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How to C (as of 2016) This is a draft I wrote in early 2015 and never got around to publishing. Here's the mostly unpolished version because it wasn't doing anybody any good sitting in my drafts folder. The simplest change was updating year 2015 to 2016 at publication time. Feel free to submit fixes/improvements/complaints as necessary. - Matt The first rule of C is don't write C if you can avoid it. If you must write in C, you should follow modern rules. C has been around since the early 1970s . People have "learned C" at various points during its evolution, but knowledge usually get stuck after learning, so everybody has a different set of things they believe about C based on the year(s) they first started learning. It's important to not remain stuck in your "things I learned in the 80s/90s" mindset of C development. This page assumes you are on a modern platform conformi...

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Redis CRC Speed Improvements (Spoiler: short attention havers can follow direct link to results .) Redis has a CRC-64 implementation and a lot of people have copied it into other projects. Redis also has a CRC-16 implementation but fewer people have copied that one . They work, but they could be better. CRCs are inherently non-parallelizable because the C in CRC stands for Cyclical, meaning the value of the next iteration depends depends on the previous iteration. There's no simple unrolling of loops to process multiple bytes per iteration. Redis uses CRC-64 in three places: adding a checksum when migrating keys across instances (and verifying said checksum) adding a checksum to RDB output, both for replication and persistence (optional, can be disabled by config option because of slow performance) user-initiated memory testing Redis uses CRC-16 in one place: hash functi...