jdk8-mips64-public/jaxws: src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/CollisionCheckStack.java@e530533619ec (annotated)

src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/CollisionCheckStack.java@e530533619ec (annotated)

src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/CollisionCheckStack.java

Thu, 12 Oct 2017 19:44:07 +0800

author: aoqi
date: Thu, 12 Oct 2017 19:44:07 +0800
changeset 760: e530533619ec
parent 0: 373ffda63c9a
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. 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.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package com.sun.xml.internal.bind.v2.util;
 import java.util.AbstractList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Stack;
 /**
  * {@link Stack}-like data structure that allows the following efficient operations:
  *
  * <ol>
  * <li>Push/pop operation.
  * <li>Duplicate check. When an object that's already in the stack is pushed,
  *     this class will tell you so.
  * </ol>
  *
  * <p>
  * Object equality is their identity equality.
  *
  * <p>
  * This class implements {@link List} for accessing items in the stack,
  * but {@link List} methods that alter the stack is not supported.
  *
  * @author Kohsuke Kawaguchi
  */
 public final class CollisionCheckStack<E> extends AbstractList<E> {
     private Object[] data;
     private int[] next;
     private int size = 0;
     private boolean latestPushResult = false;
     /**
      * True if the check shall be done by using the object identity.
      * False if the check shall be done with the equals method.
      */
     private boolean useIdentity = true;
     // for our purpose, there isn't much point in resizing this as we don't expect
     // the stack to grow that much.
     private final int[] initialHash;
     public CollisionCheckStack() {
         initialHash = new int[17];
         data = new Object[16];
         next = new int[16];
     }
     /**
      * Set to false to use {@link Object#equals(Object)} to detect cycles.
      * This method can be only used when the stack is empty.
      */
     public void setUseIdentity(boolean useIdentity) {
         this.useIdentity = useIdentity;
     }
     public boolean getUseIdentity() {
         return useIdentity;
     }
     public boolean getLatestPushResult() {
         return latestPushResult;
     }
     /**
      * Pushes a new object to the stack.
      *
      * @return
      *      true if this object has already been pushed
      */
     public boolean push(E o) {
         if(data.length==size)
             expandCapacity();
         data[size] = o;
         int hash = hash(o);
         boolean r = findDuplicate(o, hash);
         next[size] = initialHash[hash];
         initialHash[hash] = size+1;
         size++;
         this.latestPushResult = r;
         return latestPushResult;
     }
     /**
      * Pushes a new object to the stack without making it participate
      * with the collision check.
      */
     public void pushNocheck(E o) {
         if(data.length==size)
             expandCapacity();
         data[size] = o;
         next[size] = -1;
         size++;
     }
     public boolean findDuplicate(E o) {
         int hash = hash(o);
         return findDuplicate(o, hash);
     }
     @Override
     public E get(int index) {
         return (E)data[index];
     }
     @Override
     public int size() {
         return size;
     }
     private int hash(Object o) {
         return ((useIdentity?System.identityHashCode(o):o.hashCode())&0x7FFFFFFF) % initialHash.length;
     }
     /**
      * Pops an object from the stack
      */
     public E pop() {
         size--;
         Object o = data[size];
         data[size] = null;  // keeping references too long == memory leak
         int n = next[size];
         if(n<0) {
             // pushed by nocheck. no need to update hash
         } else {
             int hash = hash(o);
             assert initialHash[hash]==size+1;
             initialHash[hash] = n;
         }
         return (E)o;
     }
     /**
      * Returns the top of the stack.
      */
     public E peek() {
         return (E)data[size-1];
     }
     private boolean findDuplicate(E o, int hash) {
         int p = initialHash[hash];
         while(p!=0) {
             p--;
             Object existing = data[p];
             if (useIdentity) {
                 if(existing==o)     return true;
             } else {
                 if (o.equals(existing)) return true;
             }
             p = next[p];
         }
         return false;
     }
     private void expandCapacity() {
         int oldSize = data.length;
         int newSize = oldSize * 2;
         Object[] d = new Object[newSize];
         int[] n = new int[newSize];
         System.arraycopy(data,0,d,0,oldSize);
         System.arraycopy(next,0,n,0,oldSize);
         data = d;
         next = n;
     }
     /**
      * Clears all the contents in the stack.
      */
     public void reset() {
         if(size>0) {
             size = 0;
             Arrays.fill(initialHash,0);
         }
     }
     /**
      * String that represents the cycle.
      */
     public String getCycleString() {
         StringBuilder sb = new StringBuilder();
         int i=size()-1;
         E obj = get(i);
         sb.append(obj);
         Object x;
         do {
             sb.append(" -> ");
             x = get(--i);
             sb.append(x);
         } while(obj!=x);
         return sb.toString();
     }
 }

Mercurial > jdk8-mips64-public > jaxws / annotate

src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/CollisionCheckStack.java@e530533619ec (annotated)

src/share/jaxws_classes/com/sun/xml/internal/bind/v2/util/CollisionCheckStack.java