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src/jdk/internal/dynalink/support/NameCodec.java@b1a7da25b547 (annotated)

src/jdk/internal/dynalink/support/NameCodec.java

Wed, 27 Apr 2016 01:36:41 +0800

author

aoqi

date

Wed, 27 Apr 2016 01:36:41 +0800

changeset 0

b1a7da25b547

child 962

ac62e33a99b0

permissions

-rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/nashorn/
changeset: 1034:4b9cc65dd24d
tag: jdk8u25-b17

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 2010, 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	/*
aoqi@0	27	* This file is available under and governed by the GNU General Public
aoqi@0	28	* License version 2 only, as published by the Free Software Foundation.
aoqi@0	29	* However, the following notice accompanied the original version of this
aoqi@0	30	* file, and Oracle licenses the original version of this file under the BSD
aoqi@0	31	* license:
aoqi@0	32	*/
aoqi@0	33	/*
aoqi@0	34	Copyright 2009-2013 Attila Szegedi
aoqi@0	35
aoqi@0	36	Licensed under both the Apache License, Version 2.0 (the "Apache License")
aoqi@0	37	and the BSD License (the "BSD License"), with licensee being free to
aoqi@0	38	choose either of the two at their discretion.
aoqi@0	39
aoqi@0	40	You may not use this file except in compliance with either the Apache
aoqi@0	41	License or the BSD License.
aoqi@0	42
aoqi@0	43	If you choose to use this file in compliance with the Apache License, the
aoqi@0	44	following notice applies to you:
aoqi@0	45
aoqi@0	46	You may obtain a copy of the Apache License at
aoqi@0	47
aoqi@0	48	http://www.apache.org/licenses/LICENSE-2.0
aoqi@0	49
aoqi@0	50	Unless required by applicable law or agreed to in writing, software
aoqi@0	51	distributed under the License is distributed on an "AS IS" BASIS,
aoqi@0	52	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
aoqi@0	53	implied. See the License for the specific language governing
aoqi@0	54	permissions and limitations under the License.
aoqi@0	55
aoqi@0	56	If you choose to use this file in compliance with the BSD License, the
aoqi@0	57	following notice applies to you:
aoqi@0	58
aoqi@0	59	Redistribution and use in source and binary forms, with or without
aoqi@0	60	modification, are permitted provided that the following conditions are
aoqi@0	61	met:
aoqi@0	62	* Redistributions of source code must retain the above copyright
aoqi@0	63	notice, this list of conditions and the following disclaimer.
aoqi@0	64	* Redistributions in binary form must reproduce the above copyright
aoqi@0	65	notice, this list of conditions and the following disclaimer in the
aoqi@0	66	documentation and/or other materials provided with the distribution.
aoqi@0	67	* Neither the name of the copyright holder nor the names of
aoqi@0	68	contributors may be used to endorse or promote products derived from
aoqi@0	69	this software without specific prior written permission.
aoqi@0	70
aoqi@0	71	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
aoqi@0	72	IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
aoqi@0	73	TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
aoqi@0	74	PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
aoqi@0	75	BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
aoqi@0	76	CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
aoqi@0	77	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
aoqi@0	78	BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
aoqi@0	79	WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
aoqi@0	80	OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
aoqi@0	81	ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
aoqi@0	82	*/
aoqi@0	83
aoqi@0	84	package jdk.internal.dynalink.support;
aoqi@0	85
aoqi@0	86	import jdk.internal.dynalink.CallSiteDescriptor;
aoqi@0	87
aoqi@0	88	/**
aoqi@0	89	* Implements the name mangling and demangling as specified by John Rose's
aoqi@0	90	* <a href="https://blogs.oracle.com/jrose/entry/symbolic_freedom_in_the_vm" target="_blank">"Symbolic Freedom in the
aoqi@0	91	* VM"</a> article. It is recommended that implementers of languages on the JVM uniformly adopt this for symbolic
aoqi@0	92	* interoperability between languages. Normally, you would mangle the names as you're generating bytecode, and then
aoqi@0	93	* demangle them when you're creating {@link CallSiteDescriptor} objects. Note that you are expected to mangle
aoqi@0	94	* individual tokens, and not the whole name at the call site, i.e. the colon character normally separating the tokens
aoqi@0	95	* is never mangled. I.e. you wouldn't mangle {@code dyn:getProp:color} into {@code dyn\!getProp\!color}, but you would
aoqi@0	96	* mangle {@code dyn:getProp:color$} into {@code dyn:getProp:\=color\%} (only mangling the individual token containing
aoqi@0	97	* the symbol {@code color$}). {@link CallSiteDescriptorFactory#tokenizeName(String)} (and by implication, all call site
