com.sun.jdo.api.persistence.enhancer.classfile.InsnReadEnv Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of payara-micro Show documentation
Show all versions of payara-micro Show documentation
Micro Distribution of the Payara Project
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.jdo.api.persistence.enhancer.classfile;
/**
* Environment for decoding byte codes into instructions
*/
class InsnReadEnv {
/* The parent method environment */
private CodeEnv codeEnv;
/* The byte codes to be decoded */
private byte[] byteCodes;
/* The index into byteCodes for the next instruction to be decoded */
private int currPc;
/**
* Constructor
*/
InsnReadEnv(byte[] bytes, CodeEnv codeEnv) {
this.byteCodes = bytes;
this.currPc = 0;
this.codeEnv = codeEnv;
}
/**
* Return the index of the next instruction to decode
*/
int currentPC() {
return currPc;
}
/**
* Are there more byte codes to decode?
*/
boolean more() {
return currPc < byteCodes.length;
}
/**
* Get a single byte from the byte code stream
*/
byte getByte() {
if (!more())
throw new InsnError("out of byte codes");//NOI18N
return byteCodes[currPc++];
}
/**
* Get a single unsigned byte from the byte code stream
*/
int getUByte() {
return getByte() & 0xff;
}
/**
* Get a short from the byte code stream
*/
int getShort() {
byte byte1 = byteCodes[currPc++];
byte byte2 = byteCodes[currPc++];
return (byte1 << 8) | (byte2 & 0xff);
}
/**
* Get an unsigned short from the byte code stream
*/
int getUShort() {
return getShort() & 0xffff;
}
/**
* Get an int from the byte code stream
*/
int getInt() {
byte byte1 = byteCodes[currPc++];
byte byte2 = byteCodes[currPc++];
byte byte3 = byteCodes[currPc++];
byte byte4 = byteCodes[currPc++];
return (byte1 << 24) | ((byte2 & 0xff) << 16) |
((byte3 & 0xff) << 8) | (byte4 & 0xff);
}
/**
* Get the constant pool which applies to the method being decoded
*/
ConstantPool pool() {
return codeEnv.pool();
}
/**
* Get the canonical InsnTarget instance for the specified
* pc within the method.
*/
InsnTarget getTarget(int targ) {
return codeEnv.getTarget(targ);
}
}