jboner

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

XVilka

THIS GIST WAS MOVED TO TERMSTANDARD/COLORS REPOSITORY.

PLEASE ASK YOUR QUESTIONS OR ADD ANY SUGGESTIONS AS A REPOSITORY ISSUES OR PULL REQUESTS INSTEAD!

RobertAKARobin

Python is not a great programming language.

It's great for beginners. Then it turns into a mess.

• What's good
• What should be good
• What's "meh"
• What's bad
• What's bad about the culture

trevnorris

The prep-script.sh will setup the latest Node and install the latest perf version on your Linux box.

When you want to generate the flame graph, run the following (folder locations taken from install script):

sudo sysctl kernel.kptr_restrict=0
# May also have to do the following:
# (additional reading http://unix.stackexchange.com/questions/14227/do-i-need-root-admin-permissions-to-run-userspace-perf-tool-perf-events-ar )
sudo sysctl kernel.perf_event_paranoid=0

oakes

Contents

• Why care about Rust?
• The Toolchain
• Creating a New Project
• Modules
• Crates
• Types
• References
• Mutability

jFransham

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers

jlong

var parser = document.createElement('a');
parser.href = "http://example.com:3000/pathname/?search=test#hash";

parser.protocol; // => "http:"
parser.hostname; // => "example.com"
parser.port;     // => "3000"
parser.pathname; // => "/pathname/"
parser.search;   // => "?search=test"
parser.hash;     // => "#hash"
parser.host;     // => "example.com:3000"

andyyou

Rails 5.2 with webpacker, bootstrap, stimulus starter

This gist will collects all issues we solved with Rails 5.2 and Webpacker

Create Project

# Last few parameters(--skip-* part) is only my habbit not actully required
$ rails new <project_name> --webpack=stimulus --database=postgresql --skip-coffee --skip-test

kajott

#if 0  // self-compiling code: chmod +x this file and run it like a script
BINARY=vaapi_egl_interop_example
gcc -std=c99 -Wall -Wextra -pedantic -Werror -g -fsanitize=address -o $BINARY $0 \
    `pkg-config libavcodec libavformat libavutil libva gl egl libdrm --cflags --libs` \
    -lX11 -lva-x11 -lva-drm || exit 1
test "$1" = "--compile-only" && exit 0
exec env ASAN_OPTIONS=fast_unwind_on_malloc=0 ./$BINARY $*
#endif  /*

Minimal example application for hardware video decoding on Linux and display

corsix

Exploiting Lua 5.1 on 32-bit Windows

The following Lua program generates a Lua bytecode program called ignore-unsigned-sga.fnt, which in turn loads a DLL from within an extremely locked down Lua 5.1 sandbox in a program called RelicCOH2.exe. The remainder of this document attempts to explain how this program works by a whirlwind tour of relevent bits of the Lua 5.1 virtual machine.

if string.dump(function()end):sub(1, 12) ~= "\27Lua\81\0\1\4\4\4\8\0" then
  error("This generator requires a 32-bit version of Lua 5.1")
end

local function outer()
  local magic -- In bytecode, the stack slot corresponding to this local is changed