ktoso

scala> :javap MongoDB
public class MongoDB$ extends java.lang.Object {
    public static final MongoDB$ MODULE$; // actual instance of our `object`
    public static {};                     
    public MongoDB$();
    // ...
}

ktoso

import pl.project13.hadoop.scalding.NoJarTool

import com.twitter.scalding
import org.apache.hadoop.util.ToolRunner
import org.apache.hadoop.conf.Configuration


val conf = new Configuration
val masterIp = "10.0.0.1"

ktoso

def writeAsync(persistentBatch: immutable.Seq[PersistentRepr]): Future[Unit]
 
def deleteAsync(processorId: String, fromSequenceNr: Long, toSequenceNr: Long, permanent: Boolean): Future[Unit]
 
def confirmAsync(processorId: String, sequenceNr: Long, channelId: String): Future[Unit]

// and "replay":

def replayAsync(processorId: String, fromSequenceNr: Long, toSequenceNr: Long)
              (replayCallback: (PersistentRepr) => Unit): Future[Long]

ktoso

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

ktoso

/**
 * Use for testing.
 * 
 * Forwards all messages received to the system's EventStream.
 * Use this to deterministically `awaitForLeaderElection` etc.
 */
trait EventStreamAllMessages {
  this: Actor =>

  override def aroundReceive(receive: Actor.Receive, msg: Any) = {

ktoso

for {
  item <- items
  transformed = transform(item)
} yield transformed

// let's say you need a println

def print(a: Any) = { println(a); a }
for {
  item <- items

ktoso

Journal plugins

• BDB plugin
• Cassandra plugin
• HBase plugin
• MapDB plugin
• MongoDB plugin (by ddevore)
• MongoDB plugin (by scullxbones)

ktoso

case class ManyCommand(nums: List[Int])

case class State(count: Int) {
  def updated(more: Int) = State(count + more)
}

sealed trait Event
case class AddOneEvent(num: Int) extends Event

class MultiCounter extends EventsourcedProcessor {

ktoso

Monday June 16th

Scala: The Simple Parts

• Martin Odersky - @odersky

Tuesday June 17th

ktoso

2014-06-22 12:45:37
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.0-b70 mixed mode):

"Attach Listener" #87 daemon prio=9 os_prio=31 tid=0x00007fe6bc084000 nid=0x651f waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"pool-9-thread-7" #86 prio=5 os_prio=31 tid=0x00007fe6bf504800 nid=0x9d03 waiting on condition [0x0000000126b70000]
   java.lang.Thread.State: TIMED_WAITING (parking)
	at sun.misc.Unsafe.park(Native Method)
	- parking to wait for  <0x0000000780f9f760> (a java.util.concurrent.SynchronousQueue$TransferStack)