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events: optimize various functions

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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>
This commit is contained in:
Brian White 2015-02-05 15:35:33 -05:00 committed by Ben Noordhuis
parent c86e383c41
commit b677b844fc
2 changed files with 193 additions and 99 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

288
lib/events.js
View File

@ -40,7 +40,7 @@ EventEmitter.init = function() {
// that to be increased. Set to zero for unlimited.
EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) {
if (typeof n !== 'number' || n < 0 || isNaN(n))
throw TypeError('n must be a positive number');
throw new TypeError('n must be a positive number');
this._maxListeners = n;
return this;
};
@ -55,22 +55,72 @@ EventEmitter.prototype.getMaxListeners = function getMaxListeners() {
return $getMaxListeners(this);
};
EventEmitter.prototype.emit = function emit(type) {
var er, handler, len, args, i, listeners;
// These standalone emit* functions are used to optimize calling of event
// handlers for fast cases because emit() itself often has a variable number of
// arguments and can be deoptimized because of that. These functions always have
// the same number of arguments and thus do not get deoptimized, so the code
// inside them can execute faster.
function emitNone(handler, isFn, self) {
if (isFn)
handler.call(self);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self);
}
}
function emitOne(handler, isFn, self, arg1) {
if (isFn)
handler.call(self, arg1);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self, arg1);
}
}
function emitTwo(handler, isFn, self, arg1, arg2) {
if (isFn)
handler.call(self, arg1, arg2);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self, arg1, arg2);
}
}
function emitThree(handler, isFn, self, arg1, arg2, arg3) {
if (isFn)
handler.call(self, arg1, arg2, arg3);
else {
var len = handler.length;
var listeners = arrayClone(handler, len);
for (var i = 0; i < len; ++i)
listeners[i].call(self, arg1, arg2, arg3);
}
}
if (!this._events)
this._events = {};
EventEmitter.prototype.emit = function emit(type) {
var er, handler, len, args, i, listeners, events, domain;
var needDomainExit = false;
events = this._events;
if (!events)
events = this._events = {};
domain = this.domain;
// If there is no 'error' event listener then throw.
if (type === 'error' && !this._events.error) {
if (type === 'error' && !events.error) {
er = arguments[1];
if (this.domain) {
if (domain) {
if (!er)
er = new Error('Uncaught, unspecified "error" event.');
er.domainEmitter = this;
er.domain = this.domain;
er.domain = domain;
er.domainThrown = false;
this.domain.emit('error', er);
domain.emit('error', er);
} else if (er instanceof Error) {
throw er; // Unhandled 'error' event
} else {
@ -79,88 +129,94 @@ EventEmitter.prototype.emit = function emit(type) {
return false;
}
handler = this._events[type];
handler = events[type];
if (handler === undefined)
if (!handler)
return false;
if (this.domain && this !== process)
this.domain.enter();
if (typeof handler === 'function') {
switch (arguments.length) {
// fast cases
case 1:
handler.call(this);
break;
case 2:
handler.call(this, arguments[1]);
break;
case 3:
handler.call(this, arguments[1], arguments[2]);
break;
// slower
default:
len = arguments.length;
args = new Array(len - 1);
for (i = 1; i < len; i++)
args[i - 1] = arguments[i];
handler.apply(this, args);
}
} else if (handler !== null && typeof handler === 'object') {
len = arguments.length;
args = new Array(len - 1);
for (i = 1; i < len; i++)
args[i - 1] = arguments[i];
listeners = handler.slice();
len = listeners.length;
for (i = 0; i < len; i++)
listeners[i].apply(this, args);
if (domain && this !== process) {
domain.enter();
needDomainExit = true;
}
if (this.domain && this !== process)
this.domain.exit();
var isFn = typeof handler === 'function';
len = arguments.length;
switch (len) {
// fast cases
case 1:
emitNone(handler, isFn, this);
break;
case 2:
emitOne(handler, isFn, this, arguments[1]);
break;
case 3:
emitTwo(handler, isFn, this, arguments[1], arguments[2]);
break;
case 4:
emitThree(handler, isFn, this, arguments[1], arguments[2], arguments[3]);
break;
// slower
default:
args = new Array(len - 1);
for (i = 1; i < len; i++)
args[i - 1] = arguments[i];
if (isFn)
handler.apply(this, args);
else {
len = handler.length;
listeners = arrayClone(handler, len);
for (i = 0; i < len; ++i)
listeners[i].apply(this, args);
}
}
if (needDomainExit)
domain.exit();
return true;
};
EventEmitter.prototype.addListener = function addListener(type, listener) {
var m;
var events;
var existing;
if (typeof listener !== 'function')
throw TypeError('listener must be a function');
throw new TypeError('listener must be a function');
if (!this._events)
this._events = {};
events = this._events;
if (!events)
events = this._events = {};
else {
// To avoid recursion in the case that type === "newListener"! Before
// adding it to the listeners, first emit "newListener".
if (events.newListener) {
this.emit('newListener', type,
typeof listener.listener === 'function' ?
listener.listener : listener);
}
existing = events[type];
}
// To avoid recursion in the case that type === "newListener"! Before
// adding it to the listeners, first emit "newListener".
if (this._events.newListener)
this.emit('newListener', type,
typeof listener.listener === 'function' ?
