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require "digest"
require "rack"
# This class encapsulates a unit of work done for a particular tenant, connected to that tenant's database.
# ActiveRecord makes it _very_ hard to do in a simple manner and clever stuff is required, but it is knowable.
#
# What this class provides is a "misuse" of the database "roles" of ActiveRecord to have a role per tenant.
# If all the tenants are predefined, it can be done roughly so:
#
# ActiveRecord::Base.legacy_connection_handling = false if ActiveRecord::Base.respond_to?(:legacy_connection_handling)
@peterc
peterc / sinatra-react.md
Last active February 20, 2025 18:20
How to set up a basic Sinatra + React webapp

How to set up a basic Sinatra + React webapp in 2025

Let's say you want to use Ruby for the backend of a basic webapp but React on the frontend. Here's how.

(Note: All tested on January 13, 2025 with Ruby 3.3, Sinatra 4.1.1, and React 18.3. Configs may change over time.)

First, create the app folder and set up Sinatra:

mkdir my-sinatra-react-app
@Eric-Guo
Eric-Guo / DOM3D.js
Created March 27, 2024 14:23 — forked from OrionReed/dom3d.js
3D DOM viewer, copy-paste this into your console to visualise the DOM topographically.
// 3D Dom viewer, copy-paste this into your console to visualise the DOM as a stack of solid blocks.
// You can also minify and save it as a bookmarklet (https://www.freecodecamp.org/news/what-are-bookmarklets/)
(() => {
const SHOW_SIDES = false; // color sides of DOM nodes?
const COLOR_SURFACE = true; // color tops of DOM nodes?
const COLOR_RANDOM = false; // randomise color?
const COLOR_HUE = 190; // hue in HSL (https://hslpicker.com)
const MAX_ROTATION = 180; // set to 360 to rotate all the way round
const THICKNESS = 20; // thickness of layers
const DISTANCE = 10000; // ¯\\_(ツ)_/¯
@hopsoft
hopsoft / build_insert_query.rb
Created March 15, 2024 18:00
Get the SQL for an insert statement from ActiveRecord
# Builds an SQL insert query for a given record
#
# @param record [ActiveRecord::Base] Record used to build the SQL insert query
# @return [String] SQL insert query
def build_insert_query(record)
columns = record.class.columns.reject { |col| col.name == record.class.primary_key }
values = columns.map { |col| record[col.name] }
insert_manager = Arel::InsertManager.new
insert_manager.into(record.class.arel_table)
insert_manager.insert(columns.zip(values)).to_sql
@felipecsl
felipecsl / decryptRailsCookie.ts
Created January 25, 2024 13:03
Typescript/Node function to decrypt Rails 7.1 encrypted session cookies
import crypto from 'crypto';
import { promisify } from "node:util";
const pbkdf2 = promisify(crypto.pbkdf2);
// Works with Rails 7.1.3
// secretKeyBase is Rails.application.secret_key_base
async function decryptCookie(encryptedCookie: string, cookieName: string, secretKeyBase: string) {
const cookie = decodeURIComponent(encryptedCookie);
const [data, iv, authTag] = cookie.split("--").map(v => Buffer.from(v, 'base64'));

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@amirrajan
amirrajan / demo.md
Last active October 30, 2022 22:22
DragonRuby Game Toolkit - Tech Demo Source Code
the-keeper-iteration-2.mp4
@kddnewton
kddnewton / json.rb
Last active December 18, 2024 17:34
JSON parser with pattern matching
require "json"
struct = { "a" => 1, "b" => 2, "c" => [1, 2, 3], "d" => [{ "e" => 3 }, nil, false, true, [], {}] }
source = JSON.dump(struct)
tokens = []
index = 0
until source.empty?
tokens <<
@TrungNguyen1909
TrungNguyen1909 / mul53.c
Last active April 25, 2025 16:03
Apple H10 Mul53 extension
#if 0
Apple A11 (H10) introduces 2 propietary instructions called mul53lo.2d and mul53hi.2d. All of which belongs to Mul53 extensions.
Defintions:
- mul53lo.2d Vd, Vm: Multiplies 2 53-bit doublewords in the Vn vector with 2 53-bit doublewords in Vm vector and store 53 lowest bits in the Vn vector.
- mul53hi.2d Vd, Vm: Multiplies 2 53-bit doublewords in the Vn vector with 2 53-bit doublewords in Vm vector and store the result shifted 53 bits in the Vn vector.
Encodings:
- mul53lo.2d Vd, Vm: 0x00200000 | (m << 5) | (d << 0)
- mul53hi.2d Vd, Vm: 0x00200400 | (m << 5) | (d << 0)