/* This file is part of the db4o object database http://www.db4o.com
Copyright (C) 2004 - 2011 Versant Corporation http://www.versant.com
db4o is free software; you can redistribute it and/or modify it under
the terms of version 3 of the GNU General Public License as published
by the Free Software Foundation.
db4o 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
for more details.
You should have received a copy of the GNU General Public License along
with this program. If not, see http://www.gnu.org/licenses/. */
package EDU.purdue.cs.bloat.file;
import java.io.*;
import EDU.purdue.cs.bloat.reflect.*;
/**
* LineNumberTable is an attribute of a code attribute. A LineNumberTable stores
* information that relates indices into the code array (instructions) to the
* lines of code in the source file from which they were compiled. This optional
* attribute is used with debuggers (<i>duh</i>) and consists of an array of
* <tt>reflect.LineNumberDebugInfo</tt>.
*
* @see Code
* @see EDU.purdue.cs.bloat.reflect.LineNumberDebugInfo
*
* @author Nate Nystrom (<a
* href="mailto:nystrom@cs.purdue.edu">nystrom@cs.purdue.edu</a>)
*/
public class LineNumberTable extends Attribute {
private LineNumberDebugInfo[] lineNumbers;
/**
* Constructor. Create an attribute from a data stream.
*
* @param in
* The data stream of the class file.
* @param nameIndex
* The index into the constant pool of the name of the attribute.
* @param length
* The length of the attribute, excluding the header.
* @exception IOException
* If an error occurs while reading.
*/
public LineNumberTable(final DataInputStream in, final int nameIndex,
final int length) throws IOException {
super(nameIndex, length);
final int numLines = in.readUnsignedShort();
lineNumbers = new LineNumberDebugInfo[numLines];
for (int i = 0; i < lineNumbers.length; i++) {
final int startPC = in.readUnsignedShort();
final int lineNumber = in.readUnsignedShort();
lineNumbers[i] = new LineNumberDebugInfo(startPC, lineNumber);
}
}
/**
* Get the line number debug info for the code.
*
* @return The line number debug info for the code.
*/
public LineNumberDebugInfo[] lineNumbers() {
return lineNumbers;
}
/**
* Set the line number debug info for the code.
*
* @param lineNumbers
* The line number debug info for the code.
*/
public void setLineNumbers(final LineNumberDebugInfo[] lineNumbers) {
this.lineNumbers = lineNumbers;
}
/**
* Get the length of the attribute.
*
* @return The length of the attribute.
*/
public int length() {
return 2 + lineNumbers.length * 4;
}
public String toString() {
String x = "(lines";
for (int i = 0; i < lineNumbers.length; i++) {
x += "\n (line #" + lineNumbers[i].lineNumber() + " pc="
+ lineNumbers[i].startPC() + ")";
}
return x + ")";
}
/**
* Write the attribute to a data stream.
*
* @param out
* The data stream of the class file.
* @exception IOException
* If an error occurs while writing.
*/
public void writeData(final DataOutputStream out) throws IOException {
out.writeShort(lineNumbers.length);
for (int i = 0; i < lineNumbers.length; i++) {
out.writeShort(lineNumbers[i].startPC());
out.writeShort(lineNumbers[i].lineNumber());
}
}
/**
* Private constructor used in cloning.
*/
private LineNumberTable(final LineNumberTable other) {
super(other.nameIndex, other.length);
this.lineNumbers = new LineNumberDebugInfo[other.lineNumbers.length];
for (int i = 0; i < other.lineNumbers.length; i++) {
this.lineNumbers[i] = (LineNumberDebugInfo) other.lineNumbers[i]
.clone();
}
}
public Object clone() {
return (new LineNumberTable(this));
}
}