{"id":849,"date":"2020-09-02T16:34:35","date_gmt":"2020-09-02T08:34:35","guid":{"rendered":"http:\/\/prayerlaputa.com\/?p=849"},"modified":"2020-09-02T16:35:07","modified_gmt":"2020-09-02T08:35:07","slug":"guava-ratelimiter-%e7%9a%84%e4%bd%bf%e7%94%a8%e4%b8%8e%e6%ba%90%e7%a0%81%e5%88%86%e6%9e%90%ef%bc%88%e4%bb%a4%e7%89%8c%e6%a1%b6%e7%ae%97%e6%b3%95%e5%ae%9e%e7%8e%b0%e6%80%9d%e8%b7%af%ef%bc%89","status":"publish","type":"post","link":"http:\/\/prayerlaputa.com\/?p=849","title":{"rendered":"Guava RateLimiter \u7684\u4f7f\u7528\u4e0e\u6e90\u7801\u5206\u6790\uff08\u4ee4\u724c\u6876\u7b97\u6cd5\u5b9e\u73b0\u601d\u8def\uff09"},"content":{"rendered":"<h2 class=\"md-end-block md-heading\"><span class=\"md-plain\">Guava RateLimiter\u57fa\u672c\u4f7f\u7528<\/span><\/h2>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u5b66\u4e1c\u897f\u65f6\u6211\u4eec\u5e94\u8be5\u5c3d\u91cf\u53bb\u770b\u5b98\u7f51\u3001\u770b\u6e90\u7801\u3001\u770b\u5b98\u65b9\u7ed9\u51fa\u7684\u5355\u5143\u6d4b\u8bd5\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u6bd4\u5982Guava RateLimiter\uff0c\u4eceRateLimiter\u7c7b\u7684\u6e90\u7801\u6ce8\u91ca\u4e2d\u53ef\u4ee5\u770b\u5230\uff0c\u5b98\u65b9\u7ed9\u51fa\u7684\u5178\u578b\u5e94\u7528\u573a\u666f\u4e0e\u4f7f\u7528\uff1a<\/span><!--more--><\/p>\n<pre class=\"md-fences md-end-block ty-contain-cm modeLoaded\" lang=\"\" spellcheck=\"false\"><span role=\"presentation\">As an example, imagine that we have a list of tasks to execute, but we don't want to submit more than 2 per second:<\/span>\r\n \r\n<span role=\"presentation\"> final RateLimiter rateLimiter = RateLimiter.create(2.0); \/\/ rate is \"2 permits per second\"<\/span>\r\n<span role=\"presentation\"> void submitTasks(List&lt;Runnable&gt; tasks, Executor executor) {<\/span>\r\n<span role=\"presentation\"> \u00a0 for (Runnable task : tasks) {<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0 rateLimiter.acquire(); \/\/ may wait<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0 executor.execute(task);<\/span>\r\n<span role=\"presentation\"> \u00a0 }<\/span>\r\n<span role=\"presentation\"> }<\/span>\r\n \r\n<span role=\"presentation\">As another example, imagine that we produce a stream of data, and we want to cap it at 5kb per second. This could be accomplished by requiring a permit per byte, and specifying a rate of 5000 permits per second:<\/span>\r\n \r\n<span role=\"presentation\"> final RateLimiter rateLimiter = RateLimiter.create(5000.0); \/\/ rate = 5000 permits per second<\/span>\r\n<span role=\"presentation\"> void submitPacket(byte[] packet) {<\/span>\r\n<span role=\"presentation\"> \u00a0 rateLimiter.acquire(packet.length);<\/span>\r\n<span role=\"presentation\"> \u00a0 