Craydent Cache 0.4.1

by Clark Inada

This module is a caching system so api data can be retrieved quickly with minimum overhead.

Usages

Craydent-Cache constructor takes up to 1 argument.

• options - options can have any of the following properties:
  • refresh_interval - Integer interval to refresh the cache in milliseconds (Default 3600000ms).
  • in_memory - Boolean flag to keep data in memory instead of file system (Default false).
  • files - Object providing the details of the files used to populate cache. This is not typically used and the cache should be rebuilt on restart (Default {}).
  • memory_data - Object providing the data stored in memory for the cache. This is not typically used and the cache should be rebuilt on restart (Default {}).

**Note: by default Craydent-Cache will use the filesystem to cache but when in_memory is set to true, it will keep the cache in memory which will significantly increas performace but will consume much more memory resources.

###Methods Craydent-Cache has 3 methods

• add - this method allows you to add files or endpoints to cache. Returns a Promise and overloads as follows:

  • add("URL"); // (String) Url to the end point.
  • add("URL", callback); // (Function/Generator) Callback: custom method to retrieve or manipulate the data before saving. Callback should return a boolean to let Craydent Cache know that the add was successful. Callback is passed a function as an argument and this function returns a Promise.
  • add("URL",options); // (Object) options for caching.
    • options can have any of the following properties
      • headers - HTTP Headers as an Object of key value pairs.
      • method - HTTP method (GET,POST,PUT,DEL) as a String.
      • callback - Custom method to retrieve and manipulate data before saving.
      • data - HTTP body of the request.
  • add("URL", refresh_interval); // (Integer) Time interval in ms to refresh the data.
  • add("URL", refresh_interval, callback);
  • add("URL", alias); // (String) Alias to use when retrieving the cached data.
  • add("URL", alias, callback);
  • add("URL", options, refresh_interval);
  • add("URL", options, alias);
  • add("URL", options, refresh_interval, alias);
  • add("Mongo URL", mongo_options); // (String) Mongo connection string, (Object) options for the mongo query.
    • mongo_options must have any of the following properties.
      • collection - (String) Name of the collection in the MongoDB.
      • find - (Object) Query object used query MongoDB records.
  • add("Mongo URL", mongo_options, refresh_interval); // (Integer) Time interval in ms to refresh the data.
  • add("Mongo URL", mongo_options, alias); // (String) Alias to use when retrieving the cached data.
  • add("Mongo URL", mongo_options, refresh_interval, alias);

• get - This method is used to retrieve the cached data. Returns a Promise and overloads as follows:

  • get("URL"); // (String) Url to the end point stored in cache.
  • get("Alias"); // (String) Alias name set when invoking the add method.
  • get("URL", options); // (Object) options used when invoking the add method (see above).
  • get("Mongo URL", options); // (String) Mongo connection string, (Object) options used when invoking the add method (see above).

• refresh - This method is used to manually invoke a refresh on cached data. Returns a Promise and overloads as follows:

  • same as get method

• delete - This method is used to remove an item in the cache and prevent further updates. Returns a Promise and overloads as follows:

  • same as get method

###Code Examples

function* () {
	const CraydentCache = require('craydent-cache');
	let cache = new CraydentCache({refresh_interval:60000}); // 60 seconds
	let success = yield cache.add('http://example.com/some/rest/endpoint');
	if (success) {
	    var result = yield cache.get('http://example.com/some/rest/endpoint');
	    // result contains the content as a string or a JSON if parsable
	}
	yield cache.refresh('http://example.com/some/rest/endpoint');
}

function* () {
	const CraydentCache = require('craydent-cache');
	let cache = new CraydentCache({refresh_interval:60000}); // 60 seconds
	let success = yield cache.add('http://example.com/some/rest/endpoint',30000,'example_alias'); // this will refresh every 30 seconds
	let success2 = yield cache.add('http://example.com/some/rest/endpoint2','example_alias2'); // this will still refresh every 60 seconds
	
	if (success) {
	    var result = yield cache.get('example_alias');
	    // result contains the content as a string or a JSON if parsable
	}
	if (success2) {
	    var result2 = yield cache.get('example_alias2');
	    // result contains the content as a string or a JSON if parsable
	}
	yield cache.refresh('example_alias');
	yield cache.delete('example_alias2');
}

Installation

$ npm i --save craydent-cache

Download

• GitHub
• BitBucket
• GitLab

Craydent-Cache is released under the Dual licensed under the MIT or GPL Version 2 licenses.