openresty开发系列27--openresty中封装redis操作
在关于web+lua+openresty开发中，项目中会大量操作redis，
重复创建连接-->数据操作-->关闭连接（或放到连接池）这个完整的链路调用完毕，
甚至还要考虑不同的 return 情况做不同处理，就很快发现代码中有大量的重复
推荐一个二次封装的类库
---------------------------------
# 加入openresty的lib库目录
# vim openresty/lualib/resty/redis_iresty.lua
local redis_c = require "resty.redis"
local ok, new_tab = pcall(require, "table.new")
if not ok or type(new_tab) ~= "function" then
new_tab = function (narr, nrec) return {} end
end
local _M = new_tab(0, 155)
_M._VERSION = '0.01'
local commands = {
"append", "auth", "bgrewriteaof",
"bgsave", "bitcount", "bitop",
"blpop", "brpop",
"brpoplpush", "client", "config",
"dbsize",
"debug", "decr", "decrby",
"del", "discard", "dump",
"echo",
"eval", "exec", "exists",
"expire", "expireat", "flushall",
"flushdb", "get", "getbit",
"getrange", "getset", "hdel",
"hexists", "hget", "hgetall",
"hincrby", "hincrbyfloat", "hkeys",
"hlen",
"hmget", "hmset", "hscan",
"hset",
"hsetnx", "hvals", "incr",
"incrby", "incrbyfloat", "info",
"keys",
"lastsave", "lindex", "linsert",
"llen", "lpop", "lpush",
"lpushx", "lrange", "lrem",
"lset", "ltrim", "mget",
"migrate",
"monitor", "move", "mset",
"msetnx", "multi", "object",
"persist", "pexpire", "pexpireat",
"ping", "psetex", "psubscribe",
"pttl",
"publish", --[[ "punsubscribe", ]] "pubsub",
"quit",
"randomkey", "rename", "renamenx",
"restore",
"rpop", "rpoplpush", "rpush",
"rpushx", "sadd", "save",
"scan", "scard", "script",
"sdiff", "sdiffstore",
"select", "set", "setbit",
"setex", "setnx", "setrange",
"shutdown", "sinter", "sinterstore",
"sismember", "slaveof", "slowlog",
"smembers", "smove", "sort",
"spop", "srandmember", "srem",
"sscan",
"strlen", --[[ "subscribe", ]] "sunion",
"sunionstore", "sync", "time",
"ttl",
"type", --[[ "unsubscribe", ]] "unwatch",
"watch", "zadd", "zcard",
"zcount", "zincrby", "zinterstore",
"zrange", "zrangebyscore", "zrank",
"zrem", "zremrangebyrank", "zremrangebyscore",
"zrevrange", "zrevrangebyscore", "zrevrank",
"zscan",
"zscore", "zunionstore", "evalsha"
}
local mt = { __index = _M }
local function is_redis_null( res )
if type(res) == "table" then
for k,v in pairs(res) do
if v ~= ngx.null then
return false
end
end
return true
elseif res == ngx.null then
return true
elseif res == nil then
return true
end
return false
end
function _M.close_redis(self, redis)
if not redis then
return
end
--释放连接(连接池实现)
local pool_max_idle_time = self.pool_max_idle_time --最大空闲时间 毫秒
local pool_size = self.pool_size --连接池大小
local ok, err = redis:set_keepalive(pool_max_idle_time, pool_size)
if not ok then
ngx.say("set keepalive error : ", err)
end
end
-- change connect address as you need
function _M.connect_mod( self, redis )
redis:set_timeout(self.timeout)
local ok, err = redis:connect(self.ip, self.port)
if not ok then
ngx.say("connect to redis error : ", err)
return self:close_redis(redis)
end
if self.password then ----密码认证
local count, err = redis:get_reused_times()
if 0 == count then ----新建连接，需要认证密码
ok, err = redis:auth(self.password)
if not ok then
ngx.say("failed to auth: ", err)
return
end
elseif err then ----从连接池中获取连接，无需再次认证密码
ngx.say("failed to get reused times: ", err)
return
end
end
return ok,err;
end
function _M.init_pipeline( self )
self._reqs = {}
end
function _M.commit_pipeline( self )
local reqs = self._reqs
if nil == reqs or 0 == #reqs then
return {}, "no pipeline"
else
self._reqs = nil
end
local redis, err = redis_c:new()
if not redis then
return nil, err
end
local ok, err = self:connect_mod(redis)
if not ok then
return {}, err
end
redis:init_pipeline()
for _, vals in ipairs(reqs) do
local fun = redis[vals[1]]
table.remove(vals , 1)
fun(redis, unpack(vals))
end
local results, err = redis:commit_pipeline()
if not results or err then
return {}, err
end
if is_redis_null(results) then
results = {}
ngx.log(ngx.WARN, "is null")
end
-- table.remove (results , 1)
--self.set_keepalive_mod(redis)
self:close_redis(redis)
for i,value in ipairs(results) do
if is_redis_null(value) then
results[i] = nil
end
end
return results, err
end
local function do_command(self, cmd, ... )
if self._reqs then
table.insert(self._reqs, {cmd, ...})
return
end
local redis, err = redis_c:new()
if not redis then
return nil, err
end
local ok, err = self:connect_mod(redis)
if not ok or err then
return nil, err
end
redis:select(self.db_index)
local fun = redis[cmd]
local result, err = fun(redis, ...)
if not result or err then
-- ngx.log(ngx.ERR, "pipeline result:", result, " err:", err)
return nil, err
end
if is_redis_null(result) then
result = nil
end
--self.set_keepalive_mod(redis)
self:close_redis(redis)
return result, err
end
for i = 1, #commands do
local cmd = commands[i]
_M[cmd] =
function (self, ...)
return do_command(self, cmd, ...)
end
end
function _M.new(self, opts)
opts = opts or {}
local timeout = (opts.timeout and opts.timeout * 1000) or 1000
local db_index= opts.db_index or 0
local ip = opts.ip or '127.0.0.1'
local port = opts.port or 6379
local password = opts.password
local pool_max_idle_time = opts.pool_max_idle_time or 60000
local pool_size = opts.pool_size or 100
return setmetatable({
timeout = timeout,
db_index = db_index,
ip = ip,
port = port,
password = password,
pool_max_idle_time = pool_max_idle_time,
pool_size = pool_size,
_reqs = nil }, mt)
end
return _M
---------------------------------------
调用案例
local redis = require "resty.redis_iresty"
local opts = {
ip = "10.11.0.215",
port = "6379",
password = "redis123",
db_index = 1
}
local red = redis:new(opts)
local ok, err = red:set("dog", "an animal")
if not ok then
ngx.say("failed to set dog: ", err)
return
end
ngx.say("set result: ", ok)
---------------------------------------
管道
redis.set
redis.get
red:init_pipeline()
red:set("cat", "Marry")
red:set("horse", "Bob")
red:get("cat")
red:get("horse")
local results, err = red:commit_pipeline()
if not results then
ngx.say("failed to commit the pipelined requests: ", err)
return
end
for i, res in ipairs(results) do
ngx.say(res,"<br/>");
end
在日常的开发中我们不需要重复造*，只要这个* 稳定，高效就可以直接拿过来用