Scala CacheLoader类代码示例

//设置package包名称以及导入依赖的类
package com.twitter.finagle.kestrel

import _root_.java.net.SocketAddress
import _root_.java.util.concurrent.{BlockingDeque, LinkedBlockingDeque}
import com.google.common.cache.{CacheBuilder, CacheLoader}
import com.twitter.finagle.builder.{Server => BuiltServer, ServerBuilder}
import com.twitter.finagle.{ServiceFactory, ClientConnection}
import com.twitter.util.{Future, Time}
import org.jboss.netty.buffer.ChannelBuffer
import protocol.{Kestrel, Command, Response}

class Server(address: SocketAddress) {
  private[this] val serviceFactory = new ServiceFactory[Command, Response] {

    private[this] val queues = CacheBuilder.newBuilder()
      .build(new CacheLoader[ChannelBuffer, BlockingDeque[ChannelBuffer]] {
        def load(k: ChannelBuffer) = new LinkedBlockingDeque[ChannelBuffer]
      })

    def apply(conn: ClientConnection) = Future.value(new InterpreterService(new Interpreter(queues)))
    def close(deadline: Time) = Future.Done
  }

  private[this] val serverSpec =
    ServerBuilder()
      .name("schmestrel")
      .codec(Kestrel())
      .bindTo(address)

  private[this] var server: Option[BuiltServer] = None

  def start(): BuiltServer = {
    server = Some(serverSpec.build(serviceFactory))
    server.get
  }

  def stop() {
    require(server.isDefined, "Server is not open!")

    server.foreach { server =>
      server.close()
      this.server = None
    }
  }
} 

//设置package包名称以及导入依赖的类
package webby.commons.cache

import java.util.concurrent.TimeUnit
import java.{lang => jl}

import com.google.common.cache.{CacheBuilder, CacheLoader, LoadingCache}


abstract class TimedCache[K, RealK, V](val cache: LoadingCache[RealK, V]) {
  def get(key: K): V = cache.get(transformKey(key))

  def invalidate(key: K): Unit = cache.invalidate(transformKey(key))
  def refresh(key: K): Unit = cache.refresh(transformKey(key))

  protected def transformKey(key: K): RealK
}

object TimedCache {

  def default[K <: AnyRef, V <: AnyRef](expireDuration: Long, expireUnit: TimeUnit)(cacheLoader: K => V): TimedCache[K, K, V] =
    new TimedCache[K, K, V](
      CacheBuilder.newBuilder().expireAfterWrite(expireDuration, expireUnit).build(new CacheLoader[K, V] {
        def load(key: K): V = cacheLoader(key)
      })) {
      protected def transformKey(key: K): K = key
    }

  def intKey[V <: AnyRef](expireDuration: Long, expireUnit: TimeUnit)(cacheLoader: Int => V): TimedCache[Int, jl.Integer, V] =
    new TimedCache[Int, jl.Integer, V](
      CacheBuilder.newBuilder().expireAfterWrite(expireDuration, expireUnit).build(new CacheLoader[jl.Integer, V] {
        def load(key: jl.Integer): V = cacheLoader(key)
      })) {
      protected def transformKey(key: Int): Integer = key
    }

  def stringKey[V <: AnyRef](expireDuration: Long, expireUnit: TimeUnit)(cacheLoader: String => V): TimedCache[String, String, V] =
    default[String, V](expireDuration, expireUnit)(cacheLoader)
} 

//设置package包名称以及导入依赖的类
package com.twitter.cache.guava

import com.google.common.cache.{CacheLoader, CacheBuilder}
import com.twitter.cache.AbstractFutureCacheTest
import com.twitter.util.{Future, Promise}
import org.junit.runner.RunWith
import org.scalatest.junit.JUnitRunner

@RunWith(classOf[JUnitRunner])
class GuavaCacheTest extends AbstractFutureCacheTest {
  def name: String = "GuavaCache"

  def mkCtx(): Ctx = new Ctx {
    val guava = CacheBuilder.newBuilder().build[String, Future[String]]()
    val cache = new GuavaCache[String, String](guava)
  }

  def mkCache() =
    CacheBuilder
      .newBuilder()
      .build(
        new CacheLoader[String, Future[Int]] {
          override def load(k: String): Future[Int] = new Promise[Int]
        }
      )

  test("GuavaCache#fromLoadingCache is interrupt safe") {
    val fCache = GuavaCache.fromLoadingCache(mkCache())
    interruptSafe(fCache)
  }

  test("GuavaCache#fromCache is interrupt safe") {
    val fCache = GuavaCache.fromCache((_:String) => new Promise[Int], mkCache())
    interruptSafe(fCache)
  }
} 

//设置package包名称以及导入依赖的类
package com.twitter.cache.guava

import com.google.common.cache.{CacheLoader, CacheBuilder}
import com.twitter.cache.AbstractLoadingFutureCacheTest
import com.twitter.util.Future
import org.junit.runner.RunWith
import org.scalatest.junit.JUnitRunner

@RunWith(classOf[JUnitRunner])
class LoadingFutureCacheTest extends AbstractLoadingFutureCacheTest {

  def name: String = "LoadingFutureCache (guava)"

  // NB we can't reuse AbstractFutureCacheTest since
  // loading cache semantics are sufficiently unique
  // to merit distinct tests.

  def mkCtx: Ctx = new Ctx {
    val cache = new LoadingFutureCache(
      CacheBuilder
        .newBuilder()
        .build(
          new CacheLoader[String,Future[Int]] {
            override def load(k: String): Future[Int] = {
              cacheLoaderCount += 1
              Future.value(k.hashCode)
            }
          }
        )
    )
  }
}