I wanted to distribute the desktop client I made for https://cryptabyte.com/ as a single .exe, without any install or additional DLL’s. I used ILMerge, a tool from Microsoft Research to merge all the assemblies into one DLL. (If you have the .Net 4.5 beta installed like me, read this to target .Net 4.0.) I merged the assemblies with ILMerge:
ILMerge.exe /target:CryptAByte /out:Crypt.exe /targetplatform:"v4,C:Program Files (x86)Reference AssembliesMicrosoftFramework.NETFrameworkv4.0" CryptAByte.exe CryptAByte.CryptoLibrary.dll CryptAByte.Domain.dll Ionic.Zip.dll
ILMerge has the added benefit of making the merged DLL slightly smaller that than the sum of its parts.
I wanted my app to run on OS X too. After I stripped out the Entity Framework Code First data annotations from my data structures, it compiled and ran smoothly on OS X:
Actually, that doesn’t look very good at all. The Mono WinForms color scheme has some kind of sickly yellow tinge to it. I want to distribute this without requiring Mono to be installed, so I used macpack:
macpack -m:2 -o:. -r:/Library/Frameworks/Mono.framework/Versions/Current/lib/ CryptAByte.Domain.dll CryptAByte.CryptoLibrary.dll Ionic.Zip.dll -n:CryptAByte -a:CryptAByte.exe
The resulting .app was over 300MB! Looks like I’m going to have to write a native client for OS X.
Speaking of power usage, there are two nice apps to help monitor battery usage in OS X. CoconutBattery is mostly useful for checking the health of the battery.
MiniBatteryLogger is a more advanced tool that monitors power consumption and levels over time. You can use it to see how particular configurations are consuming power.
Another, slightly related app is fseventer. fseventer shows filesystem access in real time and provides nice insight into what apps are using the hard drive.
There is some confusion about the impact of background apps on iOS on battery life. Some prominent sources advise “quitting” all background apps to maximize batter life while others say that background apps are suspended and use no battery.
Actually, both statements are true. The confusing part is that iOS does not visually indicate suspended versus running background apps. Some apps are will obviously use power in the background – GPS navigation, instant messaging, or a music player. In other cases, it is not clear.
While there are many apps in the App Store that claim to help “improve” battery life, Apple does not allow access to any API which can have any impact on battery life. The only way to do so is to jailbreak your iPhone/iPad and install an app like BatteryDetective, which can measure how much power background apps and services actually use. (It also the only app which can tell you how much charge your iPhone battery can retain.)
In my brief testing, I made a few surprises. When an iPhone is not actively being used (the screen is off), the biggest power drain are the various radios: WiFi, 3G and Bluetooth. So first tip is to turn off any service you don’t need. SBSettings is useful in doing so with one tap:
Here are some sample measurements (not intended to be typical) in milli-amp drain in the background: iPod: 50mA, Gmail App: 185mA, Skype: 265mA. I found that some apps are seeming unnecessary energy-hogs: why does Skype use so much power in idle mode? I also found that the built-in Messages app was using way too much power – which went down after I deleted some of four years of received SMS and MMS messages.
BatteryMeter has a manual mode so you can take samples when toggling background services:
Unfortunately, measuring the power usage of apps and services is not practical for most users. So if you want to maximize battery life, just (1) turn off any function/service you don’t need and (2) remember that when and only when an app is doing anything in the background, it will drain the battery.
I recently gave a presentation/tutorial on information security for the Shanghai Rationalist group. Here are the PowerPoint slides with links (1MB).
Part 1: Secure Web Browsing
Part 2: Secure Networks
Part 3: Secure Email and IM
Part 4: Securing Operating Systems & mobile devices
Part 5: Secure Organizations
Conclusion: Limitations of Security Measures
It is very possible and probably common to go through a major team development effort without spending very much time reading other people’s code. It’s possible to spend an entire career like that. If over 90% of the code you read is your own, how will you learn to be a better programmer? No matter how many thousands of hours you spend programming, if you are doing only what you already know, you will not improve your skills. You must challenge yourself and sometimes fail to improve.
How can you read other people’s code?
- Read your team members code
- Read (& refactor) your old code – you probably forgot what you did already
- Read books on software & algorithms
- Participate in open source projects
- Read blogs on software
- Write a programming blog
(Batch files are not meant to be a substitute for CI)
Getting latest from TFS:
"C:Program Files (x86)Microsoft Visual Studio 10.0Common7IDEtf.exe" get
(use /preview to preview)
Getting latest from Subversion:
"C:Program Files (x86)VisualSVN Serverbinsvn.exe" update "F:webBeta"
Building a Visual Studio solution via MSBuild:
C:WindowsMicrosoft.NETFramework64v4.0.30319MSBuild.exe D:MisesMisesWeb.sln /p:configuration="Debug"
Checking whether the build succeded:
if %errorlevel% neq 0 exit /b %errorlevel%
REM BUILD OK, GO TO NEXT STEP
Copying build output:
xcopy F:webBetaMisesWebbin* F:webMisesbin /Y
REM /Y don’t prompt for overwrite
REM /S recursive
REM /Z restartable mode
REM /D only copy files newer than those at destination
REM More: http://www.computerhope.com/xcopyhlp.htm
I know this is nothing new, but I will share my perspective anyway:
How I fix bugs with unit tests:
- Write a unit test that reproduces the bug so the test fails
- Fix the bug so the unit test passes
- Send a link with both to the bug submitter
Why I like it:
- Saves time debugging – just run the unit test instead of recreating the bug scenario every time
- Creates a simple yes/no criteria to verify whether the bug is fixed
- Regression can be detected quickly in the future
- Better communication: bug is documented for other developers looking at this code
- If you don’t have time to fix the bug immediately, write a failing test. Then you or someone else can fix the bug later
- An organic way to increase code coverage for existing code
In February, I did a high-level review of the Mises.org CMS admin UI. Today I want to highlight both the public and private parts a part of it: the multimedia CMS.