networkService.send(packet);<\/span>\r\n<span role=\"presentation\"> }<\/span>\r\n<\/pre>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u4e00\u4e2a\u662f\u9650\u5236\u6267\u884c\u4efb\u52a1\u7684\u6570\u91cf\uff0c\u4e00\u4e2a\u662f\u9650\u5236\u6bcf\u6b21\u53d1\u9001\u7684\u5b57\u8282\u6570\u91cf\u3002\u6ce8\u610f\uff0c\u5982\u679c\u8d85\u8fc7<\/span><span class=\"md-pair-s\" spellcheck=\"false\"><code>RateLimiter.create<\/code><\/span><span class=\"md-plain\">\u6240\u5bb9\u8bb8\u7684permits\u6570\u91cf\uff0cacquire\u65b9\u6cd5\u5c06\u963b\u585e\uff0c\u76f4\u5230\u4ea7\u751f\u65b0\u7684permit\u3002\u5f53\u7136\uff0c\u5982\u679c\u4e0d\u60f3\u4e00\u76f4\u963b\u585e\uff0c\u53ef\u4ee5\u4f7f\u7528tryAcquire(Duration timeout)\uff0c\u8be5\u65b9\u6cd5\uff0c\u6307\u5b9a\u4e00\u4e2a\u8d85\u65f6\u65f6\u95f4\uff0c\u4e00\u65e6\u5224\u65ad\u51fa\u5728timeout\u65f6\u95f4\u5185\u8fd8\u65e0\u6cd5\u53d6\u5f97\u4ee4\u724c\uff0c\u5c31\u8fd4\u56defalse\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u6b64\u5916RateLimiter\u8fd8\u652f\u6301\u9884\u70ed\u529f\u80fd\uff0c\u9884\u70ed\u540e\u7f13\u5b58\u80fd\u652f\u6301 5 \u4e07 TPS \u7684\u5e76\u53d1\uff0c\u4f46\u662f\u5728\u9884\u70ed\u524d 5 \u4e07 TPS \u7684\u5e76\u53d1\u76f4\u63a5\u5c31\u628a\u7f13\u5b58\u51fb\u57ae\u3002<\/span><\/p>\n<h2 class=\"md-end-block md-heading\"><span class=\"md-plain\">\u539f\u7406 <\/span><\/h2>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">Guava RateLimiter\u91c7\u7528\u7684\u662f\u4ee4\u724c\u6876\u7b97\u6cd5\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u7ecf\u5178\u7684\u4ee4\u724c\u6876\u7b97\u6cd5\u63cf\u8ff0\u5982\u4e0b\uff1a<\/span><\/p>\n<pre class=\"md-fences md-end-block ty-contain-cm modeLoaded\" lang=\"\" spellcheck=\"false\"><span role=\"presentation\">1. \u4ee4\u724c\u4ee5\u56fa\u5b9a\u7684\u901f\u7387\u6dfb\u52a0\u5230\u4ee4\u724c\u6876\u4e2d\uff0c\u5047\u8bbe\u9650\u6d41\u7684\u901f\u7387\u662f r\/ \u79d2\uff0c\u5219\u4ee4\u724c\u6bcf 1\/r \u79d2\u4f1a\u6dfb\u52a0\u4e00\u4e2a\uff1b<\/span>\r\n<span role=\"presentation\">2. \u5047\u8bbe\u4ee4\u724c\u6876\u7684\u5bb9\u91cf\u662f b \uff08burst\uff0c\u9650\u6d41\u5668\u5bb9\u8bb8\u7684\u6700\u5927\u7a81\u53d1\u6d41\u91cf\uff09\uff0c\u5982\u679c\u4ee4\u724c\u6876\u5df2\u6ee1\uff0c\u5219\u65b0\u7684\u4ee4\u724c\u4f1a\u88ab\u4e22\u5f03\uff1b<\/span>\r\n<span role=\"presentation\">3. \u8bf7\u6c42\u80fd\u591f\u901a\u8fc7\u9650\u6d41\u5668\u7684\u524d\u63d0\u662f\u4ee4\u724c\u6876\u4e2d\u6709\u4ee4\u724c\u3002<\/span><\/pre>\n<h3 class=\"md-end-block md-heading\"><span