创建基于时间的分块枚举 [英] Creating a time-based chunking Enumeratee
问题描述
我想创建一个Play 2枚举,该枚举以每x
秒/毫秒的方式接收值并将其分块输出.这样,在具有大量用户输入的多用户Websocket环境中,可以限制每秒接收的帧数.
I want to create a Play 2 Enumeratee that takes in values and outputs them, chunked together, every x
seconds/milliseconds. That way, in a multi-user websocket environment with lots of user input, one could limit the number of received frames per second.
我知道可以像这样将一组项目组合在一起:
I know that it's possible to group a set number of items together like this:
val chunker = Enumeratee.grouped(
Traversable.take[Array[Double]](5000) &>> Iteratee.consume()
)
是否有内置的方法可以根据时间而不是根据项目数进行操作?
Is there a built-in way to do this based on time rather than based on the number of items?
我当时正在考虑通过预定的Akka作业来执行此操作,但是乍看之下这似乎效率不高,而且我不确定是否会出现并发问题.
I was thinking about doing this somehow with a scheduled Akka job, but on first sight this seems inefficient, and I'm not sure if concurency issues would arise.
推荐答案
这样怎么样?希望对您有帮助.
How about like this? I hope this is helpful for you.
package controllers
import play.api._
import play.api.Play.current
import play.api.mvc._
import play.api.libs.iteratee._
import play.api.libs.concurrent.Akka
import play.api.libs.concurrent.Promise
object Application extends Controller {
def index = Action {
val queue = new scala.collection.mutable.Queue[String]
Akka.future {
while( true ){
Logger.info("hogehogehoge")
queue += System.currentTimeMillis.toString
Thread.sleep(100)
}
}
val timeStream = Enumerator.fromCallback { () =>
Promise.timeout(Some(queue), 200)
}
Ok.stream(timeStream.through(Enumeratee.map[scala.collection.mutable.Queue[String]]({ queue =>
var str = ""
while(queue.nonEmpty){
str += queue.dequeue + ", "
}
str
})))
}
}
此文档也对您有所帮助. http://www.playframework.com/documentation/2.0/Enumerators
And this document is also helpful for you. http://www.playframework.com/documentation/2.0/Enumerators
更新 这是play2.1版本.
UPDATE This is for play2.1 version.
package controllers
import play.api._
import play.api.Play.current
import play.api.mvc._
import play.api.libs.iteratee._
import play.api.libs.concurrent.Akka
import play.api.libs.concurrent.Promise
import scala.concurrent._
import ExecutionContext.Implicits.global
object Application extends Controller {
def index = Action {
val queue = new scala.collection.mutable.Queue[String]
Akka.future {
while( true ){
Logger.info("hogehogehoge")
queue += System.currentTimeMillis.toString
Thread.sleep(100)
}
}
val timeStream = Enumerator.repeatM{
Promise.timeout(queue, 200)
}
Ok.stream(timeStream.through(Enumeratee.map[scala.collection.mutable.Queue[String]]({ queue =>
var str = ""
while(queue.nonEmpty){
str += queue.dequeue + ", "
}
str
})))
}
}
这篇关于创建基于时间的分块枚举的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!