The Mises.org Media Management System is part of the Mises.org open source project. It was started around 2004, and evolved slowly from there, with the latest release around February. It is used to manage over 6400 audio/visual files. Total document size is 275GB. Monthly bandwidth exceeds 10 terabytes.
The front-end features:
- Dynamic, AJAX-based interface build with JQuery UI
- Advanced search and browsing based navigation
- Detects the best media player for the current browser: HTML5, Flash, or Silverlight
- Extensive RSS support. Integrates with iTunes and iTunes University with iTunes-specific feed extensions
- Optimized for scalable deployment, CDN’s, SEO, external embedding, and social network sharing
The media asset management includes:
- Support for internal and externally hosted content: MP4, MP3, WMA, streaming video, & YouTube
- Integrated drag and drop uploader: management interface allows uploading multi-gigabyte media files straight from the browser us
- Meta data parsing: reads full meta information such as embedded thumbnails, duration, keywords, description, etc. Able to process all popular audio/video formats as well as PDF.
- Catalog builder: organizes files in a human-friendly format: http://library.mises.org/media/
- Define arbitrary hierarchical categories
- Versioning and multi-volume support.
- Backend: ASP.Net 4.0, MVC3 (frontend) & Web Forms (backend), Entity Framework, and SQL Server
- Frontend: JQuery UI, HTML5,
How to get it for your site:
Continue reading “Project highlight: Mises.org Multimedia CMS” »
I am excited by the growing popularity of the HTTPS Everywhere plugin. I became aware of it recently when users wrote me to complain that some part of Mises.org did not work over SSL. It turns out that our store
software redirects visitors to the official hostname, so going to https://mises.org/store would redirect to http://mises.org/store, which HTTPS Everywhere would redirect back to https://mises.org/store, and so on. I decided to fix this and also to fix the “this page includes other resources which are not secure” warning.
How I implemented automatic SSL switching:
- SSL proxy: We use CloudFlare as an SSL proxy. Even though we already had SSL configured on our Windows server, CloudFlare makes it easy to share SSL certificates between Windows and Linux servers, which is otherwise quite tricky. But it’s also great if your web server does not have SSL support.
- Relative (scheme-less) Urls: I removed the scheme from all our resources, so they look like <img src=”//images.mises.org/Theme/images/bf_lvmi.png” alt=”" /> We are transitioning to scheme-less URLs for everything. It allows users to choose HTTPS even if your site is served over HTTP by default.
- Request.Url.Scheme: I used to append the URL scheme used by the request when I was not sure if the client (rss reader, email, templates etc) would support scheme-less URL’s. But this has the disadvantage of not working with cached pages. So far, it seems that scheme-less URL’s are safe for all popular web clients.
I don’t think there was ever much sense in having the http://www. prefix in URI’s, so getting it down to just // is very nice.
How to find non-SSL resources on a page:
One frustrating debugging step for me used to be finding the http resources within a page. I would have to search for http resources in the source code. If the page references scripts that load other resources, this could get complicated. Fortunately, Google Chrome offers a simple solution – the network inspector can export information to a searchable JSON file:
- Open a new private browsing session in chrome (to disable your extensions, which may inject non-SSL links within the page)
- Alt-click and “Inspect element”
- Go to the Network tab
- Open the URL to inspect
- Right click inside the Network tab and “Copy all as HAR”
- Paste the JSON into notepad, and search for http:// resources
One last note: If you use third-party widgets or services which do not fully support SSL, please take the time to contact the vendor and request that they add full support for SSL.
You’ve probably heard about the “retina” displays on the iPhone 4/4S and the new iPad. These devices have double the display density of most other devices. The high-DPI displays of these devices are unique, but they won’t be for long. Most analysts are predicting that within a few months, Apple will introduce the same “retina” displays for their laptops as well. Once display manufacturers like Samsung and Sharp ramp up production, the rest of the industry will very likely follow.
In other words, we are facing the equivalent of the HD TV transition for personal computing. It will come to smartphones, tablets and then desktops. Speculating about the timeline of the transition is of course risky, but I suspect that there will be many high-DPI devices being sold by the end of 2012 – not limited to Apple. Certainly within a few years, we can expect the rest of the industry to follow. Because websites and applications can display content appropriate to the viewer’s hardware, they can gain a competitive advantage without imposing costs on non-HD visitors.
What this means in practical terms:
- You should start preparing double resolution graphics and video for new content, especially important elements like headers & front page content.
- If you target iPad or iPhone users, you should already be updating your website’s technology to support HD graphics & video.
- When initiating projects going forward, you should give increasing consideration to adding support for high-DPI resolutions.
Update: visual guide.