{"id":10008004,"date":"2023-06-27T17:59:59","date_gmt":"2023-06-27T09:59:59","guid":{"rendered":"https:\/\/ityet.com\/?p=10008004"},"modified":"2023-06-27T17:59:59","modified_gmt":"2023-06-27T09:59:59","slug":"redis%e8%b7%b3%e8%b7%83%e8%a1%a8%e6%98%af%e5%a6%82%e4%bd%95%e6%b7%bb%e5%8a%a0%e5%85%83%e7%b4%a0%e7%9a%84%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10008004","title":{"rendered":"Redis\u8df3\u8dc3\u8868\u662f\u5982\u4f55\u6dfb\u52a0\u5143\u7d20\u7684\uff1f"},"content":{"rendered":"<p>\u4eca\u5929\u5206\u4eab\u7684\u8fd9\u9053\u9898\u6765\u81ea\u4e8e\u851a\u6765\u7684\u771f\u5b9e\u9762\u8bd5\u9898\u3002<\/p>\n<p>Java \u9762\u8bd5\u4e0d\u53ef\u80fd\u4e0d\u95ee Redis\uff0c\u95ee\u5230 Redis \u4e0d\u53ef\u80fd\u4e0d\u95ee Redis \u7684\u5e38\u7528\u6570\u636e\u7c7b\u578b\uff0c\u95ee\u5230 Redis \u7684\u5e38\u7528\u6570\u636e\u7c7b\u578b\uff0c\u4e0d\u53ef\u80fd\u4e0d\u95ee\u8df3\u8dc3\u8868\uff0c\u5f53\u95ee\u5230\u8df3\u8dc3\u8868\u7ecf\u5e38\u4f1a\u88ab\u95ee\u5230\u8df3\u8dc3\u8868\u7684\u67e5\u8be2\u548c\u6dfb\u52a0\u6d41\u7a0b\uff0c\u6240\u4ee5\u63a5\u4e0b\u6765\u6211\u4eec\u4e00\u8d77\u6765\u770b\u8fd9\u9053\u9898\u7684\u7b54\u6848\u5427\u3002<\/p>\n<p>Redis \u6709\u5e8f\u96c6\u5408 <strong>ZSet \u662f\u7531 ziplist (\u538b\u7f29\u5217\u8868) \u6216 skiplist (\u8df3\u8dc3\u8868) \u7ec4\u6210\u7684\u3002<\/strong><\/p>\n<ol>\n<li>\u538b\u7f29\u5217\u8868 ziplist \u672c\u8d28\u4e0a\u5c31\u662f\u4e00\u4e2a\u5b57\u8282\u6570\u7ec4\uff0c\u662f Redis \u4e3a\u4e86\u8282\u7ea6\u5185\u5b58\u800c\u8bbe\u8ba1\u7684\u4e00\u79cd\u7ebf\u6027\u6570\u636e\u7ed3\u6784\uff0c\u53ef\u4ee5\u5305\u542b\u591a\u4e2a\u5143\u7d20\uff0c\u6bcf\u4e2a\u5143\u7d20\u53ef\u4ee5\u662f\u4e00\u4e2a\u5b57\u8282\u6570\u7ec4\u6216\u4e00\u4e2a\u6574\u6570\u3002<\/li>\n<li>\n<p>\u8df3\u8dc3\u8868 skiplist \u662f\u4e00\u79cd\u6709\u5e8f\u6570\u636e\u7ed3\u6784\uff0c\u5b83\u901a\u8fc7\u5728\u6bcf\u4e2a\u8282\u70b9\u4e2d\u7ef4\u6301\u591a\u4e2a\u6307\u5411\u5176\u4ed6\u8282\u70b9\u7684\u6307\u9488\uff0c\u4ece\u800c\u8fbe\u5230\u5feb\u901f\u8bbf\u95ee\u8282\u70b9\u7684\u76ee\u7684\u3002\u8df3\u8dc3\u8868\u652f\u6301\u5e73\u5747 O(logN)\u3001\u6700\u574f