Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright 1999-2005 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.  Sun designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Sun in the LICENSE file that accompanied this code.

  *

  * 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 com.sun.tools.javac.jvm;

 import java.util.*;

 import com.sun.tools.javac.util.*;

 import com.sun.tools.javac.code.Symbol.*;

 import com.sun.tools.javac.code.Type;

 /** An internal structure that corresponds to the constant pool of a classfile.

  *

  *  <p><b>This is NOT part of any API supported by Sun Microsystems.  If

  *  you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public class Pool {

     public static final int MAX_ENTRIES = 0xFFFF;

     public static final int MAX_STRING_LENGTH = 0xFFFF;

     /** Index of next constant to be entered.

      */

     int pp;

     /** The initial pool buffer.

      */

     Object[] pool;

     /** A hashtable containing all constants in the pool.

      */

     Map<Object,Integer> indices;

     /** Construct a pool with given number of elements and element array.

      */

     public Pool(int pp, Object[] pool) {

         this.pp = pp;

         this.pool = pool;

         this.indices = new HashMap<Object,Integer>(pool.length);

         for (int i = 1; i < pp; i++) {

             if (pool[i] != null) indices.put(pool[i], i);

         }

     }

     /** Construct an empty pool.

      */

     public Pool() {

         this(1, new Object[64]);

     }

     /** Return the number of entries in the constant pool.

      */

     public int numEntries() {

         return pp;

     }

     /** Remove everything from this pool.

      */

     public void reset() {

         pp = 1;

         indices.clear();

     }

     /** Double pool buffer in size.

      */

     private void doublePool() {

         Object[] newpool = new Object[pool.length * 2];

         System.arraycopy(pool, 0, newpool, 0, pool.length);

         pool = newpool;

     }

     /** Place an object in the pool, unless it is already there.

      *  If object is a symbol also enter its owner unless the owner is a

      *  package.  Return the object's index in the pool.

      */

     public int put(Object value) {

         if (value instanceof MethodSymbol)

             value = new Method((MethodSymbol)value);

         else if (value instanceof VarSymbol)

             value = new Variable((VarSymbol)value);

 //      assert !(value instanceof Type.TypeVar);

         Integer index = indices.get(value);

         if (index == null) {

 //          System.err.println("put " + value + " " + value.getClass());//DEBUG

             index = pp;

             indices.put(value, index);

             if (pp == pool.length) doublePool();

             pool[pp++] = value;

             if (value instanceof Long || value instanceof Double) {

                 if (pp == pool.length) doublePool();

                 pool[pp++] = null;

             }

         }

         return index.intValue();

     }

     /** Return the given object's index in the pool,

      *  or -1 if object is not in there.

      */

     public int get(Object o) {

         Integer n = indices.get(o);

         return n == null ? -1 : n.intValue();

     }

     static class Method extends DelegatedSymbol {

         MethodSymbol m;

         Method(MethodSymbol m) {

             super(m);

             this.m = m;

         }

         public boolean equals(Object other) {

             if (!(other instanceof Method)) return false;

             MethodSymbol o = ((Method)other).m;

             return

                 o.name == m.name &&

                 o.owner == m.owner &&

                 o.type.equals(m.type);

         }

         public int hashCode() {

             return

                 m.name.hashCode() * 33 +

                 m.owner.hashCode() * 9 +

                 m.type.hashCode();

         }

     }

     static class Variable extends DelegatedSymbol {

         VarSymbol v;

         Variable(VarSymbol v) {

             super(v);

             this.v = v;

         }

         public boolean equals(Object other) {

             if (!(other instanceof Variable)) return false;

             VarSymbol o = ((Variable)other).v;

             return

                 o.name == v.name &&

                 o.owner == v.owner &&

                 o.type.equals(v.type);

         }

         public int hashCode() {

             return

                 v.name.hashCode() * 33 +

                 v.owner.hashCode() * 9 +

                 v.type.hashCode();

         }

     }

 }