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seanlinsley / malloc_trim.md
Created June 25, 2023 18:18
Prevent memory bloat on Linux with malloc_trim(0)

The default allocator on Linux has a tendency to free unused memory less aggressively than Mac and Windows. This creates the appearance of memory bloat. Calling malloc_trim(0) may not prevent out of memory events of that single process, but it helps you see the real memory usage, and frees up memory for use by other processes.

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@seanlinsley
seanlinsley / map_test.go
Last active January 3, 2023 17:53
// sourced from https://github.com/golang/go/issues/13271, with additions at the bottom of the file
package main
import (
"testing"
//
"reflect"
"unsafe"
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seanlinsley / iterable_weak_set.js
Last active August 2, 2023 03:58
Iterable WeakSet in JavaScript
// spec: https://github.com/tc39/proposal-weakrefs
// the spec contains an [iterable WeakMap implementation](https://github.com/tc39/proposal-weakrefs#iterable-weakmaps)
// NOTE: this WeakSet implementation is incomplete, only does what I needed
// In Firefox Nightly, visit about:config and enable javascript.options.experimental.weakrefs
class IterableWeakSet extends Set {
add(el) {
super.add(new WeakRef(el))
}
forEach(fn) {
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seanlinsley / chromedriver.rb
Created March 14, 2019 00:55
Ensures that chromedriver always matches the version of Chrome that's currently installed
# https://github.com/flavorjones/chromedriver-helper/issues/79
# http://chromedriver.storage.googleapis.com/index.html
require 'open-uri'
require 'shellwords'
executable = if RUBY_PLATFORM =~ /darwin/
'/Applications/Google Chrome.app/Contents/MacOS/Google Chrome'
else
'google-chrome'
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seanlinsley / better_precompile.rb
Created April 11, 2018 14:12
# Sprockets no longer creates undigested assets, so we have to emulate the old behavior to keep vendored JS libraries happy.
# This automatically uses the newest asset in cases where the same file exists multiple times (like with Capistrano).
#
# https://github.com/rails/sprockets-rails/issues/49
#
# digested: 4-star-aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa.jpg
# undigested: 4-star.jpg
assets_without_digest = -> do
digest = /(-{1}[a-z0-9]{64}*\.{1}){1}/
assets = Dir.glob File.join Rails.root, 'public/assets/**/*'
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seanlinsley / example_usage.js.erb
Last active July 10, 2021 03:13
Handlebars + ERB
Backbone.View.extend({
template: Handlebars.compile(
<%= embed('template.hbs').inspect %>
// some .hbs.erb files are also loaded
),
// ...
})
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seanlinsley / gem_analytics.rb
Last active November 1, 2017 17:33
# written for https://github.com/rails/rails/pull/30919
# 1. find all gems that depend on a particular gem
# 2. download them all
# 3. search through their source!
auth = 'Authorization:YOUR_API_KEY'
gems = JSON.parse(`curl -H '#{auth}' https://rubygems.org/api/v1/gems/activerecord/reverse_dependencies.json`); nil
gems.size
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seanlinsley / gist:2aa653362b11094cab5562016b1138f1
Created April 22, 2016 15:46
http://www.rubydoc.info/gems/rack/Rack/Lobster
,.---._
,,,, / `,
\\\\ / '\_ ;
|||| /\/``-.__\;'
::::/\/_
{{`-.__.-'(`(^^(^^^(^ 9 `.========='
{{{{{{ { ( ( ( ( (-----:=
{{.-'~~'-.(,(,,(,,,(__6_.'=========.
::::\/\
|||| \/\ ,-'/,
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seanlinsley / psqlprompt.sh
Last active June 10, 2016 18:40
# This asks the user if they want a read-only or read-write PSQL session. PSQL
# provides `\prompt`, but that doesn't provide a way to conditionally prompt
# based on whether it was being run interactively, or from bash-completion.
#
# Save this file to ~/.psqlprompt and add the below to ~/.psqlrc:
#
# \set read_only `bash ~/.psqlprompt`
# set default_transaction_read_only = :read_only;
#
function psql_prompt() {
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seanlinsley / retry.rb
Created December 27, 2015 00:07
begin
# your code
rescue
tries ||= 0
(tries += 1) < 3 ? retry : raise
end