/*
* FindBugs - Find bugs in Java programs
* Copyright (C) 2004-2006 University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs.detect;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import org.apache.bcel.classfile.Constant;
import org.apache.bcel.classfile.ConstantString;
import org.apache.bcel.classfile.ConstantValue;
import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.IntAnnotation;
import edu.umd.cs.findbugs.ba.XFactory;
import edu.umd.cs.findbugs.ba.XField;
public class HugeSharedStringConstants extends BytecodeScanningDetector {
/**
*
*/
private static final int SIZE_OF_HUGE_CONSTANT = 500;
String getStringKey(String s) {
return s.length() + ":" + s.hashCode();
}
HashMap<String, SortedSet<String>> map = new HashMap<String, SortedSet<String>>();
HashMap<String, XField> definition = new HashMap<String, XField>();
HashMap<String, Integer> stringSize = new HashMap<String, Integer>();
BugReporter bugReporter;
public HugeSharedStringConstants(BugReporter bugReporter) {
this.bugReporter = bugReporter;
}
@Override
public void visit(ConstantString s) {
String value = s.getBytes(getConstantPool());
if (value.length() < SIZE_OF_HUGE_CONSTANT) {
return;
}
String key = getStringKey(value);
SortedSet<String> set = map.get(key);
if (set == null) {
set = new TreeSet<String>();
map.put(key, set);
}
set.add(getDottedClassName());
}
@Override
public void visit(ConstantValue s) {
if (!visitingField()) {
return;
}
int i = s.getConstantValueIndex();
Constant c = getConstantPool().getConstant(i);
if (c instanceof ConstantString) {
String value = ((ConstantString) c).getBytes(getConstantPool());
if (value.length() < SIZE_OF_HUGE_CONSTANT) {
return;
}
String key = getStringKey(value);
definition.put(key, XFactory.createXField(this));
stringSize.put(key, value.length());
}
}
@Override
public void report() {
for (Map.Entry<String, SortedSet<String>> e : map.entrySet()) {
Set<String> occursIn = e.getValue();
if (occursIn.size() == 1) {
continue;
}
XField field = definition.get(e.getKey());
if (field == null) {
continue;
}
Integer length = stringSize.get(e.getKey());
int overhead = length * (occursIn.size() - 1);
if (overhead < 3 * SIZE_OF_HUGE_CONSTANT) {
continue;
}
String className = field.getClassName();
BugInstance bug = new BugInstance(this, "HSC_HUGE_SHARED_STRING_CONSTANT",
overhead > 20 * SIZE_OF_HUGE_CONSTANT ? HIGH_PRIORITY
: (overhead > 8 * SIZE_OF_HUGE_CONSTANT ? NORMAL_PRIORITY : LOW_PRIORITY)).addClass(className)
.addField(field).addInt(length).addInt(occursIn.size()).describe(IntAnnotation.INT_OCCURRENCES);
for (String c : occursIn) {
if (!c.equals(className)) {
bug.addClass(c);
}
}
bugReporter.reportBug(bug);
}
}
}