class=\"md-plain\">\u5982\u4f55\u7528Java\u5b9e\u73b0\uff1f<\/span><\/h3>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u76f4\u89c2\u601d\u8def\uff1a\u751f\u4ea7\u8005-\u6d88\u8d39\u8005\u6a21\u5f0f\uff0c\u751f\u4ea7\u8005\u7ebf\u7a0b\u5b9a\u65f6\u5411\u963b\u585e\u961f\u5217\u6dfb\u52a0\u4ee4\u724c\uff0c\u88ab\u9650\u6d41\u7684\u7ebf\u7a0b\u4f5c\u4e3a\u6d88\u8d39\u8005\u4ece\u963b\u585e\u961f\u5217\u83b7\u53d6\u4ee4\u724c\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u4f46\u8fd9\u79cd\u5b9e\u73b0\u7684\u95ee\u9898\uff1a\u5b9a\u65f6\u5668\u3002\u9ad8\u5e76\u53d1\u573a\u666f\u4e0b\uff0c\u5f53\u7cfb\u7edf\u538b\u529b\u5df2\u7ecf\u4e34\u8fd1\u6781\u9650\u7684\u65f6\u5019\uff0c\u5b9a\u65f6\u5668\u7684\u7cbe\u5ea6\u8bef\u5dee\u4f1a\u975e\u5e38\u5927\uff0c\u540c\u65f6\u5b9a\u65f6\u5668\u672c\u8eab\u4f1a\u521b\u5efa\u8c03\u5ea6\u7ebf\u7a0b\uff0c\u4e5f\u4f1a\u5bf9\u7cfb\u7edf\u7684\u6027\u80fd\u4ea7\u751f\u5f71\u54cd\u3002<\/span><\/p>\n<h3 class=\"md-end-block md-heading md-focus\"><span class=\"md-plain md-expand\">Guava\u5982\u4f55\u5b9e\u73b0\u4ee4\u724c\u6876\u7b97\u6cd5\uff1f<\/span><\/h3>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u6838\u5fc3\u601d\u60f3\uff1a\u8bb0\u5f55\u5e76\u52a8\u6001\u8ba1\u7b97\u4e0b\u4e00\u4ee4\u724c\u53d1\u653e\u7684\u65f6\u95f4\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u57fa\u672c\u601d\u8def\uff1a<\/span><\/p>\n<pre class=\"md-fences md-end-block ty-contain-cm modeLoaded\" lang=\"\" spellcheck=\"false\"><span role=\"presentation\">\u200b<\/span>\r\n<span role=\"presentation\">class SimpleLimiter {<\/span>\r\n<span role=\"presentation\">  \/*<\/span>\r\n<span role=\"presentation\">  \u5f53\u524d\u4ee4\u724c\u6876\u4e2d\u7684\u4ee4\u724c\u6570\u91cf\u3002<\/span>\r\n<span role=\"presentation\">  notes:\u6ce8\u610f\u6b64\u5904\u7684\u4ee4\u724c\u6570\u91cf\u662f\u4ece\u5f53\u524d\u65f6\u523b\u5f80\u540e\u5f00\u59cb\u8ba1\u7b97\u3002\u4f46\u662f\u8fd9\u4e2a\u53d8\u91cf\u53ea\u6709\u5728\u6d88\u8d39\u8005\u7ebf\u7a0b\u8c03\u7528acquire()\u65b9\u6cd5\u65f6\u624d\u4f1a\u66f4\u65b0\u3002\u8fd9\u5c06\u5bfc\u81f4\u5728\u8c03\u7528acquire()\u65b9\u6cd5\u65f6\uff0cstoredPermits\u662f\u6ede\u540e\u7684\uff0c\u9700\u8981\u5148\u66f4\u65b0\u8be5\u503c\u3002\u6240\u4ee5\u6709\u4e86resync\u65b9\u6cd5<\/span>\r\n<span role=\"presentation\">  *\/<\/span>\r\n<span role=\"presentation\">  long storedPermits = 0;<\/span>\r\n<span role=\"presentation\">  \/\/\u4ee4\u724c\u6876\u7684\u5bb9\u91cf<\/span>\r\n<span role=\"presentation\">  long maxPermits = 3;<\/span>\r\n<span role=\"presentation\">  \/\/\u4e0b\u4e00\u4ee4\u724c\u4ea7\u751f\u65f6\u95f4<\/span>\r\n<span role=\"presentation\">  long next = System.nanoTime();<\/span>\r\n<span role=\"presentation\">  \/\/\u53d1\u653e\u4ee4\u724c\u95f4\u9694\uff1a\u7eb3\u79d2<\/span>\r\n<span role=\"presentation\">  long interval = 1000_000_000;<\/span>\r\n<span role=\"presentation\"> \u00a0<\/span>\r\n<span role=\"presentation\">  \/\/\u8bf7\u6c42\u65f6\u95f4\u5728\u4e0b\u4e00\u4ee4\u724c\u4ea7\u751f\u65f6\u95f4\u4e4b\u540e,\u5219<\/span>\r\n<span role=\"presentation\">  \/\/ 1.