jdk8-mips64-public/langtools: comparison src/share/classes/com/sun/tools/javac/util/SharedNameTable.java

-:7e2249b1c13d
+:eff38cc97183
+/*
+* Copyright 1999-2006 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 / file comparison

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

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