ChrisBlom

(ns datomic-cdc.core
  "proof-of-concept that shows how setup change-data-capture for datomic"
  (:require [datomic.api :as d]))

(def processed-t- (atom nil))

(defn start-cdc-thread
  "starts a new thread to processes all past transactions starting at start-t, then continues processing incoming transactions, using the provided `change-handler`

   `change-handler` must be a function that takes a single map argument with

ChrisBlom

import com.github.benmanes.caffeine.cache.Caffeine
import com.github.benmanes.caffeine.cache.Ticker
import io.kotest.matchers.shouldBe
import org.junit.jupiter.api.Test
import java.util.concurrent.ConcurrentHashMap
import java.util.concurrent.atomic.AtomicLong
import kotlin.time.Duration
import kotlin.time.Duration.Companion.seconds
import kotlin.time.toJavaDuration

ChrisBlom

import io.micrometer.core.instrument.MeterRegistry
import io.micrometer.core.instrument.Tag
import java.time.Instant
import java.util.concurrent.TimeUnit
import java.util.concurrent.atomic.AtomicLong
import java.util.function.ToDoubleFunction

fun MeterRegistry.timeGaugeMillis(name: String, tags: Iterable<Tag>, initialValue: Long = 0): (Instant) -> Unit {
    val a = AtomicLong(initialValue)
    a.apply {

ChrisBlom

  (let [l [0 0 1 1 1 14 5 13 6 3 ]
      m   [0.01 0.02 0.05 0.1 0.2 0.5 1 2 5 10 20 50 100]
      subtotals (map * m l)
      total (reduce + subtotals)]
  (doseq [[munt totaal]  (sort-by key > (zipmap m subtotals))]
    (printf "%s\t%.2f%n" munt (float totaal)))
  total)

ChrisBlom

(defun add-clj-format-before-save ()
  (interactive)
  (add-hook 'before-save-hook
            'cider-format-buffer
            t
	    t))

(add-hook 'clojure-mode-hook 'add-clj-format-before-save)

ChrisBlom

(defn invert
  "inverts a graph represented as a map from source to target nodes"
  [graph]
  (reduce-kv (fn [acc src trgs]
               (if (seq trgs)
                 (reduce (fn [acc- trg]
                           (update acc- trg (fnil conj #{}) src))
                         acc
                         trgs)
                 ;; to preserve nodes without edges

ChrisBlom

sudo wget http://repos.fedorapeople.org/repos/dchen/apache-maven/epel-apache-maven.repo -O /etc/yum.repos.d/epel-apache-maven.repo
sudo sed -i s/\$releasever/6/g /etc/yum.repos.d/epel-apache-maven.repo
sudo yum install -y apache-maven
mvn --version

ChrisBlom

{"AWSTemplateFormatVersion":"2010-09-09",
 "Description":"Creates a classic-link enabled VPC, the custom resource hangs",
 "Parameters":{},
 "Resources":
 {"VPC":
  {"Type":"AWS::EC2::VPC",
   "Properties":
   {"EnableDnsSupport":true,
    "EnableDnsHostnames":true,
    "CidrBlock":"10.0.0.0/16",

ChrisBlom

;; Toggle a counter that tracks how manny times a function is called 

(defn instrument-fn [f]
  (let [counter (atom 0)]
    (-> (fn [& args] ;; NOTE could unroll for 1-n args for speed
          (swap! counter inc)
          (apply f args))
        (with-meta
          {:uninstrumented f
           :counter counter}))))

ChrisBlom

(defmacro eval-with-bindings [bindings form]
  (assert (even? (count bindings)) "an even number of forms in binding vector")
  (let [binding-pairs (partition 2 bindings)
        args (mapv first binding-pairs)
        vals (map second binding-pairs)]
    `((eval (fn ~args ~form))
      ~@vals)))

(let [foo inc]
  (eval '(foo 1)))