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
values.add(value);
		} else { 
			final Collection values = new ArrayList(1);
			values.add(value);
			map.put(key, values);
		}
	}
	/**
	 * <p>
	 * Takes a fully-specified string, and converts it into an array of
	 * increasingly less-specific strings. So, for example, "en_GB" would become
	 * ["en_GB", "en", "", null].
	 * </p>
	 * <p>
	 * This method runs in linear time (O(n)) over the length of the string.
	 * </p>
	 * 
	 * @param string
	 *            The string to break apart into its less specific components;
	 *            should not be <code>null</code>.
	 * @param separator
	 *            The separator that indicates a separation between a degrees of
	 *            specificity; should not be <code>null</code>.
	 * @return An array of strings from the most specific (i.e.,
	 *         <code>string</code>) to the least specific (i.e.,
	 *         <code>null</code>).
	 */
	private static final String[] expand(String string, final String separator) {
		
		if (string == null || separator == null) {