X-Git-Url: https://git.piment-noir.org/?a=blobdiff_plain;f=docs%2Fclasses%2FPoolEmitter.html;h=a20d6ef2185fb34c83561bddd48d51bedf6d337f;hb=5decbf239157d04bdf38a642fe2757f565a8d466;hp=da05fefe3f6582519f51c4cec4d19be3ab4ebfdd;hpb=15e4d8f3cafe9f7412913b0e440921e813bdf3cd;p=poolifier.git diff --git a/docs/classes/PoolEmitter.html b/docs/classes/PoolEmitter.html index da05fefe..a20d6ef2 100644 --- a/docs/classes/PoolEmitter.html +++ b/docs/classes/PoolEmitter.html @@ -25,7 +25,7 @@
Optional
options: EventEmitterOptionsStatic
Readonly
captureStatic
captureInherited from EventEmitter.addListener
+Inherited from EventEmitterAsyncResource.addListener
'error'
listener is installed.
Synchronously calls each of the listeners registered for the event namedeventName
, in the order they were registered, passing the supplied arguments
to each.
Returns true
if the event had listeners, false
otherwise.
const EventEmitter = require('events');
const myEmitter = new EventEmitter();
// First listener
myEmitter.on('event', function firstListener() {
console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
const parameters = args.join(', ');
console.log(`event with parameters ${parameters} in third listener`);
});
console.log(myEmitter.listeners('event'));
myEmitter.emit('event', 1, 2, 3, 4, 5);
// Prints:
// [
// [Function: firstListener],
// [Function: secondListener],
// [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener
-
+import { EventEmitter } from 'node:events';
const myEmitter = new EventEmitter();
// First listener
myEmitter.on('event', function firstListener() {
console.log('Helloooo! first listener');
});
// Second listener
myEmitter.on('event', function secondListener(arg1, arg2) {
console.log(`event with parameters ${arg1}, ${arg2} in second listener`);
});
// Third listener
myEmitter.on('event', function thirdListener(...args) {
const parameters = args.join(', ');
console.log(`event with parameters ${parameters} in third listener`);
});
console.log(myEmitter.listeners('event'));
myEmitter.emit('event', 1, 2, 3, 4, 5);
// Prints:
// [
// [Function: firstListener],
// [Function: secondListener],
// [Function: thirdListener]
// ]
// Helloooo! first listener
// event with parameters 1, 2 in second listener
// event with parameters 1, 2, 3, 4, 5 in third listener
+
v0.1.26
Rest
...args: any[]Inherited from EventEmitter.emit
+Inherited from EventEmitterAsyncResource.emit
Returns an array listing the events for which the emitter has registered
listeners. The values in the array are strings or Symbol
s.
const EventEmitter = require('events');
const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});
const sym = Symbol('symbol');
myEE.on(sym, () => {});
console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]
-
+import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => {});
myEE.on('bar', () => {});
const sym = Symbol('symbol');
myEE.on(sym, () => {});
console.log(myEE.eventNames());
// Prints: [ 'foo', 'bar', Symbol(symbol) ]
+
v6.0.0
Inherited from EventEmitter.eventNames
+Inherited from EventEmitterAsyncResource.eventNames
emitter.setMaxListeners(n)
or defaults to Returns numberInherited from EventEmitter.getMaxListeners
+Inherited from EventEmitterAsyncResource.getMaxListeners
Returns the number of listeners listening to the event named eventName
.
Returns the number of listeners listening for the event named eventName
.
+If listener
is provided, it will return how many times the listener is found
+in the list of the listeners of the event.
v3.2.0
emitter.setMaxListeners(n)
or defaults to eventName: string | symbol
The name of the event being listened for
+Optional
listener: FunctionThe event handler function
Inherited from EventEmitter.listenerCount
+Inherited from EventEmitterAsyncResource.listenerCount
Returns a copy of the array of listeners for the event named eventName
.
server.on('connection', (stream) => {
console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]
-
+server.on('connection', (stream) => {
console.log('someone connected!');
});
console.log(util.inspect(server.listeners('connection')));
// Prints: [ [Function] ]
+
v0.1.26
emitter.setMaxListeners(n)
or defaults to eventName: string | symbolInherited from EventEmitter.listeners
+Inherited from EventEmitterAsyncResource.listeners
emitter.setMaxListeners(n)
or defaults to Rest ...args: any[]Inherited from EventEmitter.off
+Inherited from EventEmitterAsyncResource.off
eventName
. No checks are made to see if the liste
already been added. Multiple calls passing the same combination of eventName
and listener
will result in the listener
being added, and called, multiple
times.
server.on('connection', (stream) => {
console.log('someone connected!');
});
-
+
Returns a reference to the EventEmitter
, so that calls can be chained.