\u91cd\u65b0\u8ba1\u7b97\u4ee4\u724c\u6876\u4e2d\u7684\u4ee4\u724c\u6570<\/span>\r\n<span role=\"presentation\">  \/\/ 2.\u5c06\u4e0b\u4e00\u4e2a\u4ee4\u724c\u53d1\u653e\u65f6\u95f4\u91cd\u7f6e\u4e3a\u5f53\u524d\u65f6\u95f4\u3002<\/span>\r\n<span role=\"presentation\">  \/\/notes:\u56e0\u4e3a\u6b64\u65f6\u5df2\u7ecf\u66f4\u65b0\u4e86\u4ee4\u724c\u6876\u4e2d\u5df2\u6709\u4ee4\u724c\u6570\u91cf\uff0c\u5fc5\u987b\u5c06next\u66f4\u65b0<\/span>\r\n<span role=\"presentation\">  void resync(long now) {<\/span>\r\n<span role=\"presentation\"> \u00a0  if (now &gt; next) {<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  \/\/\u65b0\u4ea7\u751f\u7684\u4ee4\u724c\u6570<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  long newPermits=(now-next)\/interval;<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  \/\/\u65b0\u4ee4\u724c\u589e\u52a0\u5230\u4ee4\u724c\u6876\uff0c\u7531\u4e8e\u6876\u7684\u5bb9\u91cf\u6709\u9650\uff0c\u901a\u8fc7\u53d6\u4e24\u8005\u6700\u5c0f\u503c\u6765\u4e22\u5f03\u6389\u591a\u51fa\u6765\u7684\u4ee4\u724c<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  storedPermits=min(maxPermits, <\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0 \u00a0  storedPermits + newPermits);<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  \/\/\u5c06\u4e0b\u4e00\u4e2a\u4ee4\u724c\u53d1\u653e\u65f6\u95f4\u91cd\u7f6e\u4e3a\u5f53\u524d\u65f6\u95f4\u3002<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  next = now;<\/span>\r\n<span role=\"presentation\"> \u00a0  }<\/span>\r\n<span role=\"presentation\">  }<\/span>\r\n<span role=\"presentation\">  \/\/\u9884\u5360\u4ee4\u724c\uff0c\u8fd4\u56de\u80fd\u591f\u83b7\u53d6\u4ee4\u724c\u7684\u65f6\u95f4<\/span>\r\n<span role=\"presentation\">  synchronized long reserve(long now){<\/span>\r\n<span role=\"presentation\">    \/\/notes:\u5148\u66f4\u65b0\u5f53\u524d\u6876\u4e2d\u7684\u4ee4\u724c\u6570\u91cf\u3001\u4e0b\u4e00\u4e2a\u4ee4\u724c\u7684\u53d1\u653e\u65f6\u95f4\u3002\u5982\u679c\u4ee4\u724c\u6876\u4e2d\u5df2\u6709\u4ee4\u724c\u591f\u7528\uff0c\u6b64\u65f6resync\u65b9\u6cd5\u4e2d\u5c06\u6267\u884cnext=now\uff0c\u4e5f\u5c31\u662f\u7acb\u5373\u53d1\u653e\u4ee4\u724c\u3002<\/span>\r\n<span role=\"presentation\">    \/\/\u5982\u679c\u4ee4\u724c\u4e0d\u591f\u7528\u3001\u9700\u8981\u7b49\u5f85\uff0c\u90a3\u4e48\u9700\u8981\u7b49\u5230next\u65f6\u95f4\u3002<\/span>\r\n<span role=\"presentation\"> \u00a0  resync(now);<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u80fd\u591f\u83b7\u53d6\u4ee4\u724c\u7684\u65f6\u95f4<\/span>\r\n<span