怎么快速学习一门新的语言呢？
如果你已经熟练掌握了一门语言，那么其他语言都是想通的。一个小小的需求，可能会遇到很多问题，但是搜索相关的关键字，就能快速实现出来，完成一个小目标，事半功倍。
死记硬背手册，太枯燥了，反正我是看不下去，不如直接来个小项目。
一个小需求
pc、mobile 一个地址有两套页面，需要在后端根据浏览器的 user_agent 来显示不同的页面。
通过 php 来做，当然可以，但是活动页面访问量一般都比较大，想优化些，所以想尝试下 lua。
nginx 安装 lua-nginx-module
可以直接上 openresty，不过有时候就是想折腾。
安装的步骤 https://mengkang.net/994.html （如果你想实践的话再看吧）
lua demo 脚本
-- 判断是否是手机浏览器
function isMobile(userAgent)
-- 99% 前三个都能匹配上吧
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) do
if string.match(userAgent, v) then
return true
end
end
return false
end
-- 根据id + 浏览器类型展示活动页面
function showPromotionHtml(id, isMobile)
local path = "/data/www/mengkang/demo/promotion/"
local filename
if isMobile then
path = path .. "mobile"
else
path = path .. "pc"
end
filename = path .. "/" .. id .. ".html"
if file_exists(filename) then
local file = io.open(filename,"r")
io.input(file)
print(io.read("*a"))
io.close(file)
else
print("文件不存在: " .. string.gsub(filename, "/data/www/mengkang/demo", ""))
end
end
-- 判断文件是否存在
function file_exists(path)
local file = io.open(path, "rb")
if file then file:close() end
return file ~= nil
end
local 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))小结
作为一个 lua 菜鸟，通过这个小需求我查了哪些资料
变量的定义
函数的写法
循环的了解
判断逻辑的写法
注释的写法
文件 i/o
字符串拼接 ..
字符串查找 string.match
字符串转小写 string.lower
稍微调整适配 nginx lua 模块
-- 判断是否是手机浏览器
function isMobile(userAgent)
-- 99% 前三个都能匹配上吧
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) do
if string.match(userAgent, v) then
return true
end
end
return false
end
-- 根据id + 浏览器类型展示活动页面
function showPromotionHtml(id, isMobile)
local path = "/data/www/mengkang/demo/promotion/"
local filename
if isMobile then
path = path .. "mobile"
else
path = path .. "pc"
end
filename = path .. "/" .. id .. ".html"
if file_exists(filename) then
local file = io.open(filename,"r")
io.input(file)
ngx.say(io.read("*a"))
io.close(file)
else
ngx.say("file not found : " .. string.gsub(filename, "/data/www/mengkang/demo", ""))
end
end
-- 判断文件是否存在
function file_exists(path)
local file = io.open(path, "rb")
if file then file:close() end
return file ~= nil
end
local 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.net
location ~ /promotion/(\d+)
{
set $id $1;
default_type "text/html";
content_by_lua_file /data/www/lua/1.lua;
}
}nginx 单独安装 lua 模块也行，使用 openresty 也可以。单独安装参考：https://mengkang.net/994.html
演示地址
https://mengkang.net/promotion/1
https://mengkang.net/promotion/100
切换 user_agent 即可看到，不同的 pc 和 mobile 两个版本的页面
和 php 性能对比
nginx 配置
rewrite ^/promotion2/(.*)$ /demo/promotion.php last;php 代码
<?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;也就是说访问
http://mengkang.net/promotion/1
和
http://mengkang.net/promotion2/1
是一样的结果
配置说明
双核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 = 10php 压测结果
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: 259
ab -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: 654
ab -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: 9150lua 压测结果
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](mean
ab -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)对比发现性能提示相当可观。
PHP qps 在 3000左右，nginx_lua qps 在 7000 左右。
php 在 400 个并发的时候开始出现比较多的失败请求，吞吐率开始下降。
而 lua 的结果在 1000 个并发的时候，失败的请求数依旧是0。