1 files changed, 448 insertions, 0 deletions
diff --git a/tags/java/sca/2.0-M3-RC4/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/JAXBContextCache.java b/tags/java/sca/2.0-M3-RC4/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/JAXBContextCache.java
new file mode 100644
index 0000000000..d616b9328e
--- /dev/null
+++ b/tags/java/sca/2.0-M3-RC4/modules/databinding-jaxb/src/main/java/org/apache/tuscany/sca/databinding/jaxb/JAXBContextCache.java
@@ -0,0 +1,448 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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.    
+ */
+package org.apache.tuscany.sca.databinding.jaxb;
+
+import java.awt.Image;
+import java.lang.ref.SoftReference;
+import java.net.URI;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.activation.DataHandler;
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.JAXBException;
+import javax.xml.bind.Marshaller;
+import javax.xml.bind.Unmarshaller;
+import javax.xml.transform.Source;
+
+import org.apache.tuscany.sca.databinding.util.LRUCache;
+
+/**
+ * @version $Rev$ $Date$
+ */
+public class JAXBContextCache {
+    private static final int CACHE_SIZE = 128;
+
+    private static HashMap<String, Class<?>> loadClassMap = new HashMap<String, Class<?>>();
+
+    static {
+        loadClassMap.put("byte", byte.class);
+        loadClassMap.put("int", int.class);
+        loadClassMap.put("short", short.class);
+        loadClassMap.put("long", long.class);
+        loadClassMap.put("float", float.class);
+        loadClassMap.put("double", double.class);
+        loadClassMap.put("boolean", boolean.class);
+        loadClassMap.put("char", char.class);
+        loadClassMap.put("void", void.class);
+    }
+
+    protected static Class<?>[] JAXB_BUILTIN_CLASSES =
+        {byte[].class, boolean.class, byte.class, char.class, double.class, float.class, int.class, long.class,
+         short.class, void.class, java.awt.Image.class, java.io.File.class, java.lang.Boolean.class,
+         java.lang.Byte.class, java.lang.Character.class, java.lang.Class.class, java.lang.Double.class,
+         java.lang.Float.class, java.lang.Integer.class, java.lang.Long.class, java.lang.Object.class,
+         java.lang.Short.class, java.lang.String.class, java.lang.Void.class, java.math.BigDecimal.class,
+         java.math.BigInteger.class, java.net.URI.class, java.net.URL.class, java.util.Calendar.class,
+         java.util.Date.class, java.util.GregorianCalendar.class, java.util.UUID.class,
+         javax.activation.DataHandler.class, javax.xml.bind.JAXBElement.class, javax.xml.datatype.Duration.class,
+         javax.xml.datatype.XMLGregorianCalendar.class, javax.xml.namespace.QName.class,
+         javax.xml.transform.Source.class};
+
+    protected static final Set<Class<?>> BUILTIN_CLASSES_SET = new HashSet<Class<?>>(Arrays.asList(JAXB_BUILTIN_CLASSES));
+
+    /*
+    protected static Class<?>[] COMMON_ARRAY_CLASSES =
+        new Class[] {char[].class, short[].class, int[].class, long[].class, float[].class, double[].class,
+                     String[].class
+                     };
+
+    protected static final Set<Class<?>> COMMON_CLASSES_SET = new HashSet<Class<?>>(Arrays.asList(COMMON_ARRAY_CLASSES));
+    */
+
+    protected LRUCache<Object, JAXBContext> cache;
+    protected Pool<JAXBContext, Marshaller>  mpool;
+    protected Pool<JAXBContext, Unmarshaller> upool;
+    
+    // protected JAXBContext commonContext;
+    protected JAXBContext defaultContext;
+
+    public JAXBContextCache() {
+        this(CACHE_SIZE, CACHE_SIZE, CACHE_SIZE);
+    }
+
+    public JAXBContextCache(int contextSize, int marshallerSize, int unmarshallerSize) {
+        cache = new LRUCache<Object, JAXBContext>(contextSize);
+        mpool = new Pool<JAXBContext, Marshaller>();
+        upool = new Pool<JAXBContext, Unmarshaller>();
+        defaultContext = getDefaultJAXBContext();
+    }
+    
+    private static JAXBContext newJAXBContext(final Class<?>... classesToBeBound) throws JAXBException {
+        try {
+            return AccessController.doPrivileged(new PrivilegedExceptionAction<JAXBContext>() {
+                public JAXBContext run() throws JAXBException {
+                    return JAXBContext.newInstance(classesToBeBound);
+                }
+            });
+        } catch (PrivilegedActionException e) {
+            throw (JAXBException)e.getException();
+        }
+    }
+
+    private static JAXBContext newJAXBContext(final String contextPath, final ClassLoader classLoader)
+        throws JAXBException {
+        try {
+            return AccessController.doPrivileged(new PrivilegedExceptionAction<JAXBContext>() {
+                public JAXBContext run() throws JAXBException {
+                    return JAXBContext.newInstance(contextPath, classLoader);
+                }
+            });
+        } catch (PrivilegedActionException e) {
+            throw (JAXBException)e.getException();
+        }
+    }    
+    
+    public static JAXBContext getDefaultJAXBContext() {
+        try {
+            return newJAXBContext();
+        } catch (JAXBException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+
+    /**