role=\"presentation\"> \u00a0  long at = next;<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u4ee4\u724c\u6876\u4e2d\u80fd\u63d0\u4f9b\u7684\u4ee4\u724c\u3002\u672c\u8eab\u53ea\u9700\u89811\u4e2a\u4ee4\u724c\uff0c\u4f46\u9700\u8981\u5148\u770b\u4ee4\u724c\u6876\u4e2d\u7684\u6570\u91cfstoredPermits\u662f\u5426\u591f\u7528\u3002<\/span>\r\n<span role=\"presentation\"> \u00a0  long fb=min(1, storedPermits);<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u4ee4\u724c\u51c0\u9700\u6c42\uff1a\u9996\u5148\u51cf\u6389\u4ee4\u724c\u6876\u4e2d\u7684\u4ee4\u724c<\/span>\r\n<span role=\"presentation\"> \u00a0  \/*<\/span>\r\n<span role=\"presentation\"> \u00a0  \u4e24\u79cd\u60c5\u51b5\uff1a<\/span>\r\n<span role=\"presentation\">    1. \u4ee4\u724c\u6876\u5df2\u7ecf\u6709\u8db3\u591f\u7684\u4ee4\u724c\uff1astoredPermits &gt;= 1, fb=1, \u6b64\u65f6nr=0, \u4e0b\u4e00\u4e2a\u4ee4\u724c\u4ea7\u751f\u65f6\u95f4 next = next\uff0c\u800c\u901a\u8fc7\u4e0a\u9762\u53ef\u77e5\u6b64\u65f6\u7684next\u5c31\u662f\u5f53\u524d\u65f6\u95f4now\uff0c\u63a5\u7740\u5269\u4f59\u4ee4\u724c\u6570\u91cf\u51cf\u4e00\u3001\u66f4\u65b0\u5e93\u5b58(this.storedPermits -= fb;)<\/span>\r\n<span role=\"presentation\">    2. \u4ee4\u724c\u6876\u5185\u4ee4\u724c\u4e0d\u591f\uff1a &lt;= storedPermits &lt; 1, fb=storedPermits, \u6b64\u65f6 0 &lt; nr &lt;= 1, nr\u662f\u63a5\u4e0b\u6765\u8fd8\u9700\u8981\u4ea7\u751f\u7684\u4ee4\u724c\u6570\u91cf\uff08\u9700\u8981\u5e73\u6ed1\u4ea7\u751f\uff09\uff0cnext = next + nr*interval,  \u5c31\u662f\u8bf4\u7b49\u5f85nr*interval\u65f6\u95f4\u4e4b\u540e\uff0c\u4ee4\u724c\u6876\u4e2d\u5c06\u4ea7\u751f1\u4e2a\u5b8c\u6574\u7684\u4ee4\u724c\u53ef\u4f9b\u8c03\u7528\u3002<\/span>\r\n    \r\n<span role=\"presentation\"> \u00a0  *\/<\/span>\r\n<span role=\"presentation\"> \u00a0  long nr = 1 - fb;<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u91cd\u65b0\u8ba1\u7b97\u4e0b\u4e00\u4ee4\u724c\u4ea7\u751f\u65f6\u95f4<\/span>\r\n<span role=\"presentation\"> \u00a0  next = next + nr*interval;<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u91cd\u65b0\u8ba1\u7b97\u4ee4\u724c\u6876\u4e2d\u7684\u4ee4\u724c<\/span>\r\n<span role=\"presentation\"> \u00a0  this.storedPermits -= fb;<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u8fd4\u56de\u672c\u6b21\u8c03\u7528\u83b7\u53d6\u4ee4\u724c\u7684\u65f6\u95f4<\/span>\r\n<span role=\"presentation\"> \u00a0  return at;<\/span>\r\n<span role=\"presentation\">  }<\/span>\r\n<span role=\"presentation\">  \/\/\u7533\u8bf7\u4ee4\u724c<\/span>\r\n<span role=\"presentation\">  void acquire() {<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u7533\u8bf7\u4ee4\u724c\u65f6\u7684\u65f6\u95f4<\/span>\r\n<span