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src/share/classes/com/sun/tools/javac/util/UnsharedNameTable.java@93012e2a5d1d (annotated)

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

Sat, 07 Nov 2020 10:30:02 +0800

author

aoqi

date

Sat, 07 Nov 2020 10:30:02 +0800

changeset 3938

93012e2a5d1d

parent 2525

2eb010b6cb22

permissions

-rw-r--r--

Added tag mips-jdk8u275-b01 for changeset eb6ee6a5f2fe

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation. Oracle designates this
aoqi@0	8	* particular file as subject to the "Classpath" exception as provided
aoqi@0	9	* by Oracle in the LICENSE file that accompanied this code.
aoqi@0	10	*
aoqi@0	11	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	14	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	15	* accompanied this code).
aoqi@0	16	*
aoqi@0	17	* You should have received a copy of the GNU General Public License version
aoqi@0	18	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	19	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	20	*
aoqi@0	21	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	22	* or visit www.oracle.com if you need additional information or have any
aoqi@0	23	* questions.
aoqi@0	24	*/
aoqi@0	25
aoqi@0	26	package com.sun.tools.javac.util;
aoqi@0	27
aoqi@0	28	import java.lang.ref.WeakReference;
aoqi@0	29
aoqi@0	30	/**
aoqi@0	31	* Implementation of Name.Table that stores names in individual arrays
aoqi@0	32	* using weak references. It is recommended for use when a single shared
aoqi@0	33	* byte array is unsuitable.
aoqi@0	34	*
aoqi@0	35	* <p><b>This is NOT part of any supported API.
aoqi@0	36	* If you write code that depends on this, you do so at your own risk.
aoqi@0	37	* This code and its internal interfaces are subject to change or
aoqi@0	38	* deletion without notice.</b>
aoqi@0	39	*/
aoqi@0	40	public class UnsharedNameTable extends Name.Table {
aoqi@0	41	static public Name.Table create(Names names) {
aoqi@0	42	return new UnsharedNameTable(names);
aoqi@0	43	}
aoqi@0	44
aoqi@0	45	static class HashEntry extends WeakReference<NameImpl> {
aoqi@0	46	HashEntry next;
aoqi@0	47	HashEntry(NameImpl referent) {
aoqi@0	48	super(referent);
aoqi@0	49	}
aoqi@0	50	}
aoqi@0	51
aoqi@0	52	/** The hash table for names.
aoqi@0	53	*/
aoqi@0	54	private HashEntry[] hashes = null;
aoqi@0	55
aoqi@0	56	/** The mask to be used for hashing
aoqi@0	57	*/
aoqi@0	58	private int hashMask;
aoqi@0	59
aoqi@0	60	/** Index counter for names in this table.
aoqi@0	61	*/
aoqi@0	62	public int index;
aoqi@0	63
aoqi@0	64	/** Allocator
aoqi@0	65	* @param names The main name table
aoqi@0	66	* @param hashSize the (constant) size to be used for the hash table
aoqi@0	67	* needs to be a power of two.
aoqi@0	68	*/
aoqi@0	69	public UnsharedNameTable(Names names, int hashSize) {
aoqi@0	70	super(names);
aoqi@0	71	hashMask = hashSize - 1;
aoqi@0	72	hashes = new HashEntry[hashSize];
aoqi@0	73	}
aoqi@0	74
aoqi@0	75	public UnsharedNameTable(Names names) {
aoqi@0	76	this(names, 0x8000);
aoqi@0	77	}
