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
}
			return bindings;
		}
		return null;
	}
	/**
	 * <p>
	 * Gets the currently active scheme.
	 * </p>
	 * <p>
	 * This method completes in <code>O(1)</code>.
	 * </p>
	 * 
	 * @return The active scheme; may be <code>null</code> if there is no
	 *         active scheme. If a scheme is returned, it is guaranteed to be
	 *         defined.
	 */
	public final Scheme getActiveScheme() {
		return activeScheme;
	}
	/**
	 * Gets the best active binding for a command. The best binding is the one
	 * that would be most appropriate to show in a menu. Bindings which belong
	 * to a child scheme are given preference over those in a parent scheme.
	 * Bindings which belong to a particular locale or platform are given
	 * preference over those that do not. The rest of the calculaton is based
	 * most on various concepts of "length", as well as giving some modifier
	 * keys preference (e.g., <code>Alt</code> is less likely to appear than
	 * <code>Ctrl</code>).
	 *