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| local redis = require('resty.redis')
local red = redis:new()
red:set_timeouts(1000, 1000, 1000)
-- 创建一个本地缓存对象item_cache
local item_cache = ngx.shared.item_cache;
-- 关闭redis连接的工具方法，其实是放入连接池
local function close_redis(red)
local pool_max_idle_time = 10000 -- 连接的空闲时间，单位是毫秒
local pool_size = 100 --连接池大小
local ok, err = red:set_keepalive(pool_max_idle_time, pool_size)
if not ok then
ngx.log(ngx.ERR, "放入redis连接池失败: ", err)
end
end
-- 查询redis的方法 ip和port是redis地址，key是查询的key
local function read_redis(ip, port, key)
-- 获取一个连接
local ok, err = red:connect(ip, port)
if not ok then
ngx.log(ngx.ERR, "连接redis失败 : ", err)
return nil
end
-- 查询redis
local resp, err = red:get(key)
-- 查询失败处理
if not resp then
ngx.log(ngx.ERR, "查询Redis失败: ", err, ", key = " , key)
end
--得到的数据为空处理
if resp == ngx.null then
resp = nil
ngx.log(ngx.ERR, "查询Redis数据为空, key = ", key)
end
close_redis(red)
return resp
end
-- 函数，向openresty本身发送类似/path/item/10001请求，根据conf配置，将被删除/path前缀并代理至tomcat程序
local function read_get(path, params)
local rsp = ngx.location.capture('/path'..path,{
method = ngx.HTTP_GET,
args = params,
})
if not rsp then
ngx.log(ngx.ERR, "http not found, path: ", path, ", args: ", params);
ngx.exit(404)
end
return rsp.body
end
-- 函数，如果本地有缓存，使用缓存，如果没有代理到tomcat然后将数据存入缓存
local function read_data(key, expire, path, params)
-- query local cache
local rsp = item_cache:get(key)
-- query redis
if not rsp then
ngx.log(ngx.ERR, "local cache miss, try redis, key: ", key)
rsp = read_redis("172.30.3.21", 6379, key)
if not rsp then
ngx.log(ngx.ERR, "redis cache miss, try tomcat, key: ", key)
rsp = read_get(path, params)
end
end
-- write into local cache
item_cache:set(key, rsp, expire)
return rsp
end
local _M = {
read_get = read_get,
read_redis = read_redis,
read_data = read_data
}
return _M
|
