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How can I tell the difference between acceleration and up/down?
Einstein once proposed a thought experiment involving an elevator, basically, you can’t tell the difference between acceleration and gravity. Since I spend a lot of time on trains, metros, and buses, I’ve been curious about how my body can tell the difference between acceleration and going up or down a hill. Ultimately, I can tell…
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Linux Kernel: A Single Point of Failure
The last 24 hours have been an absolute disaster of downtime for me. I’m talking about servers being down kind of downtime, not the netflix-and-chill kind of downtime. The end result of this is that I discovered a new (to me) single point of failure This blog is one of several things that run on…
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I don’t know why ‘spaces’ won against ‘tabs’
I spent five years in a codebase with tabs instead of spaces. In my editor, I had indents set to 2 spaces. GitHub annoyingly defaults to 8 and requires customization in order to fix that. Because of the prevalence of spaces, we often had to maintain forks of tooling to support tabs because ‘spaces has…
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Wait, a 304 reply can change headers?
This evening I was optimizing some caching things for a web app I’ve been working on when I discovered something obvious when you think about it. Now, this is specific to Chrome-ish browsers and Firefox; I have no idea what will happen in Safari. Imagine the following PHP code: This code sets a random integer…
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Algorithms in PHP: Deques (circular buffers & linked lists)
In the previous post, I talked about priority queues. But in my explanation of an alternative implementation, I neglected to mention a few things: The alternative implementation isn’t for production; there are edge cases and unhandled errors. The alternative implementation is meant for a short queue, not an infinite one, such as the one you…
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Algorithms in PHP: Priority Queues (and Heaps)
This is the beginning of a series on implementing various algorithms in idiomatic PHP and their reference implementation (usually based on C++). Today we’re going to be talking about Priority Queues. A priority queue is where each value has an associated “priority” that determines which order things come out of the queue. The best real-life…
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Stateless-Passwordless Authentication using Cryptography
Say you want to ensure a user has access to a given email address (or phone number) on the device that they are trying to access your service. This is handy in a number of circumstances, but more importantly, can you authenticate the user without using a database? It turns out the answer is yes,…
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Um, since when is PHP faster than C++?
Last week I was working on porting an encryption scheme to PHP from C++, mostly to embed it in a website and make changes to it specific to my use case; and for fun. Needless to say, I was surprised to see my PHP version was faster than the C++ version. TL;DR: it isn’t faster,…
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Finally Getting ipv6 in WSL2
I really like using Windows to get around the web and write software, but I prefer Linux and bash for a CLI. Thus I tend to use WSL2 to do lots of things around the house. One thing missing for a long time is IPv6. Finally, today, I managed to get IPv6 working. Requirements If…
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A More In-Depth Reasoning behind PHP as a good language
Yesterday, I wrote a post over lunch that people just absolutely hated. It was great, in sort of weird way, to see that many people didn’t see what I saw when I posted it. I think it was a somewhat-not-gentle reminder that I see the world differently. The post was shared on Reddit and I…