怎么快速學(xué)習(xí)一門新的語言呢？
如果你已經(jīng)熟練掌握了一門語言，那么其他語言都是想通的。一個小小的需求，可能會遇到很多問題，但是搜索相關(guān)的關(guān)鍵字，就能快速實現(xiàn)出來，完成一個小目標(biāo)，事半功倍。
死記硬背手冊，太枯燥了，反正我是看不下去，不如直接來個小項目。

一個小需求

pc、mobile 一個地址有兩套頁面，需要在后端根據(jù)瀏覽器的 user_agent 來顯示不同的頁面。
通過 php 來做，當(dāng)然可以，但是活動頁面訪問量一般都比較大，想優(yōu)化些，所以想嘗試下 lua。

nginx 安裝 lua-nginx-module

可以直接上 openresty，不過有時候就是想折騰。
安裝的步驟 https://mengkang.net/994.html （如果你想實踐的話再看吧）

lua demo 腳本

-- 判斷是否是手機瀏覽器 function isMobile(userAgent)-- 99% 前三個都能匹配上吧local mobile = {"phone", "android", "mobile", "itouch", "ipod", "symbian", "htc", "palmos", "blackberry", "opera mini", "windows ce", "nokia", "fennec","hiptop", "kindle", "mot", "webos", "samsung", "sonyericsson", "wap", "avantgo", "eudoraweb", "minimo", "netfront", "teleca"}userAgent = string.lower(userAgent)for i, v in ipairs(mobile) doif string.match(userAgent, v) thenreturn trueendendreturn false end-- 根據(jù)id + 瀏覽器類型展示活動頁面 function showPromotionHtml(id, isMobile)local path = "/data/www/mengkang/demo/promotion/"local filenameif isMobile thenpath = path .. "mobile"elsepath = path .. "pc"endfilename = path .. "/" .. id .. ".html"if file_exists(filename) thenlocal file = io.open(filename,"r")io.input(file)print(io.read("*a"))io.close(file)elseprint("文件不存在: " .. string.gsub(filename, "/data/www/mengkang/demo", ""))end end-- 判斷文件是否存在 function file_exists(path)local file = io.open(path, "rb")if file then file:close() endreturn file ~= nil endlocal id = 1 local userAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.79 Safari/537.36" showPromotionHtml(id, isMobile(userAgent))

小結(jié)

作為一個 lua 菜鳥，通過這個小需求我查了哪些資料

變量的定義
函數(shù)的寫法
循環(huán)的了解
判斷邏輯的寫法
注釋的寫法
文件 i/o
字符串拼接 ..
字符串查找 string.match
字符串轉(zhuǎn)小寫 string.lower

稍微調(diào)整適配 nginx lua 模塊

-- 判斷是否是手機瀏覽器 function isMobile(userAgent)-- 99% 前三個都能匹配上吧local mobile = {"phone", "android", "mobile", "itouch", "ipod", "symbian", "htc", "palmos", "blackberry", "opera mini", "windows ce", "nokia", "fennec","hiptop", "kindle", "mot", "webos", "samsung", "sonyericsson", "wap", "avantgo", "eudoraweb", "minimo", "netfront", "teleca"}userAgent = string.lower(userAgent)for i, v in ipairs(mobile) doif string.match(userAgent, v) thenreturn trueendendreturn false end-- 根據(jù)id + 瀏覽器類型展示活動頁面 function showPromotionHtml(id, isMobile)local path = "/data/www/mengkang/demo/promotion/"local filenameif isMobile thenpath = path .. "mobile"elsepath = path .. "pc"endfilename = path .. "/" .. id .. ".html"if file_exists(filename) thenlocal file = io.open(filename,"r")io.input(file)ngx.say(io.read("*a"))io.close(file)elsengx.say("file not found : " .. string.gsub(filename, "/data/www/mengkang/demo", ""))end end-- 判斷文件是否存在 function file_exists(path)local file = io.open(path, "rb")if file then file:close() endreturn file ~= nil endlocal id = ngx.var.id local userAgent = ngx.req.get_headers().user_agent showPromotionHtml(id, isMobile(userAgent))

nginx 配置

server {listen 80;server_name mengkang.netlocation ~ /promotion/(\d+){set $id $1;default_type "text/html";content_by_lua_file /data/www/lua/1.lua;} }

nginx 單獨安裝 lua 模塊也行，使用 openresty 也可以。單獨安裝參考：https://mengkang.net/994.html

演示地址

https://mengkang.net/promotion/1
https://mengkang.net/promotion/100
切換 user_agent 即可看到，不同的 pc 和 mobile 兩個版本的頁面

