Michael Taylor Scheer ScheerMT

Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

Automatic build versions from git in Xcode (and other goodies)

Installation procedure for pre-build actions to automatically populate Xcode Info.plist with dynamic data.

1. Xcode Scheme pre-action

Edit Xcode Scheme and add a pre-action script. Copy the contents of preaction.sh into the pre-action script box.

Using Python 3 + Google Cloud Vision API's OCR to extract text from photos and scanned documents

Just a quickie test in Python 3 (using Requests) to see if Google Cloud Vision can be used to effectively OCR a scanned data table and preserve its structure, in the way that products such as ABBYY FineReader can OCR an image and provide Excel-ready output.

The short answer: No. While Cloud Vision provides bounding polygon coordinates in its output, it doesn't provide it at the word or region level, which would be needed to then calculate the data delimiters.

On the other hand, the OCR quality is pretty good, if you just need to identify text anywhere in an image, without regards to its physical coordinates. I've included two examples:

####### 1. A low-resolution photo of road signs

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

iOS Cell Registration & Reusing with Swift Protocol Extensions and Generics

A common task when developing iOS apps is to register custom cell subclasses for both UITableView and UICollectionView. Well, that is if you don’t use Storyboards, of course.

Both UITableView and UICollectionView offer a similar API to register custom cell classes:

public func registerClass(cellClass: AnyClass?, forCellWithReuseIdentifier identifier: String)
public func registerNib(nib: UINib?, forCellWithReuseIdentifier identifier: String)

Himawari-8 animation tutorial

Here’s how to make animations like this one. It requires intermediate Unix command-line knowledge, to install some tools and to debug if they don’t work. You’ll need these utilities:

curl (or you can translate to wget)
convert and montage, part of ImageMagick
ffmpeg, plus whatever codecs
parallel, for iteration that’s nicer than shell for loops or xargs
run everything in zsh for leading 0s in numerical ranges to work

	"""
	Install Systemd units using Ansible

	Handles unit restarting and systemd daemon reloading when the unit changes.

	Also stops the unit correctly when uninstalled

	In your playbook put this file to library/systemdunit.py and make sure the
	server has python-sh package installed

	/**
	1. Install the Stylish(https://chrome.google.com/webstore/detail/stylish/fjnbnpbmkenffdnngjfgmeleoegfcffe?hl=en) extension for Chrome.
	2. Open up extension options and paste the whole CSS mentioned below.
	3. Specify the domain name to be `github.com`.
	4. Add a title and save.
	*/

	.header {
	padding-top: 10px;
	padding-bottom: 10px;

	Result: 1
	Items {
	TemplateId: "BADGE_BATTLE_ATTACK_WON"
	Badge {
	BadgeType: BADGE_BATTLE_ATTACK_WON
	BadgeRanks: 4
	Targets: "\nd\350\007"
	}
	}
	Items {

	import UIKit


	extension UICollectionReusableView {
	/// The default implementation of `defaultIdentifier()` uses `NSStringFromClass(class)` rather than `String(class)` so that the module name is includded.
	/// The hope being that this makes collisions unlikely making it unnnecessary to provide your own implementations.
	public class func defaultIdentifier() -> String {
	return NSStringFromClass(self)
	}
	}