Handler.java

/*******************************************************************************
 * Copyright (c) 2004, 2006
 * Thomas Hallgren, Kenneth Olwing, Mitch Sonies
 * Pontus Rydin, Nils Unden, Peer Torngren
 * The code, documentation and other materials contained herein have been
 * licensed under the Eclipse Public License - v 1.0 by the individual
 * copyright holders listed above, as Initial Contributors under such license.
 * The text of such license is available at www.eclipse.org.
 *******************************************************************************/

package org.eclipse.buckminster.cvspkg.scheme.cvspkg;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Map;

import org.eclipse.buckminster.core.CorePlugin;
import org.eclipse.buckminster.core.common.model.Format;
import org.eclipse.buckminster.core.ctype.IComponentType;
import org.eclipse.buckminster.core.helpers.AccessibleByteArrayOutputStream;
import org.eclipse.buckminster.core.helpers.FileUtils;
import org.eclipse.buckminster.core.query.builder.ComponentQueryBuilder;
import org.eclipse.buckminster.core.reader.ICatalogReader;
import org.eclipse.buckminster.core.reader.IComponentReader;
import org.eclipse.buckminster.core.reader.IReaderType;
import org.eclipse.buckminster.core.reader.IStreamConsumer;
import org.eclipse.buckminster.core.resolver.ResolutionContext;
import org.eclipse.buckminster.core.rmap.model.Provider;
import org.eclipse.buckminster.core.version.VersionMatch;
import org.eclipse.buckminster.core.version.VersionSelector;
import org.eclipse.buckminster.cvspkg.Messages;
import org.eclipse.buckminster.runtime.URLUtils;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.osgi.util.NLS;
import org.osgi.service.url.AbstractURLStreamHandlerService;

/**
 * Provides access to single files in a CVS repository using a URL. The URL must
 * be formatted in the following way:
 * 
 * <pre>
 * 
 * cvs://[user@]<host>/<path to file>?repository=<repository path>[protocol=<cvs protocol>][#<tag>]
 * 
 * </pre>
 * 
 * @author Thomas Hallgren
 */
public class Handler extends AbstractURLStreamHandlerService {
	class CVSConnection extends URLConnection {
		private ICatalogReader reader;

		private String fileName;

		protected CVSConnection(URL entryURL) {
			super(entryURL);
		}

		@Override
		public void connect() throws IOException {
			if (connected)
				return;

			try {
				URI uri = this.getURL().toURI();
				Map<String, String> params = URLUtils.queryAsParameters(uri.getQuery());

				String host = uri.getHost();
				if (host == null)
					throw new MalformedURLException(Messages.cvs_URL_host_cannot_be_empty);

				String rootStr = uri.getPath();
				if (rootStr == null)
					throw new MalformedURLException(Messages.cvs_URL_path_cannot_be_empty);

				IPath rootPath = new Path(rootStr);
				if (!rootPath.isAbsolute())
					throw new MalformedURLException(Messages.cvs_URL_path_must_be_absolute);
				if (rootPath.segmentCount() < 1)
					throw new MalformedURLException(Messages.cvs_URL_path_must_have_segment);
				if (rootPath.hasTrailingSeparator())
					throw new MalformedURLException(Messages.cvs_URL_path_must_not_have_trailing_separator);

				String moduleStr = uri.getFragment();
				if (moduleStr == null)
					throw new MalformedURLException(NLS.bind(Messages.cvs_URL_must_end_with_0, "#<" //$NON-NLS-1$
							+ Messages.cvs_URL_module_path + ">")); //$NON-NLS-1$

				IPath modulePath = new Path(moduleStr);
				if (!modulePath.isAbsolute())
					throw new MalformedURLException(Messages.cvs_URL_module_must_be_absolute);
				if (modulePath.segmentCount() < 1)
					throw new MalformedURLException(Messages.cvs_URL_module_must_have_segment);
				if (modulePath.hasTrailingSeparator())
					throw new MalformedURLException(Messages.cvs_URL_module_must_not_have_trailing_separator);

				String user = uri.getUserInfo();
				if (user == null)
					user = "anonymous"; //$NON-NLS-1$

				String cvsProto = params.get("method"); //$NON-NLS-1$
				if (cvsProto == null)
					cvsProto = "pserver"; //$NON-NLS-1$

				fileName = modulePath.lastSegment();
				modulePath = modulePath.removeLastSegments(1);
				StringBuilder bld = new StringBuilder();
				bld.append(':');
				bld.append(cvsProto);
				bld.append(':');
				bld.append(user);
				bld.append('@');
				bld.append(host);
				bld.append(':');
				bld.append(rootPath.toPortableString());
				if (modulePath.segmentCount() > 0) {
					bld.append(',');
					bld.append(modulePath.toPortableString());
				}

				CorePlugin plugin = CorePlugin.getDefault();
				String versionSelector = params.get("version"); //$NON-NLS-1$
				IReaderType cvsReaderType = plugin.getReaderType("cvs"); //$NON-NLS-1$
				VersionMatch vm = versionSelector == null ? null
						: new VersionMatch(null, VersionSelector.fromString(versionSelector), -1, null, null);
				IProgressMonitor nullMon = new NullProgressMonitor();
				Provider provider = new Provider(null,
						"cvs", new String[] { IComponentType.UNKNOWN }, null, new Format(bld.toString()), null, null, null, null, null, null); //$NON-NLS-1$
				ComponentQueryBuilder cqBld = new ComponentQueryBuilder();
				cqBld.getRootRequestBuilder().setName(fileName);
				if (vm == null)
					vm = VersionMatch.DEFAULT;
				reader = (ICatalogReader) cvsReaderType.getReader(provider, plugin.getComponentType(IComponentType.UNKNOWN), new ResolutionContext(
						cqBld.createComponentQuery()).getRootNodeQuery(), vm, nullMon);
			} catch (URISyntaxException e) {
				throw new MalformedURLException(e.getMessage());
			} catch (IllegalArgumentException e) {
				throw new MalformedURLException(e.getMessage());
			} catch (IOException e) {
				throw e;
			} catch (Exception e) {
				Throwable t = e.getCause();
				if (t instanceof IOException)
					throw (IOException) t;
				throw new IOException(e.getMessage());
			}
			connected = true;
		}

		@Override
		public InputStream getInputStream() throws IOException {
			this.connect();
			try {
				return reader.readFile(fileName, new IStreamConsumer<InputStream>() {
					@Override
					public InputStream consumeStream(IComponentReader componentReader, String streamName, InputStream stream, IProgressMonitor monitor)
							throws IOException {
						final AccessibleByteArrayOutputStream builder = new AccessibleByteArrayOutputStream();
						FileUtils.copyFile(stream, builder, monitor);
						return new FilterInputStream(builder.getInputStream()) {
							@Override
							public void close() throws IOException {
								try {
									super.close();
								} finally {
									reader.close();
								}
							}
						};
					}
				}, new NullProgressMonitor());
			} catch (CoreException e) {
				Throwable t = e.getCause();
				if (t instanceof IOException)
					throw (IOException) t;
				throw new IOException(e.getMessage());
			}
		}
	}

	public static final String PROTOCOL = "cvs"; //$NON-NLS-1$

	@Override
	public URLConnection openConnection(URL url) throws IOException {
		return new CVSConnection(url);
	}
}