O(N) \u590d\u6742\u5ea6\u7684\u8282\u70b9\u67e5\u627e\uff0c\u8fd8\u53ef\u4ee5\u901a\u8fc7\u987a\u5e8f\u6027\u64cd\u4f5c\u6765\u6279\u91cf\u5904\u7406\u8282\u70b9\u3002<\/p>\n<h2>\u8df3\u8dc3\u8868\u4ecb\u7ecd<\/h2>\n<p>\u8df3\u8dc3\u8868 Skip List\uff0c\u4e5f\u79f0\u4e4b\u4e3a\u8df3\u8868\uff0c\u662f\u4e00\u79cd\u6570\u636e\u7ed3\u6784\uff0c\u7528\u4e8e\u5728\u6709\u5e8f\u5143\u7d20\u7684\u96c6\u5408\u4e2d\u8fdb\u884c\u9ad8\u6548\u7684\u67e5\u627e\u64cd\u4f5c\u3002\u5b83\u901a\u8fc7\u6dfb\u52a0\u591a\u5c42\u94fe\u8868\u7684\u65b9\u5f0f\uff0c\u63d0\u4f9b\u4e86\u4e00\u79cd\u4ee5\u7a7a\u95f4\u6362\u65f6\u95f4\u7684\u65b9\u5f0f\u6765\u52a0\u901f\u67e5\u627e\u3002<\/p>\n<\/li>\n<\/ol>\n<p>\u8df3\u8dc3\u8868\u7531\u4e00\u4e2a\u5e26\u6709\u591a\u5c42\u8282\u70b9\u7684\u94fe\u8868\u7ec4\u6210\uff0c\u6bcf\u4e00\u5c42\u90fd\u662f\u539f\u59cb\u94fe\u8868\u7684\u4e00\u4e2a\u5b50\u96c6\u3002\u6700\u5e95\u5c42\u662f\u4e00\u4e2a\u5b8c\u6574\u7684\u6709\u5e8f\u94fe\u8868\uff0c\u5305\u542b\u6240\u6709\u5143\u7d20\u3002\u6bcf\u4e2a\u66f4\u9ad8\u5c42\u7ea7\u90fd\u662f\u4e0b\u5c42\u7ea7\u7684\u5b50\u96c6\uff0c\u901a\u8fc7\u6dfb\u52a0\u989d\u5916\u7684\u6307\u9488\u6765\u8df3\u8fc7\u4e00\u4e9b\u5143\u7d20\u3002\u8fd9\u4e9b\u989d\u5916\u7684\u6307\u9488\u79f0\u4e3a\u201c\u8df3\u8dc3\u6307\u9488\u201d\uff0c\u5b83\u4eec\u5141\u8bb8\u5feb\u901f\u8bbf\u95ee\u66f4\u8fdc\u7684\u8282\u70b9\uff0c\u4ece\u800c\u51cf\u5c11\u4e86\u67e5\u627e\u6240\u9700\u7684\u6bd4\u8f83\u6b21\u6570\u3002<\/p>\n<p>\u8df3\u8dc3\u8868\u7684\u5e73\u5747\u67e5\u627e\u65f6\u95f4\u590d\u6742\u5ea6\u4e3a O(log n)\uff0c\u5176\u4e2d n \u662f\u5143\u7d20\u7684\u6570\u91cf\u3002\u8fd9\u4f7f\u5f97\u5b83\u6bd4\u666e\u901a\u7684\u6709\u5e8f\u94fe\u8868\u5177\u6709\u66f4\u5feb\u7684\u67e5\u627e\u6027\u80fd\uff0c\u5e76\u4e14\u4e0e\u5e73\u8861\u4e8c\u53c9\u641c\u7d22\u6811\uff08\u5982\u7ea2\u9ed1\u6811\uff09\u76f8\u6bd4\uff0c\u5b9e\u73b0\u8d77\u6765\u66f4\u4e3a\u7b80\u5355\u3002<\/p>\n<p>\u7b80\u5355\u7684\u8df3\u8dc3\u8868\u5982\u4e0b\u56fe\u6240\u793a\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043941918\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<h2>\u8df3\u8dc3\u8868\u6dfb\u52a0\u6d41\u7a0b<\/h2>\n<h3>\u524d\u7f6e\u77e5\u8bc6\uff1a\u8282\u70b9\u968f\u673a\u5c42\u6570<\/h3>\n<p>\u5728\u5f00\u59cb\u8bb2\u8df3\u8dc3\u8868\u7684\u6dfb\u52a0\u6d41\u7a0b\u4e4b\u524d\uff0c\u5fc5\u987b\u5148\u641e\u61c2\u4e00\u4e2a\u6982\u5ff5\uff1a\u8282\u70b9\u7684\u968f\u673a\u5c42\u6570\u3002<br \/><strong>\u6240\u8c13\u7684\u968f\u673a\u5c42\u6570\u6307\u7684\u662f\u6bcf\u6b21\u6dfb\u52a0\u8282\u70b9\u4e4b\u524d\uff0c\u4f1a\u5148\u751f\u6210\u5f53\u524d\u8282\u70b9\u7684\u968f\u673a\u5c42\u6570\uff0c\u6839\u636e\u751f\u6210\u7684\u968f\u673a\u5c42\u6570\u6765\u51b3\u5b9a\u5c06\u5f53\u524d\u8282\u70b9\u5b58\u5728\u51e0\u5c42\u94fe\u8868\u4e2d\u3002<\/strong><\/p>\n<h4>\u4e3a\u4ec0\u4e48\u8981\u8fd9\u6837\u8bbe\u8ba1\u5462\uff1f<\/h4>\n<p>\u8fd9\u6837\u8bbe\u8ba1\u7684\u76ee\u7684\u662f\u4e3a\u4e86\u4fdd\u8bc1 Redis \u7684\u6267\u884c\u6548\u7387\u3002<\/p>\n<p>\u4e3a\u4ec0\u4e48\u8981\u751f\u6210\u968f\u673a\u5c42\u6570\uff0c\u800c\u4e0d\u662f\u5236\u5b9a\u4e00\u4e2a\u56fa\u5b9a\u7684\u89c4\u5219\uff0c\u6bd4\u5982\u4e0a\u5c42\u8282\u70b9\u662f\u4e0b\u5c42\u8de8\u8d8a\u4e24\u4e2a\u8282\u70b9\u7684\u94fe\u8868\u7ec4\u6210\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043941919\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><\/p>\n<p>\u5982\u679c\u5236\u5b9a\u4e86\u89c4\u5219\uff0c\u90a3\u4e48\u5c31\u9700\u8981\u5728\u6dfb\u52a0\u6216\u5220\u9664\u65f6\uff0c\u4e3a\u4e86\u6ee1\u8db3\u5176\u89c4\u5219\uff0c\u505a\u989d\u5916\u7684\u5904\u7406\uff0c\u6bd4\u5982\u6dfb\u52a0\u4e86\u4e00\u4e2a\u65b0\u8282\u70b9\uff0c\u5982\u4e0b\u56fe\u6240\u793a\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043941920\" alt=\"image.png\" title=\"image.png\" loading=\"lazy\"><br \/>\u8fd9\u6837\u5c31\u4e0d\u6ee1\u8db3\u5236\u5b9a\u7684\u4e0a\u5c42\u8282\u70b9\u8de8\u8d8a\u4e0b\u5c42\u4e24\u4e2a\u8282\u70b9\u7684\u89c4\u5219\u4e86\uff0c\u5c31\u9700\u8981\u989d\u5916\u7684\u8c03\u6574\u4e0a\u5c42\u4e2d\u7684\u6240\u6709\u8282\u70b9\uff0c\u8fd9\u6837\u7a0b\u5e8f\u7684\u6548\u7387\u5c31\u964d\u4f4e\u4e86\uff0c\u6240\u4ee5\u4f7f\u7528\u968f\u673a\u5c42\u6570\uff0c\u4e0d\u5f3a\u5236\u5236\u5b9a\u89c4\u5219\uff0c\u8fd9\u6837\u5c31\u4e0d\u9700\u8981\u8fdb\u884c\u989d\u5916\u7684\u64cd\u4f5c\uff0c\u4ece\u800c\u4e5f\u5c31\u4e0d\u4f1a\u5360\u7528\u670d\u52a1\u6267\u884c\u7684\u65f6\u95f4\u4e86\u3002<\/p>\n<h3>\u6dfb\u52a0\u6d41\u7a0b<\/h3>\n<p>Redis \u4e2d\u8df3\u8dc3\u8868\u7684\u6dfb\u52a0\u6d41\u7a0b\u5982\u4e0b\u56fe\u6240\u793a\uff1a<br \/><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043941921\" alt=\"43df041841fad96d60c6385ac23b23d.jpg\" title=\"43df041841fad96d60c6385ac23b23d.jpg\" loading=\"lazy\"><\/p>\n<ol>\n<li>\u7b2c\u4e00\u4e2a\u5143\u7d20\u6dfb\u52a0\u5230\u6700\u5e95\u5c42\u7684\u6709\u5e8f\u94fe\u8868\u4e2d\uff08\u6700\u5e95\u5c42\u5b58\u50a8\u4e86\u6240\u6709\u5143\u7d20\u6570\u636e\uff09\u3002<\/li>\n<li>\u7b2c\u4e8c\u4e2a\u5143\u7d20\u751f\u6210\u7684\u968f\u673a\u5c42\u6570\u662f 2\uff0c\u6240\u4ee5\u518d\u589e\u52a0 1 \u5c42\uff0c\u5e76\u5c06\u6b64\u5143\u7d20\u5b58\u50a8\u5728\u7b2c 1 \u5c42\u548c\u6700\u4f4e\u5c42\u3002<\/li>\n<li>\u7b2c\u4e09\u4e2a\u5143\u7d20\u751f\u6210\u7684\u968f\u673a\u5c42\u6570\u662f 4\uff0c\u6240\u4ee5\u518d\u589e\u52a0 2 \u5c42\uff0c\u6574\u4e2a\u8df3\u8dc3\u8868\u53d8\u6210\u4e86 4 \u5c42\uff0c\u5c06\u6b64\u5143\u7d20\u4fdd\u5b58\u5230\u6240\u6709\u5c42\u4e2d\u3002<\/li>\n<li>\u7b2c\u56db\u4e2a\u5143\u7d20\u751f\u6210\u7684\u968f\u673a\u5c42\u6570\u662f 1\uff0c\u6240\u4ee5\u628a\u5b83\u6309\u987a\u5e8f\u4fdd\u5b58\u5230\u6700\u540e\u4e00\u5c42\u4e2d\u5373\u53ef\u3002<\/li>\n<\/ol>\n<p>\u5176\u4ed6\u65b0\u589e\u8282\u70b9\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n<h3>\u968f\u673a\u5c42\u6570\u6e90\u7801\u5206\u6790<\/h3>\n<p>\u968f\u673a\u5c42\u6570\u7684\u6e90\u7801\u5728 t_zset.c\/zslRandomLevel(void) \u4e2d\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre><code class=\"c\">int zslRandomLevel(void) {\n    int level = 1;\n    while ((random()&amp;0xFFFF) &lt; (ZSKIPLIST_P * 0xFFFF))\n        level += 1;\n    return (level&lt;ZSKIPLIST_MAXLEVEL) ? level : ZSKIPLIST_MAXLEVEL;\n}<\/code><\/pre>\n<p>\u4ece\u6e90\u7801\u53ef\u77e5\uff0c\u968f\u673a\u5c42\u6570\u6709 50% \u7684\u6982\u7387\u88ab\u5206\u914d\u5230 Level 1\uff0c25% \u7684\u6982\u7387\u88ab\u5206\u914d\u5230 Level 2\uff0c12.5% \u7684\u6982\u7387\u88ab\u5206\u914d\u5230 Level 3\uff0c\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n<p>Redis \u8df3\u8dc3\u8868\u9ed8\u8ba4\u5141\u8bb8\u6700\u5927\u7684\u5c42\u6570\u662f 32\uff0c\u6b64\u503c\u5728 ZSKIPLIST_MAXLEVEL \u6e90\u7801\u4e2d\u88ab\u5b9a\u4e49\u3002<\/p>\n<h2>\u5c0f\u7ed3<\/h2>\n<p>\u8df3\u8dc3\u8868\u662f\u7531\u591a\u4e2a\u6709\u5e8f\u7684\u94fe\u8868\u7ec4\u6210\u7684\uff0c\u6700\u5e95\u5c42\u5b58\u50a8\u4e86\u6240\u6709\u5143\u7d20\u7684\u6570\u636e\uff0c\u8fd9\u6837\u5b58\u50a8\u8ba9\u5b83\u7684\u67e5\u8be2\u6548\u7387\u66f4\u9ad8\uff0c\u67e5\u8be2\u590d\u6742\u5ea6\u4ece O(n) \u53d8\u4e3a\u4e86 O(log n)\u3002\u8df3\u8dc3\u8868\u7684\u6dfb\u52a0\u6d41\u7a0b\u662f\u6839\u636e\u8282\u70b9\u751f\u6210\u7684\u968f\u673a\u5c42\u6570\uff0c\u5c06\u5b83\u63d2\u5165\u5230\u6700\u5e95\u5c42\u8282\u70b9\u548c\u4e0a\u5c42\u7684 N-1 \u5c42\u8282\u70b9\u4e2d\uff0c\u63cf\u8ff0\u6dfb\u52a0\u6d41\u7a0b\u7684\u5173\u952e\u5c31\u662f\u7406\u89e3\u968f\u673a\u5c42\u6570\u4ee5\u53ca\u5176\u80cc\u540e\u7684\u539f\u7406\u3002<\/p>\n<h4>\u53c2\u8003 &#038; \u9e23\u8c22<\/h4>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000022028505\">https:\/\/segmentfault.com\/a\/1190000022028505<\/a><\/p>\n<blockquote><p>\u672c\u6587\u5df2\u6536\u5f55\u5230\u6211\u7684\u9762\u8bd5\u5c0f\u7ad9 www.javacn.site\uff0c\u5176\u4e2d\u5305\u542b\u7684\u5185\u5bb9\u6709\uff1aRedis\u3001JVM\u3001\u5e76\u53d1\u3001\u5e76\u53d1\u3001MySQL\u3001Spring\u3001Spring MVC\u3001Spring Boot\u3001Spring Cloud\u3001MyBatis\u3001\u8bbe\u8ba1\u6a21\u5f0f\u3001\u6d88\u606f\u961f\u5217\u7b49\u6a21\u5757\u3002<\/p><\/blockquote>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000043941915\">https:\/\/segmentfault.com\/a\/1190000043941915<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4eca\u5929\u5206\u4eab\u7684\u8fd9\u9053\u9898\u6765\u81ea\u4e8e\u851a\u6765\u7684\u771f\u5b9e\u9762\u8bd5\u9898\u3002 Java \u9762\u8bd5\u4e0d\u53ef\u80fd\u4e0d\u95ee Redis\uff0c\u95ee\u5230 Redis \u4e0d\u53ef\u80fd\u4e0d\u95ee  [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10008004","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10008004","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10008004"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10008004\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10008004"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10008004"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10008004"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}