{"id":41,"date":"2024-12-14T09:21:02","date_gmt":"2024-12-14T01:21:02","guid":{"rendered":"https:\/\/genetop.top\/?p=41"},"modified":"2024-12-14T09:22:01","modified_gmt":"2024-12-14T01:22:01","slug":"std-string-sso","status":"publish","type":"post","link":"https:\/\/genetop.top\/index.php\/2024\/12\/14\/std-string-sso\/","title":{"rendered":"\u5c0f\u5b57\u7b26\u4e32\u4f18\u5316 SSO"},"content":{"rendered":"

\u4ec0\u4e48\u662f\u5c0f\u5b57\u7b26\u4e32\u4f18\u5316\uff08SSO, Small String Optimization\uff09<\/h3>\n

\u5c0f\u5b57\u7b26\u4e32\u4f18\u5316\uff08SSO\uff09<\/strong> \u662f\u73b0\u4ee3 C++ \u6807\u51c6\u5e93\u5bf9 std::string<\/code> \u7684\u4e00\u79cd\u4f18\u5316\u6280\u672f\uff0c\u7528\u4e8e\u51cf\u5c11\u77ed\u5b57\u7b26\u4e32\u7684\u5185\u5b58\u5206\u914d\u5f00\u9500\u3002SSO \u7684\u6838\u5fc3\u601d\u60f3\u662f\uff1a\u5c06\u957f\u5ea6\u8f83\u77ed\u7684\u5b57\u7b26\u4e32\u76f4\u63a5\u5b58\u50a8\u5728 std::string<\/code> \u5bf9\u8c61\u5185\u90e8\uff0c\u800c\u4e0d\u4f7f\u7528\u52a8\u6001\u5185\u5b58\u5206\u914d<\/strong>\u3002<\/p>\n

\n

SSO \u7684\u5de5\u4f5c\u539f\u7406<\/strong><\/h3>\n
    \n
  1. \u666e\u901a\u60c5\u51b5\u4e0b\u7684\u5b57\u7b26\u4e32\u5b58\u50a8<\/strong>\uff1a\n
      \n
    • \u5982\u679c\u6ca1\u6709 SSO\uff0cstd::string<\/code> \u4f1a\u5c06\u5b57\u7b26\u4e32\u5185\u5bb9\u5b58\u50a8\u5728\u5806\u5185\u5b58\u4e2d\u3002<\/li>\n
    • \u8fd9\u610f\u5473\u7740\u6bcf\u6b21\u5206\u914d\u548c\u91ca\u653e\u5b57\u7b26\u4e32\u65f6\u90fd\u4f1a\u8c03\u7528\u52a8\u6001\u5185\u5b58\u5206\u914d\u51fd\u6570\uff08\u5982 new<\/code> \u548c delete<\/code> \u6216\u7c7b\u4f3c\u673a\u5236\uff09\uff0c\u8fd9\u4f1a\u589e\u52a0\u6027\u80fd\u5f00\u9500\u3002<\/li>\n<\/ul>\n<\/li>\n
    • \u542f\u7528 SSO \u65f6\u7684\u884c\u4e3a<\/strong>\uff1a\n
        \n
      • \u5bf9\u4e8e\u77ed\u5b57\u7b26\u4e32\uff08\u5982 15 \u4e2a\u5b57\u7b26\u4ee5\u5185\u7684\u5b57\u7b26\u4e32\uff09\uff0cstd::string<\/code> \u7684\u5b9e\u73b0\u4f1a\u76f4\u63a5\u5c06\u5b57\u7b26\u4e32\u5185\u5bb9\u5b58\u50a8\u5728\u5bf9\u8c61\u7684\u5185\u90e8\u7f13\u51b2\u533a\u4e2d\uff0c\u800c\u4e0d\u662f\u4f7f\u7528\u52a8\u6001\u5206\u914d\u3002<\/li>\n
      • \u8fd9\u6837\uff0c\u77ed\u5b57\u7b26\u4e32\u7684\u521b\u5efa\u3001\u4fee\u6539\u548c\u9500\u6bc1\u53d8\u5f97\u66f4\u52a0\u9ad8\u6548\uff0c\u56e0\u4e3a\u907f\u514d\u4e86\u5806\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<\/li>\n
      • \u5927\u5b57\u7b26\u4e32\u7684\u884c\u4e3a<\/strong>\uff1a\n
          \n
        • \u5982\u679c\u5b57\u7b26\u4e32\u957f\u5ea6\u8d85\u8fc7\u4e86 std::string<\/code> \u5bf9\u8c61\u7684\u5185\u90e8\u7f13\u51b2\u533a\u5bb9\u91cf\uff0c\u5c31\u4f1a\u56de\u9000\u5230\u52a8\u6001\u5206\u914d\u6a21\u5f0f\uff0c\u5c06\u5b57\u7b26\u4e32\u5b58\u50a8\u5728\u5806\u4e0a\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
          \n

