{"id":1094,"date":"2025-07-02T17:52:26","date_gmt":"2025-07-02T09:52:26","guid":{"rendered":"https:\/\/beijian99.top\/?p=1094"},"modified":"2025-07-07T17:21:57","modified_gmt":"2025-07-07T09:21:57","slug":"go-map%e5%ba%95%e5%b1%82%e5%ae%9e%e7%8e%b0","status":"publish","type":"post","link":"https:\/\/beijian99.top\/?p=1094","title":{"rendered":"Go Map\u5e95\u5c42\u5b9e\u73b0"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"419\" height=\"179\" src=\"https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-8.png\" alt=\"\" class=\"wp-image-1133\" srcset=\"https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-8.png 419w, https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-8-300x128.png 300w\" sizes=\"auto, (max-width: 419px) 100vw, 419px\" \/><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u5728Go\u8bed\u8a00\u4e2d\uff0cmap\u662f\u6700\u91cd\u8981\u4e14\u6700\u5e38\u7528\u7684\u6570\u636e\u7ed3\u6784\u4e4b\u4e00\uff0c\u5b83\u63d0\u4f9b\u4e86\u9ad8\u6548\u7684\u952e\u503c\u5bf9\u5b58\u50a8\u548c\u67e5\u627e\u80fd\u529b\u3002<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u3001map\u7684\u57fa\u672c\u67b6\u6784<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1.1 \u6838\u5fc3\u6570\u636e\u7ed3\u6784<\/h3>\n\n\n\n<p>Go\u7684map\u5b9e\u73b0\u662f\u4e00\u4e2a\u590d\u6742\u7684\u54c8\u5e0c\u8868\u7cfb\u7edf\uff0c\u4e3b\u8981\u7531\u4ee5\u4e0b\u51e0\u4e2a\u6838\u5fc3\u7ed3\u6784\u7ec4\u6210\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: go; title: ; notranslate\" title=\"\">\n\/\/ runtime\/map.go\u4e2d\u7684\u6838\u5fc3\u7ed3\u6784\ntype hmap struct {\n    count     int    \/\/ \u5f53\u524d\u5143\u7d20\u6570\u91cf\n    flags     uint8  \n    B         uint8  \/\/ \u6876\u6570\u91cf\u7684\u5bf9\u6570(\u53ef\u4ee5\u5bb9\u7eb32^B\u4e2a\u6876)\n    noverflow uint16 \/\/ \u6ea2\u51fa\u6876\u7684\u5927\u6982\u6570\u91cf\n    hash0     uint32 \/\/ \u54c8\u5e0c\u79cd\u5b50\n    \n    buckets    unsafe.Pointer \/\/ \u6307\u5411\u6876\u6570\u7ec4\u7684\u6307\u9488\n    oldbuckets unsafe.Pointer \/\/ \u6269\u5bb9\u65f6\u7528\u4e8e\u8fc1\u79fb\u7684\u65e7\u6876\n    nevacuate  uintptr        \/\/ \u8fc1\u79fb\u8fdb\u5ea6\u8ba1\u6570\u5668\n    \n    extra *mapextra \/\/ \u53ef\u9009\u5b57\u6bb5\n}\n\ntype bmap struct {\n    tophash  &#x5B;8]uint8 \/\/ \u5b58\u50a8\u952e\u54c8\u5e0c\u503c\u7684\u9ad88\u4f4d\n    keys     &#x5B;8]keytype\n    values   &#x5B;8]valuetype\n    overflow *bmap    \/\/ \u6ea2\u51fa\u6876\u6307\u9488\n}\n<\/pre><\/div>\n\n\n<h3 class=\"wp-block-heading\">1.2 \u5185\u5b58\u5e03\u5c40\u53ef\u89c6\u5316<\/h3>\n\n\n\n<p>\u4e00\u4e2a\u5178\u578b\u7684Go map\u5185\u5b58\u5e03\u5c40\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nhmap\u7ed3\u6784\u4f53\n\u2502\n\u251c\u2500\u2500 count: \u5143\u7d20\u6570\u91cf\n\u251c\u2500\u2500 B: \u6876\u6570\u91cf\u7684\u5bf9\u6570\n\u251c\u2500\u2500 buckets: \u2192 bucket\u6570\u7ec4\n\u2502              \u2502\n\u2502              \u251c\u2500\u2500 bmap0\n\u2502              \u2502    \u251c\u2500\u2500 tophash: &#x5B;h1,h2,...,h8]\n\u2502              \u2502    \u251c\u2500\u2500 keys:    &#x5B;k1,k2,...,k8]\n\u2502              \u2502    \u251c\u2500\u2500 values:  &#x5B;v1,v2,...,v8]\n\u2502              \u2502    \u2514\u2500\u2500 overflow: \u2192 \u6ea2\u51fabmap\n\u2502              \u251c\u2500\u2500 bmap1\n\u2502              \u2514\u2500\u2500 ...\n\u2514\u2500\u2500 oldbuckets: \u6269\u5bb9\u65f6\u6307\u5411\u65e7\u6876\u6570\u7ec4\n<\/pre><\/div>\n\n\n<h2 class=\"wp-block-heading\">\u4e8c\u3001\u54c8\u5e0c\u51fd\u6570\u8bbe\u8ba1<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">2.1 \u54c8\u5e0c\u8ba1\u7b97\u8fc7\u7a0b<\/h3>\n\n\n\n<p>Go\u4e3a\u6bcf\u79cd\u952e\u7c7b\u578b\u5b9e\u73b0\u4e86\u7279\u5b9a\u7684\u54c8\u5e0c\u7b97\u6cd5\uff0c\u8fd9\u4e9b\u7b97\u6cd5\u5728\u7f16\u8bd1\u65f6\u786e\u5b9a\u3002\u54c8\u5e0c\u8ba1\u7b97\u8fc7\u7a0b\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5bf9\u4e8e\u6bcf\u4e2a\u952e\uff0c\u8c03\u7528\u7c7b\u578b\u7279\u5b9a\u7684\u54c8\u5e0c\u51fd\u6570\u8ba1\u7b97\u54c8\u5e0c\u503c<\/li>\n\n\n\n<li>\u4f7f\u7528hmap.hash0\u8fdb\u884c\u54c8\u5e0c\u6df7\u6dc6\uff0c\u9632\u6b62\u54c8\u5e0c\u78b0\u649e\u653b\u51fb<\/li>\n\n\n\n<li>\u53d6\u54c8\u5e0c\u503c\u7684\u540eB\u4f4d\u786e\u5b9a\u6876\u4f4d\u7f6e<\/li>\n\n\n\n<li>\u53d6\u54c8\u5e0c\u503c\u7684\u9ad88\u4f4d\u4f5c\u4e3atophash\u5b58\u50a8\u5728bmap\u4e2d<\/li>\n<\/ol>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\n\/\/ \u4f2a\u4ee3\u7801\uff1a\u8ba1\u7b97\u952e\u7684\u54c8\u5e0c\u548c\u4f4d\u7f6e\nfunc (h *hmap) hashAndPosition(key Key) (hash uint64, bucket uintptr) {\n    hash = alg.hash(key, h.hash0) \/\/ \u8ba1\u7b97\u54c8\u5e0c\u503c\n    bucket = hash &amp;amp; (1&amp;lt;&amp;lt;h.B - 1)  \/\/ \u53d6\u540eB\u4f4d\u786e\u5b9a\u6876\u4f4d\u7f6e\n    return hash, bucket\n}\n<\/pre><\/div>\n\n\n<h3 class=\"wp-block-heading\">2.2 \u54c8\u5e0c\u79cd\u5b50\u4e0e\u5b89\u5168\u6027<\/h3>\n\n\n\n<p>\u6bcf\u4e2amap\u5728\u521b\u5efa\u65f6\u90fd\u4f1a\u521d\u59cb\u5316\u4e00\u4e2a\u968f\u673a\u54c8\u5e0c\u79cd\u5b50(hash0)\uff0c\u8fd9\u79cd\u8bbe\u8ba1\u53ef\u4ee5\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u9632\u6b62\u54c8\u5e0c\u78b0\u649e\u653b\u51fb\uff08Hash Collision DoS\uff09<\/li>\n\n\n\n<li>\u4f7f\u54c8\u5e0c\u5206\u5e03\u66f4\u52a0\u5747\u5300<\/li>\n\n\n\n<li>\u4fdd\u8bc1\u7a0b\u5e8f\u6bcf\u6b21\u8fd0\u884c\u7684\u54c8\u5e0c\u987a\u5e8f\u4e0d\u540c\uff08\u8fd9\u4e5f\u662fGo map\u65e0\u5e8f\u7684\u539f\u56e0\uff09<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e09\u3001\u6876\u4e0e\u6ea2\u51fa\u6876\u673a\u5236<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">3.1 bmap\u7684\u7cbe\u5de7\u8bbe\u8ba1<\/h3>\n\n\n\n<p>\u6bcf\u4e2abmap\uff08\u6876\uff09\u53ef\u4ee5\u5b58\u50a88\u4e2a\u952e\u503c\u5bf9\uff0c\u91c7\u7528\u4ee5\u4e0b\u5185\u5b58\u5e03\u5c40\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nbmap\u5185\u5b58\u5e03\u5c40\uff1a\n+--------+--------+--------+--------+\n| tophash|  