| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
| //addEventListener polyfill 1.0 / Eirik Backer / MIT Licence | |
| (function(win, doc){ | |
| if(win.addEventListener)return; //No need to polyfill | |
| function docHijack(p){var old = doc[p];doc[p] = function(v){return addListen(old(v))}} | |
| function addEvent(on, fn, self){ | |
| return (self = this).attachEvent('on' + on, function(e){ | |
| var e = e || win.event; | |
| e.preventDefault = e.preventDefault || function(){e.returnValue = false} | |
| e.stopPropagation = e.stopPropagation || function(){e.cancelBubble = true} |
This article has been given a more permanent home on my blog. Also, since it was first written, the development of the Promises/A+ specification has made the original emphasis on Promises/A seem somewhat outdated.
Promises are a software abstraction that makes working with asynchronous operations much more pleasant. In the most basic definition, your code will move from continuation-passing style:
getTweetsFor("domenic", function (err, results) {
// the rest of your code goes here.
JavaScript engines such as Google’s V8 (Chrome, Node) are specifically designed for the fast execution of large JavaScript applications. As you develop, if you care about memory usage and performance, you should be aware of some of what’s going on in your user’s browser’s JavaScript engine behind the scenes.
Continue reading Writing Fast, Memory-Efficient JavaScript, great general overview of a Google employee
The spec has moved to a repo: https://github.com/defunctzombie/package-browser-field-spec to facilitate collaboration.
Sometimes you want to have a subdirectory on the master branch be the root directory of a repository’s gh-pages branch. This is useful for things like sites developed with Yeoman, or if you have a Jekyll site contained in the master branch alongside the rest of your code.
For the sake of this example, let’s pretend the subfolder containing your site is named dist.
Remove the dist directory from the project’s .gitignore file (it’s ignored by default by Yeoman).
| // 32 bit FNV-1a hash | |
| // Ref.: http://isthe.com/chongo/tech/comp/fnv/ | |
| function fnv32a( str ) | |
| { | |
| var FNV1_32A_INIT = 0x811c9dc5; | |
| var hval = FNV1_32A_INIT; | |
| for ( var i = 0; i < str.length; ++i ) | |
| { | |
| hval ^= str.charCodeAt(i); | |
| hval += (hval << 1) + (hval << 4) + (hval << 7) + (hval << 8) + (hval << 24); |
| node_modules |
| angular.module('ymusica').controller('AlbumSearch', ['$scope', 'Albums', 'Artists', '$q', function($scope, albums, artists, $q) { | |
| $scope.albums = []; | |
| $scope.artists = []; | |
| var terms = new Rx.Subject(); | |
| $scope.searchMusic = terms.onNext.bind(terms); | |
| terms.sample(250) |
One of the best ways to reduce complexity (read: stress) in web development is to minimize the differences between your development and production environments. After being frustrated by attempts to unify the approach to SSL on my local machine and in production, I searched for a workflow that would make the protocol invisible to me between all environments.
Most workflows make the following compromises:
Use HTTPS in production but HTTP locally. This is annoying because it makes the environments inconsistent, and the protocol choices leak up into the stack. For example, your web application needs to understand the underlying protocol when using the secure flag for cookies. If you don't get this right, your HTTP development server won't be able to read the cookies it writes, or worse, your HTTPS production server could pass sensitive cookies over an insecure connection.
Use production SSL certificates locally. This is annoying