          SSO \u7684\u5b9e\u73b0\u7ec6\u8282<\/strong><\/h3>\n

          \u5bf9\u8c61\u7ed3\u6784<\/strong><\/h4>\n

          \u5178\u578b\u7684 std::string<\/code> \u5728\u542f\u7528 SSO \u65f6\uff0c\u5176\u5185\u90e8\u7ed3\u6784\u53ef\u80fd\u5982\u4e0b\uff1a<\/p>\n

            \n
          1. \u5185\u90e8\u7f13\u51b2\u533a<\/strong>\uff1a\n
              \n
            • \u5b58\u50a8\u77ed\u5b57\u7b26\u4e32\u7684\u6570\u636e\u3002<\/li>\n
            • \u901a\u5e38\u4e3a\u56fa\u5b9a\u5927\u5c0f\uff08\u5982 15 \u6216 23 \u5b57\u8282\uff0c\u6839\u636e\u5177\u4f53\u7684\u5b9e\u73b0\u548c\u5bf9\u9f50\u89c4\u5219\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n
            • \u5143\u6570\u636e<\/strong>\uff1a\n
                \n
              • \u5305\u62ec\u5b57\u7b26\u4e32\u7684\u5f53\u524d\u957f\u5ea6\uff08size<\/code>\uff09\u548c\u7f13\u51b2\u533a\u7684\u5bb9\u91cf\uff08capacity<\/code>\uff09\u3002<\/li>\n
              • \u4f7f\u7528\u989d\u5916\u7684\u6807\u5fd7\u4f4d\uff08\u5982\u9ad8\u4f4d\u6216\u5bb9\u91cf\u5b57\u6bb5\uff09\u6765\u533a\u5206\u77ed\u5b57\u7b26\u4e32\u548c\u52a8\u6001\u5206\u914d\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n<\/li>\n
              • \u52a8\u6001\u7f13\u51b2\u533a\u6307\u9488<\/strong>\uff1a\n
                  \n
                • \u5bf9\u4e8e\u957f\u5b57\u7b26\u4e32\uff0c\u6307\u5411\u5806\u4e0a\u7684\u5b9e\u9645\u5b57\u7b26\u4e32\u5b58\u50a8\u4f4d\u7f6e\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                  \u793a\u610f\u56fe<\/strong><\/h4>\n

                  \u4ee5\u4e0b\u5c55\u793a\u4e86\u4e00\u4e2a\u53ef\u80fd\u7684 SSO \u5185\u90e8\u7ed3\u6784\uff1a<\/p>\n\n\n\n\n\n\n\n
                  \u5b57\u6bb5<\/th>\n\u7c7b\u578b<\/th>\n\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n
                  \u957f\u5ea6\uff08size\uff09<\/td>\nsize_t<\/code><\/td>\n\u5f53\u524d\u5b57\u7b26\u4e32\u7684\u957f\u5ea6<\/td>\n<\/tr>\n
                  \u7f13\u51b2\u533a\uff08data\uff09<\/td>\nchar[16]<\/code><\/td>\n\u5b58\u50a8\u77ed\u5b57\u7b26\u4e32\u6216\u5806\u7f13\u51b2\u533a\u5730\u5740\u7684\u7a7a\u95f4<\/td>\n<\/tr>\n
                  \u5bb9\u91cf\uff08capacity\/flag\uff09<\/td>\nsize_t<\/code><\/td>\n\u7f13\u51b2\u533a\u7684\u5bb9\u91cf\u6216\u6807\u5fd7\u4f4d<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
                    \n
                  • \u77ed\u5b57\u7b26\u4e32\uff1adata<\/code> \u5b57\u6bb5\u5b58\u50a8\u5b9e\u9645\u5185\u5bb9\uff0c\u957f\u5ea6\u53d7\u9650\u4e8e\u56fa\u5b9a\u7684\u5185\u90e8\u7f13\u51b2\u533a\u5927\u5c0f\u3002<\/li>\n
                  • \u957f\u5b57\u7b26\u4e32\uff1adata<\/code> \u5b57\u6bb5\u5b58\u50a8\u6307\u5411\u5806\u5206\u914d\u5185\u5b58\u7684\u6307\u9488\u3002<\/li>\n<\/ul>\n
                    \n

                    SSO \u7684\u5178\u578b\u5b9e\u73b0<\/strong><\/h3>\n

                    \u542f\u7528 SSO \u7684\u793a\u4f8b\u4ee3\u7801<\/strong><\/h4>\n

                    \u4ee5\u4e0b\u4ee3\u7801\u5c55\u793a\u4e86\u5982\u4f55\u9a8c\u8bc1 SSO \u662f\u5426\u751f\u6548\uff1a<\/p>\n

                    \n
                    cpp<\/div>\n
                    \n
                    \n
                    <\/div>\n<\/div>\n<\/div>\n
                    #include<\/span> <iostream><\/span><\/span>
                    \n#include<\/span> <string><\/span><\/span>
                    \n#include<\/span> <cstring><\/span><\/span><\/code><\/code>int<\/span> main<\/span>()<\/span> <\/span>{
                    \n\/\/ \u6d4b\u8bd5\u77ed\u5b57\u7b26\u4e32<\/span>
                    \nstd::string shortStr = “Short”<\/span>;
                    \nstd::cout << “Short string: “<\/span> << shortStr << std::endl;
                    \nstd::cout << “Address of short string content: “<\/span>
                    \n<< static_cast<\/span><const<\/span> void<\/span>*>(shortStr.data<\/span>()) << std::endl;<\/code><\/code>\/\/ \u6d4b\u8bd5\u957f\u5b57\u7b26\u4e32<\/span>
                    \nstd::string longStr = “This is a very long string that exceeds the SSO limit.”<\/span>;
                    \nstd::cout << “Long string: “<\/span> << longStr << std::endl;
                    \nstd::cout << “Address of long string content: “<\/span>
                    \n<< static_cast<\/span><const<\/span> void<\/span>*>(longStr.data<\/span>()) << std::endl;<\/p>\n

                    <\/code><\/code>\/\/ \u9a8c\u8bc1\u77ed\u5b57\u7b26\u4e32\u4e0e\u957f\u5b57\u7b26\u4e32\u7684\u5730\u5740\u662f\u5426\u4e00\u81f4<\/span>
                    \nif<\/span> (shortStr.data<\/span>() >= reinterpret_cast<\/span><const<\/span> char<\/span>*>(&shortStr) &&
                    \nshortStr.data<\/span>() < reinterpret_cast<\/span><const<\/span> char<\/span>*>(&shortStr + 1<\/span>)) {
                    \nstd::cout << “SSO enabled for short strings.”<\/span> << std::endl;
                    \n} else<\/span> {
                    \nstd::cout << “Short strings are dynamically allocated.”<\/span> << std::endl;
                    \n}<\/p>\n

                    <\/code><\/code>return<\/span> 0<\/span>;
                    \n}<\/p>\n<\/div>\n<\/div>\n

                    \u8f93\u51fa\u793a\u4f8b<\/strong><\/h4>\n

                    \u5047\u8bbe SSO<\/code> \u5df2\u542f\u7528\uff0c\u8f93\u51fa\u53ef\u80fd\u7c7b\u4f3c\u5982\u4e0b\uff1a<\/p>\n

