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

src/share/classes/com/sun/tools/javac/util/UnsharedNameTable.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

jjg@113	1	/*
xdono@117	2	* Copyright 1999-2008 Sun Microsystems, Inc. All Rights Reserved.
jjg@113	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jjg@113	4	*
jjg@113	5	* This code is free software; you can redistribute it and/or modify it
jjg@113	6	* under the terms of the GNU General Public License version 2 only, as
jjg@113	7	* published by the Free Software Foundation. Sun designates this
jjg@113	8	* particular file as subject to the "Classpath" exception as provided
jjg@113	9	* by Sun in the LICENSE file that accompanied this code.
jjg@113	10	*
jjg@113	11	* This code is distributed in the hope that it will be useful, but WITHOUT
jjg@113	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jjg@113	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
jjg@113	14	* version 2 for more details (a copy is included in the LICENSE file that
jjg@113	15	* accompanied this code).
jjg@113	16	*
jjg@113	17	* You should have received a copy of the GNU General Public License version
jjg@113	18	* 2 along with this work; if not, write to the Free Software Foundation,
jjg@113	19	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jjg@113	20	*
jjg@113	21	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
jjg@113	22	* CA 95054 USA or visit www.sun.com if you need additional information or
jjg@113	23	* have any questions.
jjg@113	24	*/
jjg@113	25
jjg@113	26	package com.sun.tools.javac.util;
jjg@113	27
jjg@113	28	import java.lang.ref.WeakReference;
jjg@113	29
jjg@113	30	/**
jjg@113	31	* Implementation of Name.Table that stores names in individual arrays
jjg@113	32	* using weak references. It is recommended for use when a single shared
jjg@113	33	* byte array is unsuitable.
jjg@113	34	*
jjg@113	35	* <p><b>This is NOT part of any API supported by Sun Microsystems. If
jjg@113	36	* you write code that depends on this, you do so at your own risk.
jjg@113	37	* This code and its internal interfaces are subject to change or
jjg@113	38	* deletion without notice.</b>
jjg@113	39	*/
jjg@113	40	public class UnsharedNameTable extends Name.Table {
jjg@113	41	static public Name.Table create(Names names) {
jjg@113	42	return new UnsharedNameTable(names);
jjg@113	43	}
jjg@113	44
jjg@113	45	static class HashEntry extends WeakReference<NameImpl> {
jjg@113	46	HashEntry next;
jjg@113	47	HashEntry(NameImpl referent) {
jjg@113	48	super(referent);
jjg@113	49	}
jjg@113	50	}
jjg@113	51
jjg@113	52	/** The hash table for names.
jjg@113	53	*/
jjg@113	54	private HashEntry[] hashes = null;
jjg@113	55
jjg@113	56	/** The mask to be used for hashing
jjg@113	57	*/
jjg@113	58	private int hashMask;
jjg@113	59
jjg@113	60	/** Index counter for names in this table.
jjg@113	61	*/
jjg@113	62	public int index;
jjg@113	63
jjg@113	64	/** Allocator
jjg@113	65	* @param names The main name table
jjg@113	66	* @param hashSize the (constant) size to be used for the hash table
jjg@113	67	* needs to be a power of two.