By default, event listeners are invoked in the order they are added. Theemitter.prependListener()
method can be used as an alternative to add the
event listener to the beginning of the listeners array.
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
// b
// a
-
+import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.on('foo', () => console.log('a'));
myEE.prependListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
// b
// a
+
v0.1.101
@@ -316,9 +353,9 @@ event listener to the beginning of the listeners array.Rest
...args: any[]Inherited from EventEmitter.on
+Inherited from EventEmitterAsyncResource.on
Adds a one-timelistener
function for the event named eventName
. The
next time eventName
is triggered, this listener is removed and then invoked.
server.once('connection', (stream) => {
console.log('Ah, we have our first user!');
});
-
+
Returns a reference to the EventEmitter
, so that calls can be chained.
By default, event listeners are invoked in the order they are added. Theemitter.prependOnceListener()
method can be used as an alternative to add the
event listener to the beginning of the listeners array.
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
// b
// a
-
+import { EventEmitter } from 'node:events';
const myEE = new EventEmitter();
myEE.once('foo', () => console.log('a'));
myEE.prependOnceListener('foo', () => console.log('b'));
myEE.emit('foo');
// Prints:
// b
// a
+
v0.3.0
Rest
...args: any[]Inherited from EventEmitter.once
+Inherited from EventEmitterAsyncResource.once
eventName
. No checks are made to see if the liste
already been added. Multiple calls passing the same combination of eventName
and listener
will result in the listener
being added, and called, multiple
times.
server.prependListener('connection', (stream) => {
console.log('someone connected!');
});
-
+
Returns a reference to the EventEmitter
, so that calls can be chained.
v6.0.0
@@ -400,9 +437,9 @@ times.Rest
...args: any[]Inherited from EventEmitter.prependListener
+Inherited from EventEmitterAsyncResource.prependListener
Adds a one-timelistener
function for the event named eventName
to the beginning of the listeners array. The next time eventName
is triggered, this
listener is removed, and then invoked.
server.prependOnceListener('connection', (stream) => {
console.log('Ah, we have our first user!');
});
-
+
Returns a reference to the EventEmitter
, so that calls can be chained.
v6.0.0
@@ -439,9 +476,9 @@ listener is removed, and then invoked.Rest
...args: any[]Inherited from EventEmitter.prependOnceListener
+Inherited from EventEmitterAsyncResource.prependOnceListener
Returns a copy of the array of listeners for the event named eventName
,
including any wrappers (such as those created by .once()
).
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));
// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];
// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();
// Logs "log once" to the console and removes the listener
logFnWrapper();
emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');
// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');
-
+import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.once('log', () => console.log('log once'));
// Returns a new Array with a function `onceWrapper` which has a property
// `listener` which contains the original listener bound above
const listeners = emitter.rawListeners('log');
const logFnWrapper = listeners[0];
// Logs "log once" to the console and does not unbind the `once` event
logFnWrapper.listener();
// Logs "log once" to the console and removes the listener
logFnWrapper();
emitter.on('log', () => console.log('log persistently'));
// Will return a new Array with a single function bound by `.on()` above
const newListeners = emitter.rawListeners('log');
// Logs "log persistently" twice
newListeners[0]();
emitter.emit('log');
+
v9.4.0
.once()
).
Inherited from EventEmitter.rawListeners
+Inherited from EventEmitterAsyncResource.rawListeners
Optional
event: string | symbolInherited from EventEmitter.removeAllListeners
+Inherited from EventEmitterAsyncResource.removeAllListeners
Removes the specified listener
from the listener array for the event namedeventName
.
const callback = (stream) => {
console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);
-
+const callback = (stream) => {
console.log('someone connected!');
};
server.on('connection', callback);
// ...
server.removeListener('connection', callback);
+
removeListener()
will remove, at most, one instance of a listener from the
listener array. If any single listener has been added multiple times to the
listener array for the specified eventName
, then removeListener()
must be
@@ -500,8 +537,8 @@ called multiple times to remove each instance.
