kjmph

-- Based off IETF draft, https://datatracker.ietf.org/doc/draft-peabody-dispatch-new-uuid-format/

create or replace function uuid_generate_v7()
returns uuid
as $$
begin
  -- use random v4 uuid as starting point (which has the same variant we need)
  -- then overlay timestamp
  -- then set version 7 by flipping the 2 and 1 bit in the version 4 string
  return encode(

bjeanes

CREATE EXTENSION IF NOT EXISTS "uuid-ossp";

-- My port of https://github.com/kurttheviking/uuid-with-v6-js
-- A hacky translation of:
--   - http://gh.peabody.io/uuidv6/
--   - https://tools.ietf.org/html/draft-peabody-dispatch-new-uuid-format
CREATE OR REPLACE FUNCTION uuid_v1_to_v6(v1 uuid)
RETURNS uuid AS $$
DECLARE
    v6 text;

frankpf

type Omit<T, K extends keyof T> = Pick<T, Exclude<keyof T, K>>

/* Source: https://github.com/Microsoft/TypeScript/pull/21316#issuecomment-364982638 */
type DiscriminateUnion<Union, TagKey extends keyof Union, TagValue extends Union[TagKey]> =
	Union extends Record<TagKey, TagValue> ? Union : never

type MatchingFunc<A extends { kind: string }, K extends A['kind'], U> = (a: Omit<DiscriminateUnion<A, 'kind', K>, 'kind'>) => U

function match<A extends { kind: string }>(discriminant: A) {

andymatuschak

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

plentz

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

andrzejsliwa

%% See LICENSE for licensing information.
-module(cowboy_debug).

-export([onrequest_hook/1]).
-export([onresponse_hook/4]).

onrequest_hook(Req) ->
    Method = to_string(extract(cowboy_req:method(Req))),
    Path   = to_string(extract(cowboy_req:path(Req))),
    Params = params_to_string(extract(cowboy_req:qs_vals(Req))),

bohde

# graphite-web install is hardcoded in setup.cfg to /opt/graphite
sudo mkdir /opt/graphite
sudo chown brad.users /opt/graphite

# run under python2.7 virtualenv
virtualenv --python=python2.7 ~/ve/graphite
source ~/ve/graphite/bin/activate

# install the necessary python packages (simplejson is for flot graphs)
pip install graphite-web carbon whisper django django-tagging uwsgi simplejson

felixge

# Here a few bash one-liners that helped me analyze / fight a weak DOS attack against debuggable.com. Mostly for future reference.
# The attacker was opening lots of tcp connections without sending data, I believe it's called a SYN flood, see: http://tools.ietf.org/html/rfc4987#section-3.2

# Step 0: Check what is going on at port 80
$ netstat -tan | grep ':80 ' | awk '{print $6}' | sort | uniq -c

# Step 1: Increase the number of available fds
$ ulimit -n 32000

# Step 2: Restart your webserver, for me: