Bug 335865 - [metadata] Provide serialization API

4 files changed, 189 insertions, 6 deletions

diff --git a/bundles/org.eclipse.equinox.p2.metadata.repository/META-INF/MANIFEST.MF b/bundles/org.eclipse.equinox.p2.metadata.repository/META-INF/MANIFEST.MF
index 92ea0e436..ee10c5c9e 100644
--- a/bundles/org.eclipse.equinox.p2.metadata.repository/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.equinox.p2.metadata.repository/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.equinox.p2.metadata.repository;singleton:=true
-Bundle-Version: 1.1.100.qualifier
+Bundle-Version: 1.2.0.qualifier
 Bundle-Activator: org.eclipse.equinox.internal.p2.metadata.repository.Activator
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
@@ -15,7 +15,8 @@ Export-Package: org.eclipse.equinox.internal.p2.metadata.repository;
    org.eclipse.equinox.p2.updatesite,
    org.eclipse.equinox.p2.extensionlocation,
    org.eclipse.equinox.p2.repository.tools",
- org.eclipse.equinox.internal.p2.metadata.repository.io;x-friends:="org.eclipse.equinox.p2.engine"
+ org.eclipse.equinox.internal.p2.metadata.repository.io;x-friends:="org.eclipse.equinox.p2.engine",
+ org.eclipse.equinox.p2.metadata.io
 Require-Bundle: org.eclipse.equinox.common;bundle-version="[3.5.0,4.0.0)",
  org.eclipse.equinox.registry,
  org.eclipse.ecf.filetransfer;bundle-version="2.0.0"
diff --git a/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/internal/p2/metadata/repository/io/MetadataWriter.java b/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/internal/p2/metadata/repository/io/MetadataWriter.java
index 98ff47f4c..995cb5f73 100644
--- a/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/internal/p2/metadata/repository/io/MetadataWriter.java
+++ b/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/internal/p2/metadata/repository/io/MetadataWriter.java
@@ -23,7 +23,7 @@ import org.eclipse.equinox.internal.p2.persistence.XMLWriter;
 import org.eclipse.equinox.p2.metadata.*;
 import org.eclipse.equinox.p2.metadata.expression.*;
 
-public abstract class MetadataWriter extends XMLWriter implements XMLConstants {
+public class MetadataWriter extends XMLWriter implements XMLConstants {
 
 	public MetadataWriter(OutputStream output, ProcessingInstruction[] piElements) throws UnsupportedEncodingException {
 		super(output, piElements);
@@ -35,8 +35,8 @@ public abstract class MetadataWriter extends XMLWriter implements XMLConstants {
 	 * @param units An Iterator of {@link IInstallableUnit}.
 	 * @param size The number of units to write
 	 */
-	protected void writeInstallableUnits(Iterator<IInstallableUnit> units, int size) {
-		if (size == 0)
+	public void writeInstallableUnits(Iterator<IInstallableUnit> units, int size) {
+		if (!units.hasNext())
 			return;
 		start(INSTALLABLE_UNITS_ELEMENT);
 
