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colinbendell / js-get-last-array-entry.js
Last active Jul 5, 2021
Compare Javascript v8 .slice.pop() vs. .slice(-1) memory and timing performance
View js-get-last-array-entry.js
const { PerformanceObserver, performance, constants } = require('perf_hooks');
const MAX_TEST_SIZE = Math.pow(2,16); //65536
// pre-allocate an array filled with objects (primatives like Number and Boolean have internal cpp optimizations)
const a = new Array(MAX_TEST_SIZE).map(v => ({}));
// pre-allocate an array for the results. this way we don't count the heap overhead from assigning the target variables
const b = new Array(MAX_TEST_SIZE);
let totalHeapUsed = 0;
let heapUsed = 0;
View macOS Install Image
cd ~/Downloads/
sudo hdiutil create -o InstallMedia -size 20G -layout SPUD -fs HFS+J -type SPARSE
sudo hdiutil attach InstallMedia.sparseimage -noverify -mountpoint /Volumes/install_build
sudo /Applications/Install\ macOS\ --volume /Volumes/install_build
sudo hdiutil detach -force /Volumes/Install\ macOS\ */
# ^^ Might fail; manually eject using finder.
sudo hdiutil convert InstallMedia.sparseimage -format UDZO -o InstallMedia.dmg
colinbendell / snowflake-r
Last active Feb 24, 2021
simple query in R backing against snowflake
View snowflake-r
options(dplyr.jdbc.classpath = "~/Downloads/snowflake-jdbc-3.5.3.jar")
# Update with credentials
snowflake_db <- src_snowflakedb(user = ""password = "", account = "ab123456", region = "us-east-1", opts = list(warehouse = "import", db = "cloudinary", schema = "public"))
benchmarks <- tbl(snowflake_db, in_schema("cto","lossy_benchmark_fast_v1_1"))
colinbendell /
Created Dec 4, 2017
Simple mass conversion of GIF to MP4 (h264/h265), WebM (vp8/vp9) and WebP
curl '' -o gipyurls.json
jq .[].gifs[].images.original.url gipyurls.json |cut -d / -f 5 | parallel -j 20 --gnu curl{}/giphy.gif -o {}.gif
parallel -j 20 --gnu "ffmpeg -f gif -i {} {}.h264.mp4" ::: *.gif
parallel -j 20 --gnu "ffmpeg -f gif -i {} -c:v libx265 {}.h265.mp4" ::: *.gif
parallel -j 20 --gnu "ffmpeg -f gif -i {} -c:v libvpx {}.vp8.webm" ::: *.gif
parallel -j 20 --gnu "ffmpeg -f gif -i {} -c:v libvpx-vp9 {}.vp9.webm" ::: *.gif
colinbendell / imagedata.js
Last active Dec 5, 2017
Extract a set of image information from a webpage
View imagedata.js
let imgData = Array.from(document.getElementsByTagName("img"))
.map(v => {
var rect = v.getBoundingClientRect();
var vHeight = (window.innerHeight || doc.documentElement.clientHeight);
var vWidth = (window.innerWidth || doc.documentElement.clientWidth);
var vDPR = window.devicePixelRatio;
return {
src: v.currentSrc,
cssWidth: v.clientWidth,
naturalWidth: v.naturalWidth,