pithyless

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

pithyless

(ns background
  (:require [clojure.tools.logging :as log])
  (:import [java.util.concurrent]))

(defonce !executor (delay (java.util.concurrent.Executors/newCachedThreadPool)))

(defn background
  "Calls the fn passed in a thread from a thread pool, returning immediately.
  Unlike future, background does not swallow exceptions."
  [f]

pithyless

-- Optimized MYSQL schema for datomic
-- Unfortunately the bin/sql/mysql-*.sql bootstrapping files for datomic are not
-- very good, and can actually cause failures if not adjusted.
-- One symptom of this is the following error:

-- SQL Error (1071): Specified key was too long; max key length is 767 bytes.

-- Reported here: https://support.cognitect.com/entries/28462168-MySQL-Caveats

-- This is caused by the default collation for the `id` column possibly being

pithyless

(ns front.utilities.i18n-impl
  (:require [front.i18n]))

(defn build-domain-index [text-vec]
  (let [by-msgid (atom (transient {}))
        by-msg   (atom (transient {}))]
    (doseq [{:keys [s_message s_message_id] :as text} text-vec]
      (when-not (clojure.string/blank? s_message_id)
        (swap! by-msgid assoc! s_message_id text))
      (when-not (clojure.string/blank? s_message)