express-cache-tool

How to use
------------
``javascript
var CacheTool = require('express-cache-tool');
var cache = new CacheTool.Cache({
duplicate: false, //default false, if true, will create a no expiration cache for this key
expired: null //default null, ms
}, [debug], [sync_key]);
//sync_key defaul '_cacheSync', if you want to refresh the cache, you can add ?{sync_key}=1 in url

cache.use(CacheTool.MemoryCache);

var test_cache1 = cache.set('key1', {duplicate: true, expired: 60000}, [alias]);

app.get('/', test_cache1, function(req, res, next){
//if define alias, use req.cache.alias
//else use req.cache
req.cache.get_or_create(function(fail, done){
//if duplicate set true and the asyncFunc is fail, it will get the cache from duplicate
asyncFunc().then(done).catch(fail);
}).then(function(result){
res.json(result);
}).catch(next);
});
`

> You also can set multiple cache in one route, like app.get('/', test_cache1, test_cache2, function(req, res, next){})

Cache scheme in express-cache-tool
------------------------------------
1. MemoryCache - cache.use(MemoryCache)
2. FileCache - cache.use(FileCache)
3. RedisCache - base on ioredis

#### Use RedisCache
`javascript
redisCache = RedisCache({
conf: 'host:port', //or use cluster [{host: host, port: port}, ...]
db: 0
}, [redis], [prefix]);
//if set redis and the first parameter is null, use a already exists redis connet, must be base on ioredis

cache.use(redisCache);
`

Custom cache scheme
--------------------
`javascript
var scheme = {
set: function(key, value, expired){
//return promise
},
get: function(key){
//return promise
}
}
cache.use(scheme);
``