和 php 性能對比

nginx 配置

rewrite ^/promotion2/(.*)$ /demo/promotion.php last;

php 代碼

<?php header("Content-type:text/html;charset=utf-8"); header_remove('x-powered-by'); ini_set('display_errors', 'Off');function getId(){$uri = $_SERVER["REQUEST_URI"];$tmp = explode("?",$uri);$uri = $tmp[0];$uri = trim($uri,"/");$tmp = explode("/",$uri);return intval(array_pop($tmp)); }function isMobile() {$user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? strtolower ( $_SERVER['HTTP_USER_AGENT'] ) : '';if ( preg_match ( "/phone|itouch|ipod|symbian|android|htc_|htc-|palmos|blackberry|opera mini|windows ce|nokia|fennec|hiptop|kindle|mot |mot-|webos\/|samsung|sonyericsson|mobile|pda;|avantgo|eudoraweb|minimo|netfront|nintendo/", $user_agent ) ) {return true;}return false; }$id = getId();$isMobile = isMobile();if ($isMobile){$filename = __DIR__."/promotion/mobile/".$id.".html"; }else{$filename = __DIR__."/promotion/pc/".$id.".html"; }if (file_exists($filename)) {echo file_get_contents($filename); }else{echo "file not found : /promotion/pc/".$id.".html"; }exit;

也就是說訪問
http://mengkang.net/promotion/1
和
http://mengkang.net/promotion2/1
是一樣的結(jié)果

配置說明

雙核4G
nginx 配置一致
php 版本：7.0.11
php-fpm 配置

pm = dynamic pm.max_children = 10 pm.start_servers = 4 pm.min_spare_servers = 4 pm.max_spare_servers = 10

php 壓測結(jié)果

ab -n 1000 -c 100 http://mengkang.net/promotion2/1 Requests per second: 3105.21 [#/sec](mean) Time per request: 32.204 [ms](mean)ab -n 4000 -c 400 http://mengkang.net/promotion2/1 Requests per second: 3361.87 [#/sec](mean) Time per request: 118.981 [ms](mean) Complete requests: 4000 Failed requests: 259ab -n 8000 -c 800 http://mengkang.net/promotion2/1 Requests per second: 3358.20 [#/sec](mean) Time per request: 238.223 [ms](mean) Complete requests: 8000 Failed requests: 654ab -n 10000 -c 1000 http://mengkang.net/promotion2/1 Requests per second: 3275.30 [#/sec](mean) Time per request: 305.315 [ms](mean) Complete requests: 10000 Failed requests: 9150

lua 壓測結(jié)果

ab -n 1000 -c 100 http://mengkang.net/promotion/1 Requests per second: 6014.89 [#/sec](mean) Time per request: 16.625 [ms](mean)ab -n 4000 -c 400 http://mengkang.net/promotion/1 Complete requests: 4000 Failed requests: 0 Requests per second: 6190.57 [#/sec](mean) Time per request: 64.614 [ms](mean)ab -n 8000 -c 800 http://mengkang.net/promotion/1 Complete requests: 8000 Failed requests: 0 Requests per second: 7046.66 [#/sec](mean) Time per request: 113.529 [ms](meanab -n 10000 -c 1000 http://mengkang.net/promotion/1 Complete requests: 10000 Failed requests: 0 Requests per second: 5670.38 [#/sec](mean) Time per request: 176.355 [ms](mean)

對比發(fā)現(xiàn)性能提示相當(dāng)可觀。
PHP qps 在 3000左右，nginx_lua qps 在 7000 左右。
php 在 400 個并發(fā)的時候開始出現(xiàn)比較多的失敗請求，吞吐率開始下降。
而 lua 的結(jié)果在 1000 個并發(fā)的時候，失敗的請求數(shù)依舊是0。

總結(jié)

以上是生活随笔為你收集整理的nginx lua 小项目：根据 user_agent 显示不同的页面，附带和 php 性能的对比的全部內(nèi)容，希望文章能夠幫你解決所遇到的問題。

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