Once an event is emitted, all listeners attached to it at the
time of emitting are called in order. This implies that anyremoveListener()
or removeAllListeners()
calls after emitting and before the last listener finishes execution
will not remove them fromemit()
in progress. Subsequent events behave as expected.
const myEmitter = new MyEmitter();
const callbackA = () => {
console.log('A');
myEmitter.removeListener('event', callbackB);
};
const callbackB = () => {
console.log('B');
};
myEmitter.on('event', callbackA);
myEmitter.on('event', callbackB);
// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
// A
// B
// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
// A
-
+import { EventEmitter } from 'node:events';
class MyEmitter extends EventEmitter {}
const myEmitter = new MyEmitter();
const callbackA = () => {
console.log('A');
myEmitter.removeListener('event', callbackB);
};
const callbackB = () => {
console.log('B');
};
myEmitter.on('event', callbackA);
myEmitter.on('event', callbackB);
// callbackA removes listener callbackB but it will still be called.
// Internal listener array at time of emit [callbackA, callbackB]
myEmitter.emit('event');
// Prints:
// A
// B
// callbackB is now removed.
// Internal listener array [callbackA]
myEmitter.emit('event');
// Prints:
// A
+
Because listeners are managed using an internal array, calling this will
change the position indices of any listener registered after the listener
being removed. This will not impact the order in which listeners are called,
@@ -510,8 +547,8 @@ the emitter.listeners()
method will need to be recreated.
When a single function has been added as a handler multiple times for a single
event (as in the example below), removeListener()
will remove the most
recently added instance. In the example the once('ping')
listener is removed:
const ee = new EventEmitter();
function pong() {
console.log('pong');
}
ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);
ee.emit('ping');
ee.emit('ping');
-
+import { EventEmitter } from 'node:events';
const ee = new EventEmitter();
function pong() {
console.log('pong');
}
ee.on('ping', pong);
ee.once('ping', pong);
ee.removeListener('ping', pong);
ee.emit('ping');
ee.emit('ping');
+
Returns a reference to the EventEmitter
, so that calls can be chained.
v0.1.26
@@ -535,9 +572,9 @@ recently added instance. In the example theonce('ping')
lis
Rest
...args: any[]Inherited from EventEmitter.removeListener
+Inherited from EventEmitterAsyncResource.removeListener
EventEmitter
instance. The value can be
Inherited from EventEmitter.setMaxListeners
+Inherited from EventEmitterAsyncResource.setMaxListeners
Static
getEventEmitter
instance. The value can be
the emitter.
For EventTarget
s this is the only way to get the event listeners for the
event target. This is useful for debugging and diagnostic purposes.
const { getEventListeners, EventEmitter } = require('events');
{
const ee = new EventEmitter();
const listener = () => console.log('Events are fun');
ee.on('foo', listener);
getEventListeners(ee, 'foo'); // [listener]
}
{
const et = new EventTarget();
const listener = () => console.log('Events are fun');
et.addEventListener('foo', listener);
getEventListeners(et, 'foo'); // [listener]
}
-
+import { getEventListeners, EventEmitter } from 'node:events';
{
const ee = new EventEmitter();
const listener = () => console.log('Events are fun');
ee.on('foo', listener);
console.log(getEventListeners(ee, 'foo')); // [ [Function: listener] ]
}
{
const et = new EventTarget();
const listener = () => console.log('Events are fun');
et.addEventListener('foo', listener);
console.log(getEventListeners(et, 'foo')); // [ [Function: listener] ]
}
+
v15.2.0, v14.17.0
@@ -583,17 +620,17 @@ event target. This is useful for debugging and diagnostic purposes.Inherited from EventEmitter.getEventListeners
+Inherited from EventEmitterAsyncResource.getEventListeners
Static
listenerA class method that returns the number of listeners for the given eventName
registered on the given emitter
.
const { EventEmitter, listenerCount } = require('events');
const myEmitter = new EventEmitter();
myEmitter.on('event', () => {});
myEmitter.on('event', () => {});
console.log(listenerCount(myEmitter, 'event'));
// Prints: 2
-
+import { EventEmitter, listenerCount } from 'node:events';
const myEmitter = new EventEmitter();
myEmitter.on('event', () => {});
myEmitter.on('event', () => {});
console.log(listenerCount(myEmitter, 'event'));
// Prints: 2
+
v0.9.12
@@ -611,27 +648,25 @@ event target. This is useful for debugging and diagnostic purposes.The event name
Inherited from EventEmitter.listenerCount
+Inherited from EventEmitterAsyncResource.listenerCount
Static
onconst { on, EventEmitter } = require('events');
(async () => {
const ee = new EventEmitter();
// Emit later on
process.nextTick(() => {
ee.emit('foo', 'bar');
ee.emit('foo', 42);
});
for await (const event of on(ee, 'foo')) {
// The execution of this inner block is synchronous and it
// processes one event at a time (even with await). Do not use
// if concurrent execution is required.