jjg@113	68	*/
jjg@113	69	public UnsharedNameTable(Names names, int hashSize) {
jjg@113	70	super(names);
jjg@113	71	hashMask = hashSize - 1;
jjg@113	72	hashes = new HashEntry[hashSize];
jjg@113	73	}
jjg@113	74
jjg@113	75	public UnsharedNameTable(Names names) {
jjg@113	76	this(names, 0x8000);
jjg@113	77	}
jjg@113	78
jjg@113	79
jjg@113	80	@Override
jjg@113	81	public Name fromChars(char[] cs, int start, int len) {
jjg@113	82	byte[] name = new byte[len * 3];
jjg@113	83	int nbytes = Convert.chars2utf(cs, start, name, 0, len);
jjg@113	84	return fromUtf(name, 0, nbytes);
jjg@113	85	}
jjg@113	86
jjg@113	87	@Override
jjg@113	88	public Name fromUtf(byte[] cs, int start, int len) {
jjg@113	89	int h = hashValue(cs, start, len) & hashMask;
jjg@113	90
jjg@113	91	HashEntry element = hashes[h];
jjg@113	92
jjg@113	93	NameImpl n = null;
jjg@113	94
jjg@113	95	HashEntry previousNonNullTableEntry = null;
jjg@113	96	HashEntry firstTableEntry = element;
jjg@113	97
jjg@113	98	while (element != null) {
jjg@113	99	if (element == null) {
jjg@113	100	break;
jjg@113	101	}
jjg@113	102
jjg@113	103	n = element.get();
jjg@113	104
jjg@113	105	if (n == null) {
jjg@113	106	if (firstTableEntry == element) {
jjg@113	107	hashes[h] = firstTableEntry = element.next;
jjg@113	108	}
jjg@113	109	else {
jjg@113	110	assert previousNonNullTableEntry != null : "previousNonNullTableEntry cannot be null here.";
jjg@113	111	previousNonNullTableEntry.next = element.next;
jjg@113	112	}
jjg@113	113	}
jjg@113	114	else {
jjg@113	115	if (n.getByteLength() == len && equals(n.bytes, 0, cs, start, len)) {
jjg@113	116	return n;
jjg@113	117	}
jjg@113	118	previousNonNullTableEntry = element;
jjg@113	119	}
jjg@113	120
jjg@113	121	element = element.next;
jjg@113	122	}
jjg@113	123
jjg@113	124	byte[] bytes = new byte[len];
jjg@113	125	System.arraycopy(cs, start, bytes, 0, len);
jjg@113	126	n = new NameImpl(this, bytes, index++);
jjg@113	127
jjg@113	128	System.arraycopy(cs, start, n.bytes, 0, len);
jjg@113	129
jjg@113	130	HashEntry newEntry = new HashEntry(n);
jjg@113	131
jjg@113	132	if (previousNonNullTableEntry == null) { // We are not the first name with that hashCode.
jjg@113	133	hashes[h] = newEntry;
jjg@113	134	}
jjg@113	135	else {
jjg@113	136	assert previousNonNullTableEntry.next == null : "previousNonNullTableEntry.next must be null.";
jjg@113	137	previousNonNullTableEntry.next = newEntry;
jjg@113	138	}
jjg@113	139
jjg@113	140	return n;
jjg@113	141	}
jjg@113	142
jjg@113	143	@Override
jjg@113	144	public void dispose() {
jjg@113	145	hashes = null;
jjg@113	146	}
jjg@113	147
jjg@113	148	static class NameImpl extends Name {
jjg@113	149	NameImpl(UnsharedNameTable table, byte[] bytes, int index) {
jjg@113	150	super(table);
jjg@113	151	this.bytes = bytes;
jjg@113	152	this.index = index;
jjg@113	153	}
jjg@113	154
jjg@113	155	final byte[] bytes;
jjg@113	156	final int index;
jjg@113	157
jjg@113	158	@Override
jjg@113	159	public int getIndex() {
jjg@113	160	return index;
jjg@113	161	}
jjg@113	162
jjg@113	163	@Override
jjg@113	164	public int getByteLength() {
jjg@113	165	return bytes.length;
jjg@113	166	}
jjg@113	167
jjg@113	168	@Override
jjg@113	169	public byte getByteAt(int i) {
jjg@113	170	return bytes[i];
jjg@113	171	}
jjg@113	172
jjg@113	173	@Override
jjg@113	174	public byte[] getByteArray() {
jjg@113	175	return bytes;
jjg@113	176	}
jjg@113	177
jjg@113	178	@Override
jjg@113	179	public int getByteOffset() {
jjg@113	180	return 0;
jjg@113	181	}
jjg@113	182
jjg@113	183	}
jjg@113	184
jjg@113	185	}