olim7t

import java.util.Date;

/**
 * Example code for my blog post "The TOCTTOU attack", available at http://out-println.appspot.com/posts/tocttou.
 */
public class Tocttou {
  
  public static final class Interval {
    
    private final Date min;

olim7t

package test;

import java.util.concurrent.ConcurrentLinkedQueue;

/**
 * Illustrates a case when Collection.size() cannot reliably indicate how many elements were dumped by
 * Collection.toArray().
 *
 * Assuming that the array is reused and was previously filled with unrelated values, the fact that toArray()
 * writes null after the last element is the only way to find out how many elements were actually dumped.

olim7t

/**
 * Clear-headed attempt at a functional-style, "Scala-way" implementation.
 *
 * Seems to work on trivial cases. Too lazy to write unit tests now (note to self: write them later and then pretend I did TDD).
 */
class GameOfLife(val width: Int, val height: Int, val liveCells: Set[(Int, Int)]) {

  def nextIteration: GameOfLife = {
    val newCells = for {
      (cell, liveNeighborCount) <- liveNeighborCounts

olim7t

/* Finds the version history of a POM in a Subversion repository */

import scala.sys.process.Process

object Conf {
  val url = "put the url of your POM here"
  val svn = "svn --username xxx"
}

case class Revision(number: Int, date: String, version: String) {

olim7t

import java.io.BufferedReader;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;

/** Streams the lines of a {@link BufferedReader} while applying some parsing method. */
abstract class LineParsingIterator<T> implements Iterator<T> {
	private final BufferedReader input;

	private T buffered; // parsed but not yet returned to the client

olim7t

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Session;
import com.datastax.driver.mapping.Mapper;
import com.datastax.driver.mapping.MappingManager;
import com.datastax.driver.mapping.annotations.Frozen;
import com.datastax.driver.mapping.annotations.PartitionKey;
import com.datastax.driver.mapping.annotations.Table;
import com.datastax.driver.mapping.annotations.UDT;

public class DriverDemo {

olim7t

# Install graphite 0.9.10 on a Mac (Python 2.6 preinstalled)
# Gathered from my notes, might not be 100% accurate

brew install py2cairo
sudo pip install Django==1.3
sudo pip install django-tagging
sudo pip install carbon
sudo pip install whisper
sudo pip install graphite-web
sudo pip install tagging # not sure if really useful

olim7t

import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global
import scala.util.{Try, Success, Failure}

val f: Future[Int] = Future(1 / 0)

// answer C
def applyC[T](f: Future[T]): Future[Try[T]] = f.map(x => Try(x))

// answer D

olim7t

// Naive solution (two passes)
def volume(l: List[Int]) = {
  def peakRight(l: List[Int]) = l.foldRight(List(0)) { case (i, acc) => (i max acc.head) :: acc }.tail
  def peakLeft(l: List[Int]) = peakRight(l.reverse).reverse
  val waterLevels = peakLeft(l) zip peakRight(l) map { case (l, r) => l min r }
  val volumes = l zip waterLevels map { case (g, w) => (w - g) max 0 }
  volumes reduceLeft (_ + _)
}

olim7t

import com.datastax.driver.core.*;
import com.datastax.driver.core.policies.Policies;

import java.net.InetAddress;

public class GatherAllListenAddresses {
    public static void main(String[] args) {
        Cluster cluster = null;
        try {
            cluster = Cluster.builder()