keys  | values |overflow|\n+--------+--------+--------+--------+\n| &#x5B;8]uint8| &#x5B;8]key |&#x5B;8]value|  *bmap |\n+--------+--------+--------+--------+\n<\/pre><\/div>\n\n\n<p>\u8fd9\u79cd\u8bbe\u8ba1\u5c06tophash\u3001keys\u548cvalues\u5206\u5f00\u5b58\u50a8\uff0c\u800c\u975e\u4f20\u7edf\u7684\u952e\u503c\u5bf9\u76f8\u90bb\u5b58\u50a8\uff0c\u4e3b\u8981\u4f18\u52bf\u5728\u4e8e\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5185\u5b58\u5bf9\u9f50\u66f4\u597d<\/li>\n\n\n\n<li>\u67e5\u627e\u65f6\u53ef\u4ee5\u5148\u6bd4\u8f83tophash\uff0c\u4e0d\u5339\u914d\u5219\u65e0\u9700\u6bd4\u8f83\u5b8c\u6574\u952e<\/li>\n\n\n\n<li>\u5bf9\u4e8e\u5927\u5c3a\u5bf8\u7684value\u7c7b\u578b\u66f4\u8282\u7701\u7a7a\u95f4<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">3.2 \u6ea2\u51fa\u6876\u5904\u7406<\/h3>\n\n\n\n<p>\u5f53\u4e00\u4e2a\u6876\u5b58\u50a8\u8d85\u8fc78\u4e2a\u5143\u7d20\u65f6\uff0c\u4f1a\u521b\u5efa\u6ea2\u51fa\u6876\u5e76\u901a\u8fc7\u94fe\u8868\u8fde\u63a5\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\n\u4e3b\u6876                       \u6ea2\u51fa\u68761                     \u6ea2\u51fa\u68762\n+---------------+          +---------------+          +---------------+\n| tophash | ... |          | tophash | ... |          | tophash | ... |\n| keys    | ... |---overflow---&gt;| keys    | ... |---overflow---&gt;| keys    | ... |\n| values  | ... |          | values  | ... |          | values  | ... |\n+---------------+          +---------------+          +---------------+\n<\/pre><\/div>\n\n\n<p>\u67e5\u627e\u8fc7\u7a0b\u4f1a\u4f9d\u6b21\u68c0\u67e5\u4e3b\u6876\u548c\u6240\u6709\u6ea2\u51fa\u6876\uff0c\u76f4\u5230\u627e\u5230\u5339\u914d\u7684\u952e\u6216\u904d\u5386\u5b8c\u6574\u4e2a\u94fe\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u56db\u3001\u52a8\u6001\u6269\u5bb9\u673a\u5236<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">4.1 \u89e6\u53d1\u6269\u5bb9\u7684\u6761\u4ef6<\/h3>\n\n\n\n<p>Go map\u5728\u4ee5\u4e0b\u4e24\u79cd\u60c5\u51b5\u4e0b\u4f1a\u89e6\u53d1\u6269\u5bb9\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u88c5\u8f7d\u56e0\u5b50\u8fc7\u9ad8\u200b<\/strong>\u200b\uff1a\u5143\u7d20\u6570\u91cf\/\u6876\u6570\u91cf &gt; 6.5 <code>\/\/ \u88c5\u8f7d\u56e0\u5b50\u68c0\u67e5 if h.count &gt;= bucketCnt*(h.B+1) &amp;&amp; h.count &gt;= 2*h.noverflow { \/\/ \u89e6\u53d1\u6269\u5bb9 }<\/code><\/li>\n\n\n\n<li>\u200b<strong>\u200b\u6ea2\u51fa\u6876\u8fc7\u591a\u200b<\/strong>\u200b\uff1a\n<ul class=\"wp-block-list\">\n<li>\u5e38\u89c4\u6876\u6570\u91cf &lt; 2^15\u4e14\u6ea2\u51fa\u6876\u6570\u91cf &gt;= \u5e38\u89c4\u6876\u6570\u91cf<\/li>\n\n\n\n<li>\u6216\u5e38\u89c4\u6876\u6570\u91cf &gt;= 2^15\u4e14\u6ea2\u51fa\u6876\u6570\u91cf &gt;= 2^15<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">4.2 \u6269\u5bb9\u7c7b\u578b<\/h3>\n\n\n\n<p>\u6839\u636e\u89e6\u53d1\u6761\u4ef6\u4e0d\u540c\uff0c\u6269\u5bb9\u5206\u4e3a\u4e24\u79cd\u7c7b\u578b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u589e\u91cf\u6269\u5bb9\u200b<\/strong>\u200b\uff08\u6b63\u5e38\u6269\u5bb9\uff09\uff1a\n<ul class=\"wp-block-list\">\n<li>\u6876\u6570\u91cf\u589e\u52a0\u4e00\u500d\uff08B+1\uff09<\/li>\n\n\n\n<li>\u91cd\u65b0\u5206\u914d\u952e\u503c\u5bf9\u5230\u65b0\u6876\u4e2d<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u7b49\u91cf\u6269\u5bb9\u200b<\/strong>\u200b\uff08\u6ea2\u51fa\u6876\u6574\u7406\uff09\uff1a\n<ul class=\"wp-block-list\">\n<li>\u6876\u6570\u91cf\u4e0d\u53d8<\/li>\n\n\n\n<li>\u91cd\u65b0\u6392\u5217\u952e\u503c\u5bf9\u4ee5\u51cf\u5c11\u6ea2\u51fa\u6876\u4f7f\u7528<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">4.3 \u6e10\u8fdb\u5f0f\u8fc1\u79fb<\/h3>\n\n\n\n<p>Go\u91c7\u7528\u6e10\u8fdb\u5f0f\u6269\u5bb9\u7b56\u7565\uff0c\u907f\u514d\u4e00\u6b21\u6027\u8fc1\u79fb\u5e26\u6765\u7684\u6027\u80fd\u6296\u52a8\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5206\u914d\u65b0\u6876\u6570\u7ec4\uff0c\u8bbe\u7f6ehmap.oldbuckets\u6307\u5411\u65e7\u6876<\/li>\n\n\n\n<li>\u5728\u6bcf\u6b21\u63d2\u5165\u3001\u5220\u9664\u6216\u67e5\u627e\u64cd\u4f5c\u65f6\u8fc1\u79fb1-2\u4e2a\u65e7\u6876\u5230\u65b0\u6876<\/li>\n\n\n\n<li>\u8fc1\u79fb\u5b8c\u6210\u540e\u91ca\u653eoldbuckets<\/li>\n<\/ol>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\n\/\/ \u4f2a\u4ee3\u7801\uff1a\u6e10\u8fdb\u5f0f\u8fc1\u79fb\nfunc mapassign(t *maptype, h *hmap, key unsafe.Pointer) unsafe.Pointer {\n    \/\/ \u5982\u679c\u6b63\u5728\u6269\u5bb9\uff0c\u8fc1\u79fb\u4e00\u4e2a\u6876\n    if h.growing() {\n        evacuate(t, h, h.nevacuate)\n    }\n    \/\/ ...\u6267\u884c\u63d2\u5165\u64cd\u4f5c\n}\n<\/pre><\/div>\n\n\n<h2 class=\"wp-block-heading\">\u4e94\u3001\u64cd\u4f5c\u539f\u7406\u89e3\u6790<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">5.1 \u67e5\u627e\u8fc7\u7a0b<\/h3>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nv := m&#x5B;key]\n<\/pre><\/div>\n\n\n<p>\u5e95\u5c42\u6267\u884c\u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u8ba1\u7b97key\u7684\u54c8\u5e0c\u503c<\/li>\n\n\n\n<li>\u53d6\u54c8\u5e0c\u540eB\u4f4d\u786e\u5b9a\u6876\u4f4d\u7f6e<\/li>\n\n\n\n<li>\u53d6\u54c8\u5e0c\u9ad88\u4f4d(tophash)\u5728\u6876\u4e2d\u67e5\u627e\uff1a\n<ul class=\"wp-block-list\">\n<li>\u5148\u6bd4\u8f83tophash\uff0c\u4e0d\u5339\u914d\u5219\u8df3\u8fc7<\/li>\n\n\n\n<li>tophash\u5339\u914d\u518d\u6bd4\u8f83\u5b8c\u6574key<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u5982\u679c\u5728\u4e3b\u6876\u6ca1\u627e\u5230\uff0c\u7ee7\u7eed\u5728\u6ea2\u51fa\u6876\u4e2d\u67e5\u627e<\/li>\n\n\n\n<li>\u627e\u5230\u8fd4\u56devalue\uff0c\u672a\u627e\u5230\u8fd4\u56de\u96f6\u503c<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">5.2 \u63d2\u5165\u8fc7\u7a0b<\/h3>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nm&#x5B;key] = value\n<\/pre><\/div>\n\n\n<p>\u5e95\u5c42\u6267\u884c\u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u68c0\u67e5\u662f\u5426\u6b63\u5728\u6269\u5bb9\uff0c\u5982\u679c\u662f\u5219\u6267\u884c\u8fc1\u79fb<\/li>\n\n\n\n<li>\u8ba1\u7b97key\u7684\u54c8\u5e0c\u503c\u5e76\u5b9a\u4f4d\u6876<\/li>\n\n\n\n<li>\u5728\u6876\u4e2d\u67e5\u627e\uff1a\n<ul class=\"wp-block-list\">\n<li>\u5982\u679ckey\u5df2\u5b58\u5728\uff0c\u66f4\u65b0value<\/li>\n\n\n\n<li>\u5982\u679c\u627e\u5230\u7a7a\u4f4d\uff0c\u63d2\u5165tophash\u3001key\u548cvalue<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u5982\u679c\u6876\u5df2\u6ee1\uff0c\u521b\u5efa\u6ea2\u51fa\u6876\u5e76\u63d2\u5165<\/li>\n\n\n\n<li>\u68c0\u67e5\u662f\u5426\u9700\u8981\u89e6\u53d1\u6269\u5bb9<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">5.3 \u5220\u9664\u8fc7\u7a0b<\/h3>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\ndelete(m, key)\n<\/pre><\/div>\n\n\n<p>\u5e95\u5c42\u6267\u884c\u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u67e5\u627ekey\u6240\u5728\u4f4d\u7f6e\uff08\u7c7b\u4f3c\u67e5\u627e\u8fc7\u7a0b\uff09<\/li>\n\n\n\n<li>\u5982\u679c\u627e\u5230\uff0c\u5c06\u5bf9\u5e94tophash\u7f6e\u4e3aemptyOne(1)<\/li>\n\n\n\n<li>\u68c0\u67e5\u662f\u5426\u53ef\u4ee5\u6807\u8bb0\u4e3aemptyRest\u4ee5\u4f18\u5316\u540e\u7eed\u67e5\u627e<\/li>\n\n\n\n<li>count\u51cf1\uff08\u4f46\u4e0d\u4f1a\u89e6\u53d1\u7f29\u5bb9\uff09<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u516d\u3001\u5e76\u53d1\u5b89\u5168\u4e0e\u6027\u80fd\u4f18\u5316<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">6.1 \u975e\u7ebf\u7a0b\u5b89\u5168\u8bbe\u8ba1<\/h3>\n\n\n\n<p>Go map\u8bbe\u8ba1\u4e3a\u975e\u7ebf\u7a0b\u5b89\u5168\uff0c\u5e76\u53d1\u8bfb\u5199\u4f1a\u5bfc\u81f4panic\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\n\/\/ \u5e76\u53d1\u8bfb\u5199\u4f1a\u5bfc\u81f4fatal error\nfatal error: concurrent map read and map write\n<\/pre><\/div>\n\n\n<p>\u8fd9\u79cd\u8bbe\u8ba1\u57fa\u4e8e\u4ee5\u4e0b\u8003\u8651\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u4fdd\u6301\u7b80\u5355\u9ad8\u6548\u7684\u5e38\u6001\u6027\u80fd<\/li>\n\n\n\n<li>\u5927\u591a\u6570\u4f7f\u7528\u573a\u666f\u4e0d\u9700\u8981\u5e76\u53d1\u5b89\u5168<\/li>\n\n\n\n<li>\u9700\u8981\u5e76\u53d1\u65f6\u53ef\u914d\u5408sync.Mutex\u6216\u4f7f\u7528sync.Map<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">6.2 \u6027\u80fd\u4f18\u5316\u6280\u5de7<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u9884\u5206\u914d\u7a7a\u95f4\u200b<\/strong>\u200b\uff1a <code>m := make(map[string]int, hint) \/\/ \u9884\u5148\u5206\u914dhint\u5927\u5c0f\u7684\u7a7a\u95f4<\/code> \u907f\u514d\u9891\u7e41\u6269\u5bb9\u5e26\u6765\u7684\u6027\u80fd\u635f\u8017<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u4f7f\u7528\u5c0f\u5c3a\u5bf8\u952e\u7c7b\u578b\u200b<\/strong>\u200b\uff1a\n<ul