                    \n
                    text<\/div>\n
                    \n
                    \n
                    <\/div>\n<\/div>\n<\/div>\n
                    Short string: Short
                    \nAddress of short string content: 0x7ffee4d1c760
                    \nLong string: This is a very long string that exceeds the SSO limit.
                    \nAddress of long string content: 0x5634c8d1fba0
                    \nSSO enabled for short strings.
                    \n<\/code><\/div>\n<\/div>\n
                      \n
                    • \u77ed\u5b57\u7b26\u4e32\u7684\u5730\u5740\u4f4d\u4e8e\u5bf9\u8c61\u5185\u90e8\u3002<\/li>\n
                    • \u957f\u5b57\u7b26\u4e32\u7684\u5730\u5740\u4f4d\u4e8e\u5806\u4e0a\u3002<\/li>\n<\/ul>\n
                      \n

                      SSO \u7684\u4f18\u70b9<\/strong><\/h3>\n
                        \n
                      1. \u6027\u80fd\u63d0\u5347<\/strong>\uff1a\n
                          \n
                        • \u907f\u514d\u52a8\u6001\u5185\u5b58\u5206\u914d\u548c\u91ca\u653e\u7684\u5c0f\u5b57\u7b26\u4e32\u64cd\u4f5c\u975e\u5e38\u9ad8\u6548\u3002<\/li>\n
                        • \u5c0f\u5b57\u7b26\u4e32\u7684\u521b\u5efa\u3001\u62f7\u8d1d\u548c\u9500\u6bc1\u64cd\u4f5c\u663e\u8457\u52a0\u901f\u3002<\/li>\n<\/ul>\n<\/li>\n
                        • \u8282\u7701\u5185\u5b58<\/strong>\uff1a\n
                            \n
                          • \u5c0f\u5b57\u7b26\u4e32\u4e0d\u9700\u8981\u989d\u5916\u7684\u5806\u5206\u914d\uff0c\u51cf\u5c11\u4e86\u5185\u5b58\u5206\u914d\u7684\u788e\u7247\u5316\u3002<\/li>\n<\/ul>\n<\/li>\n
                          • \u964d\u4f4e\u5806\u538b\u529b<\/strong>\uff1a\n
                              \n
                            • \u51cf\u5c11\u5806\u5206\u914d\u7684\u6b21\u6570\uff0c\u9002\u5408\u5c0f\u578b\u9891\u7e41\u64cd\u4f5c\u7684\u5e94\u7528\u573a\u666f\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
                              \n

                              SSO \u7684\u9650\u5236<\/strong><\/h3>\n
                                \n
                              1. \u4ec5\u9650\u77ed\u5b57\u7b26\u4e32<\/strong>\uff1a\n
                                  \n
                                • \u4e00\u65e6\u5b57\u7b26\u4e32\u957f\u5ea6\u8d85\u8fc7\u4e86\u5185\u90e8\u7f13\u51b2\u533a\u5bb9\u91cf\uff0c\u5c31\u9700\u8981\u56de\u9000\u5230\u52a8\u6001\u5206\u914d\u3002<\/li>\n<\/ul>\n<\/li>\n
                                • \u5b9e\u73b0\u4f9d\u8d56<\/strong>\uff1a\n
                                    \n
                                  • SSO \u662f\u6807\u51c6\u5e93\u7684\u5b9e\u73b0\u7ec6\u8282\uff0c\u5177\u4f53\u884c\u4e3a\u548c\u4f18\u5316\u53d6\u51b3\u4e8e\u4f7f\u7528\u7684 C++ \u6807\u51c6\u5e93\uff08\u5982 GCC \u7684 libstdc++ \u6216 Clang \u7684 libc++\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n
                                  • \u5bf9\u8c61\u5927\u5c0f<\/strong>\uff1a\n
                                      \n
                                    • \u542f\u7528 SSO \u4f1a\u5bfc\u81f4 std::string<\/code> \u5bf9\u8c61\u672c\u8eab\u53d8\u5f97\u66f4\u5927\uff08\u901a\u5e38\u662f 24 \u5b57\u8282\u6216 32 \u5b57\u8282\uff09\uff0c\u4f46\u8fd9\u5bf9\u6027\u80fd\u63d0\u5347\u662f\u503c\u5f97\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
                                      \n

