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RequestQueue

A simple queue for GM_xmlhttpRequests or other async functions

此脚本不应直接安装。它是供其他脚本使用的外部库，要使用该库请加入元指令 // @require https://update.cn-greasyfork.org/scripts/370011/610040/RequestQueue.js 

  1. // ==UserScript==
  2. // @exclude     *
  3. // ==UserLibrary==
  4. // @name        RequestQueue
  5. // @description A simple queue for GM_xmlhttpRequests or other async functions
  6. // @version     6
  7. // @license     MIT
  8. // ==/UserLibrary==
  9. // @namespace   cuzi
  10. // @homepageURL https://github.com/cvzi/RequestQueue/
  11. // @grant       GM_xmlhttpRequest
  12. // @grant       GM.xmlhttpRequest
  13. // ==/UserScript==
  14.  
  15. // ==OpenUserJS==
  16. // @author      cuzi
  17. // ==/OpenUserJS==
  18.  
  19. "use strict";
  20.  
  21. function RequestQueue(maxParallel,maxTotal) {
  22.   // A simple queue for GM_xmlhttpRequests or other async functions
  23.  
  24.   maxParallel = parseInt(maxParallel)>0?parseInt(maxParallel):1;
  25.   maxTotal = parseInt(maxTotal)>0?parseInt(maxTotal):Number.POSITIVE_INFINITY;
  26.  
  27.   var index = 0; // incrementing, used for unique ids
  28.   var finished = 0; // Number of finished requests
  29.   var pending = [];
  30.   var running = [];
  31.   
  32.   
  33.   
  34.   
  35.   var defaultFunction;
  36.   if(typeof GM != "undefined" && "xmlHttpRequest" in GM) {
  37.     defaultFunction = GM.xmlHttpRequest;
  38.   } else {
  39.     defaultFunction = function(a,b,c,d) { return GM_xmlhttpRequest(a,b,c,d);} // Wrap GM_xmlhttpRequest to avoid security exception
  40.   }
  41.  
  42.  
  43.   /*
  44.   The internal request Object extended by add(req,fun,thisArg)
  45.   {
  46.     __fun : fun, defaults to GM_xmlhttpRequest
  47.     __thisArg : thisArg, the this object for the above function
  48.     __result : the return value of __fun is saved in this property
  49.  
  50.     __org_onload : The original event callbacks of req
  51.     __org_onerror
  52.     __org_onabort
  53.  
  54.     onload : The new event callbacks that wrap the above callbacks
  55.     onerror
  56.     onabort
  57.  
  58.     ... and all the original properties of the "req" object
  59.   }
  60.  
  61.   */
  62.  
  63.   var fire = function() {
  64.     // Check for pending requests and send them.
  65.     if(pending.length > 0 && running.length < maxParallel && finished < maxTotal) {
  66.       var req = pending.shift();
  67.       running.push(req);
  68.       req.__result = req.__fun.call(req.__thisArg,req);
  69.       fire();
  70.     }
  71.   };
  72.  
  73.   var remove = function(id) {
  74.     // Remove the request with id from the the running array
  75.     for(var i = 0; i < running.length; i++) {
  76.       if(running[i].id == id) {
  77.         running.splice(i, 1);
  78.         finished++;
  79.         fire();
  80.         break;
  81.       }
  82.     }
  83.   };
  84.  
  85.   this.add = function(req,fun,thisArg) {
  86.     // Schedule a request: add(req[, fun[, thisArg]])
  87.     // fun:      defaults to GM.xmlHttpRequest
  88.     // thisArg:  The value of this provided for the call to fun. Keep strict mode in mind!
  89.     req.id = index++;
  90.  
  91.     req.__fun = typeof(fun) === 'function'?fun:defaultFunction; 
  92.     req.__thisArg = thisArg;
  93.  
  94.     // Wrap events that indicate that the request has finished
  95.     req.__org_onload = req.onload;
  96.     req.onload = function(response) {
  97.      if(response.status === 0) { // This is true if a request was aborted. This seems to happen only sporadically
  98.         req.onabort(response);
  99.         return;
  100.       }
  101.       remove(req.id);
  102.       if(req.__org_onload) req.__org_onload(response);
  103.       };
  104.  
  105.     req.__org_onerror = req.onerror;
  106.     req.onerror = function(response) {
  107.       remove(req.id);
  108.       if(req.__org_onerror) req.__org_onerror(response);
  109.       };
  110.  
  111.     req.__org_onabort = req.onabort;
  112.     req.onabort = function(response) {
  113.       remove(req.id);
  114.       if(req.__org_onabort) req.__org_onabort(response);
  115.       };
  116.  
  117.     pending.push(req);
  118.     fire();
  119.   };
  120.  
  121.   this.abortRunning = function() {
  122.     // For any added function that was already run: result = thisArg.fun(req)
  123.     // it will call result.abort()
  124.     // For GM_xmlhttpRequest this will subsequently fire an onabort event
  125.     for(var i = 0; i < running.length; i++) {
  126.       if(running[i] && typeof running[i].__result.abort === 'function') {
  127.         running[i].__result.abort();
  128.       }
  129.     }
  130.   };
  131.  
  132.   this.abortPending = function() {
  133.     // Clear the pending list
  134.     pending = [];
  135.   };
  136.  
  137.   this.abort = function() {
  138.     // Abort both running and pending requests
  139.     this.abortPending();
  140.     this.abortRunning();
  141.   };
  142.   
  143.   this.resetTotal = function() {
  144.     // Reset number of finished requests
  145.     finished = 0;
  146.   }
  147.   
  148.   this.hasReachedTotal = function() {
  149.     // Number of maximum allowed requests reached?
  150.     return finished >= maxTotal;
  151.   }
  152.   
  153.   this.hasRunning = function() {
  154.     // Are there any running requests?
  155.     return running.length > 0;
  156.   }
  157.   
  158.   
  159. }