examples/src/main/scala/org/apache/ignite/scalar/examples/ScalarCacheExample.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ignite.scalar.examples

import org.apache.ignite.events.Event
import org.apache.ignite.events.EventType._
import org.apache.ignite.lang.IgnitePredicate
import org.apache.ignite.scalar.scalar
import org.apache.ignite.scalar.scalar._

import scala.collection.JavaConversions._

/**
 * Demonstrates basic In-Memory Data Ignite Cluster operations with Scalar.
 * <p/>
 * Remote nodes should always be started with special configuration file which
 * enables P2P class loading: `'ignite.{sh|bat} examples/config/example-ignite.xml'`.
 * <p/>
 * Alternatively you can run `ExampleNodeStartup` in another JVM which will
 * start node with `examples/config/example-ignite.xml` configuration.
 */
object ScalarCacheExample extends App {
    /** Configuration file name. */
    private val CONFIG = "examples/config/example-ignite.xml"

    /** Name of cache specified in spring configuration. */
    private val NAME = ScalarCacheExample.getClass.getSimpleName

    scalar(CONFIG) {
        val cache = createCache$[String, Int](NAME)

        try {
            registerListener()

            basicOperations()
        }
        catch {
            case e: Throwable =>
                e.printStackTrace();
        }
        finally {
            cache.destroy()
        }
    }

    /**
     * Demos basic cache operations.
     */
    def basicOperations() {
        val c = cache$[String, Int](NAME).get

        // Add few values.
        c += (1.toString -> 1)
        c += (2.toString -> 2)

        // Update values.
        c += (1.toString -> 11)
        c += (2.toString -> 22)

        c += (1.toString -> 31)
        c += (2.toString -> 32)
        c += ((2.toString, 32))

        // Remove couple of keys (if any).
        c -= (11.toString, 22.toString)

        // Put one more value.
        c += (3.toString -> 11)

        try {
            c.opt(44.toString) match {
                case Some(v) => sys.error("Should never happen.")
                case _ => println("Correct")
            }
        }
        catch {
            case e: Throwable =>
                e.printStackTrace()
        }


        // Print all values.
        println("Print all values.")
        c.iterator() foreach println
    }

    /**
     * This method will register listener for cache events on all nodes,
     * so we can actually see what happens underneath locally and remotely.
     */
    def registerListener() {
        val g = ignite$

        g *< (() => {
            val lsnr = new IgnitePredicate[Event] {
                override def apply(e: Event): Boolean = {
                    println(e.shortDisplay)

                    true
                }
            }

            if (g.cluster().nodeLocalMap[String, AnyRef].putIfAbsent("lsnr", lsnr) == null) {
                g.events().localListen(lsnr,
                    EVT_CACHE_OBJECT_PUT,
                    EVT_CACHE_OBJECT_READ,
                    EVT_CACHE_OBJECT_REMOVED)

                println("Listener is registered.")
            }
        }, null)
    }
}