content: /*
   * Copyright (c) 2001-2008 Caucho Technology, Inc.  All rights reserved.
   *
   * The Apache Software License, Version 1.1
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution, if
   *    any, must include the following acknowlegement:
   *       "This product includes software developed by the
   *        Caucho Technology (http://www.caucho.com/)."
   *    Alternately, this acknowlegement may appear in the software itself,
   *    if and wherever such third-party acknowlegements normally appear.
   *
   * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
   *    endorse or promote products derived from this software without prior
   *    written permission. For written permission, please contact
   *    info@caucho.com.
   *
   * 5. Products derived from this software may not be called "Resin"
   *    nor may "Resin" appear in their names without prior written
   *    permission of Caucho Technology.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
   * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
   * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
   * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
   * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
   * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * @author Scott Ferguson
   */
  
  package com.caucho.hessian.io;
  
  import com.caucho.hessian.HessianUnshared;
  import sun.misc.Unsafe;
  
  import java.io.IOException;
  import java.lang.ref.SoftReference;
  import java.lang.reflect.Field;
  import java.lang.reflect.Modifier;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.WeakHashMap;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  /**
   * Serializing an object for known object types.
   */
  public class UnsafeSerializer extends AbstractSerializer
  {
    private static final Logger log
      = Logger.getLogger(UnsafeSerializer.class.getName());
  
    private static boolean _isEnabled;
    private static final Unsafe _unsafe;
    
    private static final WeakHashMap<Class<?>,SoftReference<UnsafeSerializer>> _serializerMap
      = new WeakHashMap<Class<?>,SoftReference<UnsafeSerializer>>();
  
    private Field []_fields;
    private FieldSerializer []_fieldSerializers;
    
    public static boolean isEnabled()
    {
      return _isEnabled;
    }
  
    public UnsafeSerializer(Class<?> cl)
    {
      introspect(cl);
    }
  
    public static UnsafeSerializer create(Class<?> cl)
    {
      synchronized (_serializerMap) {
        SoftReference<UnsafeSerializer> baseRef
          = _serializerMap.get(cl);
  
        UnsafeSerializer base = baseRef != null ? baseRef.get() : null;
  
        if (base == null) {
          if (cl.isAnnotationPresent(HessianUnshared.class))
            base = new UnsafeUnsharedSerializer(cl);
          else
            base = new UnsafeSerializer(cl);
          
          baseRef = new SoftReference<UnsafeSerializer>(base);
          _serializerMap.put(cl, baseRef);
        }
  
        return base;
      }
    }
  
    protected void introspect(Class<?> cl)
    {
      ArrayList<Field> primitiveFields = new ArrayList<Field>();
      ArrayList<Field> compoundFields = new ArrayList<Field>();
  
      for (; cl != null; cl = cl.getSuperclass()) {
        Field []fields = cl.getDeclaredFields();
        
        for (int i = 0; i < fields.length; i++) {
          Field field = fields[i];
          
          if (Modifier.isTransient(field.getModifiers())
              || Modifier.isStatic(field.getModifiers())) {
            continue;
          }
  
          // XXX: could parameterize the handler to only deal with public
          field.setAccessible(true);
  
          if (field.getType().isPrimitive()
              || (field.getType().getName().startsWith("java.lang.")
                  && ! field.getType().equals(Object.class))) {
            primitiveFields.add(field);
          }
          else {
            compoundFields.add(field);
          }
        }
      }
  
      ArrayList<Field> fields = new ArrayList<Field>();
      fields.addAll(primitiveFields);
      fields.addAll(compoundFields);
      // 属性倒序，先写入父类属性，再写入子类属性，保证子类属性不被覆盖
      Collections.reverse(fields);
      _fields = new Field[fields.size()];
      fields.toArray(_fields);
  
      _fieldSerializers = new FieldSerializer[_fields.length];
  
      for (int i = 0; i < _fields.length; i++) {
        _fieldSerializers[i] = getFieldSerializer(_fields[i]);
      }
    }
  
    @Override
    public void writeObject(Object obj, AbstractHessianOutput out)
      throws IOException
    {
      if (out.addRef(obj)) {
        return;
      }
      
      Class<?> cl = obj.getClass();
  
      int ref = out.writeObjectBegin(cl.getName());
  
      if (ref >= 0) {
        writeInstance(obj, out);
      }
      else if (ref == -1) {
        writeDefinition20(out);
        out.writeObjectBegin(cl.getName());
        writeInstance(obj, out);
      }
      else {
        writeObject10(obj, out);
      }
    }
  
    protected void writeObject10(Object obj, AbstractHessianOutput out)
      throws IOException
    {
      for (int i = 0; i < _fields.length; i++) {
        Field field = _fields[i];
  
        out.writeString(field.getName());
  
