ConcurrentCaller changes

- Different constructor parameters
- id property for logging
- fcall() -> start()
- add() to enqueue without starting
- runAll() to run down queue and return promises for all current tasks
- wait() to wait for all running tasks to finish
This commit is contained in:
Dan Stillman 2015-10-29 02:50:29 -04:00
parent 62e586073d
commit ee6793a9e6
2 changed files with 543 additions and 78 deletions

View file

@ -34,43 +34,61 @@ Components.utils.import("resource://zotero/bluebird.js");
*
* Example:
*
* var caller = new ConcurrentCaller(2);
* caller.stopOnError = true;
* caller.fcall([foo, bar, baz, qux);
* var caller = new ConcurrentCaller({
* numConcurrent: 2,
* stopOnError: true
* });
* yield caller.start([foo, bar, baz, qux);
*
* In this example, foo and bar would run immediately, and baz and qux would
* be queued for later. When foo or bar finished, baz would be run, followed
* by qux when another slot opened.
*
* @param {Integer} numConcurrent The number of concurrent functions to run.
* Additional functions can be added at any time with another call to start(). The promises for
* all open start() calls will be resolved when all requests are finished.
*
* @param {Object} options
* @param {Integer} options.numConcurrent - The number of concurrent functions to run.
* @param {String} [options.id] - Identifier to use in debug output
* @param {Boolean} [options.stopOnError]
* @param {Function} [options.onError]
* @param {Integer} [options.interval] - Interval between the end of one function run and the
* beginning of another, in milliseconds
* @param {Function} [options.logger]
*/
ConcurrentCaller = function (numConcurrent) {
if (typeof numConcurrent == 'undefined') {
throw new Error("numConcurrent not provided");
ConcurrentCaller = function (options = {}) {
if (typeof options == 'number') {
this._log("ConcurrentCaller now takes an object rather than a number");
options = {
numConcurrent: options
};
}
this.stopOnError = false;
this.onError = null;
if (!options.numConcurrent) throw new Error("numConcurrent must be provided");
this._numConcurrent = numConcurrent;
this.stopOnError = options.stopOnError || false;
this.onError = options.onError || null;
this._id = options.id;
this._numConcurrent = options.numConcurrent;
this._numRunning = 0;
this._queue = [];
this._logger = null;
this._interval = 0;
this._logger = options.logger || null;
this._interval = options.interval || 0;
this._pausing = false;
this._pauseUntil = 0;
this._deferred = null;
};
/**
* Set the interval between the end of one function run and the beginning
* of another, in milliseconds
*/
ConcurrentCaller.prototype.setInterval = function (ms) {
this._log("setInterval() is deprecated -- pass .interval to constructor");
this._interval = ms;
};
ConcurrentCaller.prototype.setLogger = function (func) {
this._log("setLogger() is deprecated -- pass .logger to constructor");
this._logger = func;
};
@ -84,35 +102,81 @@ ConcurrentCaller.prototype.pause = function (ms) {
/**
* @param {Function[]|Function} func One or more functions to run
* Add a task to the queue without starting it
*
* @param {Function|Function[]} - One or more functions to run
* @return {Promise[]} - An array of promises for passed functions, resolved once the queue is
* empty
*/
ConcurrentCaller.prototype.fcall = function (func) {
ConcurrentCaller.prototype.add = function (func) {
if (Array.isArray(func)) {
var promises = [];
let promises = [];
for (let i = 0; i < func.length; i++) {
promises.push(this.fcall(func[i]));
promises.push(this.start(func[i]));
}
return Promise.settle(promises);
return this._deferred.promise.return(promises);
}
// If we're at the maximum number of concurrent functions,
// queue this function for later
if (this._numRunning == this._numConcurrent) {
if (!this._deferred || !this._deferred.promise.isPending()) {
this._deferred = Promise.defer();
}
var deferred = Promise.defer();
this._queue.push({
func: Promise.method(func),
deferred: deferred
});
return this._deferred.promise.return(deferred.promise);
}
/**
* @param {Function|Function[]} - One or more functions to run
* @return {Promise[]} - An array of promises for passed functions, resolved once the queue is
* empty
*/
ConcurrentCaller.prototype.start = function (func) {
var promise = this.add(func);
var run = this._processNext();
if (!run) {
this._log("Already at " + this._numConcurrent + " -- queueing for later");
var deferred = Promise.defer();