console.log(event); // prints ['bar'] [42]
}
// Unreachable here
})();
-
+import { on, EventEmitter } from 'node:events';
import process from 'node:process';
const ee = new EventEmitter();
// Emit later on
process.nextTick(() => {
ee.emit('foo', 'bar');
ee.emit('foo', 42);
});
for await (const event of on(ee, 'foo')) {
// The execution of this inner block is synchronous and it
// processes one event at a time (even with await). Do not use
// if concurrent execution is required.
console.log(event); // prints ['bar'] [42]
}
// Unreachable here
+
Returns an AsyncIterator
that iterates eventName
events. It will throw
if the EventEmitter
emits 'error'
. It removes all listeners when
exiting the loop. The value
returned by each iteration is an array
composed of the emitted event arguments.
An AbortSignal
can be used to cancel waiting on events:
const { on, EventEmitter } = require('events');
const ac = new AbortController();
(async () => {
const ee = new EventEmitter();
// Emit later on
process.nextTick(() => {
ee.emit('foo', 'bar');
ee.emit('foo', 42);
});
for await (const event of on(ee, 'foo', { signal: ac.signal })) {
// The execution of this inner block is synchronous and it
// processes one event at a time (even with await). Do not use
// if concurrent execution is required.
console.log(event); // prints ['bar'] [42]
}
// Unreachable here
})();
process.nextTick(() => ac.abort());
-
+import { on, EventEmitter } from 'node:events';
import process from 'node:process';
const ac = new AbortController();
(async () => {
const ee = new EventEmitter();
// Emit later on
process.nextTick(() => {
ee.emit('foo', 'bar');
ee.emit('foo', 42);
});
for await (const event of on(ee, 'foo', { signal: ac.signal })) {
// The execution of this inner block is synchronous and it
// processes one event at a time (even with await). Do not use
// if concurrent execution is required.
console.log(event); // prints ['bar'] [42]
}
// Unreachable here
})();
process.nextTick(() => ac.abort());
+
v13.6.0, v12.16.0
- -that iterates eventName
events emitted by the emitter
Optional
options: StaticEventEmitterOptionsInherited from EventEmitter.on
+that iterates eventName
events emitted by the emitter
Inherited from EventEmitterAsyncResource.on
Static
oncePromise
will resolve with an array of all the arguments emitted
given event.
This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error'
event
semantics and does not listen to the 'error'
event.
const { once, EventEmitter } = require('events');
async function run() {
const ee = new EventEmitter();
process.nextTick(() => {
ee.emit('myevent', 42);
});
const [value] = await once(ee, 'myevent');
console.log(value);
const err = new Error('kaboom');
process.nextTick(() => {
ee.emit('error', err);
});
try {
await once(ee, 'myevent');
} catch (err) {
console.log('error happened', err);
}
}
run();
-
+import { once, EventEmitter } from 'node:events';
import process from 'node:process';
const ee = new EventEmitter();
process.nextTick(() => {
ee.emit('myevent', 42);
});
const [value] = await once(ee, 'myevent');
console.log(value);
const err = new Error('kaboom');
process.nextTick(() => {
ee.emit('error', err);
});
try {
await once(ee, 'myevent');
} catch (err) {
console.error('error happened', err);
}
+
The special handling of the 'error'
event is only used when events.once()
is used to wait for another event. If events.once()
is used to wait for the
'error'
event itself, then it is treated as any other kind of event without
special handling:
const { EventEmitter, once } = require('events');
const ee = new EventEmitter();
once(ee, 'error')
.then(([err]) => console.log('ok', err.message))
.catch((err) => console.log('error', err.message));
ee.emit('error', new Error('boom'));
// Prints: ok boom
-
+import { EventEmitter, once } from 'node:events';
const ee = new EventEmitter();
once(ee, 'error')
.then(([err]) => console.log('ok', err.message))
.catch((err) => console.error('error', err.message));
ee.emit('error', new Error('boom'));
// Prints: ok boom
+
An AbortSignal
can be used to cancel waiting for the event:
const { EventEmitter, once } = require('events');
const ee = new EventEmitter();
const ac = new AbortController();
async function foo(emitter, event, signal) {
try {
await once(emitter, event, { signal });
console.log('event emitted!');
} catch (error) {
if (error.name === 'AbortError') {
console.error('Waiting for the event was canceled!');
} else {
console.error('There was an error', error.message);
}
}
}
foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!
