From 66d6bbe7f174bc3adebf71d23d43d6bf05a64fb3 Mon Sep 17 00:00:00 2001
From: Graeme Yeates <yeatesgraeme@gmail.com>
Date: Sat, 23 Jul 2016 11:13:22 -0400
Subject: [PATCH 1/2] Unroll simple loop abstractions

---
 lib/internal/queue.js | 27 +++++++++++++--------------
 lib/priorityQueue.js  |  7 +++----
 lib/race.js           |  7 +++----
 3 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/lib/internal/queue.js b/lib/internal/queue.js
index 41d6c904f..d318ba03c 100644
--- a/lib/internal/queue.js
+++ b/lib/internal/queue.js
@@ -1,4 +1,4 @@
-import arrayEach from 'lodash/_arrayEach';
+import indexOf from 'lodash/_baseIndexOf';
 import isArray from 'lodash/isArray';
 import noop from 'lodash/noop';
 import rest from 'lodash/rest';
@@ -23,15 +23,16 @@ export default function queue(worker, concurrency, payload) {
         if (!isArray(data)) {
             data = [data];
         }
-        if(data.length === 0 && q.idle()) {
+        if (data.length === 0 && q.idle()) {
             // call drain immediately if there are no tasks
             return setImmediate(function() {
                 q.drain();
             });
         }
-        arrayEach(data, function(task) {
+
+        for (var i = 0, l = data.length; i < l; i++) {
             var item = {
-                data: task,
+                data: data[i],
                 callback: callback || noop
             };
 
@@ -40,8 +41,7 @@ export default function queue(worker, concurrency, payload) {
             } else {
                 q._tasks.push(item);
             }
-
-        });
+        }
         setImmediate(q.process);
     }
 
@@ -49,20 +49,19 @@ export default function queue(worker, concurrency, payload) {
         return rest(function(args){
             workers -= 1;
 
-            arrayEach(tasks, function (task) {
-                arrayEach(workersList, function (worker, index) {
-                    if (worker === task) {
-                        workersList.splice(index, 1);
-                        return false;
-                    }
-                });
+            for (var i = 0, l = tasks.length; i < l; i++) {
+                var task = tasks[i];
+                var index = indexOf(workersList, task, 0);
+                if (index >= 0) {
+                    workersList.splice(index)
+                }
 
                 task.callback.apply(task, args);
 
                 if (args[0] != null) {
                     q.error(args[0], task.data);
                 }
-            });
+            }
 
             if (workers <= (q.concurrency - q.buffer) ) {
                 q.unsaturated();
diff --git a/lib/priorityQueue.js b/lib/priorityQueue.js
index d8b601638..0af01577c 100644
--- a/lib/priorityQueue.js
+++ b/lib/priorityQueue.js
@@ -1,4 +1,3 @@
-import arrayEach from 'lodash/_arrayEach';
 import isArray from 'lodash/isArray';
 import noop from 'lodash/noop';
 
@@ -57,9 +56,9 @@ export default function(worker, concurrency) {
             nextNode = nextNode.next;
         }
 
-        arrayEach(data, function(task) {
+        for (var i = 0, l = data.length; i < l; i++) {
             var item = {
-                data: task,
+                data: data[i],
                 priority: priority,
                 callback: callback
             };
@@ -69,7 +68,7 @@ export default function(worker, concurrency) {
             } else {
                 q._tasks.push(item);
             }
-        });
+        }
         setImmediate(q.process);
     };
 
diff --git a/lib/race.js b/lib/race.js
index 55d37ee7d..693762787 100644
--- a/lib/race.js
+++ b/lib/race.js
@@ -1,5 +1,4 @@
 import isArray from 'lodash/isArray';
-import arrayEach from 'lodash/_arrayEach';
 import noop from 'lodash/noop';
 import once from './internal/once';
 
@@ -44,7 +43,7 @@ export default function race(tasks, callback) {
     callback = once(callback || noop);
     if (!isArray(tasks)) return callback(new TypeError('First argument to race must be an array of functions'));
     if (!tasks.length) return callback();
-    arrayEach(tasks, function (task) {
-        task(callback);
-    });
+    for (var i = 0, l = tasks.length; i < l; i++) {
+        tasks[i](callback);
+    }
 }

From 5b8931d40205778a5bf4e936efb10046b79eb018 Mon Sep 17 00:00:00 2001
From: Graeme Yeates <yeatesgraeme@gmail.com>
Date: Sat, 23 Jul 2016 11:13:31 -0400
Subject: [PATCH 2/2] Add filter benchmark

---
 perf/suites.js | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/perf/suites.js b/perf/suites.js
index 244b32b67..dfef9f610 100644
--- a/perf/suites.js
+++ b/perf/suites.js
@@ -1,5 +1,6 @@
 var _ = require("lodash");
 var tasks;
+var count;
 
 module.exports = [{
     name: "each",
@@ -93,6 +94,42 @@ module.exports = [{
             async.setImmediate(cb);
         }, done);
     }
+}, {
+    name: "filter",
+    args: [
+        [10],
+        [300],
+        [10000]
+    ],
+    setup: function(c) {
+        count = c;
+        tasks = _.range(count);
+    },
+    fn: function(async, done) {
+        async.filter(tasks, function(num, cb) {
+            async.setImmediate(function() {
+                cb(null, num > (count / 2));
+            });
+        }, done);
+    }
+}, {
+    name: "filterLimit",
+    args: [
+        [10],
+        [300],
+        [10000]
+    ],
+    setup: function(c) {
+        count = c;
+        tasks = _.range(count);
+    },
+    fn: function(async, done) {
+        async.filterLimit(tasks, 10, function(num, cb) {
+            async.setImmediate(function() {
+                cb(null, num > (count / 2));
+            });
+        }, done);
+    }
 }, {
     name: "eachOf",
     // args lists are passed to the setup function