this._queue.push({
func: Promise.method(func),
deferred: deferred
});
return deferred.promise;
}
this._numRunning++;
// Otherwise run it now
this._log("Running function (" + this._numRunning + "/" + this._numConcurrent + ")");
return this._onFunctionDone(Promise.try(func));
return promise;
}
/**
* Start processing if not already running and wait for all tasks to complete
*
* @return {Promise[]} - An array of promises for all currently queued tasks
*/
ConcurrentCaller.prototype.runAll = function () {
// If nothing queued, return immediately
if (!this._deferred) {
return Promise.resolve([]);
}
var promises = this._queue.map(x => x.deferred.promise);
do {
var run = this._processNext();
}
while (run);
return this._deferred.promise.return(promises);
}
ConcurrentCaller.prototype.fcall = function (func) {
this._log("fcall() is deprecated -- use start()");
return this.start(func);
}
/**
* Wait for all running tasks to complete
*
* @return {Promise}
*/
ConcurrentCaller.prototype.wait = function () {
return this._deferred ? this._deferred.promise : Promise.resolve();
}
@ -122,62 +186,85 @@ ConcurrentCaller.prototype.stop = function () {
};
ConcurrentCaller.prototype._onFunctionDone = function (promise) {
var self = this;
ConcurrentCaller.prototype._processNext = function () {
if (this._numRunning >= this._numConcurrent) {
return false;
}
return promise.then(function (result) {
self._numRunning--;
// If there's a function to call and we're under the concurrent limit, run it now
var f = this._queue.shift();
if (!f) {
if (this._numRunning == 0 && !this._pausing) {
this._log("All tasks are done");
this._deferred.resolve();
}
else {
this._log("Nothing left to run -- waiting for running tasks to complete");
}
return false;
}
this._log("Running function ("
+ this._numRunning + "/" + this._numConcurrent + " running, "
+ this._queue.length + " queued)");
this._numRunning++;
f.func().bind(this).then(function (value) {
this._numRunning--;
self._log("Done with function ("
+ self._numRunning + "/" + self._numConcurrent + " running, "
+ self._queue.length + " queued)");
this._log("Done with function ("
+ this._numRunning + "/" + this._numConcurrent + " running, "
+ this._queue.length + " queued)");
return result;
this._waitForPause().bind(this).then(function () {
this._processNext();
});
f.deferred.resolve(value);
})
.catch(function (e) {
self._numRunning--;
this._numRunning--;
self._log("Error in function (" + self._numRunning + "/" + self._numConcurrent + ", "
+ self._queue.length + " in queue)");
this._log("Error in function (" + this._numRunning + "/" + this._numConcurrent + ", "
+ this._queue.length + " in queue)");
if (self.onError) {
self.onError(e);
if (this.onError) {
this.onError(e);
}
if (self.stopOnError && self._queue.length) {
self._log("Stopping on error: " + e);
self._queue = [];
if (this.stopOnError && this._queue.length) {
this._log("Stopping on error: " + e);
this._queue = [];
}
throw e;
})
.finally(function () {
// If there's a function to call and we're under the concurrent limit, run it now
var f = self._queue.shift();
if (f && self._numRunning < self._numConcurrent) {
// Wait until the specified interval has elapsed or the current
// pause (if there is one) is over, whichever is longer
let interval = self._interval;
let now = Date.now();
if (self._pauseUntil > now && (self._pauseUntil - now > interval)) {
interval = self._pauseUntil - now;
}
Promise.delay(interval)
.then(function () {
self._log("Running new function ("
+ self._numRunning + "/" + self._numConcurrent + " running, "
+ self._queue.length + " queued)");
self._numRunning++;
f.deferred.resolve(self._onFunctionDone(f.func()));
});
}
this._waitForPause().bind(this).then(function () {
this._processNext();
});
f.deferred.reject(e);
});
};
return true;
}
/**
* Wait until the specified interval has elapsed or the current pause (if there is one) is over,
* whichever is longer
*/
ConcurrentCaller.prototype._waitForPause = Promise.coroutine(function* () {
let interval = this._interval;
let now = Date.now();
if (this._pauseUntil > now && (this._pauseUntil - now > interval)) {
interval = this._pauseUntil - now;
}
this._pausing = true;
yield Promise.delay(interval);
this._pausing = false;
});
ConcurrentCaller.prototype._log = function (msg) {
if (this._logger) {
this._logger("[ConcurrentCaller] " + msg);
this._logger("[ConcurrentCaller] " + (this._id ? `[${this._id}] ` : "") + msg);
}
};