+     * @param name of primitive type
+     * @return primitive Class or null
+     */
+    public static Class<?> getPrimitiveClass(String text) {
+        return loadClassMap.get(text);
+    }
+
+    /**
+     * Return the class for this name
+     *
+     * @return Class
+     */
+    private static Class<?> forName(final String className, final boolean initialize, final ClassLoader classloader)
+        throws ClassNotFoundException {
+        // NOTE: This method must remain private because it uses AccessController
+        Class<?> cl = null;
+        try {
+            cl = AccessController.doPrivileged(new PrivilegedExceptionAction<Class<?>>() {
+                public Class<?> run() throws ClassNotFoundException {
+                    // Class.forName does not support primitives
+                    Class<?> cls = getPrimitiveClass(className);
+                    if (cls == null) {
+                        cls = Class.forName(className, initialize, classloader);
+                    }
+                    return cls;
+                }
+            });
+        } catch (PrivilegedActionException e) {
+            throw (ClassNotFoundException)e.getException();
+        }
+
+        return cl;
+    }
+
+    /**
+     * @param p  Package
+     * @param cl
+     * @return true if each package has a ObjectFactory class or package-info
+     */
+    public static boolean checkPackage(String p, ClassLoader cl) {
+
+        // Each package must have an ObjectFactory
+        try {
+            Class<?> cls = forName(p + ".ObjectFactory", false, cl);
+            if (cls != null) {
+                return true;
+            }
+            //Catch Throwable as ClassLoader can throw an NoClassDefFoundError that
+            //does not extend Exception. So we will absorb any Throwable exception here.
+        } catch (Throwable e) {
+            // Ignore
+        }
+
+        // [rfeng] If no ObjectFactory or jaxb.index is present, JAXBContext.newInstance(contextPath, classloader)
+        // will fail
+        /*
+        try {
+            Class<?> cls = forName(p + ".package-info", false, cl);
+            if (cls != null) {
+                return cls.isAnnotationPresent(XmlSchema.class);
+            }
+            //Catch Throwable as ClassLoader can throw an NoClassDefFoundError that
+            //does not extend Exception. So we will absorb any Throwable exception here.
+        } catch (Throwable e) {
+            // Ignore
+        }
+        */
+
+        return false;
+    }
+
+    public Marshaller getMarshaller(JAXBContext context) throws JAXBException {
+        Marshaller marshaller = mpool.get(context);
+        if (marshaller == null) {
+            marshaller = context.createMarshaller();
+        }
+        marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE); 
+        return marshaller;
+    }
+
+    public void releaseJAXBMarshaller(JAXBContext context, Marshaller marshaller) {   
+        if (marshaller != null) {
+            marshaller.setAttachmentMarshaller(null);
+            mpool.put(context, marshaller);
+            // No point unsetting marshaller's JAXB_FRAGMENT property, since we'll just reset it when
+            // doing the next get.
+        }
+    }
+    
+    public Unmarshaller getUnmarshaller(JAXBContext context) throws JAXBException {
+        Unmarshaller unmarshaller = upool.get(context);
+        if (unmarshaller == null) {
+            unmarshaller = context.createUnmarshaller();
+        }
+        return unmarshaller;
+    }
+
+    public void releaseJAXBUnmarshaller(JAXBContext context, Unmarshaller unmarshaller) {   
+        if (unmarshaller != null) {
+            unmarshaller.setAttachmentUnmarshaller(null);
+            upool.put(context, unmarshaller);
+        }
+    }
+    
+    public LRUCache<Object, JAXBContext> getCache() {
+        return cache;
+    }
+
+    public JAXBContext getJAXBContext(Class<?> cls) throws JAXBException {
+        if (BUILTIN_CLASSES_SET.contains(cls)) {
+            return defaultContext;
+        }
+        synchronized (cache) {
+            JAXBContext context = cache.get(cls);
+            if (context != null) {
+                return context;
+            }
+            Package pkg = cls.getPackage();
+            if (pkg != null) {
+                context = cache.get(pkg);
+                if (context != null) {
+                    return context;
+                }
+            }
+
+            if (pkg != null && checkPackage(pkg.getName(), cls.getClassLoader())) {
+                context = newJAXBContext(pkg.getName(), cls.getClassLoader());
+                cache.put(pkg, context);
+            } else {
+                context = newJAXBContext(cls);
+                cache.put(cls, context);
+            }
+            return context;
+
+        }
+    }
+
+    public JAXBContext getJAXBContext(Class<?>[] classes) throws JAXBException {
+        Set<Class<?>> classSet = new HashSet<Class<?>>(Arrays.asList(classes));
+        return getJAXBContext(classSet);
+    }
+
+    public JAXBContext getJAXBContext(Set<Class<?>> classes) throws JAXBException {
