A JSON/XML resource caching library based on Request

Pantry is an HTTP client cache used to minimize requests for external JSON and XML feeds. The Pantry will cache resources to minimize round trips, utilizing the local cache when available and refresh the cache (asynchronously) as needed.

As with any of our projects, constructive criticism is encouraged.

Just grab node.js and npm and you're set:

npm install pantry

Note that Pantry was developed using CoffeeScript. It uses the amazing Request library for all HTTP requests and xml2js to parse xml resources.

Work in progress. See the examples for the time being.

To utilize the pantry, simply require it, optionally override some default values, and then request your resource(s) via the fetch method

pantry = require 'pantry'
pantry.configure { shelfLife: 5 }

pantry.fetch { uri: 'http://search.twitter.com/search.json?q=winning'}, (error, item) ->
	console.log "\t#{item.results[0].text}"

At this item, the following configuration options can be specified:

• shelfLife - number of seconds before a resource reaches it's best-before-date
• maxLife - number of seconds before a resource spoils
• capacity - the maximum number of items to keep in the pantry
• ideal - when cleaning up, the ideal number of items to keep in the pantry
• caseSensitive - URI should be considered case sensitive when inferring cache key
• verbosity - possible values are 'DEBUG', 'INFO', 'WARNING' and 'ERROR' (default is 'INFO')
• parser - possible values are 'json' and 'xml' (default is undefined, in which auto-detection by content-type header is used)
• ignoreCacheControl - do not utilize the cache-control header to override the cache configuration if present (default if false)

When you request a resource from the pantry, a couple interesting things happen. If the item is available in the pantry, and hasn't 'spoiled', it will be returned immediately via the callback. If it has expired (it's beyond its best before date) but hasn't spoiled, it will still be returned and then refreshed in the background.

Ode to my immigrant mother: The best before date is treated as a recommendation. If it hasn't visibly spoiled it's probably still good to use, so use it until we have a chance to go shopping. Especially if it's salad dressing, that stuff never goes bad as long as it's in the fridge.

If the resource isn't available in the pantry, or the item has spoiled, then the item will be retrieved immediately and won't be passed on to the callback method until we have the resource on hand.

Finally, every time an item is added to pantry, we ensure we haven't reached capacity. If we have, then we first start with throwing out any spoiled items. After that, if we are still above capacity we will get rid of the expired items, and if we're really desperate we will need to throw out some good items just to make room.

• Better handling of not-GET requests
• Ability to execute array of requests in parallel
• Support for Redis
• Support for cookies (including cache key)

• Edward de Groot
• Keith Benedict
• Stephen Veerman
• Kevin Gamble