Merge pull request #8 from wilsonpage/dev

Change the way callback context is stored and scheduled jobs are cleared (closes #7)

7 files changed, 129 insertions, 70 deletions

diff --git a/bower.json b/bower.json
index a12556b..d9eb9c9 100644
--- a/bower.json
+++ b/bower.json
@@ -1,7 +1,7 @@
 {
   "name": "fastdom",
   "description": "Eliminates layout thrashing by batching DOM read/write operations",
-  "version": "0.4.2",
+  "version": "0.5.0",
   "main": "lib/fastdom.js",
   "scripts": [
     "lib/fastdom.js"
diff --git a/component.json b/component.json
index 56ebe0f..c73a26f 100644
--- a/component.json
+++ b/component.json
@@ -1,7 +1,7 @@
 {
   "name": "fastdom",
   "description": "Eliminates layout thrashing by batching DOM read/write operations",
-  "version": "0.4.2",
+  "version": "0.5.0",
   "main": "lib/fastdom.js",
   "scripts": [
     "lib/fastdom.js"
diff --git a/lib/fastdom.js b/lib/fastdom.js
index 6cba5c0..60b38d8 100644
--- a/lib/fastdom.js
+++ b/lib/fastdom.js
@@ -33,10 +33,12 @@
    * @constructor
    */
   function FastDom() {
-    this.reads = [];
-    this.writes = [];
+    this.lastId = 0;
+    this.jobs = {};
     this.mode = null;
     this.pending = false;
+    this.reads = [];
+    this.writes = [];
   }
 
   /**
@@ -47,8 +49,9 @@
    * @api public
    */
   FastDom.prototype.read = function(fn, ctx) {
-    add(this.reads, fn, ctx);
-    this.request('read');
+    var id = this._add(this.reads, fn, ctx);
+    this._request('read');
+    return id;
   };
 
   /**
@@ -59,30 +62,31 @@
    * @api public
    */
   FastDom.prototype.write = function(fn, ctx) {
-    add(this.writes, fn, ctx);
-    this.request('write');
+    var id = this._add(this.writes, fn, ctx);
+    this._request('write');
+    return id;
   };
 
   /**
    * Removes a job from
    * the 'reads' queue.
    *
-   * @param  {Function} fn
+   * @param  {Number} id
    * @api public
    */
-  FastDom.prototype.clearRead = function(fn) {
-    remove(this.reads, fn);
+  FastDom.prototype.clearRead = function(id) {
+    this._remove(this.reads, id);
   };
 
   /**
    * Removes a job from
    * the 'writes' queue.
    *
-   * @param  {Function} fn
+   * @param  {Number} id
    * @api public
    */
-  FastDom.prototype.clearWrite = function(fn) {
-    remove(this.writes, fn);
+  FastDom.prototype.clearWrite = function(id) {
+    this._remove(this.writes, id);
   };
 
   /**
@@ -93,31 +97,32 @@
    * @param  {String} type
    * @api private
    */
-  FastDom.prototype.request = function(type) {
+  FastDom.prototype._request = function(type) {
+    var mode = this.mode;
     var self = this;
 
     // If we are currently writing, we don't
     // need to scedule a new frame as this
     // job will be emptied from the write queue
-    if (this.mode === 'writing' && type === 'write') return;
+    if (mode === 'writing' && type === 'write') return;
 
     // If we are reading we don't need to schedule
     // a new frame as this read will be emptied
     // in the currently active read queue
-    if (this.mode === 'reading' && type === 'read') return;
+    if (mode === 'reading' && type === 'read') return;
 
     // If we are reading we don't need to schedule
     // a new frame and this write job will be run
     // after the read queue has been emptied in the
     // currently active frame.
-    if (this.mode === 'reading' && type === 'write') return;
+    if (mode === 'reading' && type === 'write') return;
 
     // If there is already a frame
     // scheduled, don't schedule another one
     if (this.pending) return;
 