                                      SSO \u7684\u9a8c\u8bc1\u65b9\u5f0f<\/strong><\/h3>\n

                                      \u5982\u679c\u4f60\u5e0c\u671b\u9a8c\u8bc1\u67d0\u4e2a std::string<\/code> \u662f\u5426\u4f7f\u7528\u4e86 SSO\uff0c\u53ef\u4ee5\u89c2\u5bdf data()<\/code> \u8fd4\u56de\u7684\u5730\u5740\u662f\u5426\u4e0e std::string<\/code> \u5bf9\u8c61\u7684\u5185\u90e8\u5730\u5740\u91cd\u53e0\u3002\u4f8b\u5982\uff1a<\/p>\n

                                      \n
                                      cpp<\/div>\n
                                      \n
                                      \n
                                      <\/div>\n<\/div>\n<\/div>\n
                                      if<\/span> (str.data<\/span>() >= reinterpret_cast<\/span><const<\/span> char<\/span>*>(&str) &&
                                      \nstr.data<\/span>() < reinterpret_cast<\/span><const<\/span> char<\/span>*>(&str + 1<\/span>)) {
                                      \nstd::cout << \"SSO is active.\"<\/span> << std::endl;
                                      \n} else<\/span> {
                                      \nstd::cout << \"SSO is not active.\"<\/span> << std::endl;
                                      \n}
                                      \n<\/code><\/div>\n<\/div>\n
                                      \n

                                      \u603b\u7ed3<\/strong><\/h3>\n
                                        \n
                                      • \u4ec0\u4e48\u662f SSO<\/strong>\uff1a\u77ed\u5b57\u7b26\u4e32\u76f4\u63a5\u5b58\u50a8\u5728 std::string<\/code> \u5bf9\u8c61\u5185\u90e8\uff0c\u907f\u514d\u5806\u5206\u914d\u3002<\/li>\n
                                      • \u5982\u4f55\u5224\u65ad\u662f\u5426\u542f\u7528 SSO<\/strong>\uff1a\u68c0\u67e5\u77ed\u5b57\u7b26\u4e32\u5185\u5bb9\u7684\u5730\u5740\u662f\u5426\u4e0e std::string<\/code> \u5bf9\u8c61\u91cd\u53e0\u3002<\/li>\n
                                      • \u4f18\u70b9<\/strong>\uff1a\u63d0\u5347\u5c0f\u5b57\u7b26\u4e32\u64cd\u4f5c\u6027\u80fd\uff0c\u51cf\u5c11\u5806\u5185\u5b58\u5f00\u9500\u3002<\/li>\n
                                      • \u6ce8\u610f\u4e8b\u9879<\/strong>\uff1a\u4ec5\u5bf9\u77ed\u5b57\u7b26\u4e32\u6709\u6548\uff0c\u957f\u5b57\u7b26\u4e32\u4ecd\u7136\u4f1a\u52a8\u6001\u5206\u914d\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                                        \u4ec0\u4e48\u662f\u5c0f\u5b57\u7b26\u4e32\u4f18\u5316\uff08SSO, Small String Optimization\uff09 \u5c0f\u5b57\u7b26\u4e32\u4f18\u5316\uff08SSO\uff09 \u662f […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,3],"tags":[],"class_list":["post-41","post","type-post","status-publish","format-standard","hentry","category-c","category-language"],"_links":{"self":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts\/41","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/comments?post=41"}],"version-history":[{"count":2,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts\/41\/revisions"}],"predecessor-version":[{"id":43,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/posts\/41\/revisions\/43"}],"wp:attachment":[{"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/media?parent=41"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/categories?post=41"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/genetop.top\/index.php\/wp-json\/wp\/v2\/tags?post=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}