class=\"wp-block-list\">\n<li>\u5c0f\u952e\u7c7b\u578b\u51cf\u5c11\u54c8\u5e0c\u8ba1\u7b97\u65f6\u95f4<\/li>\n\n\n\n<li>\u6307\u9488\u7c7b\u578b\u6bd4\u503c\u7c7b\u578b\u66f4\u9ad8\u6548<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u907f\u514d\u503c\u62f7\u8d1d\u200b<\/strong>\u200b\uff1a <code>\/\/ \u5b58\u50a8\u6307\u9488\u800c\u975e\u5927\u7ed3\u6784\u4f53 m := make(map[int]*LargeStruct)<\/code><\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e03\u3001\u7279\u6b8a\u573a\u666f\u4e0e\u9677\u9631<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">7.1 \u4e0d\u53ef\u53d6\u5740\u6027<\/h3>\n\n\n\n<p>\u65e0\u6cd5\u76f4\u63a5\u83b7\u53d6map\u5143\u7d20\u7684\u5730\u5740\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: go; title: ; notranslate\" title=\"\">\nm := make(map&#x5B;string]int)\n\/\/ \u4ee5\u4e0b\u7f16\u8bd1\u9519\u8bef\n_ = &amp;m&#x5B;&quot;key&quot;] \/\/ cannot take the address of m&#x5B;&quot;key&quot;]\n<\/pre><\/div>\n\n\n<p>\u539f\u56e0\u5728\u4e8emap\u53ef\u80fd\u6269\u5bb9\u5bfc\u81f4\u5730\u5740\u53d8\u5316\uff0c\u4e14value\u53ef\u80fd\u5b58\u50a8\u5728\u6ea2\u51fa\u6876\u4e2d\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">7.2 \u8fed\u4ee3\u65e0\u5e8f\u6027<\/h3>\n\n\n\n<p>Go map\u7684\u8fed\u4ee3\u987a\u5e8f\u662f\u968f\u673a\u7684\uff1a<\/p>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: go; title: ; notranslate\" title=\"\">\nfor k, v := range m {\n    \/\/ \u6bcf\u6b21\u8fd0\u884c\u987a\u5e8f\u53ef\u80fd\u4e0d\u540c\n}\n<\/pre><\/div>\n\n\n<p>\u8fd9\u662f\u6709\u610f\u4e3a\u4e4b\u7684\u8bbe\u8ba1\uff0c\u9632\u6b62\u5f00\u53d1\u8005\u4f9d\u8d56\u8fed\u4ee3\u987a\u5e8f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">7.3 nil map\u7684\u884c\u4e3a<\/h3>\n\n\n<div class=\"wp-block-syntaxhighlighter-code \"><pre class=\"brush: plain; title: ; notranslate\" title=\"\">\nvar m map&#x5B;string]int  \/\/ nil map\n<\/pre><\/div>\n\n\n<ul class=\"wp-block-list\">\n<li>\u8bfb\u53d6\u64cd\u4f5c\uff1a\u8fd4\u56de\u96f6\u503c\uff0c\u4e0d\u4f1apanic<\/li>\n\n\n\n<li>\u5199\u5165\u64cd\u4f5c\uff1a\u89e6\u53d1panic<\/li>\n\n\n\n<li>\u5fc5\u987b\u4f7f\u7528make\u521d\u59cb\u5316\u6216\u5b57\u9762\u91cf\u521b\u5efa<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u516b\u3001\u4e0e\u5176\u5b83\u8bed\u8a00\u5b9e\u73b0\u7684\u5bf9\u6bd4<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7279\u6027<\/th><th>Go map<\/th><th>Java HashMap<\/th><th>Python dict<\/th><\/tr><\/thead><tbody><tr><td>\u51b2\u7a81\u89e3\u51b3<\/td><td>\u94fe\u5730\u5740\u6cd5+\u6ea2\u51fa\u6876<\/td><td>\u94fe\u8868\u8f6c\u7ea2\u9ed1\u6811<\/td><td>\u5f00\u653e\u5b9a\u5740\u6cd5<\/td><\/tr><tr><td>\u6269\u5bb9\u7b56\u7565<\/td><td>\u6e10\u8fdb\u5f0f\u6269\u5bb9<\/td><td>\u4e00\u6b21\u6027\u6269\u5bb9<\/td><td>\u4e00\u6b21\u6027\u6269\u5bb9<\/td><\/tr><tr><td>\u5e76\u53d1\u5b89\u5168<\/td><td>\u975e\u5b89\u5168<\/td><td>\u975e\u5b89\u5168<\/td><td>\u6709GIL\u4fdd\u62a4<\/td><\/tr><tr><td>\u88c5\u8f7d\u56e0\u5