Enhanced Scala REPL

Following is a short demo of what can be done with the GigaSpaces scala shell. It should be noted that this shell is a regular Scala REPL with some initial imports and initialization code.

Demo Setup

• Run $GS_HOME/bin/gs-agent.sh (or .bat)
• Start the shell $GS_HOME/tools/scala/shell.sh (or .bat)

The Demo

java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

Initializing... This may take a few seconds.
Welcome to Scala version 2.11.6 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_45).
Type in expressions to have them evaluated.
Type :help for more information.
Please enjoy the predefined 'admin' val.

xap>

We'll start by deploying a single space to the service grid, notice we already have an admin instance in scope to simplify this process.:

Command:

val gsm = admin.getGridServiceManagers.waitForAtLeastOne

Output:

gsm: org.openspaces.admin.gsm.GridServiceManager = org.openspaces.admin.internal.gsm.DefaultGridServiceManager@ca43aa97

Command:

gsm.deploy(new org.openspaces.admin.space.SpaceDeployment("mySpace"))

Output:

res0: org.openspaces.admin.pu This is the unit of packaging and deployment in the GigaSpaces Data Grid, and is essentially the main GigaSpaces service. The Processing Unit (PU) itself is typically deployed onto the Service Grid. When a Processing Unit is deployed, a Processing Unit instance is the actual runtime entity..ProcessingUnit = org.openspaces.admin.internal.pu.DefaultProcessingUnit@59479eba

 

We'll use some helper method that is imported into the session scope (from org.openspaces.scala.repl.GigaSpacesScalaReplUtils) to get a GigaSpace proxy:

Command:

val Some(gigaSpace) = getGigaSpace("mySpace")

Output:

gigaSpace: org.openspaces.core.GigaSpace = mySpace_container:mySpace

 

Now we'll execute a task using another helper method:

Command:

execute(gigaSpace) { holder => holder.clusterInfo.getNumberOfInstances}

Output:

res1: com.gigaspaces.async.AsyncFuture[Integer] = org.openspaces.core.transaction.internal.InternalAsyncFuture@f1423ba

Command:

val numberOfInstances = res1.get

Output:

numberOfInstances: Integer = 1

 

Let's define a new case class and write an entry to the space:

Command:

case class Data @SpaceClassConstructor() (@BeanProperty @SpaceId id: String = null, @BeanProperty content: String = null)

Output:

defined class Data

Command:

gigaSpace.write(Data(id = "id1", content = "my data content"))

Output:

res2: com.j_spaces.core.LeaseContext[Data] = SpaceEntryLease[uid=-792314720^58^id1^0^0,typeName=Data,routingValue=id1,expirationTime=9223372036854775807]

 

Now execute a task that reads this entry and returns is content property:

Command:

execute(gigaSpace) { holder =>holder.gigaSpace.read(Data()).content}

Output:

res3: com.gigaspaces.async.AsyncFuture[String] = org.openspaces.core.transaction.internal.InternalAsyncFuture@7c767c0d

Command:

val dataContent = res3.get

Output:

dataContent: String = my data content

Configuration

It is possible to customize the initialization code, the shutdown code and the initial imports. GigaSpaces 10.2 introduced alternative method to customize initialization code along with initial imports.

Standard method

GigaSpaces REPL during initialization phase will load imports from initial imports file and then execute init code. The end of shell session will be preceded by execution of shutdown code.

Initial imports

By default the initial imports will be loaded from $GS_HOME/tools/scala/conf/repl-imports.conf. This location can be overridden by the system property: org.os.scala.repl.imports. Each import should be in its own line. (empty lines and lines beginning with # are ignored)

Init code

By default the initialization code will be loaded from $GS_HOME/tools/scala/conf/init-code.scala. This location can be overridden by the system property: org.os.scala.repl.initcode.

Shutdown code

By default the shutdown code will be loaded from $GS_HOME/tools/scala/conf/shutdown-code.scala. This location can be overridden by the system property: org.os.scala.repl.shutdowncode.

New method

The difference between the two methods is that the new one does not use a file with initial imports. Those imports should be placed in initialization code script (with import prefix added). Alternative method is used if system property org.os.scala.repl.newinitstyle is set as "yes', "on' or "true'.

Init code

By default the initialization code will be loaded from $GS_HOME/tools/scala/conf/new-init-code.scala. This location can be overridden by the system property: org.os.scala.repl.initcode. Please note that new init code script should also contain necessary imports.

Shutdown code

Please refer to Shutdown code described above in the standard method.