cache-ex

Caches all responses to HTTP GET requests in memory using node-cache. Provides admin urls to manage the cache

Install

  npm install cache-ex

Examples:

Initialization

var cacheEx=require('cache-ex')({secret:'dont tell a soul'});

Options

secret,timeToLive

• timeToLive: the standard ttl as number in seconds for every generated cache element. Default = 0 = unlimited
• secret: A secret word to protect flusing of the cache = cacheControlMaxAge: HTTP Cache-Control header will be sent with this max-age if set and > 0 when serving content from the cache.

Retrieve and Serve cached data:

Relies on expressjs. The following code instructs express to use the serve method of cache-ex on all requests. Subsequent handlers are only called if the object has not been served from the cache.

app.use(cacheEx.serve());
 
app.get('/any',function(req,res){
    cacheEx.put({object:'Cached Object',req:req.query},req);
    res.send({status:'Not from cache',req:req.query});
});
 
Or add and send in one fn call. This ensures any cache control headers configured are sent the same from first and subsequent calls.
 
app.get('/any',function(req,res){
    cacheEx.putAndServe({object:'Cached Object',req:req.query},req, res);
});
 

cache-ex does not cache POST requests only GET.

Manage the cache

The admin urls for managing the cache are available after the /cache root in this example.

  app.use('/cache',cacheEx.admin());

Cache Keys :

Are automatically created based on the url path and the query string. Query parameters are sorted before key generation so that the order of parameters in the request is unimportant.

Store data :

cacheEx.put(data,req);

Puts a new value into the cache.

View the cache keys

HTTP get to /cache/keys

View the cache statistics

HTTP get to /cache/stats Includes the number of hits and misses

Flush the cache

HTTP POST to '/cache/flush' with the following json to match the secret configured during initialization.

{"secret":"mySecret"}

Test

Install the required node modules and run test/app.js

npm install
node test.js

Browse to the following urls

http://localhost:8080/any?product=22&catalog=music

http://localhost:8080/any?catalog=music&product=22

Notice that the order of query parameters does not matter

http://localhost:8080/any?catalog=music&product=33&nocache

Adding the nocache parameter retrives a new value every time. This enables you to refresh the value of a single key

Check out the admin urls http://localhost:8080/cache/keys

"/any|catalog:music|product:22|"
"/any|catalog:music|product:33|"
]

http://localhost:8080/cache/stats

{
"hits": "2",
"misses": "3",
"keys": "2",
"ksize": "64",
"vsize": "160"
}

Flush the cache POST to http://localhost:8080/cache/flush with {"secret":"mySecret"}

Returns a HTTP Status 200 with the following json

{
"flushed": "OK"
}	

Release History

Version	Date	Description
v0.3.2	2014-06-17	Bug fix
v0.3.2	2014-06-17	Simple HTML form to flush the cache
v0.3.1	2014-05-13	Added serve method. Multiple caches can be required and used in the same service
v0.2.1	2013-12-05	Added sorting of query parameters

License

(The MIT License)

Copyright (c) 2013 PC

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.