根据元素值后关闭窗口 [英] Close window after based on element value
问题描述
当输入元素在DoFn的侧面输出中具有标志值时，是否可以关闭窗口?例如.指示会话关闭的事件会关闭窗口.
Is there a way to close a window when an input element has a flag value in the side output of a DoFn? E.g. event which indicates closing of a session closes the window.
我一直在阅读文档，并且触发器主要基于时间.一个例子将是很好的.
I've been reading the docs, and triggers are time based mostly. An example would be great.
Trigger.OnElementContext.forTrigger(ExecutableTrigger触发器)似乎很有希望，但ExecutableTrigger文档目前非常苗条.
Trigger.OnElementContext.forTrigger(ExecutableTrigger trigger) seems promising but ExecutableTrigger docs are pretty slim at the moment.
推荐答案
我认为这不可用.现在只有一个数据驱动触发器，elementCountAtLeast.
I don't think that this is available. There is only one Data Driven Trigger right now, elementCountAtLeast.
https://cloud.google.com/dataflow/model/triggers#data-driven-triggers
一种解决方法是复制会话窗口功能代码并编写自定义窗口功能.
A work around for this would be to copy the sessions window function code and write a custom window function.
简而言之，您一直将元素分配到同一窗口中，直到看到终止元素为止.然后开始创建一个新窗口.
In short, you keep assigning elements into the same window, until you see your terminating element. Then start creating a new window.
这篇关于根据元素值后关闭窗口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！
