Lift Framework example source code file (TemplateCache.scala)

This example Lift Framework source code file (TemplateCache.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lift Framework tags/keywords

box, inmemorycache, int, k, k, list, lru, nodeseq, nodeseq, t, t, templatecache, util, v, v

The Lift Framework TemplateCache.scala source code

/*
 * Copyright 2009-2011 WorldWide Conferencing, LLC
 *
 * Licensed 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 net.liftweb
package util

import scala.xml.{NodeSeq}
import java.util.{Locale}
import common._

trait TemplateCache[K, V] {

  type T = K

  /**
   * Returns a cached template by a key. If the template is not cached yet,
   * it will be provided by templateProvider.
   */
  def get(key: K): Box[V];

  /**
   * Adds the node in the cache
   */
  def set(key: K, node: V): V

  def update(key: K, node: V): V = set(key, node)

  /**
   * Removes a template from the cache
   */
  def delete(key: K): Unit
}

/**
 * A cache that caches nothing
 */
object NoCache extends TemplateCache[(Locale, List[String]), NodeSeq] {

  def get(key: T): Box[NodeSeq] = Empty

  def set(key: T, node: NodeSeq): NodeSeq = node

  def delete(key: T) {
  }
}

/**
 * Companion module for InMemoryCache
 */
object InMemoryCache {
  def apply(templatesCount: Int) = new InMemoryCache(templatesCount)
}

/**
 * Caches templates in a LRU map
 */
class InMemoryCache(templatesCount: Int) extends
TemplateCache[(Locale, List[String]), NodeSeq] {
  private val cache : LRU[(Locale, List[String]), NodeSeq] = new LRU(templatesCount)

  def get(key: T): Box[NodeSeq] = {
    cache.synchronized {
      cache.get(key)
    }
  }

  def set(key: T, node: NodeSeq): NodeSeq = cache.synchronized {
    cache(key) = node
    node
  }

  override def delete(key: T) {
    cache.synchronized(cache.remove(key))
  }

}