-
+import { EventEmitter, once } from 'node:events';
const ee = new EventEmitter();
const ac = new AbortController();
async function foo(emitter, event, signal) {
try {
await once(emitter, event, { signal });
console.log('event emitted!');
} catch (error) {
if (error.name === 'AbortError') {
console.error('Waiting for the event was canceled!');
} else {
console.error('There was an error', error.message);
}
}
}
foo(ee, 'foo', ac.signal);
ac.abort(); // Abort waiting for the event
ee.emit('foo'); // Prints: Waiting for the event was canceled!
+
v11.13.0, v10.16.0
@@ -682,9 +718,9 @@ special handling:Optional
options: StaticEventEmitterOptionsInherited from EventEmitter.once
+Inherited from EventEmitterAsyncResource.once
Optional
options: StaticEventEmitterOptionsInherited from EventEmitter.once
+Inherited from EventEmitterAsyncResource.once
Static
setconst {
setMaxListeners,
EventEmitter
} = require('events');
const target = new EventTarget();
const emitter = new EventEmitter();
setMaxListeners(5, target, emitter);
-
+import { setMaxListeners, EventEmitter } from 'node:events';
const target = new EventTarget();
const emitter = new EventEmitter();
setMaxListeners(5, target, emitter);
+
v15.4.0
Rest
...eventTargets: (EventEmitter | _DOMEventTarget)[]Inherited from EventEmitter.setMaxListeners
+Inherited from EventEmitterAsyncResource.setMaxListeners
Generated using TypeDoc
Sets or gets the default captureRejection value for all emitters.
+Value: boolean
+Change the default
+ +captureRejections
option on all newEventEmitter
objects.Since
v13.4.0, v12.16.0
Inherited from EventEmitter.captureRejections
+Inherited from EventEmitterAsyncResource.captureRejections
-- Defined in node_modules/.pnpm/@types+node@18.15.11/node_modules/@types/node/events.d.ts:333
Max Listeners
-Static
defaultInherited from EventEmitter.defaultMaxListeners
+By default, a maximum of
+10
listeners can be registered for any single +event. This limit can be changed for individualEventEmitter
instances +using theemitter.setMaxListeners(n)
method. To change the default +for allEventEmitter
instances, theevents.defaultMaxListeners
property can be used. If this value is not a positive number, aRangeError
is thrown.Take caution when setting the
+events.defaultMaxListeners
because the +change affects allEventEmitter
instances, including those created before +the change is made. However, callingemitter.setMaxListeners(n)
still has +precedence overevents.defaultMaxListeners
.This is not a hard limit. The
+ +EventEmitter
instance will allow +more listeners to be added but will output a trace warning to stderr indicating +that a "possible EventEmitter memory leak" has been detected. For any singleEventEmitter
, theemitter.getMaxListeners()
andemitter.setMaxListeners()
methods can be used to +temporarily avoid this warning:The
+--trace-warnings
command-line flag can be used to display the +stack trace for such warnings.The emitted warning can be inspected with
+ +process.on('warning')
and will +have the additionalemitter
,type
, andcount
properties, referring to +the event emitter instance, the event's name and the number of attached +listeners, respectively. +Itsname
property is set to'MaxListenersExceededWarning'
.Since
v0.11.2
+Inherited from EventEmitterAsyncResource.defaultMaxListeners
-- Defined in node_modules/.pnpm/@types+node@18.15.11/node_modules/@types/node/events.d.ts:334
Static
Readonly
errorThis symbol shall be used to install a listener for only monitoring
-'error'
-events. Listeners installed using this symbol are called before the regular -'error'
listeners are called.Installing a listener using this symbol does not change the behavior once an -
'error'
event is emitted, therefore the process will still crash if no +This symbol shall be used to install a listener for only monitoring
+'error'
events. Listeners installed using this symbol are called before the regular'error'
listeners are called.Installing a listener using this symbol does not change the behavior once an
+ +'error'
event is emitted. Therefore, the process will still crash if no regular'error'
listener is installed.Since
v13.6.0, v12.17.0
Inherited from EventEmitter.errorMonitor
+Inherited from EventEmitterAsyncResource.errorMonitor
-- Defined in node_modules/.pnpm/@types+node@18.15.11/node_modules/@types/node/events.d.ts:327
Methods
'error'
listener is installed.Rest
...args: any[]Returns void