Bug 136763 Performance improvements to BindingManager
Build id: I20060413-0010 One of our performance tests that still shows significant regression is opening editors. With profiling I found that 0.8% of that time is in Collections.unmodifiableMap(...) called by three methods in BindingManager. Another 0.15% is from instantiating new TrigerSequence[0] in three locations in BindingManager. In the first case, the creation of an immutable map is completely unnecessary - the methods are private, the maps are never exposed across API boundaries, and there is never any risk that the maps will be modified. The creation of empty TriggerSequence arrays can also be avoided with a singleton. I will attach a patch that collectively saves about 1% of the total editor startup time (elapsed time as measured by sampling profiler). These are very simple and safe fixes that I recommend considering for RC2.
bundles/org.eclipse.jface/src/org/eclipse/jface/bindings/BindingManager.java
* <p>
	 * Returns the active locale for this binding manager. The locale is in the
	 * same format as <code>Locale.getDefault().toString()</code>.
	 * </p>
	 * <p>
	 * This method completes in <code>O(1)</code>.
	 * </p>
	 * 
	 * @return The active locale; never <code>null</code>.
	 */
	public final String getLocale() {
		return locale;
	}
	/**
	 * <p>
	 * Returns all of the possible bindings that start with the given trigger
	 * (but are not equal to the given trigger).
	 * </p>
	 * <p>
	 * This method completes in <code>O(1)</code>. If the bindings aren't
	 * currently computed, then this completes in <code>O(n)</code>, where
	 * <code>n</code> is the number of bindings.
	 * </p>
	 * 
	 * @param trigger
	 *            The prefix to look for; must not be <code>null</code>.
	 * @return A map of triggers (<code>TriggerSequence</code>) to bindings (<code>Binding</code>).
	 *         This map may be empty, but it is never <code>null</code>.
	 */
	public final Map getPartialMatches(final TriggerSequence trigger) {