role=\"presentation\"> \u00a0  long now = System.nanoTime();<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u9884\u5360\u4ee4\u724c<\/span>\r\n<span role=\"presentation\"> \u00a0  long at=reserve(now);<\/span>\r\n<span role=\"presentation\"> \u00a0  \/*<\/span>\r\n<span role=\"presentation\"> \u00a0  \u8fd8\u662f\u8981\u5206\u4e24\u79cd\u60c5\u51b5\uff1a<\/span>\r\n<span role=\"presentation\"> \u00a0  1. \u4ee4\u724c\u6876\u5df2\u7ecf\u6709\u8db3\u591f\u7684\u4ee4\u724c: \u6b64\u65f6at=now\uff0cwaitTime=0\uff0c\u83b7\u5f97\u4ee4\u724c\uff0c\u76f4\u63a5\u8fd4\u56de<\/span>\r\n<span role=\"presentation\"> \u00a0  2. \u4ee4\u724c\u6876\u5185\u4ee4\u724c\u4e0d\u591f\uff1a \u6b64\u65f6at=\u4e0b\u6b21\u4ea7\u751f\u4ee4\u724c\u65f6\u95f4\uff0c\u9700\u8981\u7b49\u5f85<\/span>\r\n<span role=\"presentation\"> \u00a0  *\/<\/span>\r\n<span role=\"presentation\"> \u00a0  long waitTime=max(at-now, 0);<\/span>\r\n<span role=\"presentation\"> \u00a0  \/\/\u6309\u7167\u6761\u4ef6\u7b49\u5f85<\/span>\r\n<span role=\"presentation\"> \u00a0  if(waitTime &gt; 0) {<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  try {<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0 \u00a0  TimeUnit.NANOSECONDS<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0 \u00a0 \u00a0  .sleep(waitTime);<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  }catch(InterruptedException e){<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0 \u00a0  e.printStackTrace();<\/span>\r\n<span role=\"presentation\"> \u00a0 \u00a0  }<\/span>\r\n<span role=\"presentation\"> \u00a0  }<\/span>\r\n<span role=\"presentation\">  }<\/span>\r\n<span role=\"presentation\">}<\/span><\/pre>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u6709\u5173\u7b97\u6cd5\u7684\u7b80\u8981\u89e3\u91ca\uff1a<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">next \u53d8\u91cf\u7684\u610f\u601d\u662f\u4e0b\u4e00\u4e2a\u4ee4\u724c\u7684\u751f\u6210\u65f6\u95f4\uff0c\u53ef\u4ee5\u7406\u89e3\u4e3a\u5f53\u524d\u7ebf\u7a0b\u8bf7\u6c42\u7684\u4ee4\u724c\u7684\u751f\u6210\u65f6\u523b\uff0c\u5982\u7b2c\u4e00\u5f20\u56fe\u6240\u793a\uff1a\u7ebf\u7a0b T1 \u7684\u4ee4\u724c\u7684\u751f\u6210\u65f6\u523b\u662f\u7b2c\u4e09\u79d2\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u7ebf\u7a0b T \u8bf7\u6c42\u65f6\uff0c\u5b58\u5728\u4e09\u79cd\u573a\u666f\uff1a<\/span><\/p>\n<ol class=\"ol-list\">\n<li class=\"md-list-item\">\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u6876\u91cc\u6709\u5269\u4f59\u4ee4\u724c\u3002<\/span><\/p>\n<\/li>\n<li class=\"md-list-item\">\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u521a\u521b\u5efa\u4ee4\u724c\uff0c\u7ebf\u7a0b\u540c\u65f6\u8bf7\u6c42\u3002<\/span><\/p>\n<\/li>\n<li