+        // Remove the JAXB built-in types to maximize the cache hit 
+        Set<Class<?>> classSet = new HashSet<Class<?>>(classes);
+        classSet.removeAll(BUILTIN_CLASSES_SET);
+        
+        // FIXME: [rfeng] Remove java classes that are mapped to the same XSD type to avoid
+        // conflicts
+        if (classSet.contains(Date[].class)) {
+            classSet.remove(Calendar[].class);
+        }
+
+        if (classSet.contains(URI[].class)) {
+            classSet.remove(UUID[].class);
+        }
+
+        if (classSet.contains(Source[].class)) {
+            classSet.remove(Image[].class);
+            classSet.remove(DataHandler[].class);
+        } 
+        
+        if(classSet.isEmpty()) {
+            return defaultContext;
+        }
+        
+        // For single class
+        if (classSet.size() == 1) {
+            return getJAXBContext(classSet.iterator().next());
+        }
+        synchronized (cache) {
+            JAXBContext context = cache.get(classSet);
+            if (context != null) {
+                return context;
+            }
+            context = newJAXBContext(classSet.toArray(new Class<?>[classSet.size()]));
+            cache.put(classSet, context);
+            return context;
+        }
+    }
+
+    public void clear() {
+        synchronized (cache) {
+            cache.clear();
+        }
+        /*
+        synchronized (upool) {
+            upool.clear();
+        }
+        synchronized (upool) {
+            upool.clear();
+        }
+        */
+    }
+
+    //
+    // This inner class is copied in its entirety from the Axis2 utility class,
+    // org.apache.axis2.jaxws.message.databinding.JAXBUtils.   We could look into extending but it's such a basic data structure
+    // without other dependencies so we might be better off copying it and avoiding a new
+    // Axis2 dependency here.
+    //
+    
+    /**
+     * Pool a list of items for a specific key
+     *
+     * @param <K> Key
+     * @param <V> Pooled object
+     */
+    private static class Pool<K,V> {
+        private SoftReference<Map<K,List<V>>> softMap = 
+            new SoftReference<Map<K,List<V>>>(
+                    new ConcurrentHashMap<K, List<V>>());
+
+        // The maps are freed up when a LOAD FACTOR is hit
+        private static final int MAX_LIST_FACTOR = 50;
+        private static final int MAX_LOAD_FACTOR = 32;  // Maximum number of JAXBContext to store
+        
+        /**
+         * @param key
+         * @return removed item from pool or null.
+         */
+        public V get(K key) {
+            List<V> values = getValues(key);
+            synchronized (values) {
+                if (values.size()>0) {
+                    V v = values.remove(values.size()-1);
+                    return v;
+                    
+                }
+            }
+            return null;
+        }
+
+        /**
+         * Add item back to pool
+         * @param key
+         * @param value
+         */
+        public void put(K key, V value) {
+            adjustSize();
+            List<V> values = getValues(key);
+            synchronized (values) {
+                if (values.size() < MAX_LIST_FACTOR) {
+                    values.add(value);
+                }
+            }
+        }
+
+        /**
+         * Get or create a list of the values for the key
+         * @param key
+         * @return list of values.
+         */
+        private List<V> getValues(K key) {
+            Map<K,List<V>> map = softMap.get();
+            List<V> values = null;
+            if (map != null) {
+                values = map.get(key);
+                if(values !=null) {
+                    return values;
+                }
+            }
+            synchronized (this) {
+                if (map != null) {
+                    values = map.get(key);
+                }
+                if (values == null) {
+                    if (map == null) {
+                        map = new ConcurrentHashMap<K, List<V>>();
+                        softMap = 
+                            new SoftReference<Map<K,List<V>>>(map);
+                    }
+                    values = new ArrayList<V>();
+                    map.put(key, values);
+
+                }
+                return values;
+            }
+        }
+        
+        /**
+         * AdjustSize
+         * When the number of keys exceeds the maximum load, half
+         * of the entries are deleted.
+         * 
+         * The assumption is that the JAXBContexts, UnMarshallers, Marshallers, etc. require
+         * a large footprint.
+         */
+        private void adjustSize() {
+            Map<K,List<V>> map = softMap.get();
+            if (map != null && map.size() > MAX_LOAD_FACTOR) {
+                // Remove every other Entry in the map.
+                Iterator it = map.entrySet().iterator();
+                boolean removeIt = false;
+                while (it.hasNext()) {
+                    it.next();
+                    if (removeIt) {
+                        it.remove();
+                    }
+                    removeIt = !removeIt;
+                }
+            }
+        }
+    }
+}