/**
* Constructor. Initialises the servlet, reading the ontology model from static files and creating
* a cleaner thread that removes obsolete sessions.
*/
public LiberServletImpl() {
System.out.println("Starting up");
try {
ontology = new OntologyReader(); // reads PolicyGrid ontologies
// ontology = new GeographyOntologyReader(); //reads geography ontology
clean =
new TimerTask() {
public void run() { // Removes obsolete sessions from the map, running every 10 min.
long time = new GregorianCalendar().getTimeInMillis();
synchronized (userMap) {
Iterator it = userMap.keySet().iterator();
List<String> obsolete = new ArrayList<String>();
while (it.hasNext()) {
String key = (String) it.next();
long timeDif = time - userMap.get(key).getLastUpdated();
if ((timeDif < 0)
|| (timeDif > 3600000)) // if an hour has lapsed, or the next day has started
obsolete.add(key); // (let's just hope no-one starts using the tool at midnight)
}
for (int i = 0; i < obsolete.size(); i++) // then remove that session
userMap.remove(obsolete.get(i));
}
}
};
Timer timer = new Timer();
timer.schedule(clean, 0, 600000);
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Creates a new session for the editing tool.
*
* @param user user id
* @param project Project ID
* @param resource Resource ID
* @return String[] with user id and name
*/
public String[] newSession(String user, String project, String resource) {
try {
LiberSession session = new LiberSession(ontology, user, project, resource, LiberSession.EDIT);
userMap.put(user, session);
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
return session.getUserDetails();
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* Called when the users asks to show or hide all known information about a certain object from
* the database.
*
* @param user User ID
* @param anchor Unique ID of Anchor
* @param show If true, show more information, if false, hide information
* @param type Session type (edit, query, browse)
* @param key browsing session id (null if session type is EDIT)
* @return AnchorInfo[] with serialisable version of feedback text, empty if the user's session is
* expired or null if an error occurred
*/
public AnchorInfo[] changeTextContent(
String user, String anchor, boolean show, int type, String key) {
if (!userMap.containsKey(user)) return new AnchorInfo[0];
LiberSession session = userMap.get(user);
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
synchronized (session) {
session.setLastUpdated();
return session.changeTextContent(anchor, show, type, key);
}
}
/**
* Ends this particular session. If it's a browsing session, the browsing generator is removed;
* otherwise, the entire user's session can be removed.
*
* @param user user id
* @param type type of session
* @param key browsing session id (null if session type is EDIT)
*/
public void endSession(String user, int type, String key) {
if (!userMap.containsKey(user)) return;
if (type == LiberSession.BROWSE) {
LiberSession session = userMap.get(user);
synchronized (session) {
session.removeBrowsingGenerator(key);
}
} else {
if (type == LiberSession.QUERY) userMap.get(user).printQueryTimes();
userMap.remove(user);
}
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
}
/**
* Initialises a new editing session.
*
* @param user user id
* @param data Data provided about resource
* @return AnchorInfo[] containing the feedback text.
*/
public AnchorInfo[] initSession(String user, InstanceData data) {
try {
LiberSession session = userMap.get(user);
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
synchronized (session) {
session.setLastUpdated();
return session.init(data); // initialise the session and return the text
}
} catch (Exception e) {
e.printStackTrace();
return new AnchorInfo[0];
}
}
/**
* Initialises a new query session, and returns the class hierarchy. This hierarchy is special
* because it includes the number of instances of each type.
*
* @param user user id
* @param roots root classes of the hierarchy (null to get complete hierarchy)
* @return Hierarchy[] containing class hierarchy
*/
public Hierarchy[] initSessionAndGetClassHierarchy(String user, String[] roots) {
try {
if (userMap.containsKey(user)) userMap.get(user).setLastUpdated();
else userMap.put(user, new LiberSession(ontology, user, null, null, LiberSession.QUERY));
LiberSession session = userMap.get(user);
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
synchronized (session) {
return session.getCountedClassHierarchy(roots);
}
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static void fullGC(boolean verbose) {
if (verbose)
System.out.print(
new Date().toString()
+ ' '
+ String.valueOf((RUNTIME.totalMemory() - RUNTIME.freeMemory()) / 1024L)
+ "Kb used");
long isFree = RUNTIME.freeMemory();
long wasFree;
do {
wasFree = isFree;
RUNTIME.runFinalization();
RUNTIME.gc();
isFree = RUNTIME.freeMemory();
} while (isFree > wasFree);
if (verbose)
System.out.println(
" --> "
+ String.valueOf((RUNTIME.totalMemory() - RUNTIME.freeMemory()) / 1024L)
+ "Kb used");
}
/**
* Initialises a new browsing session, creating a new session for this user.
