/*

 * Copyright 2000-2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

package sun.jvm.hotspot.oops;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

public class Klass extends Oop implements ClassConstants {

  static {

    VM.registerVMInitializedObserver(new Observer() {

        public void update(Observable o, Object data) {

          initialize(VM.getVM().getTypeDataBase());

        }

      });

  }

  // anon-enum constants for _layout_helper.

  public static int LH_INSTANCE_SLOW_PATH_BIT;

  public static int LH_LOG2_ELEMENT_SIZE_SHIFT;

  public static int LH_ELEMENT_TYPE_SHIFT;

  public static int LH_HEADER_SIZE_SHIFT;

  public static int LH_ARRAY_TAG_SHIFT;

  public static int LH_ARRAY_TAG_TYPE_VALUE;

  public static int LH_ARRAY_TAG_OBJ_VALUE;

  private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {

    Type type    = db.lookupType("Klass");

    javaMirror   = new OopField(type.getOopField("_java_mirror"), Oop.getHeaderSize());

    superField   = new OopField(type.getOopField("_super"), Oop.getHeaderSize());

    layoutHelper = new IntField(type.getJIntField("_layout_helper"), Oop.getHeaderSize());

    name         = new OopField(type.getOopField("_name"), Oop.getHeaderSize());

    accessFlags  = new CIntField(type.getCIntegerField("_access_flags"), Oop.getHeaderSize());

    subklass     = new OopField(type.getOopField("_subklass"), Oop.getHeaderSize());

    nextSibling  = new OopField(type.getOopField("_next_sibling"), Oop.getHeaderSize());

    allocCount   = new CIntField(type.getCIntegerField("_alloc_count"), Oop.getHeaderSize());

    LH_INSTANCE_SLOW_PATH_BIT  = db.lookupIntConstant("Klass::_lh_instance_slow_path_bit").intValue();

    LH_LOG2_ELEMENT_SIZE_SHIFT = db.lookupIntConstant("Klass::_lh_log2_element_size_shift").intValue();

    LH_ELEMENT_TYPE_SHIFT      = db.lookupIntConstant("Klass::_lh_element_type_shift").intValue();

    LH_HEADER_SIZE_SHIFT       = db.lookupIntConstant("Klass::_lh_header_size_shift").intValue();

    LH_ARRAY_TAG_SHIFT         = db.lookupIntConstant("Klass::_lh_array_tag_shift").intValue();

    LH_ARRAY_TAG_TYPE_VALUE    = db.lookupIntConstant("Klass::_lh_array_tag_type_value").intValue();

    LH_ARRAY_TAG_OBJ_VALUE     = db.lookupIntConstant("Klass::_lh_array_tag_obj_value").intValue();

  }

  Klass(OopHandle handle, ObjectHeap heap) {

    super(handle, heap);

  }

  // jvmdi support - see also class_status in VM code

  public int getClassStatus() {

    return 0; // overridden in derived classes

  }

  public boolean isKlass()             { return true; }

  // Fields

  private static OopField  javaMirror;

  private static OopField  superField;

  private static IntField layoutHelper;

  private static OopField  name;

  private static CIntField accessFlags;

  private static OopField  subklass;

  private static OopField  nextSibling;

  private static CIntField allocCount;

  // Accessors for declared fields

  public Instance getJavaMirror()       { return (Instance) javaMirror.getValue(this);   }

  public Klass    getSuper()            { return (Klass)    superField.getValue(this);   }

  public Klass    getJavaSuper()        { return null;  }

  public int      getLayoutHelper()     { return (int)           layoutHelper.getValue(this); }

  public Symbol   getName()             { return (Symbol)   name.getValue(this);         }

  public long     getAccessFlags()      { return            accessFlags.getValue(this);  }

  // Convenience routine

  public AccessFlags getAccessFlagsObj(){ return new AccessFlags(getAccessFlags());      }

  public Klass    getSubklassKlass()    { return (Klass)    subklass.getValue(this);     }

  public Klass    getNextSiblingKlass() { return (Klass)    nextSibling.getValue(this);  }

  public long     getAllocCount()       { return            allocCount.getValue(this);   }

  // computed access flags - takes care of inner classes etc.