@@ -104,7 +104,7 @@ public abstract class MetadataWriter extends XMLWriter implements XMLConstants {
 					return false;
 			}
 		}
-		
+
 		for (IRequirement r : iu.getMetaRequirements())
 			if (r.getMax() == 0 || !RequiredCapability.isSimpleRequirement(r.getMatches()))
 				return false;
diff --git a/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/p2/metadata/io/IUDeserializer.java b/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/p2/metadata/io/IUDeserializer.java
new file mode 100644
index 000000000..ff7266cee
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/p2/metadata/io/IUDeserializer.java
@@ -0,0 +1,138 @@
+/*******************************************************************************
+ * Copyright (c) 2011 Sonatype, Inc. 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:
+ *     Sonatype, Inc - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.equinox.p2.metadata.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+import java.util.Collection;
+import javax.xml.parsers.*;
+import org.eclipse.equinox.internal.p2.metadata.repository.io.MetadataParser;
+import org.eclipse.equinox.internal.p2.persistence.Messages;
+import org.eclipse.equinox.p2.metadata.IInstallableUnit;
+import org.xml.sax.*;
+
+/**
+ * This class allows to deserialize {@link IInstallableUnit}s that have been serialized with {@link IUSerializer}.
+ * The deserializer is able to read data that have been serialized with previous versions of the serializer.
+ * @since 1.2
+ *
+ */
+public class IUDeserializer {
+	private IUDeserializerParser deserializer;
+
+	/**
+	 * Construct a new instance of the deserializer.
+	 */
+	public IUDeserializer() {
+		deserializer = new IUDeserializerParser(SAXParserFactory.newInstance());
+	}
+
+	/**
+	 * Deserialize a set of {@link IInstallableUnit} from the input stream.
+	 * @param input the input stream to deserialize {@link IInstallableUnit}s from. 
+	 * @return the collection of {@link IInstallableUnit}s read from the input stream.
+	 * @throws IOException
+	 */
+	public Collection<IInstallableUnit> read(InputStream input) throws IOException {
+		return deserializer.parse(input);
+	}
+
+	private class IUDeserializerParser extends MetadataParser {
+		private IUOnlyHandler iusHandler;
+		private SAXParserFactory parserFactory;
+
+		public IUDeserializerParser(SAXParserFactory factory) {
+			super(null, null);
+			this.parserFactory = factory;
+		}
+
+		public Collection<IInstallableUnit> parse(InputStream stream) throws IOException {
+			try {
+				getParser();
+				iusHandler = new IUOnlyHandler();
+				xmlReader.setContentHandler(iusHandler);
+				xmlReader.parse(new InputSource(stream));
+				if (isValidXML()) {
+					return Arrays.asList(iusHandler.getInstallableUnits());
+				}
+				throw new IOException(status.toString());
+			} catch (ParserConfigurationException configException) {
+				throw new IOException(configException);
+			} catch (SAXException saxException) {
+				throw new IOException(saxException);
+			}
+		}
+
+		protected SAXParser getParser() throws ParserConfigurationException, SAXException {
+			super.getParser();
+			if (parserFactory == null) {
+				throw new SAXException(Messages.XMLParser_No_SAX_Parser);
+			}
+			parserFactory.setNamespaceAware(true);
+			parserFactory.setValidating(false);
+			try {
+				parserFactory.setFeature("http://xml.org/sax/features/string-interning", true); //$NON-NLS-1$
+			} catch (SAXException se) {
+				// some parsers may not support string interning
+			}
+			SAXParser theParser = parserFactory.newSAXParser();
+			if (theParser == null) {
+				throw new SAXException(Messages.XMLParser_No_SAX_Parser);
+			}
+			xmlReader = theParser.getXMLReader();
+			return theParser;
+		}
+
+		class IUOnlyHandler extends RootHandler {
+
+			private InstallableUnitsHandler unitsHandler;
+
+			public IUOnlyHandler() {
+				// default
+			}
+
+			protected void handleRootAttributes(Attributes attributes) {
+				//Nothing to do
+			}
+
+			public void startElement(String name, Attributes attributes) {
+				if (INSTALLABLE_UNITS_ELEMENT.equals(name)) {
+					if (unitsHandler == null) {
+						unitsHandler = new InstallableUnitsHandler(this, attributes);
+					} else {
+						duplicateElement(this, name, attributes);
+					}
+				} else {
+					invalidElement(name, attributes);
+				}
+			}
+
+			public IInstallableUnit[] getInstallableUnits() {
+				if (unitsHandler == null)
+					return null;
+				return unitsHandler.getUnits();
+			}
+		}
+
+		@Override
+		protected Object getRootObject() {
+			// TODO Auto-generated method stub
+			return null;
+		}
+
+		@Override
+		protected String getErrorMessage() {
+			// TODO Auto-generated method stub
+			return null;
+		}
+	}
+}
diff --git a/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/p2/metadata/io/IUSerializer.java b/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/p2/metadata/io/IUSerializer.java
new file mode 100644
index 000000000..4539326be
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.metadata.repository/src/org/eclipse/equinox/p2/metadata/io/IUSerializer.java
@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (c) 2011 Sonatype, Inc. 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:
+ *     Sonatype, Inc - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.equinox.p2.metadata.io;
+
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+import java.util.Collection;
+import org.eclipse.equinox.internal.p2.metadata.repository.io.MetadataWriter;
+import org.eclipse.equinox.p2.metadata.IInstallableUnit;
+
+/**
+ * This class allows to serialize a collection of {@link IInstallableUnit}s.
+ * These serialized IUs can be read using the {@link IUDeserializer}.
+ * @since 1.2
+ */
+public class IUSerializer {
+	MetadataWriter writer;
+
+	/**
+	 * Construct a serializer.
+	 * @param os the output stream against which the serializer will work.
+	 * @throws UnsupportedEncodingException
+	 */
+	public IUSerializer(OutputStream os) throws UnsupportedEncodingException {
+		writer = new MetadataWriter(os, null);
+	}
+
+	/**
+	 * Serialize the given collections of IU.
+	 * @param ius the collection of {@link IInstallableUnit}s to serialize
+	 */
+	public void write(Collection<IInstallableUnit> ius) {
+		writer.writeInstallableUnits(ius.iterator(), ius.size());
+		writer.flush();
+	}
+}