SerhiiKozachenko

;; This stuff is pretty useful in many contexts.

 ...
 (:import (com.google.common.cache CacheBuilder CacheLoader))
 ...
  
  

quantataraxia.core> (with (-> (CacheBuilder/newBuilder)
                              (.weakKeys)

SerhiiKozachenko

(let [f (future
          (try
            (Thread/sleep 10000)
            (catch Throwable e
              (println e)
              (println "isInterrupted:" (.isInterrupted (Thread/currentThread)))
              (println "isAlive:" (.isAlive (Thread/currentThread)))
              (println "interrupted:" (Thread/interrupted)))))]
  (Thread/sleep 500)
  (future-cancel f)

SerhiiKozachenko

;; I keep forgetting how to do this stuff for some reason, so here goes:

(let [c (async/chan 1 (map #(* % 2)))]
  (async/go
    (loop []
      (when-let [e (async/<! c)]
        (println "async/go, e:" e)
        (recur))))
  (async/>!! c 1)
  (async/>!! c 2))

SerhiiKozachenko

;; www.Quanto.ga
;;
;; cp/upmap is from https://github.com/TheClimateCorporation/claypoole


quantataraxia.core> (do
                      (println "MAP:")
                      (println (time (doall (map (fn [x] (Thread/sleep x) x)
                                                  (range 500 50 -9)))))
                      (println "PMAP:")

SerhiiKozachenko

;; Performance of with-local-vars vs. atom vs. volatile vs. unsynchronized-mutable field.


(definterface IOObject
  (setVal [new-val])
  (getVal [])
  (oswap [f])
  (oswap [f x])
  (oswap [f x y])
  (oswap [f x y z]))

SerhiiKozachenko

PostgreSQL is Enough

• Simplify: move code into database functions
• Just Use Postgres for Everything
• PostgreSQL is the worlds’ best database
• Postgres is eating the database world
• Hacker News discussion

Background and Cron Jobs

SerhiiKozachenko

Videos http://www.pyvideo.org/

SerhiiKozachenko

Videos http://www.pyvideo.org/

SerhiiKozachenko

How to create root user

```
db.createUser({user: 'sa', pwd:'Serg1990SA', roles: ['root']})
Successfully added user: { "user" : "sa", "roles" : [ "root" ] }
```

Admin user
```
use admin

SerhiiKozachenko

1. Mongo DB ObjectId tricks:
 - http://www.mongotips.com/b/a-few-objectid-tricks/