StreamHandleCache.jsm

"use strict";

var EXPORTED_SYMBOLS = ["StreamHandleCache"];

var singleton;

class StreamHandleCache extends Map {
  constructor() {
    super();
    Services.obs.addObserver(this, "xpcom-will-shutdown");
  }
  
  destructor() {
    for (const [handle, stream] of this.entries()) {
      // do whatever is necessary to destroy stream
    }
  }
  
  observe(subject, topic, data) {
    this.destructor();
  }
  
  static get() {
    if (!singleton) {
      singleton = new StreamHandleCache();
    }
    return singleton;
  }
}



…


// In bc test:
const { StreamHandleCache } = ChromeUtils.import(…);

const cache = StreamHandleCache.get();

add_task(function() {
  cache.add(handle, new Stream());
  cache.destructor();
  is(cache.size, 0);
});