     // Schedule frame (preserving context)
-    raf(function() { self.frame(); });
+    raf(function() { self._frame(); });
 
     // Set flag to indicate
     // a frame has been scheduled
@@ -125,6 +130,16 @@
   };
 
   /**
+   * Generates a unique
+   * id for a job.
+   *
+   * @return {Number}
+   */
+  FastDom.prototype._uniqueId = function() {
+    return ++this.lastId;
+  };
+
+  /**
    * Calls each job in
    * the list passed.
    *
@@ -136,18 +151,16 @@
    * @param  {Array} list
    * @api private
    */
-  FastDom.prototype.run = function(list) {
-    var fn;
+  FastDom.prototype._run = function(list) {
     var ctx;
+    var job;
+    var id;
 
-    while (list.length) {
-      fn = list.shift();
-      ctx = fn._dbctx || this;
-      try {
-        fn.call(ctx);
-      } catch (err) {
-        // TODO: console.error if options.silent === false.
-      }
+    while (id = list.shift()) {
+      job = this.jobs[id];
+      ctx = job.ctx || this;
+      delete this.jobs[id];
+      try { job.fn.call(ctx); } catch (e) {}
     }
   };
 
@@ -157,7 +170,7 @@
    *
    * @api private
    */
-  FastDom.prototype.frame = function() {
+  FastDom.prototype._frame = function() {
 
     // Set the pending flag to
     // false so that any new requests
@@ -167,12 +180,12 @@
     // Set the mode to 'reading',
     // then empty all read jobs
     this.mode = 'reading';
-    this.run(this.reads);
+    this._run(this.reads);
 
     // Set the mode to 'writing'
     // then empty all write jobs
     this.mode = 'writing';
-    this.run(this.writes);
+    this._run(this.writes);
 
     this.mode = null;
   };
@@ -182,8 +195,6 @@
    * by the number of frames
    * specified.
    *
-   * TODO:
-   *
    * @param  {Function} fn
    * @param  {Number}   frames
    * @api public
@@ -191,7 +202,7 @@
   FastDom.prototype.defer = function(fn, frames) {
     (function wrapped() {
       if (frames-- === 0) {
-        try { fn(); } catch (e){}
+        try { fn(); } catch (e) {}
       } else {
         raf(wrapped);
       }
@@ -199,40 +210,45 @@
   };
 
   /**
-   * Util
-   */
-
-  /**
-   * Adds a function to
-   * the given array.
+   * Adds a new job to
+   * the given queue.
    *
-   * If a context is given
-   * it is stored on the
-   * function object for
-   * later.
-   *
-   * @param {Array}   array
+   * @param {Array}   list
    * @param {Function} fn
    * @param {Object}   ctx
+   * @returns {Number} id
    * @api private
    */
-  function add(array, fn, ctx) {
-    if (ctx) fn._dbctx = ctx;
-    array.push(fn);
-  }
+  FastDom.prototype._add = function(list, fn, ctx) {
+    var id = this._uniqueId();
+
+    // Store this job
+    this.jobs[id] = {
+      fn: fn,
+      ctx: ctx
+    };
+
+    // Push the id of
+    // this job into
+    // the given queue
+    list.push(id);
+
+    // Return the id
+    return id;
+  };
 
   /**
-   * Removes a function
-   * from the given array.
-   *
-   * @param  {Array} array
-   * @param  {Function} item
+   * Removes a job from
+   * the given queue.
+   * @param  {Array} list
+   * @param  {Number} id
    * @api private
    */
-  function remove(array, fn) {
-    var index = array.indexOf(fn);
-    if (~index) array.splice(index, 1);
-  }
+  FastDom.prototype._remove = function(list, id) {
+    var index = list.indexOf(id);
+    if (~index) list.splice(index, 1);
+    delete this.jobs[id];
+  };
 