class=\"md-list-item\">\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u6876\u91cc\u65e0\u5269\u4f59\u4ee4\u724c\u3002<\/span><\/p>\n<\/li>\n<\/ol>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u573a\u666f 2 \u53ef\u4ee5\u60f3\u8c61\u6210\u7ebf\u7a0b\u8bf7\u6c42\u7684\u540c\u65f6\u4ee4\u724c\u521a\u597d\u751f\u6210\uff0c\u6ca1\u6765\u5f97\u53ca\u653e\u5165\u6876\u5185\u5c31\u88ab\u7ebf\u7a0b T \u62ff\u8d70\u4e86\u3002\u56e0\u6b64\u5c06\u573a\u666f 2 \u548c\u573a\u666f 3 \u5408\u5e76\u6210\u4e00\u79cd\u60c5\u51b5\uff0c\u90a3\u5c31\u662f\u6876\u91cc\u6ca1\u4ee4\u724c\u3002\u5373\u7ebf\u7a0b\u8bf7\u6c42\u65f6\uff0c\u6876\u91cc\u53ef\u5206\u4e3a\u6709\u4ee4\u724c\u548c\u6ca1\u4ee4\u724c\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u201c\u6876\u91cc\u6ca1\u4ee4\u724c\u201d\uff0c\u7ebf\u7a0b T \u9700\u8981\u7b49\u5f85\uff1b\u9700\u8981\u7b49\u5f85\u5219\u610f\u5473\u7740 now(\u7ebf\u7a0b T \u8bf7\u6c42\u65f6\u523b) \u5c0f\u4e8e\u7b49\u4e8e next(\u7ebf\u7a0b T \u6240\u9700\u7684\u4ee4\u724c\u7684\u751f\u6210\u65f6\u523b)\u3002\u8fd9\u91cc\u53ef\u4ee5\u60f3\u8c61\u4e00\u4e0b\u7ebf\u7a0b T \u5728\u82e6\u82e6\u7b49\u5f85\u4ee4\u724c\u751f\u6210\u7684\u573a\u666f\uff0c\u53ea\u8981\u7ebf\u7a0b T \u7b49\u5f85\u90a3\u4e48\u4e45\u4e4b\u540e\uff0c\u5c31\u4f1a\u88ab\u653e\u884c\u3002\u653e\u884c\u8fd9\u4e00\u523b\u4ee4\u724c\u540c\u65f6\u751f\u6210\uff0c\u7acb\u9a6c\u88ab\u7ebf\u7a0b\u62ff\u8d70\uff0c\u4ee4\u724c\u6ca1\u653e\u5165\u6876\u91cc\u3002\u5bf9\u5e94\u5230\u4ee3\u7801\u5c31\u662f resync \u65b9\u6cd5\u6ca1\u6709\u8fdb\u5165 if \u8bed\u53e5\u5185\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u201c\u6876\u91cc\u6709\u4ee4\u724c\u201d\uff0c\u7ebf\u7a0b T \u4e0d\u9700\u8981\u7b49\u5f85\u3002\u8bf4\u660e\u7ebf\u7a0b T \u5bf9\u5e94\u7684\u4ee4\u724c\u5df2\u7ecf\u65e9\u65e9\u751f\u6210\uff0c\u5df2\u5728\u6876\u5185\u3002\u4ee3\u7801\u5c31\u662f\uff1anow &gt; next\uff08\u8bf7\u6c42\u65f6\u523b\u5927\u4e8e\u5bf9\u5e94\u4ee4\u724c\u7684\u751f\u6210\u65f6\u523b\uff09\u3002\u56e0\u6b64\u5728\u5206\u914d\u4ee4\u724c\u7ed9\u7ebf\u7a0b\u4e4b\u524d\uff0c\u9700\u8981\u8ba1\u7b97\u7ebf\u7a0b T \u8fdf\u5230\u4e86\u591a\u4e45\uff0c\u8fdf\u5230\u7684\u8fd9\u6bb5\u65f6\u95f4\uff0c\u6709\u591a\u5c11\u4e2a\u4ee4\u724c\u751f\u6210\u00b9\uff1b\u7136\u540e\u653e\u5165\u6876\u5185\uff0c\u6ee1\u4e86\u5219\u4e22\u5f03\u00b2\uff1b\u672a\u6765\u7684\u7ebf\u7a0b\u7684\u4ee4\u724c\u5728\u8fd9\u4e2a\u65f6\u523b\u5df2\u7ecf\u751f\u6210\u653e\u5165\u6876\u5185\u00b3\uff08\u5373 resync \u65b9\u6cd5\u7684\u903b\u8f91\uff09\u3002\u7ebf\u7a0b\u65e0\u9700\u7b49\u5f85\uff0c\u6240\u4ee5\u4e0d\u9700\u8981\u589e\u52a0\u4e00\u4e2a interval \u4e86\u3002<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u89d2\u6807\u5206\u522b\u5bf9\u5e94 resync \u65b9\u6cd5\u5185\u7684\u4ee3\u7801\uff1a<\/span> <span class=\"md-plain\">\u00b9: long newPermits=(now-next)\/interval;<\/span> <span class=\"md-plain\">\u00b2: storedPermits=min(maxPermits,<\/span> <span class=\"md-plain\"> storedPermits + newPermits);<\/span> <span class=\"md-plain\">\u00b3: next = now;<\/span><\/p>\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">\u5bf9\u4e8ereverse\u65b9\u6cd5\uff0c\u9996\u5148\u80af\u5b9a\u662f\u8ba1\u7b97\u4ee4\u724c\u6876\u91cc\u9762\u7684\u4ee4\u724c\u6570\u91cf\uff0c\u7136\u540e\u53d6\u4ee4\u724c\u6876\u4e2d\u7684\u4ee4\u724c\u6570\u91cfstoredPermits \u4e0e\u5f53\u524d\u7684\u9700\u8981\u7684\u4ee4\u724c\u6570\u91cf 1 \u505a\u6bd4\u8f83\uff0c\u5927\u4e8e\u7b49\u4e8e 1\uff0c\u8bf4\u660e\u4ee4\u724c\u6876\u81f3\u5c11\u6709\u4e00\u4e2a\u4ee4\u724c\uff0c\u6b64\u65f6\u4e0b\u4e00\u4ee4\u724c\u7684\u83b7\u53d6\u662f\u4e0d\u9700\u8981\u7b49\u5f85\u7684\uff0c\u8868\u73b0\u4e3a next \u4e0d\u9700\u8981\u53d8\u5316\uff1b\u800c\u5f53\u4ee4\u724c\u6876\u4e2d\u7684\u4ee4\u724c\u6ca1\u6709\u4e86\u5373storedPermits\u7b49\u4e8e 0 \u65f6\uff0cnext \u5c31\u4f1a\u53d8\u5316\u4e3a\u4e0b\u4e00\u4e2a\u4ee4\u724c\u7684\u83b7\u53d6\u65f6\u95f4\uff0c\u6ce8\u610f nr \u7684\u503c\u53d8\u5316<\/span><\/p>\n<h2 class=\"md-end-block md-heading\"><span class=\"md-plain\">\u53c2\u8003\u8d44\u6599<\/span><\/h2>\n<ul class=\"ul-list\" data-mark=\"-\">\n<li class=\"md-list-item\">\n<p class=\"md-end-block md-p\"><span class=\"md-plain\">java\u5e76\u53d1\u7f16\u7a0b\u5b9e\u6218 \u4e13\u680f\u8bfe<\/span><\/p>\n<\/li>\n<\/ul>\n<p class=\"md-end-block md-p\">\n","protected":false},"excerpt":{"rendered":"<p>Guava RateLimiter\u57fa\u672c\u4f7f\u7528 \u5b66\u4e1c\u897f\u65f6\u6211\u4eec\u5e94\u8be5\u5c3d\u91cf\u53bb\u770b\u5b98\u7f51\u3001\u770b\u6e90\u7801\u3001\u770b\u5b98\u65b9\u7ed9\u51fa\u7684\u5355\u5143\u6d4b\u8bd5\u3002 \u6bd4\u5982 <a href='http:\/\/prayerlaputa.com\/?p=849' class='excerpt-more'>[&#8230;]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[83,18],"tags":[84,50],"_links":{"self":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts\/849"}],"collection":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=849"}],"version-history":[{"count":3,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts\/849\/revisions"}],"predecessor-version":[{"id":852,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts\/849\/revisions\/852"}],"wp:attachment":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=849"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=849"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=849"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}