org.openide.loaders.FilesSet Maven / Gradle / Ivy
/*
* Sun Public License Notice
*
* The contents of this file are subject to the Sun Public License
* Version 1.0 (the "License"). You may not use this file except in
* compliance with the License. A copy of the License is available at
* http://www.sun.com/
*
* The Original Code is NetBeans. The Initial Developer of the Original
* Code is Sun Microsystems, Inc. Portions Copyright 1997-2003 Sun
* Microsystems, Inc. All Rights Reserved.
*/
package org.openide.loaders;
import java.util.*;
import org.openide.filesystems.FileObject;
/** This class is a lazy initialized set of FileObjects representing entries
* in MultiDataObject class. Primary file object is returned as the first from
* this set, the secondary fileobjects are sorted by getNameExt()
* method result alphabetically.
*
* This class is an implementation of performance enhancement #16396.
*
* @see Issue #16396
*
* @author Petr Hamernik
*/
final class FilesSet implements Set {
/** MDO which created this set */
private MultiDataObject mymdo;
/** A flag */
private boolean lazyWorkDone;
/** Primary file. It is returned first. */
private Object primaryFile;
/** The link to secondary variable of MultiDataObject. Reading of the content
* must be synchronized on this map.
*/
private HashMap secondary;
/** The set containing all files. It is null and is lazy initialized
* when necessary.
*/
private TreeSet delegate;
/** Creates a new instance of FilesSet for the MultiDataObject.
* @param primaryFile The primary file - this object is returned first.
* @param secondary the map of secondary file objects. It is used
* for initialization delegate variable when necessary.
*/
public FilesSet(MultiDataObject mdo) {
this.mymdo = mdo;
this.lazyWorkDone = false;
this.primaryFile = null;
this.secondary = null;
}
/** Does the work which was originaly done in MDO.files() method. */
private void doLazyWork() {
synchronized (this) {
if (!lazyWorkDone) {
lazyWorkDone = true;
synchronized ( mymdo.synchObjectSecondary() ) {
mymdo.removeAllInvalid ();
primaryFile = mymdo.getPrimaryFile();
secondary = mymdo.getSecondary();
}
}
}
}
/** Perform lazy initialization of delegate TreeSet.
*/
private Set getDelegate() {
doLazyWork();
// This synchronized block was moved from MultiDataObject.files() method,
// because of lazy initialization of delegate TreeSet.
// Hopefully won't cause threading problems.
synchronized (secondary) {
if (delegate == null) {
delegate = new TreeSet(new FilesComparator());
delegate.add(primaryFile);
delegate.addAll(secondary.keySet());
}
}
return delegate;
}
// =====================================================================
// Implementation of Set interface methods
// =====================================================================
public boolean add(Object obj) {
return getDelegate().add(obj);
}
public boolean addAll(java.util.Collection collection) {
return getDelegate().addAll(collection);
}
public void clear() {
getDelegate().clear();
}
public boolean contains(Object obj) {
return getDelegate().contains(obj);
}
public boolean containsAll(java.util.Collection collection) {
return getDelegate().containsAll(collection);
}
public boolean isEmpty() {
doLazyWork();
synchronized (secondary) {
return (delegate == null) ? false : delegate.isEmpty();
}
}
public java.util.Iterator iterator() {
doLazyWork();
synchronized (secondary) {
return (delegate == null) ? new FilesIterator() : delegate.iterator();
}
}
public boolean remove(Object obj) {
return getDelegate().remove(obj);
}
public boolean removeAll(java.util.Collection collection) {
return getDelegate().removeAll(collection);
}
public boolean retainAll(java.util.Collection collection) {
return getDelegate().retainAll(collection);
}
public int size() {
doLazyWork();
synchronized (secondary) {
return (delegate == null) ? (secondary.size() + 1) : delegate.size();
}
}
public Object[] toArray() {
return getDelegate().toArray();
}
public Object[] toArray(Object[] obj) {
return getDelegate().toArray(obj);
}
/** Iterator for FilesSet. It returns the primaryFile first and
* then initialize the delegate iterator for secondary files.
*/
private final class FilesIterator implements Iterator {
/** Was the first element (primary file) already returned?
*/
private boolean first = true;
/** Delegation iterator for secondary files. It is lazy initialized after
* the first element is returned.
*/
private Iterator itDelegate = null;
FilesIterator() {}
public boolean hasNext() {
return first ? true : getIteratorDelegate().hasNext();
}
public Object next() {
if (first) {
first = false;
return FilesSet.this.primaryFile;
}
else {
return getIteratorDelegate().next();
}
}
public void remove() {
getIteratorDelegate().remove();
}
/** Initialize the delegation iterator.
*/
private Iterator getIteratorDelegate() {
if (itDelegate == null) {
// this should return iterator of all files of the MultiDataObject...
itDelegate = FilesSet.this.getDelegate().iterator();
// ..., so it is necessary to skip the primary file
itDelegate.next();
}
return itDelegate;
}
}
/** Comparator for file objects. The primary file is less than any other file,
* so it is returned first. Other files are compared by getNameExt() method
* result.
*/
private final class FilesComparator implements Comparator {
FilesComparator() {}
public int compare(Object obj1, Object obj2) {
if (obj1 == obj2)
return 0;
if (obj1 == primaryFile)
return -1;
if (obj2 == primaryFile)
return 1;
FileObject f1 = (FileObject) obj1;
FileObject f2 = (FileObject) obj2;
int res = f1.getNameExt().compareTo(f2.getNameExt());
if (res == 0) {
// check whether they both live on the same fs
try {
if (f1.getFileSystem() == f2.getFileSystem()) {
return 0;
}
// different fs --> compare the fs names
return f1.getFileSystem().getSystemName().compareTo(
f2.getFileSystem().getSystemName());
} catch (org.openide.filesystems.FileStateInvalidException fsie) {
// should not happen - but the names were the same
// so we declare they are the same (even if the filesystems
// crashed meanwhile)
return 0;
}
}
return res;
}
}
}