   /**
    * Expose 'FastDom'
diff --git a/package.json b/package.json
index f7a28a5..5022496 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "fastdom",
   "description": "Eliminates layout thrashing by batching DOM read/write operations",
-  "version": "0.4.2",
+  "version": "0.5.0",
   "main": "lib/fastdom.js",
   "scripts": {
     "test": "./node_modules/.bin/mocha-phantomjs test/index.html"
diff --git a/test/setup.js b/test/setup.js
index bfe48f1..0844695 100644
--- a/test/setup.js
+++ b/test/setup.js
@@ -9,4 +9,10 @@ var raf = window.requestAnimationFrame
 var FastDom = fastdom.constructor;
 
 // Alias chai.assert
-var assert = chai.assert;
\ No newline at end of file
+var assert = chai.assert;
+
+function objectLength(object) {
+  var l = 0;
+  for (var key in object) l++;
+  return l;
+}
\ No newline at end of file
diff --git a/test/test.clear.js b/test/test.clear.js
index be273a4..6b274fe 100644
--- a/test/test.clear.js
+++ b/test/test.clear.js
@@ -5,8 +5,8 @@ suite('Clear', function(){
     var fastdom = new FastDom();
     var read = sinon.spy();
 
-    fastdom.read(read);
-    fastdom.clearRead(read);
+    var id = fastdom.read(read);
+    fastdom.clearRead(id);
 
     raf(function() {
       assert(!read.called);
@@ -19,8 +19,8 @@ suite('Clear', function(){
     var read = sinon.spy();
     var read2 = sinon.spy();
 
-    fastdom.read(read);
-    fastdom.clearRead(read2);
+    var id = fastdom.read(read);
+    fastdom.clearRead(id);
 
     raf(function() {
       assert(!read2.called);
@@ -33,9 +33,9 @@ suite('Clear', function(){
     var read = sinon.spy();
     var write = sinon.spy();
 
-    fastdom.write(write);
+    var id = fastdom.write(write);
     fastdom.read(function() {
-      fastdom.clearWrite(write);
+      fastdom.clearWrite(id);
 
       raf(function() {
         assert(!read.called);
@@ -47,9 +47,9 @@ suite('Clear', function(){
   test("Should not run 'write' job if cleared", function(done) {
     var fastdom = new FastDom();
     var write = sinon.spy();
+    var id = fastdom.write(write);
 
-    fastdom.write(write);
-    fastdom.clearWrite(write);
+    fastdom.clearWrite(id);
 
     raf(function() {
       assert(!write.called);
diff --git a/test/test.set.js b/test/test.set.js
index c8d9989..62f7e5f 100644
--- a/test/test.set.js
+++ b/test/test.set.js
@@ -124,4 +124,41 @@ suite('Set', function() {
       done();
     }, ctx);
   });
+
+  test("Should have empty job hash when batch complete", function(done) {
+    var fastdom = new FastDom();
+
+    fastdom.read(function(){});
+    fastdom.read(function(){});
+    fastdom.write(function(){});
+    fastdom.write(function(){});
+
+    // Check there are four jobs stored
+    assert.equal(objectLength(fastdom.jobs), 4);
+
+    raf(function() {
+      assert.equal(objectLength(fastdom.jobs), 0);
+      done();
+    });
+  });
+
+  test("Should maintain correct context if single method is registered twice", function(done) {
+    var fastdom = new FastDom();
+    var ctx1 = { foo: 'bar' };
+    var ctx2 = { bar: 'baz' };
+
+    function shared(){}
+
+    var spy1 = sinon.spy(shared);
+    var spy2 = sinon.spy(shared);
+
+    fastdom.read(spy1, ctx1);
+    fastdom.read(spy2, ctx2);
+
+    raf(function() {
+      spy1.calledOn(ctx1);
+      spy2.calledOn(ctx2);
+      done();
+    });
+  });
 });
\ No newline at end of file