respatialized

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

Generating Flame Graphs for Apache Spark

Flame graphs are a nifty debugging tool to determine where CPU time is being spent. Using the Java Flight recorder, you can do this for Java processes without adding significant runtime overhead.

When are flame graphs useful?

Shivaram Venkataraman and I have found these flame recordings to be useful for diagnosing coarse-grained performance problems. We started using them at the suggestion of Josh Rosen, who quickly made one for the Spark scheduler when we were talking to him about why the scheduler caps out at a throughput of a few thousand tasks per second. Josh generated a graph similar to the one below, which illustrates that a significant amount of time is spent in serialization (if you click in the top right hand corner and search for "serialize", you can see that 78.6% of the sampled CPU time was spent in serialization). We used this insight to spee

How Clojure's documentation can leapfrog other languages

Summary

I made a documentation generator that cashes in on Clojure's dynamism. See the play-cljs docs (a ClojureScript game library) for an example of its output.

The Problem

Like many of you, I've often wondered what my final regret will be on my deathbed. My best guess came to me in a dream recently. I was walking across the charred earth of an apocalyptic future world, maneuvering around the remains of the less fortunate. I was startled to find a young girl, barely holding onto her life. She murmured something to me. I asked her to repeat it, and she said more loudly: "I...wish your Clojure projects didn't have such crappy documentation."

HTML Tags You Can Use on GitHub

Wherever HTML is rendered on GitHub (gists, README files in repos, comments on issues and pull requests, ...) you can use any of the HTML elements that GitHub Flavored Markdown (GFM) provides syntactic sugar for. You can either use the syntactic sugar that GFM (or other GitHub-supported markup language you're using) provides or, since Markdown can contain raw HTML, you can enter the HTML tags manually.

But GitHub also allows you to use a few HTML elements beyond what Markdown provides by entering the tags manually, and some of them are styled with CSS. Most raw HTML tags get stripped before rendering the HTML. Those tags that can be generated by GFM syntactic sugar, plus a few more, are whitelisted. These aren't documented anywhere that I can find. Here's what I've discovered so far:

`<details>` and `<summary>`

A `<detai

	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Ant sim ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
	; Copyright (c) Rich Hickey. All rights reserved.
	; The use and distribution terms for this software are covered by the
	; Common Public License 1.0 (http://opensource.org/licenses/cpl.php)
	; which can be found in the file CPL.TXT at the root of this distribution.
	; By using this software in any fashion, you are agreeing to be bound by
	; the terms of this license.
	; You must not remove this notice, or any other, from this software.

	;dimensions of square world

	(defproject semantic-gs "0.1.0-SNAPSHOT"
	:dependencies [[org.clojure/clojure "1.5.1"]
	[compojure "1.1.5"]
	[garden "0.1.0-beta5"]
	[hiccup "1.0.3"]]
	:plugins [[lein-ring "0.8.5"]]
	:ring {:handler semantic-gs.handler/app}
	:profiles
	{:dev {:dependencies [[ring-mock "0.1.5"]]}})

	import org.scalatest._
	import prop._
	import org.scalacheck.Arbitrary._
	import org.scalacheck.Gen

	/**
	* Solutions to the ScalaCheck problem that shrinking failing values may generate
	* invalid values, because the constraints of the generator are not respected.
	*
	* See also http://stackoverflow.com/questions/20037900/scalacheck-wont-properly-report-the-failing-case

	/**
	* Verifies that a HTML content is valid.
	* @param htmlContent the HTML content
	* @return true if it is valid, false otherwise
	* @throws Exception
	*/
	public boolean validateHtml( String htmlContent ) throws Exception {

	InputStream in = new ByteArrayInputStream( htmlContent.getBytes( "UTF-8" ));
	ByteArrayOutputStream out = new ByteArrayOutputStream();

	(advice-add 'org-clock-select-task :override #'aj/helm-org-clock-select-task)

	(defun aj/helm-org-clock-select-task (&optional prompt)
	"Select a task that was recently associated with clocking."
	(interactive)
	;; TODO sources for these
	;; (when (marker-buffer org-clock-default-task)

	;; (insert (org-add-props "Default Task\n" nil 'face 'bold))
	;; (setq s (org-clock-insert-selection-line ?d org-clock-default-task))

	~/dev/scala/cljrepl $ cat build.sbt
	scalaVersion := "2.11.8"

	libraryDependencies ++= Seq(
	"org.clojure" % "clojure" % "1.8.0"
	)

	~/dev/scala/cljrepl $ cat src/main/scala/foo.scala
	import clojure.java.api.Clojure
	import clojure.java.api.Clojure.{`var` => cvar}