These optimizations result in >2x speedup in the ee-add-remove
benchmark:
* Don't mutate array.length when removing the last listener for
an event
* Don't bother checking max listeners if listeners isn't an array
* Don't call delete when removing the last event in _events, just
re-assign a new object instead
PR-URL: https://github.com/iojs/io.js/pull/785
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Evan Lucas <evanlucas@me.com>
This keeps in line with how things are done for the fast path
and *might* even provide a *slight* performance increase.
PR-URL: https://github.com/iojs/io.js/pull/785
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Cache events and listeners objects where possible and loop over
Object.keys() instead of using for..in. These changes alone give
~60-65% improvement in the ee-add-remove benchmark.
The changes to EventEmitter.listenerCount() gives ~14%
improvement and changes to emitter.listeners() gives
significant improvements for <50 listeners
(~195% improvement for 10 listeners).
The changes to emitter.emit() gives 3x speedup for the fast
cases with multiple handlers and a minor speedup for the slow
case with multiple handlers.
The swapping out of the util.is* type checking functions with inline
checks gives another ~5-10% improvement.
PR-URL: https://github.com/iojs/io.js/pull/601
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Many of the util.is*() methods used to check data types
simply compare against a single value or the result of
typeof. This commit replaces calls to these methods with
equivalent checks. This commit does not touch calls to the
more complex methods (isRegExp(), isDate(), etc.).
Fixes: https://github.com/iojs/io.js/issues/607
PR-URL: https://github.com/iojs/io.js/pull/647
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
This commit replaces a number of var statements throughout
the lib code with const statements.
PR-URL: https://github.com/iojs/io.js/pull/541
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Commit 2931348 added EventEmitter#getMaxListeners() but introduced a
regression when people abuse EventEmitter.prototype.on.call() to call
EventEmitter#on() on a non-EE object. Add a workaround for that.
Fixes: https://github.com/iojs/io.js/issues/523
PR-URL: https://github.com/iojs/io.js/pull/527
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
The copyright and license notice is already in the LICENSE file. There
is no justifiable reason to also require that it be included in every
file, since the individual files are not individually distributed except
as part of the entire package.
Replace the call to Array#splice() with a faster open-coded version
that creates less garbage.
Add a new benchmark to prove it. With the change applied, it scores
a whopping 40% higher.
PR-URL: https://github.com/iojs/io.js/pull/185
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Turn on strict mode for the files in the lib/ directory. It helps
catch bugs and can have a positive effect on performance.
PR-URL: https://github.com/node-forward/node/pull/64
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Fedor Indutny <fedor@indutny.com>
Before this commit the EventEmitter methods were anonymous functions.
V8 tries to infer names for anonymous functions based on the execution
context but it frequently gets it wrong and when that happens, the
stack trace is usually confusing and unhelpful. This commit names all
methods so V8 can fall back to the method.name property.
The above gotcha applies to all anonymous functions but is exacerbated
for EventEmitter methods because those are invoked with a plenitude of
different receivers.
Signed-off-by: Trevor Norris <trev.norris@gmail.com>
This is a slightly modified revert of bc39bdd.
Getting domains to use AsyncListeners became too much of a challenge
with many edge cases. While this is still a goal, it will have to be
deferred for now until more test coverage can be provided.
After landing 6ed861d it is no longer possible to reliably monkey-patch
the EventEmitter constructor. However there's valid use cases for that,
and makes for easier debugging. Therefore, move the guts of the
constructor to a separate function which is monkey-patchable.
Closes#6693
Check that `listeners` is actually an array before trying to manipulate it
because it won't be if no regular event listeners have been registered yet
but there are 'removeListener' event listeners.
Emitting an event within a `EventEmitter#once` callback of the same
event name will cause subsequent `EventEmitter#once` listeners of the
same name to be called multiple times.
var emitter = new EventEmitter();
emitter.once('e', function() {
emitter.emit('e');
console.log(1);
});
emitter.once('e', function() {
console.log(2);
});
emitter.emit('e');
// Output
// 2
// 1
// 2
Fix the issue, by calling the listener method only if it was not
already called.
The domain module has been switched over to use the domain module API as
much as currently possible. There are still some hooks in the
EventEmitter, but hopefully we can remove those in the future.
This change is 100% backwards compatible.
This change will make using `EventEmitter` slightly simpler / nicer and
adheres to the best practice set forth by substack.
```js
var EventEmitter = require("events")
var emitter = new EventEmitter()
```
The only difference is that we now have to set `EventEmitter` as a
property of `EventEmitter` for backwards compatibility like we do with
[`Stream`][1]
We have also set the `usingDomains` property on the `EventEmitter`
constructor itself because that aligns with it's current usage of
`require("events").usingDomains = true`
There are other internals that would benefit from this change as well
like `StringDecoder`
Before this commit, events were set to undefined rather than deleted
from the EventEmitter's backing dictionary for performance reasons:
`delete obj.key` causes a transition of the dictionary's hidden class
and that can be costly.
Unfortunately, that introduces a memory leak when many events are added
and then removed again. The strings containing the event names are never
reclaimed by the garbage collector because they remain part of the
dictionary.
That's why this commit makes EventEmitter delete events again. This
effectively reverts commit 0397223.
Fixes#5970.
so `ee.emit('error')` doesn't throw when domains are active
create an empty error only when handled by a domain
test for when no error is provided to an error event
Strict checking for typeof types broke backwards compatibility for other
libraries. This reverts those checks.
The subclass test has been changed to ensure all operations can be
performed on the inherited EE before instantiation. Including the
ability to set event names with numbers.
By making sure the _events is always an object there is one less check
that needs to be performed by emit.
Use undefined instead of null. typeof checks are a lot faster than
isArray.
There are a few places where the this._events check cannot be removed
because it is possible for the user to call those methods after using
utils.extend to create their own EventEmitter, but before it has
actually been instantiated.
Unnecessary checks were being performed on if the event existed before
being removed.
_events starts out as null, so reset to null when emptied.
Checking typeof is a lot cheaper than isArray().
Ability to return just the length of listeners for a given type, using
EventEmitter.listenerCount(emitter, event). This will be a lot cheaper
than creating a copy of the listeners array just to check its length.
Unfortunately, it's just too slow to do this in events.js. Users will
just have to live with not having events named __proto__ or toString.
This reverts commit b48e303af0.
While it's true that error objects have a history of getting snake_case
properties attached by the host system, it's a point of confusion to
Node users that comes up a lot. It's still 'experimental', so best to
change this sooner rather than later.