aoqi@0	78
aoqi@0	79
aoqi@0	80	@Override
aoqi@0	81	public Name fromChars(char[] cs, int start, int len) {
aoqi@0	82	byte[] name = new byte[len * 3];
aoqi@0	83	int nbytes = Convert.chars2utf(cs, start, name, 0, len);
aoqi@0	84	return fromUtf(name, 0, nbytes);
aoqi@0	85	}
aoqi@0	86
aoqi@0	87	@Override
aoqi@0	88	public Name fromUtf(byte[] cs, int start, int len) {
aoqi@0	89	int h = hashValue(cs, start, len) & hashMask;
aoqi@0	90
aoqi@0	91	HashEntry element = hashes[h];
aoqi@0	92
aoqi@0	93	NameImpl n = null;
aoqi@0	94
aoqi@0	95	HashEntry previousNonNullTableEntry = null;
aoqi@0	96	HashEntry firstTableEntry = element;
aoqi@0	97
aoqi@0	98	while (element != null) {
aoqi@0	99	if (element == null) {
aoqi@0	100	break;
aoqi@0	101	}
aoqi@0	102
aoqi@0	103	n = element.get();
aoqi@0	104
aoqi@0	105	if (n == null) {
aoqi@0	106	if (firstTableEntry == element) {
aoqi@0	107	hashes[h] = firstTableEntry = element.next;
aoqi@0	108	}
aoqi@0	109	else {
aoqi@0	110	Assert.checkNonNull(previousNonNullTableEntry, "previousNonNullTableEntry cannot be null here.");
aoqi@0	111	previousNonNullTableEntry.next = element.next;
aoqi@0	112	}
aoqi@0	113	}
aoqi@0	114	else {
aoqi@0	115	if (n.getByteLength() == len && equals(n.bytes, 0, cs, start, len)) {
aoqi@0	116	return n;
aoqi@0	117	}
aoqi@0	118	previousNonNullTableEntry = element;
aoqi@0	119	}
aoqi@0	120
aoqi@0	121	element = element.next;
aoqi@0	122	}
aoqi@0	123
aoqi@0	124	byte[] bytes = new byte[len];
aoqi@0	125	System.arraycopy(cs, start, bytes, 0, len);
aoqi@0	126	n = new NameImpl(this, bytes, index++);
aoqi@0	127
aoqi@0	128	HashEntry newEntry = new HashEntry(n);
aoqi@0	129
aoqi@0	130	if (previousNonNullTableEntry == null) { // We are not the first name with that hashCode.
aoqi@0	131	hashes[h] = newEntry;
aoqi@0	132	}
aoqi@0	133	else {
aoqi@0	134	Assert.checkNull(previousNonNullTableEntry.next, "previousNonNullTableEntry.next must be null.");
aoqi@0	135	previousNonNullTableEntry.next = newEntry;
aoqi@0	136	}
aoqi@0	137
aoqi@0	138	return n;
aoqi@0	139	}
aoqi@0	140
aoqi@0	141	@Override
aoqi@0	142	public void dispose() {
aoqi@0	143	hashes = null;
aoqi@0	144	}
aoqi@0	145
aoqi@0	146	static class NameImpl extends Name {
aoqi@0	147	NameImpl(UnsharedNameTable table, byte[] bytes, int index) {
aoqi@0	148	super(table);
aoqi@0	149	this.bytes = bytes;
aoqi@0	150	this.index = index;
aoqi@0	151	}
aoqi@0	152
aoqi@0	153	final byte[] bytes;
aoqi@0	154	final int index;
aoqi@0	155
aoqi@0	156	@Override
aoqi@0	157	public int getIndex() {
aoqi@0	158	return index;
aoqi@0	159	}
aoqi@0	160
aoqi@0	161	@Override
aoqi@0	162	public int getByteLength() {
aoqi@0	163	return bytes.length;
aoqi@0	164	}
aoqi@0	165
aoqi@0	166	@Override
aoqi@0	167	public byte getByteAt(int i) {
aoqi@0	168	return bytes[i];
aoqi@0	169	}
aoqi@0	170
aoqi@0	171	@Override
aoqi@0	172	public byte[] getByteArray() {
aoqi@0	173	return bytes;
aoqi@0	174	}
aoqi@0	175
aoqi@0	176	@Override
aoqi@0	177	public int getByteOffset() {
aoqi@0	178	return 0;
aoqi@0	179	}
aoqi@0	180
aoqi@0	181	}
aoqi@0	182
aoqi@0	183	}