Some useful pool helper. A pure Scala library.
An example SBT dependency string for this library would look like this:
val pool-helper = "com.odinliu.util" %% "pool-helper" % "1.0.1"When some resource pool implementedAutoCloseable, and you have to close it manually.
usingonly ensure close the resource, you should catche any exception yourself.
import com.odinliu.util.pool.resource.AutoReleaseHelper
object Hello extends App with AutoReleaseHelper {
val mi: String = using(new BufferedReader(new FileReader(f))) { br =>
// do something with br
"returned string"
}
println(mi == "returned string")
}
autoClosereturns an Either[Unit, T], a more functionally way.
import com.odinliu.util.pool.resource.AutoReleaseHelper
object Hello extends App with AutoReleaseHelper {
val jp = JedisPool() // jedis client pool
val ret: Either[Unit, Option[String]] = autoClose(jp.getResource)({ jedis =>
val v = jedis.get("Some-KEY")
if (v == null) {
None
} else {
Some(v)
}
}, t => warn("get get key failed", t))
}t => warn("get get key failed", t) is an function you deal with exceptions(Throwable).
ConcurrentPool limits max concurrency.
import com.odinliu.util.pool.concurrent.{ConcurrentPool, PoolHelper}
import scala.concurrent.{ExecutionContext, Future}
class SomeServiceImpl extends SomeService with PoolHelper {
override val executor: ExecutionContext = scala.concurrent.ExecutionContext.global
val maxConnection = Runtime.getRuntime().availableProcessors()
val cp = new ConcurrentPool[SomeClient](maxConnection) {
override protected def makeItem(): Future[Int] = {
Future.successful(SomeClientFactory.newClient())
}
}
def callSomeClient(params: Param): Future[Result] = {
borrow(cp)(client => {
client.doSomething(params)
}, t => warn("call SomeClient failed", t))
.flatMap {
case Left(_) => Future(Result.FAILED)
case Right(x) => x
}
}
}TimedLimitsPool can limit max qps or other time-based limits.
import com.odinliu.util.pool.concurrent.{TimedLimitsPool, PoolHelper}
import scala.concurrent.{ExecutionContext, Future}
import java.util.concurrent.TimeUnit
class SomeServiceImpl extends SomeService with PoolHelper {
private val client: SomeClient = SomeClientFactory.newClient()
override val executor: ExecutionContext = scala.concurrent.ExecutionContext.global
val maxQps = 1000
// use `Int` as token
val limitsCp = new TimedLimitsPool[Int](maxQps, refresh = 1000L, tu = TimeUnit.MILLISECONDS) {
var count: Int = -1
override protected def makeItem(): Future[Int] = {
count += 1
Future.successful(count)
}
}
def callSomeClient(params: Param): Future[Result] = {
ration(limitsCp)(id => {
client.doSomething(params)
}, t => warn("call SomeClient failed", t))
.flatMap {
case Left(_) => Future(Result.FAILED)
case Right(x) => x
}
}
}