jdk8-mips64-public/langtools: src/share/classes/com/sun/tools/javac/util/SharedNameTable.java@24a47c3062fe (annotated)

src/share/classes/com/sun/tools/javac/util/SharedNameTable.java@24a47c3062fe (annotated)

src/share/classes/com/sun/tools/javac/util/SharedNameTable.java

Thu, 02 Oct 2008 19:58:40 -0700

author: xdono
date: Thu, 02 Oct 2008 19:58:40 -0700
changeset 117: 24a47c3062fe
parent 113: eff38cc97183
child 554: 9d9f26857129
permissions: -rw-r--r--

6754988: Update copyright year
Summary: Update for files that have been modified starting July 2008
Reviewed-by: ohair, tbell

 /*
  * Copyright 1999-2008 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.util;
 import java.lang.ref.SoftReference;
 /**
  * Implementation of Name.Table that stores all names in a single shared
  * byte array, expanding it as needed. This avoids the overhead incurred
  * by using an array of bytes for each name.
  *
  *  <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 SharedNameTable extends Name.Table {
     // maintain a freelist of recently used name tables for reuse.
     private static List<SoftReference<SharedNameTable>> freelist = List.nil();
     static public synchronized SharedNameTable create(Names names) {
         while (freelist.nonEmpty()) {
             SharedNameTable t = freelist.head.get();
             freelist = freelist.tail;
             if (t != null) {
                 return t;
             }
         }
         return new SharedNameTable(names);
     }
     static private synchronized void dispose(SharedNameTable t) {
         freelist = freelist.prepend(new SoftReference<SharedNameTable>(t));
     }
     /** The hash table for names.
      */
     private NameImpl[] hashes;
     /** The shared byte array holding all encountered names.
      */
     public byte[] bytes;
     /** The mask to be used for hashing
      */
     private int hashMask;
     /** The number of filled bytes in `names'.
      */
     private int nc = 0;
     /** Allocator
      *  @param names The main name table
      *  @param hashSize the (constant) size to be used for the hash table
      *                  needs to be a power of two.
      *  @param nameSize the initial size of the name table.
      */
     public SharedNameTable(Names names, int hashSize, int nameSize) {
         super(names);
         hashMask = hashSize - 1;
         hashes = new NameImpl[hashSize];
         bytes = new byte[nameSize];
     }
     public SharedNameTable(Names names) {
         this(names, 0x8000, 0x20000);
     }
     @Override
     public Name fromChars(char[] cs, int start, int len) {
         int nc = this.nc;
         byte[] bytes = this.bytes;
         while (nc + len * 3 >= bytes.length) {
             //          System.err.println("doubling name buffer of length " + names.length + " to fit " + len + " chars");//DEBUG
             byte[] newnames = new byte[bytes.length * 2];
             System.arraycopy(bytes, 0, newnames, 0, bytes.length);
             bytes = this.bytes = newnames;
         }
         int nbytes = Convert.chars2utf(cs, start, bytes, nc, len) - nc;
         int h = hashValue(bytes, nc, nbytes) & hashMask;
         NameImpl n = hashes[h];
         while (n != null &&
                 (n.getByteLength() != nbytes ||
                 !equals(bytes, n.index, bytes, nc, nbytes))) {
             n = n.next;
         }
         if (n == null) {
             n = new NameImpl(this);
             n.index = nc;
             n.length = nbytes;
             n.next = hashes[h];
             hashes[h] = n;
             this.nc = nc + nbytes;
             if (nbytes == 0) {
                 this.nc++;
             }
         }
         return n;
     }
     @Override
     public Name fromUtf(byte[] cs, int start, int len) {
         int h = hashValue(cs, start, len) & hashMask;
         NameImpl n = hashes[h];
         byte[] names = this.bytes;
         while (n != null &&
                 (n.getByteLength() != len || !equals(names, n.index, cs, start, len))) {
             n = n.next;
         }
         if (n == null) {
             int nc = this.nc;
             while (nc + len > names.length) {
                 //              System.err.println("doubling name buffer of length + " + names.length + " to fit " + len + " bytes");//DEBUG
                 byte[] newnames = new byte[names.length * 2];
                 System.arraycopy(names, 0, newnames, 0, names.length);
                 names = this.bytes = newnames;
             }
             System.arraycopy(cs, start, names, nc, len);
             n = new NameImpl(this);
             n.index = nc;
             n.length = len;
             n.next = hashes[h];
             hashes[h] = n;
             this.nc = nc + len;
             if (len == 0) {
                 this.nc++;
             }
         }
         return n;
     }
     @Override
     public void dispose() {
         dispose(this);
     }
     static class NameImpl extends Name {
         /** The next name occupying the same hash bucket.
          */
         NameImpl next;
         /** The index where the bytes of this name are stored in the global name
          *  buffer `byte'.
          */
         int index;
         /** The number of bytes in this name.
          */
         int length;
         NameImpl(SharedNameTable table) {
             super(table);
         }
         @Override
         public int getIndex() {
             return index;
         }
         @Override
         public int getByteLength() {
             return length;
         }
         @Override
         public byte getByteAt(int i) {
             return getByteArray()[index + i];
         }
         @Override
         public byte[] getByteArray() {
             return ((SharedNameTable) table).bytes;
         }
         @Override
         public int getByteOffset() {
             return index;
         }
         /** Return the hash value of this name.
          */
         public int hashCode() {
             return index;
         }
         /** Is this name equal to other?
          */
         public boolean equals(Object other) {
             if (other instanceof Name)
                 return
                     table == ((Name)other).table && index == ((Name) other).getIndex();
             else return false;
         }
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/com/sun/tools/javac/util/SharedNameTable.java@24a47c3062fe (annotated)

src/share/classes/com/sun/tools/javac/util/SharedNameTable.java