listener.listener : listener);
if (!this._events[type])
if (!existing)
// Optimize the case of one listener. Don't need the extra array object.
this._events[type] = listener;
else if (typeof this._events[type] === 'object')
existing = events[type] = listener;
else if (typeof existing !== 'function')
// If we've already got an array, just append.
this._events[type].push(listener);
existing.push(listener);
else
// Adding the second element, need to change to array.
this._events[type] = [this._events[type], listener];
existing = events[type] = [existing, listener];
// Check for listener leak
if (this._events[type] !== null && typeof this._events[type] === 'object' &&
!this._events[type].warned) {
var m = $getMaxListeners(this);
if (m && m > 0 && this._events[type].length > m) {
this._events[type].warned = true;
if (typeof existing !== 'function' && !existing.warned) {
m = $getMaxListeners(this);
if (m && m > 0 && existing.length > m) {
existing.warned = true;
console.error('(node) warning: possible EventEmitter memory ' +
'leak detected. %d %s listeners added. ' +
'Use emitter.setMaxListeners() to increase limit.',
this._events[type].length, type);
existing.length, type);
console.trace();
}
}
@ -172,7 +228,7 @@ EventEmitter.prototype.on = EventEmitter.prototype.addListener;
EventEmitter.prototype.once = function once(type, listener) {
if (typeof listener !== 'function')
throw TypeError('listener must be a function');
throw new TypeError('listener must be a function');
var fired = false;
@ -194,26 +250,29 @@ EventEmitter.prototype.once = function once(type, listener) {
// emits a 'removeListener' event iff the listener was removed
EventEmitter.prototype.removeListener =
function removeListener(type, listener) {
var list, position, length, i;
var list, events, position, length, i;
if (typeof listener !== 'function')
throw TypeError('listener must be a function');
throw new TypeError('listener must be a function');
if (!this._events || !this._events[type])
events = this._events;
if (!events)
return this;
list = events[type];
if (!list)
return this;
list = this._events[type];
length = list.length;
position = -1;
if (list === listener ||
(typeof list.listener === 'function' &&
list.listener === listener)) {
delete this._events[type];
if (this._events.removeListener)
(typeof list.listener === 'function' && list.listener === listener)) {
delete events[type];
if (events.removeListener)
this.emit('removeListener', type, listener);
} else if (list !== null && typeof list === 'object') {
} else if (typeof list !== 'function') {
for (i = length; i-- > 0;) {
if (list[i] === listener ||
(list[i].listener && list[i].listener === listener)) {
@ -227,12 +286,12 @@ EventEmitter.prototype.removeListener =
if (list.length === 1) {
list.length = 0;
delete this._events[type];
delete events[type];
} else {
spliceOne(list, position);
}
if (this._events.removeListener)
if (events.removeListener)
this.emit('removeListener', type, listener);
}
@ -241,23 +300,26 @@ EventEmitter.prototype.removeListener =
EventEmitter.prototype.removeAllListeners =
function removeAllListeners(type) {
var key, listeners;
var listeners, events;
if (!this._events)
events = this._events;
if (!events)
return this;
// not listening for removeListener, no need to emit
if (!this._events.removeListener) {
if (!events.removeListener) {
if (arguments.length === 0)
this._events = {};
else if (this._events[type])
delete this._events[type];
else if (events[type])
delete events[type];
return this;
}
// emit removeListener for all listeners on all events
if (arguments.length === 0) {
for (key in this._events) {
var keys = Object.keys(events);
for (var i = 0, key; i < keys.length; ++i) {
key = keys[i];
if (key === 'removeListener') continue;
this.removeAllListeners(key);
}
@ -266,7 +328,7 @@ EventEmitter.prototype.removeAllListeners =
return this;
}
listeners = this._events[type];
listeners = events[type];
if (typeof listeners === 'function') {
this.removeListener(type, listeners);
@ -275,30 +337,44 @@ EventEmitter.prototype.removeAllListeners =
while (listeners.length)
this.removeListener(type, listeners[listeners.length - 1]);
}
delete this._events[type];
delete events[type];
return this;
};
EventEmitter.prototype.listeners = function listeners(type) {
var evlistener;
var ret;
if (!this._events || !this._events[type])
var events = this._events;
if (!events)
ret = [];
else if (typeof this._events[type] === 'function')
ret = [this._events[type]];
else
ret = this._events[type].slice();
else {
evlistener = events[type];
if (!evlistener)
ret = [];
else if (typeof evlistener === 'function')
ret = [evlistener];
else
ret = arrayClone(evlistener);
}
return ret;
};
EventEmitter.listenerCount = function(emitter, type) {
var ret;
if (!emitter._events || !emitter._events[type])
ret = 0;
else if (typeof emitter._events[type] === 'function')
ret = 1;
else
ret = emitter._events[type].length;
var evlistener;
var ret = 0;
var events = emitter._events;
if (events) {
evlistener = events[type];
if (typeof evlistener === 'function')
ret = 1;
else if (evlistener)
ret = evlistener.length;
}
return ret;
};
@ -308,3 +384,17 @@ function spliceOne(list, index) {
list[i] = list[k];
list.pop();
}
function arrayClone(arr, len) {
var ret;
if (len === undefined)
len = arr.length;
if (len >= 50)
ret = arr.slice();
else {
ret = new Array(len);
for (var i = 0; i < len; i += 1)
ret[i] = arr[i];
}
return ret;
}