        _fieldSerializers[i].serialize(out, obj);
      }
  
      out.writeMapEnd();
    }
  
    private void writeDefinition20(AbstractHessianOutput out)
      throws IOException
    {
      out.writeClassFieldLength(_fields.length);
  
      for (int i = 0; i < _fields.length; i++) {
        Field field = _fields[i];
  
        out.writeString(field.getName());
      }
    }
  
    final public void writeInstance(Object obj, AbstractHessianOutput out)
      throws IOException
    {
      try {
        FieldSerializer []fieldSerializers = _fieldSerializers;
        int length = fieldSerializers.length;
        
        for (int i = 0; i < length; i++) {
          fieldSerializers[i].serialize(out, obj);
        }
      } catch (RuntimeException e) {
        throw new RuntimeException(e.getMessage() + "\n class: "
                                   + obj.getClass().getName()
                                   + " (object=" + obj + ")",
                                   e);
      } catch (IOException e) {
        throw new IOExceptionWrapper(e.getMessage() + "\n class: "
                                     + obj.getClass().getName()
                                     + " (object=" + obj + ")",
                                     e);
      }
    }
  
    private static FieldSerializer getFieldSerializer(Field field)
    {
      Class<?> type = field.getType();
      
      if (boolean.class.equals(type)) {
        return new BooleanFieldSerializer(field);
      }
      else if (byte.class.equals(type)) {
        return new ByteFieldSerializer(field);
      }
      else if (char.class.equals(type)) {
        return new CharFieldSerializer(field);
      }
      else if (short.class.equals(type)) {
        return new ShortFieldSerializer(field);
      }
      else if (int.class.equals(type)) {
        return new IntFieldSerializer(field);
      }
      else if (long.class.equals(type)) {
        return new LongFieldSerializer(field);
      }
      else if (double.class.equals(type)) {
        return new DoubleFieldSerializer(field);
      }
      else if (float.class.equals(type)) {
        return new FloatFieldSerializer(field);
      }
      else if (String.class.equals(type)) {
        return new StringFieldSerializer(field);
      }
      else if (java.util.Date.class.equals(type)
               || java.sql.Date.class.equals(type)
               || java.sql.Timestamp.class.equals(type)
               || java.sql.Time.class.equals(type)) {
        return new DateFieldSerializer(field);
      }
      else
        return new ObjectFieldSerializer(field);
    }
  
    abstract static class FieldSerializer {
      abstract void serialize(AbstractHessianOutput out, Object obj)
        throws IOException;
    }
  
    final static class ObjectFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      ObjectFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
  
      @Override
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        try {
          Object value = _unsafe.getObject(obj, _offset);
          
          out.writeObject(value);
        } catch (RuntimeException e) {
          throw new RuntimeException(e.getMessage() + "\n field: "
                                     + _field.getDeclaringClass().getName()
                                     + '.' + _field.getName(),
                                     e);
        } catch (IOException e) {
          throw new IOExceptionWrapper(e.getMessage() + "\n field: "
                                       + _field.getDeclaringClass().getName()
                                       + '.' + _field.getName(),
                                       e);
        }
      }
    }
  
    final static class BooleanFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      BooleanFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
  
      void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        boolean value = _unsafe.getBoolean(obj, _offset);
        
        out.writeBoolean(value);
      }
    }
  
    final static class ByteFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      ByteFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        int value = _unsafe.getByte(obj, _offset);
  
        out.writeInt(value);
      }
    }
  
    final static class CharFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      CharFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        char value = _unsafe.getChar(obj, _offset);
  
        out.writeString(String.valueOf(value));
      }
    }
  
    final static class ShortFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      ShortFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        int value = _unsafe.getShort(obj, _offset);
  
        out.writeInt(value);
      }
    }
  
    final static class IntFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      IntFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        int value = _unsafe.getInt(obj, _offset);
  
        out.writeInt(value);
      }
    }
  
    final static class LongFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      LongFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        long value = _unsafe.getLong(obj, _offset);
  
        out.writeLong(value);
      }
    }
  
    final static class FloatFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      FloatFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        double value = _unsafe.getFloat(obj, _offset);
  
        out.writeDouble(value);
      }
    }
  
    final static class DoubleFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      DoubleFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        double value = _unsafe.getDouble(obj, _offset);
  
        out.writeDouble(value);
      }
    }
  
    final static class StringFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      StringFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
      
      @Override
      final void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        String value = (String) _unsafe.getObject(obj, _offset);
  
        out.writeString(value);
      }
    }
  
    final static class DateFieldSerializer extends FieldSerializer {
      private final Field _field;
      private final long _offset;
      
      DateFieldSerializer(Field field)
      {
        _field = field;
        _offset = _unsafe.objectFieldOffset(field);
        
        if (_offset == Unsafe.INVALID_FIELD_OFFSET)
          throw new IllegalStateException();
      }
  
      @Override
      void serialize(AbstractHessianOutput out, Object obj)
        throws IOException
      {
        java.util.Date value
          = (java.util.Date) _unsafe.getObject(obj, _offset);
  
        if (value == null)
          out.writeNull();
        else
          out.writeUTCDate(value.getTime());
      }
    }
    
    static {
      boolean isEnabled = false;
      Unsafe unsafe = null;
      
      try {
        Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
        Field theUnsafe = null;
        for (Field field : unsafeClass.getDeclaredFields()) {
          if (field.getName().equals("theUnsafe"))
            theUnsafe = field;
        }
        
        if (theUnsafe != null) {
          theUnsafe.setAccessible(true);
          unsafe = (Unsafe) theUnsafe.get(null);
        }
        
        isEnabled = unsafe != null;
        
        String unsafeProp = System.getProperty("com.caucho.hessian.unsafe");
        
        if ("false".equals(unsafeProp))
          isEnabled = false;
      } catch (Throwable e) {
        log.log(Level.ALL, e.toString(), e);
      }
      
      _unsafe = unsafe;
      _isEnabled = isEnabled;
    }
  }
  