tmpDir;
	}
	
	/**
	 * Returns the total size of all archives required for the
	 * specified plug-in and non-plug-in entries (the "packaging" view).
	 * @see IFeatureContentProvider#getDownloadSizeFor(IPluginEntry[], INonPluginEntry[])
	 */
	public long getDownloadSizeFor(
		IPluginEntry[] pluginEntries,
		INonPluginEntry[] nonPluginEntries) {
		long result = 0;

		// if both are null or empty, return UNKNOWN size
		if ((pluginEntries == null || pluginEntries.length == 0)
			&& (nonPluginEntries == null || nonPluginEntries.length == 0)) {
			return ContentEntryModel.UNKNOWN_SIZE;
		}

		// loop on plugin entries
		long size = 0;
		if (pluginEntries!=null)		
			for (int i = 0; i < pluginEntries.length; i++) {
				size = ((PluginEntryModel) pluginEntries[i]).getDownloadSize();
				if (size == ContentEntryModel.UNKNOWN_SIZE) {
					return ContentEntryModel.UNKNOWN_SIZE;
				}
				result += size;
			}

		// loop on non plugin entries
		if (nonPluginEntries!=null)
			for (int i = 0; i < nonPluginEntries.length; i++) {
				size = ((NonPluginEntryModel) nonPluginEntries[i]).getDownloadSize();
				if (size == ContentEntryModel.UNKNOWN_SIZE) {
					return ContentEntryModel.UNKNOWN_SIZE;
				}
				result += size;
			}

		return result;
	}

	/**
	 * Returns the total size of all files required for the
	 * specified plug-in and non-plug-in entries (the "logical" view).
	 * @see IFeatureContentProvider#getInstallSizeFor(IPluginEntry[], INonPluginEntry[])
	 */
	public long getInstallSizeFor(
		IPluginEntry[] pluginEntries,
		INonPluginEntry[] nonPluginEntries) {
		long result = 0;

		// if both are null or empty, return UNKNOWN size
		if ((pluginEntries == null || pluginEntries.length == 0)
			&& (nonPluginEntries == null || nonPluginEntries.length == 0)) {
			return ContentEntryModel.UNKNOWN_SIZE;
		}

		// loop on plugin entries
		long size = 0;
		if (pluginEntries!=null)
			for (int i = 0; i < pluginEntries.length; i++) {
				size = ((PluginEntryModel) pluginEntries[i]).getInstallSize();
				if (size == ContentEntryModel.UNKNOWN_SIZE) {
					return ContentEntryModel.UNKNOWN_SIZE;
				}
				result += size;
			}

		// loop on non plugin entries
		if (nonPluginEntries!=null)
			for (int i = 0; i < nonPluginEntries.length; i++) {
				size = ((NonPluginEntryModel) nonPluginEntries[i]).getInstallSize();
				if (size == ContentEntryModel.UNKNOWN_SIZE) {
					return ContentEntryModel.UNKNOWN_SIZE;
				}
				result += size;
			}

		return result;
	}

	/**
	 * Returns the path identifier for a plugin entry.
	 * <code>plugins/&lt;pluginId>_&lt;pluginVersion>.jar</code> 
	 * @return the path identifier
	 */
	protected String getPathID(IPluginEntry entry) {
		return Site.DEFAULT_PLUGIN_PATH + entry.getVersionedIdentifier().toString() + JAR_EXTENSION;
	}

	/**
	 * Returns the path identifer for a non plugin entry.
	 * <code>features/&lt;featureId>_&lt;featureVersion>/&lt;dataId></code>
	 * @return the path identifier
  	 */
	protected String getPathID(INonPluginEntry entry) {
		String nonPluginBaseID=
			Site.DEFAULT_FEATURE_PATH + feature.getVersionedIdentifier().toString() + "/";
		//$NON-NLS-1$
		return nonPluginBaseID + entry.getIdentifier();
	}

}