/***

  * ASM: a very small and fast Java bytecode manipulation framework

  * Copyright (c) 2000-2005 INRIA, France Telecom

  * All rights reserved.

  *

  * 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. Neither the name of the copyright holders nor the names of its

  *    contributors may be used to endorse or promote products derived from

  *    this software without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS 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 THE COPYRIGHT OWNER OR 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.

  */

 package clojure.asm;

 

 /**

  * A constant pool item. Constant pool items can be created with the 'newXXX'

  * methods in the {@link ClassWriter} class.

  *

  * @author Eric Bruneton

  */

 final class Item{

 

 /**

  * Index of this item in the constant pool.

  */

 int index;

 

 /**

  * Type of this constant pool item. A single class is used to represent all

  * constant pool item types, in order to minimize the bytecode size of this

  * package. The value of this field is one of {@link ClassWriter#INT},

  * {@link ClassWriter#LONG}, {@link ClassWriter#FLOAT},

  * {@link ClassWriter#DOUBLE}, {@link ClassWriter#UTF8},

  * {@link ClassWriter#STR}, {@link ClassWriter#CLASS},

  * {@link ClassWriter#NAME_TYPE}, {@link ClassWriter#FIELD},

  * {@link ClassWriter#METH}, {@link ClassWriter#IMETH}.

  * <p/>

  * Special Item types are used for Items that are stored in the ClassWriter

  * {@link ClassWriter#typeTable}, instead of the constant pool, in order to

  * avoid clashes with normal constant pool items in the ClassWriter constant

  * pool's hash table. These special item types are

  * {@link ClassWriter#TYPE_NORMAL}, {@link ClassWriter#TYPE_UNINIT} and

  * {@link ClassWriter#TYPE_MERGED}.

  */

 int type;

 

 /**

  * Value of this item, for an integer item.

  */

 int intVal;

 

 /**

  * Value of this item, for a long item.

  */

 long longVal;

 

 /**

  * First part of the value of this item, for items that do not hold a

  * primitive value.

  */

 String strVal1;

 

 /**

  * Second part of the value of this item, for items that do not hold a

  * primitive value.

  */

 String strVal2;

 

 /**

  * Third part of the value of this item, for items that do not hold a

  * primitive value.

  */

 String strVal3;

 

 /**

  * The hash code value of this constant pool item.

  */

 int hashCode;

 

 /**

  * Link to another constant pool item, used for collision lists in the

  * constant pool's hash table.

  */

 Item next;

 

 /**

  * Constructs an uninitialized {@link Item}.

  */

 Item(){

 }

 

 /**

  * Constructs an uninitialized {@link Item} for constant pool element at

  * given position.

  *

  * @param index index of the item to be constructed.

  */

 Item(final int index){

 	this.index = index;

 }

 

 /**

  * Constructs a copy of the given item.

  *

  * @param index index of the item to be constructed.

  * @param i     the item that must be copied into the item to be constructed.

  */

 Item(final int index, final Item i){

 	this.index = index;

 	type = i.type;

 	intVal = i.intVal;

 	longVal = i.longVal;

 	strVal1 = i.strVal1;

 	strVal2 = i.strVal2;

 	strVal3 = i.strVal3;

 	hashCode = i.hashCode;

 }

 

 /**

  * Sets this item to an integer item.

  *

  * @param intVal the value of this item.

  */

 void set(final int intVal){

 	this.type = ClassWriter.INT;

 	this.intVal = intVal;

 	this.hashCode = 0x7FFFFFFF & (type + intVal);

 }

 

 /**

  * Sets this item to a long item.

  *

  * @param longVal the value of this item.

  */

 void set(final long longVal){

 	this.type = ClassWriter.LONG;

 	this.longVal = longVal;

 	this.hashCode = 0x7FFFFFFF & (type + (int) longVal);

 }

 

 /**

  * Sets this item to a float item.

  *

  * @param floatVal the value of this item.

  */

 void set(final float floatVal){

 	this.type = ClassWriter.FLOAT;

 	this.intVal = Float.floatToRawIntBits(floatVal);

 	this.hashCode = 0x7FFFFFFF & (type + (int) floatVal);

 }

 

 /**

  * Sets this item to a double item.

  *

  * @param doubleVal the value of this item.

  */

 void set(final double doubleVal){

 	this.type = ClassWriter.DOUBLE;

 	this.longVal = Double.doubleToRawLongBits(doubleVal);

 	this.hashCode = 0x7FFFFFFF & (type + (int) doubleVal);

 }

 

 /**

  * Sets this item to an item that do not hold a primitive value.

  *

  * @param type    the type of this item.

  * @param strVal1 first part of the value of this item.

  * @param strVal2 second part of the value of this item.

  * @param strVal3 third part of the value of this item.

  */

 void set(

 		final int type,

 		final String strVal1,

 		final String strVal2,

 		final String strVal3){

 	this.type = type;

 	this.strVal1 = strVal1;

 	this.strVal2 = strVal2;

 	this.strVal3 = strVal3;

 	switch(type)

 		{

 		case ClassWriter.UTF8:

 		case ClassWriter.STR:

 		case ClassWriter.CLASS:

 		case ClassWriter.TYPE_NORMAL:

 			hashCode = 0x7FFFFFFF & (type + strVal1.hashCode());

 			return;

 		case ClassWriter.NAME_TYPE:

 			hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()

 			                                * strVal2.hashCode());

 			return;

 			// ClassWriter.FIELD:

 			// ClassWriter.METH:

 			// ClassWriter.IMETH:

 		default:

 			hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()

 			                                * strVal2.hashCode() * strVal3.hashCode());

 		}

 }

 

 /**

  * Indicates if the given item is equal to this one.

  *

  * @param i the item to be compared to this one.

  * @return <tt>true</tt> if the given item if equal to this one,

  *         <tt>false</tt> otherwise.

  */

 boolean isEqualTo(final Item i){

 	if(i.type == type)

 		{

 		switch(type)

 			{

 			case ClassWriter.INT:

 			case ClassWriter.FLOAT:

 				return i.intVal == intVal;

 			case ClassWriter.TYPE_MERGED:

 			case ClassWriter.LONG:

 			case ClassWriter.DOUBLE:

 				return i.longVal == longVal;

 			case ClassWriter.UTF8:

 			case ClassWriter.STR:

 			case ClassWriter.CLASS:

 			case ClassWriter.TYPE_NORMAL:

 				return i.strVal1.equals(strVal1);

 			case ClassWriter.TYPE_UNINIT:

 				return i.intVal == intVal && i.strVal1.equals(strVal1);

 			case ClassWriter.NAME_TYPE:

 				return i.strVal1.equals(strVal1)

 				       && i.strVal2.equals(strVal2);

 				// ClassWriter.FIELD:

 				// ClassWriter.METH:

 				// ClassWriter.IMETH:

 			default:

 				return i.strVal1.equals(strVal1)

 				       && i.strVal2.equals(strVal2)

 				       && i.strVal3.equals(strVal3);

 			}

 		}

 	return false;

 }

 }