4
test/message/stdin_messages.out
View File

@ -9,6 +9,7 @@ SyntaxError: Strict mode code may not include a with statement
at Module._compile (module.js:*:*)
at evalScript (node.js:*:*)
at Socket.<anonymous> (node.js:*:*)
at emitNone (events.js:*:*)
at Socket.emit (events.js:*:*)
at _stream_readable.js:*:*
at process._tickCallback (node.js:*:*)
@ -25,6 +26,7 @@ Error: hello
at Module._compile (module.js:*:*)
at evalScript (node.js:*:*)
at Socket.<anonymous> (node.js:*:*)
at emitNone (events.js:*:*)
at Socket.emit (events.js:*:*)
at _stream_readable.js:*:*
at process._tickCallback (node.js:*:*)
@ -39,6 +41,7 @@ Error: hello
at Module._compile (module.js:*:*)
at evalScript (node.js:*:*)
at Socket.<anonymous> (node.js:*:*)
at emitNone (events.js:*:*)
at Socket.emit (events.js:*:*)
at _stream_readable.js:*:*
at process._tickCallback (node.js:*:*)
@ -54,6 +57,7 @@ ReferenceError: y is not defined
at Module._compile (module.js:*:*)
at evalScript (node.js:*:*)
at Socket.<anonymous> (node.js:*:*)
at emitNone (events.js:*:*)
at Socket.emit (events.js:*:*)
at _stream_readable.js:*:*
at process._tickCallback (node.js:*:*)