Green threads, userland threads, goroutines or fibers, they have
many names but for simplicity's sake I'll refer to them all as green
threads from now on.
In this article I want to explore how they work by implementing a
very simple example where we create our own green threads in 200
lines of Rust code. We'll be explaining everything along the way so
our main focus here is to understand them and learn how they work by
using simple, but working example.
Sharing files is one of the oldest but also most delicate tasks on
servers. If you would like to share your files in a simple but also
pretty secure way, here is how to do it with SSH / SFTP.
I’ve worked on websites for several years, both professionally and
for side projects. One day, I reflected on the fact that all of my
web development education had come from actually making websites. In
most cases, I’d have a specific problem, Google how to solve it, and
learn something new in the process.
I wondered what I was missing by never learning HTML in a
comprehensive way. Forget CSS and JavaScript. I’m just talking about
raw HTML. It might seem silly to go back to such a basic aspect of
web development after a decent amount of experience, but it’s easy
to become overconfident with a skill just because you know enough to
do a few useful things.
SQL pragma are statements (like SELECT … or CREATE TABLE …) that
change the database behaviors or call a special functions. This post
is a short list of SQLite pragma I use in my
projects built on SQLite, to get better performance and more
consistency.
Tom Witowsky (@devgummibeer)
shared on Twitter a scaling issue with his service
opendor.me, which helps any developer share
and highlight their open source work. As the service grows, more and
more data is stored in the database and needs to be browsed. One
particularly slow query that he needed help optimizing is fetching
random users, organizations, and repositories that are already part
of the service.
What if I needed to shuffle a list but couldn't hold the whole thing
in memory? Or what if I didn't want to shuffle a list, but just
traverse it in a shuffled manner? (That is, visit each element once
and only once, in a randomized way.) What if I wanted to traverse
it, but didn't want to precompute or store the traversal for some
reason?
This would allow me to publish items from a list in an order that
was unpredictable from the outside, but in fact deterministic and
based on a secret key, and without precomputing anything (or
worrying about collisions). Or I could use it to assign small
non-sequential IDs that would eventually saturate the space of
n-character strings in a pseudorandom order, obscuring the true size
of the set for anyone who could just view some subset of the
assigned IDs. They wouldn't even be able to tell if there were gaps
in the list of IDs they could observe.
The Rustonomicon digs into all the awful details that you need to
understand when writing Unsafe Rust programs.
Should you wish a long and happy career of writing Rust programs,
you should turn back now and forget you ever saw this book. It is
not necessary. However if you intend to write unsafe code — or just
want to dig into the guts of the language — this book contains lots
of useful information.
Facebook has released Cinder, used internally in Instagram to
improve Python performance, while another faster Python, called
Pyston, has released version 2.2 and made the project open source
(again).
Python is the world's second most popular programming language
(after JavaScript) according to some
surveys;
but it is by no means the fastest. A glance at
benchmarks
tells us that Python 3 computation is often many times slower than
compiled languages like C and Go, or JIT (Just-in-Time) compiled
languages like Java and JavaScript.
One reason is that the official implementation of Python, called
CPython, is an interpreted, dynamic language, and its creator Guido
Van Rossum has resisted optimising it for performance, saying in
2014
that "Python is about having the simplest, dumbest compiler
imaginable, and the official runtime semantics actively discourage
cleverness in the compiler like parallelizing loops or turning
recursion into loops."
With over 16 million pulls per month, Google’s distroless base
images are
widely used and depended on by large projects like Kubernetes and
Istio. These minimal images don’t include common tools like shells
or package managers, making their attack surface (and download
size!) smaller than traditional base images such as ubuntu or
alpine. Even with this additional protection, users could still
fall prey to typosquatting attacks, or receive a malicious image if
the distroless build process was compromised – making users
vulnerable to accidentally using a malicious image instead of the
actual distroless image. This problem isn’t unique to distroless
images – until now, there just hasn’t been an easy way to verify
that images are what they claim to be.
In the afternoon I noticed that Adam's Acanthoscurria
geniculata was upside
down. It was about to molt soon. It had webbed a mat on top of its
burrow and a plastic leaf the previous night.
Acanthoscurria geniculata upside down on its silk mat.
The spider had been lethargic for weeks, a possible sign of an
upcoming molt (ecdysis).
Acanthoscurria geniculata, right, and its exuviae, left.
When I checked again on the tarantula, slightly over 4 hours later, it
was resting upside down next to its molt (exuviae). It's best to leave
the spider in peace as much as possible during this delicate process.
Acanthoscurria geniculata freshly molted.
In the evening I carefully removed the exuviae. This can be used to
determine the sex of the
tarantula. The
tarantula was bought as a female and now I could confirm this by
examining the inside of the abdomen between the first pair of book
lungs.
Spermathecae of a juvenile Acanthoscurria geniculata.
In the above photo, taken with an iPhone 6S and macro lens the
spermathecae are barely visible. But good enough to confirm that this
is indeed a female.
Now the spider has to harden out before it can get its first
meal. Best is to wait about 2 weeks.
awk, named for its authors Aho, Weinberger, and Kernighan, is a very
cool little tool that you know exists and is installed on your
system, but you have never bothered to learn how to use. I’m here to
tell you that you really ought to!
If I stop for a moment to ponder the question, “what is the coolest
tool in Unix?”, the immediate answer is awk. If I insist on
pondering it for longer, giving each tool a moment for fair
evaluation, the answer is still awk. There are few tools as
perfectly suited to their problem as awk is.
Server-sent events
(SSE) is a
mechanism for sending updates from a server to a client. The
fundamental difference with
WebSockets is that the
communication only goes in one direction. In other words, the client
cannot send information to the server. For many usecases this is all
you might need. Indeed, if you just want to receive
notifications/updates/messages, then using a WebSocket is
overkill. Once you’ve implemented the SSE functionality on your
server, then all you need on a JavaScript client is an
EventSource. Trust
me, it’s very straightforward.
Web application load speed is the most basic part of UX. Neglecting
performance (load time) of your website can drive away users,
because most people tend to leave the page after about 3 seconds if
it doesn't load, therefore it's very important to make sure that
your application loads as fast as possible. But how can you achieve
that? There are many tricks and techniques for speeding up load time
of an application and most of them don't involve any actual code
change. In some cases, just a single line of config can give you a
huge performance improvement. So, in this article we will explore
the simplest and most effective tricks that will help you make your
web application load as fast as possibly can!
In this post, I will be sharing my favorite commandline one liners
that have made my workflow productive and more efficient. As a
regular Linux user, I have been using commandline extensively to
perform daily tasks such as creating files, navigating through
directories , moving files and editing files using vim.
This article will explore some examples and applications of Monte
Carlo simulations using the Go programming language. To keep this
article fun and interactive, after each Go code provided, you will
find a link to the Go Playground, where you can run it without
installing Go on your machine.