  // This is closer to actual source level than getAccessFlags() etc.

  public long computeModifierFlags() {

    return 0L; // Unless overridden, modifier_flags is 0.

  }

  // same as JVM_GetClassModifiers

  public final long getClassModifiers() {

    // unlike the VM counterpart we never have to deal with primitive type,

    // because we operator on Klass and not an instance of java.lang.Class.

    long flags = computeModifierFlags();

    if (isSuper()) {

       flags |= JVM_ACC_SUPER;

    }

    return flags;

  }

  // subclass check

  public boolean isSubclassOf(Klass k) {

    if (k != null) {

      Klass t = this;

      // Run up the super chain and check

      while (t != null) {

        if (t.equals(k)) return true;

        t = t.getSuper();

      }

    }

    return false;

  }

  // subtype check

  public boolean isSubtypeOf(Klass k) {

    return computeSubtypeOf(k);

  }

  boolean computeSubtypeOf(Klass k) {

    return isSubclassOf(k);

  }

  // Find LCA (Least Common Ancester) in class heirarchy

  public Klass lca( Klass k2 ) {

    Klass k1 = this;

    while ( true ) {

      if ( k1.isSubtypeOf(k2) ) return k2;

      if ( k2.isSubtypeOf(k1) ) return k1;

      k1 = k1.getSuper();

      k2 = k2.getSuper();

    }

  }

  public void printValueOn(PrintStream tty) {

    tty.print("Klass");

  }

  public void iterateFields(OopVisitor visitor, boolean doVMFields) {

    super.iterateFields(visitor, doVMFields);

    if (doVMFields) {

      visitor.doOop(javaMirror, true);

      visitor.doOop(superField, true);

      visitor.doInt(layoutHelper, true);

      visitor.doOop(name, true);

      visitor.doCInt(accessFlags, true);

      visitor.doOop(subklass, true);

      visitor.doOop(nextSibling, true);

      visitor.doCInt(allocCount, true);

    }

  }

  public long getObjectSize() {

    System.out.println("should not reach here");

    return 0;

  }

  /** Array class with specific rank */

  public Klass arrayKlass(int rank)       { return arrayKlassImpl(false, rank); }

  /** Array class with this klass as element type */

  public Klass arrayKlass()               { return arrayKlassImpl(false);       }

  /** These will return null instead of allocating on the heap */

  public Klass arrayKlassOrNull(int rank) { return arrayKlassImpl(true, rank);  }

  public Klass arrayKlassOrNull()         { return arrayKlassImpl(true);        }

  public Klass arrayKlassImpl(boolean orNull, int rank) {

    throw new RuntimeException("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");

  }

  public Klass arrayKlassImpl(boolean orNull) {

    throw new RuntimeException("array_klass should be dispatched to instanceKlass, objArrayKlass or typeArrayKlass");

  }

  // This returns the name in the form java/lang/String which isn't really a signature

  // The subclasses override this to produce the correct form, eg

  //   Ljava/lang/String; For ArrayKlasses getName itself is the signature.

  public String signature() { return getName().asString(); }

  // Convenience routines

  public boolean isPublic()                 { return getAccessFlagsObj().isPublic(); }

  public boolean isFinal()                  { return getAccessFlagsObj().isFinal(); }

  public boolean isInterface()              { return getAccessFlagsObj().isInterface(); }

  public boolean isAbstract()               { return getAccessFlagsObj().isAbstract(); }

  public boolean isSuper()                  { return getAccessFlagsObj().isSuper(); }

  public boolean isSynthetic()              { return getAccessFlagsObj().isSynthetic(); }

  public boolean hasFinalizer()             { return getAccessFlagsObj().hasFinalizer(); }

  public boolean isCloneable()              { return getAccessFlagsObj().isCloneable(); }

  public boolean hasVanillaConstructor()    { return getAccessFlagsObj().hasVanillaConstructor(); }

  public boolean hasMirandaMethods ()       { return getAccessFlagsObj().hasMirandaMethods(); }

}