Added the Funnel moduel

modules/funnel.js

@@ -0,0 +1,60 @@
+var util = require('util'),
+    cpus = require('os').cpus().length;
+
+module.exports = (function () {
+
+    ///////////////////////// PRIVATE METHODS /////////////////////////////////
+
+    var executors = cpus;  // # of parallel tasks executed at the same time
+    var queue     = [];
+    var running   = 0;
+
+    function execute() {
+        if (running >= executors || queue.length === 0) return;
+        ++running;
+        util.log('funnel|execute|running='+running);
+
+        var task = queue.shift();
+        var obj  = typeof(task[0]) === 'object' ? task.shift()  : null;
+        var func = task.shift();
+        var callback = (task.length > 0 && typeof(task[task.length -1]) === 'function') ? task.pop() : null;
+        var args = task; // task.slice(1, task.length -1);
+        args.push(done);
+        //console.log('obj:',obj,'args:'+args+', callback:' + callback);
+        func.apply(obj, args);
+
+        function done(err, result) {
+            --running;
+            util.log('funnel|execute|done|running='+running);
+            if (callback) {
+                process.nextTick(function () {
+                    callback.apply(obj, err, result);
+                });
+            }
+            process.nextTick(execute);
+        }
+    }
+
+    /////////////////////////// PUBLIC CLASS //////////////////////////////////
+
+    function Funnel(nbParallelExecutors) {
+        executors = nbParallelExecutors || executors;
+        util.log('funnel|executors='+executors);
+    }
+
+    // queue(function) or queue(function, param1,...,paramX) <- paramX must not be a function otherwise it will be taken as the callback
+    // queue(function, callback) or queue(function, param1,...,paramX, callback)
+    // queue(this, method) or queue(this, method, param1,...,paramX) <- paramX must not be a function otherwise it will be taken as the callback
+    // queue(this, method, callback) or queue(this, method, param1,...,paramX, callback)
+    Funnel.prototype.queue = function() {
+        var task =  Array.prototype.slice.call(arguments);
+        if (task.length < 1)
+            throw new Error('Funnel: the first parameter has to be the "function" to execute');
+        queue.push(task);
+        process.nextTick(execute);
+    };
+
+///////////////////////////////////////////////////////////////////////////////
+
+    return Funnel;
+})();

modules/tts.js

@@ -1,6 +1,7 @@
 var util  = require('util'),
     spawn = require('child_process').spawn,
     fs    = require('fs'),
+    Funnel = require('./funnel'),
     tts   = {
         init: function () {
             this.cache          = __dirname + '/cache';
@@ -9,6 +10,7 @@ var util  = require('util'),
             this.cacheCallbacks = {};
             this.cacheFiles     = {};
             this.ttl            = 0; // in ms, 0 == never expire
+            this.funnel = new Funnel();
 
             try { fs.mkdirSync(this.cache); } catch (e) { } // Ignore
 
@@ -46,7 +48,8 @@ var util  = require('util'),
             }
             // Generate it
             this.cacheCallbacks[filename] = [callback];
-            this.generate(filename, text, voice, generatedCallback);
+            this.funnel.queue(this, this.generate, filename, text, voice, generatedCallback);
+            //this.generate(filename, text, voice, generatedCallback);
 
             function generatedCallback(err, result) {
                 var $this = this;

tests/testFunnel.js

@@ -0,0 +1,91 @@
+var Funnel = require('../modules/funnel.js'),
+    util   = require('util'),
+    spawn  = require('child_process').spawn;
+
+function sleep(seconds, callback) {
+    var command  = '/bin/sleep',
+        options = {
+            "cwd": "/tmp/",
+            "env": {
+                "ENV":"development"
+            },
+            "customFds":[-1, -1, -1]
+        },
+        args = [
+            seconds || 1
+        ],
+        output = '';
+
+    util.log('sleep='+seconds);
+    var child = spawn(command, args, options);
+    child.on('exit', function (code, signal) {
+        util.log('sleep|exit=' + code + '|signal=' + (signal ? signal : 'none'));
+        if (code === 0) {
+            callback(null);
+        } else {
+            callback(new Error('sleep returned ' + code + ' or signal=' + (signal ? signal : 'none') + '\n' + output + '\n'));
+        }
+    });
+    child.stdout.on('data', function (data) {
+        util.log('sleep|stdout=' + data + '\n');
+        output += 'STDOUT:'+ data + '\n';
+    });
+    child.stderr.on('data', function (data) {
+        util.log('sleep|stderr=' + data + '\n');
+        output += 'STDERR:' + data + '\n';
+    });
+}
+
+
+function Sleep(time) {
+    this.time = time;
+}
+
+Sleep.prototype.doit = function(callback) {
+    util.log('going to Sleep ' + this.time + ' seconds');
+    sleep(this.time, callback);
+};
+
+Sleep.prototype.done = function(err, result) {
+    util.log('Sleep of ' + this.time + ' seconds, done');
+};
+
+var funnel = new Funnel(4);
+
+function sleepDone(err, result) {
+    util.log('testFunnel: sleep done');
+}
+
+var sleep1 = new Sleep(1);
+var sleep2 = new Sleep(2);
+var sleep3 = new Sleep(3);
+var sleep5 = new Sleep(5);
+var sleep10 = new Sleep(10);
+//sleep5.doit(sleep5.done);
+
+/*
+funnel.queue(sleep, 8, sleepDone);
+funnel.queue(sleep, 7, sleepDone);
+funnel.queue(sleep, 6, sleepDone);
+funnel.queue(sleep, 5, sleepDone);
+
+funnel.queue(sleep, 4, sleepDone);
+funnel.queue(sleep, 3, sleepDone);
+funnel.queue(sleep, 2, sleepDone);
+funnel.queue(sleep, 1, sleepDone);
+*/
+
+
+funnel.queue(sleep5, sleep5.doit, sleep5.done);
+funnel.queue(sleep10, sleep10.doit, sleep10.done);
+funnel.queue(sleep5, sleep5.doit, sleep5.done);
+funnel.queue(sleep10, sleep10.doit, sleep10.done);
+funnel.queue(sleep5, sleep5.doit, sleep5.done);
+funnel.queue(sleep1, sleep1.doit, sleep1.done);
+funnel.queue(sleep2, sleep2.doit, sleep2.done);
+funnel.queue(sleep3, sleep3.doit, sleep3.done);
+
+
+util.log('testFunnel: all done');
+
+