关于打开包含超长行的文件变慢问题

在vim中打开一个文件，如果文件含有超长的行，比如：

```
'Cookie': 'sess_id=8b57967d54a881c82d6da1fbf3515222;_cfduid=d0c04ad729bbbd673c512749e331ced6b1444051246; JXM702806=1;dshare_firstime=1444051283274;detail11981=%7B%22model%22%3A%221%22%2C%22id%22%3A%2211981%22%2C%22title%22%3A%22%E4%B9%9D%E6%B3%89%E4%B9%8B%E5%B2%9B%22%2C%22chapter%22%3A%22c_62105%22%2C%22chaptername%22%3A%22%E7%AC%AC3%E8%AF%9D%22%2C%22page%22%3A%221%22%2C%22url%22%3A%22%2Fcomic%2F11981%2Fc_62105%2F%22%2C%22nextpage%22%3A%22%2Fcomic%2F11981%2Fc_62105%2F2%2F%23readcontent%22%2C%22nextchapter%22%3A%22%2Fcomic%2F11981%2Fc_63630%2F%22%2C%22time%22%3A%222015-10-5%2021%3A32%3A51%22%7D; JXD702806=1; imageServerId=0; detail9955=%7B%22model%22%3A%221%22%2C%22id%22%3A%229955%22%2C%22title%22%3A%22GANGSTA%E5%8C%AA%E5%BE%92%22%2C%22chapter%22%3A%22n-1444038481-17474%22%2C%22chaptername%22%3A%22%E7%AC%AC42%E8%AF%9D%22%2C%22page%22%3A%221%22%2C%22url%22%3A%22%2Fcomic%2F9955%2Fn-1444038481-17474%2F%22%2C%22nextpage%22%3A%22%2Fcomic%2F9955%2Fn-1444038481-17474%2F2%2F%23readcontent%22%2C%22nextchapter%22%3A%22%2Fcomic%2F9955%2Frecom%22%2C%22time%22%3A%222015-10-6%2014%3A59%3A16%22%7D; detail15220=%7B%22model%22%3A%221%22%2C%22id%22%3A%2215220%22%2C%22title%22%3A%22%E5%AF%BB%E6%89%BE%E8%BA%AB%E4%BD%93%22%2C%22chapter%22%3A%22n-1411898564-95364%22%2C%22chaptername%22%3A%22%E7%AC%AC1%E8%AF%9D%22%2C%22page%22%3A%224%22%2C%22url%22%3A%22%2Fcomic%2F15220%2Fn-1411898564-95364%2F4%2F%22%2C%22nextpage%22%3A%22%2Fcomic%2F15220%2Fn-1411898564-95364%2F5%2F%23readcontent%22%2C%22nextchapter%22%3A%22%2Fcomic%2F15220%2Fn-1412948595-50697%2F%22%2C%22time%22%3A%222015-10-6%2017%3A54%3A23%22%7D; detail5267=%7B%22model%22%3A%221%22%2C%22id%22%3A%225267%22%2C%22title%22%3A%22%E5%A4%A9%E4%B8%8A%E5%A4%A9%E4%B8%8B%E9%AB%98%E6%B8%85%E6%99%B0%E7%89%88%22%2C%22chapter%22%3A%221%22%2C%22chaptername%22%3A%22%E5%8D%B71%22%2C%22page%22%3A%2212%22%2C%22url%22%3A%22%2Fcomic%2F5267%2F1%2F12%2F%22%2C%22nextpage%22%3A%22%2Fcomic%2F5267%2F1%2F13%2F%23readcontent%22%2C%22nextchapter%22%3A%22%2Fcomic%2F5267%2F2%2F%22%2C%22time%22%3A%222015-10-6%2018%3A24%3A16%22%7D; detail11754=null; readlist=%2211981%2C9955%2C15220%2C5267%2C11437%22; detail11437=%7B%22model%22%3A%221%22%2C%22id%22%3A%2211437%22%2C%22title%22%3A%22%E8%89%B2%E7%B3%BB%E5%86%9B%E5%9B%A2%22%2C%22chapter%22%3A%221%22%2C%22chaptername%22%3A%22%E7%AC%AC1%E8%AF%9D%22%2C%22page%22%3A%222%22%2C%22url%22%3A%22%2Fcomic%2F11437%2F1%2F2%2F%22%2C%22nextpage%22%3A%22%2Fcomic%2F11437%2F1%2F3%2F%23readcontent%22%2C%22nextchapter%22%3A%22%2Fcomic%2F11437%2F2%2F%22%2C%22time%22%3A%222015-10-6%2018%3A54%3A39%22%7D; readnum=25; CNZZDATA5468329=cnzz_eid%3D1038029097-1444048617-null%26ntime%3D1444129633; Hm_lvt_d82238694b9ba2f40c29ec0bec08bc2c=1444051262,1444114659; Hm_lpvt_d82238694b9ba2f40c29ec0bec08bc2c=1444131344',
```

如果文件中有这么长的行，vim在显示的时候会变慢。

这个问题是由于syntax引起的

解决方法是设置 `synmaxcol`，比如：

```
set synmaxcol=200 # 200列后的文字将失去高亮，但是却可以解决vim变慢问题
```