*
* @param user user id
* @param resource Resource id
* @param type Type of session (edit, query, browse)
* @return AnchorInfo[] containing the feedback text.
*/
public AnchorInfo[] initSession(String user, String resource, int type) {
try {
if (type == LiberSession.BROWSE) // make a new user session if this is the browse tab
userMap.put(
user, new LiberSession(ontology, user, null, resource.replaceAll("\"", ""), type));
else if (!userMap.containsKey(user)) return null;
LiberSession session = userMap.get(user);
Runtime r = Runtime.getRuntime();
r.gc(); // FORCES GARBAGE COLLECTION
r.runFinalization();
synchronized (session) {
session.setLastUpdated();
return session.init(
resource.replaceAll("\"", "")); // initialise the session and return the text
}
} catch (Exception e) {
e.printStackTrace();
return new AnchorInfo[0];
}
}
/**
* Performs intraprocedural BLOAT on a program's live methods.
*
* @param liveMethods Should be alphabetized. This way we can commit a class once we've BLOATed
* all of its methods.
*/
private static void intraBloat(final Collection liveMethods, final BloatContext context) {
ClassEditor prevClass = null;
final Iterator iter = liveMethods.iterator();
for (int count = 0; iter.hasNext(); count++) {
MethodEditor live = null;
ClassEditor ce = null; // Hack to make sure commit happens
try {
live = context.editMethod((MemberRef) iter.next());
ce = context.editClass(live.declaringClass().classInfo());
} catch (final NoSuchMethodException ex3) {
BloatBenchmark.err.println("** Could not find method " + ex3.getMessage());
System.exit(1);
}
/* So we can skip classes or packages */
final String name = ce.type().className();
final String qual = ce.type().qualifier() + "/*";
boolean skip = false;
for (int i = 0; i < BloatBenchmark.SKIP.size(); i++) {
final String pkg = (String) BloatBenchmark.SKIP.get(i);
if (name.equals(pkg) || qual.equals(pkg)) {
skip = true;
break;
}
}
if (context.ignoreMethod(live.memberRef()) || skip) {
// Don't display ignored methods, it's misleading.
context.release(live.methodInfo());
continue;
}
final Runtime runtime = Runtime.getRuntime();
runtime.gc();
final Date start = new Date();
BloatBenchmark.tr(
" " + count + ") " + live.declaringClass().name() + "." + live.name() + live.type());
BloatBenchmark.tr(" Start: " + start);
try {
EDU.purdue.cs.bloat.optimize.Main.TRACE = BloatBenchmark.TRACE;
if (!BloatBenchmark.VERIFY) {
EDU.purdue.cs.bloat.optimize.Main.VERIFY = false;
}
EDU.purdue.cs.bloat.optimize.Main.bloatMethod(live, context);
} catch (final Exception oops) {
BloatBenchmark.err.println("******************************************");
BloatBenchmark.err.println(
"Exception while BLOATing "
+ live.declaringClass().name()
+ "."
+ live.name()
+ live.type());
BloatBenchmark.err.println(oops.getMessage());
oops.printStackTrace(System.err);
BloatBenchmark.err.println("******************************************");
}
// Commit here in an attempt to conserve memory
context.commit(live.methodInfo());
context.release(live.methodInfo());
if (prevClass == null) {
prevClass = ce;
} else if (!prevClass.equals(ce)) {
// We've finished BLOATed the methods for prevClass, commit
// prevClass and move on
BloatBenchmark.tr(prevClass.type() + " != " + ce.type());
context.commit(prevClass.classInfo());
context.release(prevClass.classInfo());
// context.commitDirty();
// tr(context.toString());
prevClass = ce;
} else {
context.release(ce.classInfo());
}
final Date end = new Date();
BloatBenchmark.tr(" Ellapsed time: " + (end.getTime() - start.getTime()) + " ms");
}
context.commitDirty();
}