aoqi@0	98	* descriptors it creates) will automatically perform demangling on the passed names. If you use this factory, or you
aoqi@0	99	* have your own way of creating call site descriptors, but you still delegate to this method of the default factory
aoqi@0	100	* (it is recommended that you do), then you have demangling handled for you already, and only need to ensure that you
aoqi@0	101	* mangle the names when you're emitting them in the bytecode.
aoqi@0	102	*
aoqi@0	103	* @author Attila Szegedi
aoqi@0	104	*/
aoqi@0	105	public class NameCodec {
aoqi@0	106	private static final char ESCAPE_CHAR = '\\';
aoqi@0	107	private static final char EMPTY_ESCAPE = '=';
aoqi@0	108	private static final String EMPTY_NAME = new String(new char[] { ESCAPE_CHAR, EMPTY_ESCAPE });
aoqi@0	109	private static final char EMPTY_CHAR = 0xFEFF;
aoqi@0	110
aoqi@0	111	private static final int MIN_ENCODING = '$';
aoqi@0	112	private static final int MAX_ENCODING = ']';
aoqi@0	113	private static final char[] ENCODING = new char[MAX_ENCODING - MIN_ENCODING + 1];
aoqi@0	114	private static final int MIN_DECODING = '!';
aoqi@0	115	private static final int MAX_DECODING = '}';
aoqi@0	116	private static final char[] DECODING = new char[MAX_DECODING - MIN_DECODING + 1];
aoqi@0	117
aoqi@0	118	static {
aoqi@0	119	addEncoding('/', '|');
aoqi@0	120	addEncoding('.', ',');
aoqi@0	121	addEncoding(';', '?');
aoqi@0	122	addEncoding('$', '%');
aoqi@0	123	addEncoding('<', '^');
aoqi@0	124	addEncoding('>', '_');
aoqi@0	125	addEncoding('[', '{');
aoqi@0	126	addEncoding(']', '}');
aoqi@0	127	addEncoding(':', '!');
aoqi@0	128	addEncoding('\\', '-');
aoqi@0	129	DECODING[EMPTY_ESCAPE - MIN_DECODING] = EMPTY_CHAR;
aoqi@0	130	}
aoqi@0	131
aoqi@0	132	private NameCodec() {
aoqi@0	133	}
aoqi@0	134
aoqi@0	135	/**
aoqi@0	136	* Encodes ("mangles") an unencoded symbolic name.
aoqi@0	137	* @param name the symbolic name to mangle
aoqi@0	138	* @return the mangled form of the symbolic name.
aoqi@0	139	*/
aoqi@0	140	public static String encode(String name) {
aoqi@0	141	final int l = name.length();
aoqi@0	142	if(l == 0) {
aoqi@0	143	return EMPTY_NAME;
aoqi@0	144	}
aoqi@0	145	StringBuilder b = null;
aoqi@0	146	int lastEscape = -1;
aoqi@0	147	for(int i = 0; i < l; ++i) {
aoqi@0	148	final int encodeIndex = name.charAt(i) - MIN_ENCODING;
aoqi@0	149	if(encodeIndex >= 0 && encodeIndex < ENCODING.length) {
aoqi@0	150	final char e = ENCODING[encodeIndex];
aoqi@0	151	if(e != 0) {
aoqi@0	152	if(b == null) {
aoqi@0	153	b = new StringBuilder(name.length() + 3);
aoqi@0	154	if(name.charAt(0) != ESCAPE_CHAR && i > 0) {
aoqi@0	155	b.append(EMPTY_NAME);
aoqi@0	156	}
aoqi@0	157	b.append(name, 0, i);
aoqi@0	158	} else {
aoqi@0	159	b.append(name, lastEscape + 1, i);
aoqi@0	160	}
aoqi@0	161	b.append(ESCAPE_CHAR).append(e);
aoqi@0	162	lastEscape = i;
aoqi@0	163	}
aoqi@0	164	}
aoqi@0	165	}
aoqi@0	166	if(b == null) {
aoqi@0	167	return name.toString();
aoqi@0	168	}
aoqi@0	169	assert lastEscape != -1;
aoqi@0	170	b.append(name, lastEscape + 1, l);
aoqi@0	171	return b.toString();
aoqi@0	172	}
aoqi@0	173
aoqi@0	174	/**
aoqi@0	175	* Decodes ("demangles") an encoded symbolic name.
aoqi@0	176	* @param name the symbolic name to demangle
aoqi@0	177	* @return the demangled form of the symbolic name.
aoqi@0	178	*/
aoqi@0	179	public static String decode(String name) {
aoqi@0	180	if(name.charAt(0) != ESCAPE_CHAR) {
aoqi@0	181	return name;
aoqi@0	182	}
aoqi@0	183	final int l = name.length();
aoqi@0	184	if(l == 2 && name.charAt(1) == EMPTY_CHAR) {
aoqi@0	185	return "";
aoqi@0	186	}
aoqi@0	187	StringBuilder b = new StringBuilder(name.length());
aoqi@0	188	int lastEscape = -2;
aoqi@0	189	int lastBackslash = -1;
aoqi@0	190	for(;;) {
aoqi@0	191	int nextBackslash = name.indexOf(ESCAPE_CHAR, lastBackslash + 1);
aoqi@0	192	if(nextBackslash == -1 || nextBackslash == l - 1) {
aoqi@0	193	break;
aoqi@0	194	}
aoqi@0	195	final int decodeIndex = name.charAt(nextBackslash + 1) - MIN_DECODING;
aoqi@0	196	if(decodeIndex >= 0 && decodeIndex < DECODING.length) {
aoqi@0	197	final char d = DECODING[decodeIndex];
aoqi@0	198	if(d == EMPTY_CHAR) {
aoqi@0	199	// "\=" is only valid at the beginning of a mangled string
aoqi@0	200	if(nextBackslash == 0) {
aoqi@0	201	lastEscape = 0;
aoqi@0	202	}
aoqi@0	203	} else if(d != 0) {
aoqi@0	204	b.append(name, lastEscape + 2, nextBackslash).append(d);
aoqi@0	205	lastEscape = nextBackslash;
aoqi@0	206	}
aoqi@0	207	}
aoqi@0	208	lastBackslash = nextBackslash;
aoqi@0	209	}
aoqi@0	210	b.append(name, lastEscape + 2, l);
aoqi@0	211	return b.toString();
aoqi@0	212	}
aoqi@0	213
aoqi@0	214	private static void addEncoding(char from, char to) {
aoqi@0	215	ENCODING[from - MIN_ENCODING] = to;
aoqi@0	216	DECODING[to - MIN_DECODING] = from;
aoqi@0	217	}
aoqi@0	218	}