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Mike Gerwitz c835641dcb Private methods are no longer wrapped
This is an exciting performance optimization that seems to have eluded me
for a surprisingly long time, given that the realization was quite random.
ease.js accomplishes much of its work through a method wrapper---each and
every method definition (well, until now) was wrapped in a closure that
performed a number of steps, depending on the type of wrapper involved:

  1. All wrappers perform a context lookup, binding to the instance's private
     member object of the class that defined that particular method. (See
     "Implementation Details" in the manual for more information.)
  2. This context is restored upon returning from the call: if a method
     returns `this', it is instead converted back to the context in which
     the method was invoked, which prevents the private member object from
     leaking out of a public interface.
  3. In the event of an override, this.__super is set up (and torn down).

There are other details (e.g. the method wrapper used for method proxies),
but for the sake of this particular commit, those are the only ones that
really matter. There are a couple of important details to notice:

  - Private members are only ever accessible from within the context of the
    private member object, which is always the context when executing a
    method.
  - Private methods cannot be overridden, as they cannot be inherited.

Consequently:

  1. We do not need to perform a context lookup: we are already in the proper
     context.
  2. We do not need to restore the context, as we never needed to change it
     to begin with.
  3. this.__super is never applicable.

Method wrappers are therefore never necessary for private methods; they have
therefore been removed.

This has some interesting performance implications. While in most cases the
overhead of method wrapping is not a bottleneck, it can have a strong impact
in the event of frequent method calls or heavily recursive algorithms. There
was one particular problem that ease.js suffered from, which is mentioned in
the manual: recursive calls to methods in ease.js were not recommended
because it

  (a) made two function calls for each method call, effectively halving the
      remaining call stack size, and
  (b) tail call optimization could not be performed, because recursion
      invoked the wrapper, *not* the function that was wrapped.

By removing the method wrapper on private methods, we solve both of these
problems; now, heavily recursive algorithms need only use private methods
(which could always be exposed through a protected or public API) when
recursing to entirely avoid any performance penalty by using ease.js.

Running the test cases on my system (your results may vary) before and after
the patch, we have:

  BEFORE:
  0.170s (x1000 = 0.0001700000s each): Declare 1000 anonymous classes with
    private members
  0.021s (x500000 = 0.0000000420s each): Invoke private methods internally

  AFTER:
  0.151s (x1000 = 0.0001510000s each): Declare 1000 anonymous classes with
    private members
  0.004s (x500000 = 0.0000000080s each): Invoke private methods internally

This is all the more motivation to use private members, which enforces
encapsulation; keep in mind that, because use of private members is the
ideal in well-encapsulated and well-factored code, ease.js has been designed
to perform best under those circumstances.
2014-03-20 23:43:24 -04:00
..
ClassBuilder.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
FallbackMemberBuilder.js [no-copyright] Modified headers to reduce GPL license notice width 2014-01-15 23:56:00 -05:00
FallbackVisibilityObjectFactory.js [no-copyright] Modified headers to reduce GPL license notice width 2014-01-15 23:56:00 -05:00
MemberBuilder.js Private methods are no longer wrapped 2014-03-20 23:43:24 -04:00
MemberBuilderValidator.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
MethodWrapperFactory.js [no-copyright] Modified headers to reduce GPL license notice width 2014-01-15 23:56:00 -05:00
MethodWrappers.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
Trait.js Deleted unnecessary trait abstract method in favor of auto-abstract flag 2014-03-15 21:16:27 -04:00
VisibilityObjectFactory.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
VisibilityObjectFactoryFactory.js [no-copyright] Modified headers to reduce GPL license notice width 2014-01-15 23:56:00 -05:00
class.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
class_abstract.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
class_final.js [no-copyright] Modified headers to reduce GPL license notice width 2014-01-15 23:56:00 -05:00
interface.js [copyright] Copyright update 2014-03-15 23:56:47 -04:00
prop_parser.js Added support for `weak' keyword 2014-03-07 00:47:43 -05:00
util.js Refactored ClassBuilder.buildMembers (dynamic prop parse context) 2014-03-15 21:16:27 -04:00
version.js.in Corrected version string generation with empty suffix 2014-03-15 23:57:02 -04:00
warn.js [no-copyright] Modified headers to reduce GPL license notice width 2014-01-15 23:56:00 -05:00