b50<\/td><td>6.5<\/td><td>0.75<\/td><td>0.66<\/td><\/tr><tr><td>\u5185\u5b58\u5e03\u5c40<\/td><td>\u5206\u79bb\u952e\u503c\u5b58\u50a8<\/td><td>\u8282\u70b9\u5b58\u50a8<\/td><td>\u7d27\u51d1\u5b58\u50a8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">\u603b\u7ed3<\/h2>\n\n\n\n<p>Go\u8bed\u8a00\u7684map\u5b9e\u73b0\u878d\u5408\u4e86\u8bb8\u591a\u7cbe\u5999\u7684\u8bbe\u8ba1\u601d\u60f3\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5c06tophash\u4e0e\u952e\u503c\u5206\u79bb\u5b58\u50a8\u63d0\u9ad8\u67e5\u627e\u6548\u7387<\/li>\n\n\n\n<li>\u6e10\u8fdb\u5f0f\u6269\u5bb9\u907f\u514d\u6027\u80fd\u6296\u52a8<\/li>\n\n\n\n<li>\u968f\u673a\u79cd\u5b50\u4fdd\u8bc1\u54c8\u5e0c\u5b89\u5168<\/li>\n\n\n\n<li>\u7d27\u51d1\u7684\u5185\u5b58\u5e03\u5c40\u4f18\u5316\u7f13\u5b58\u5229\u7528\u7387<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"435\" src=\"https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-6-1024x435.png\" alt=\"\" class=\"wp-image-1131\" srcset=\"https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-6-1024x435.png 1024w, https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-6-300x128.png 300w, https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-6-768x326.png 768w, https:\/\/beijian99.top\/wp-content\/uploads\/2025\/07\/image-6.png 1080w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>\u5728Go\u8bed\u8a00\u4e2d\uff0cmap\u662f\u6700\u91cd\u8981\u4e14\u6700\u5e38\u7528\u7684\u6570\u636e\u7ed3\u6784\u4e4b\u4e00\uff0c\u5b83\u63d0\u4f9b\u4e86\u9ad8\u6548\u7684\u952e\u503c\u5bf9\u5b58\u50a8\u548c\u67e5\u627e\u80fd\u529b\u3002 \u4e00\u3001map\u7684\u57fa\u672c\u67b6\u6784 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":1133,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center 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center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[4],"tags":[],"class_list":["post-1094","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-algorithm"],"_links":{"self":[{"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/posts\/1094","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/beijian99.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1094"}],"version-history":[{"count":5,"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/posts\/1094\/revisions"}],"predecessor-version":[{"id":1134,"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/posts\/1094\/revisions\/1134"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/beijian99.top\/index.php?rest_route=\/wp\/v2\/media\/1133"}],"wp:attachment":[{"href":"https:\/\/beijian99.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1094"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/beijian99.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1094"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/beijian99.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1094"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}