Node.js Cache Layer

Cache layer compatible with express framework.

Install

First step:

Install the main package:

npm install node-cache-layer --save

Second step:

Install the handler desired to store the cache:

Redis:

npm install cache-layer-redis --save

MongoDB:

npm install cache-layer-mongodb --save

FileSystem:

npm install cache-layer-filesystem --save

Usage

Seamless integration without any major change in your application. It caches the entire body response and the headers as well.

import cache from "node-cache-layer"

const app = express();

app.use(cache());

Complete options:

app.use(
	cache({
		config_file: "./path/config.json", // If you prefer not to use the default location
		handler: "cache-layer-redis", // Name of the module that will handle the cache. It can be set here or in the config file.
		isCacheable(req: any) { // Custom function to define whether the response can be cached
			if(req.query.is_preview == "1")
				return false;
			
			return true;
		},
		callbacks: { // Optional callbacks. Customized modifications could be done here
			before_serve(key: string, body: string, headers: any, encoding?: string): void {
				// If the route is cached, this function will be called before send the output to the client.
			},
			before_cache(route: any, cache: Buffer[], headers: any, encoding?: string): void {

			},
			after_cache(key: string, route: any, body: Buffer, headers: any, encoding?: string): void {

			}
		}
	})
);

Config File

The default config file is located at the application root. It's a JSON named "cache-config.json".

{
	"prefix": "cache_",
	"handler": "",
	"status": [200],
	"expire": 86400,
	"rules": [
		{
			"name": "",
			"group": "",
			"status": [],
			"route": "",
			"regex": "",
			"ignore_case": false,
			"expire": 10,
			"methods": ["OPTIONS", "GET", "HEAD", "POST", "PUT", "DELETE", "TRACE", "CONNECT"],
			"variables": {
				"params": [],
				"query": [
					{
						"value": "",
						"ignore_case": true
					}
				],
				"cookies": [],
				"body": [],
				"session": [],
				"header": [],
				"subdomains": []
			}
		}
	]
}

General properties

Property	Description	Type	Example	Default Value
prefix	If you want to prefix the record id/key to store. In case of databases with the concept of tables/collections, this will be used to name it.	string	prefix: "cache_"	cache_
handler	The name of the module to handle the cache.	string	handler: "cache-layer-redis"	built-in memory (not recommended for production)
status	Array containg all the status code that must be cached. This is valid for all the rules without the property status declared in itself.	number[]	status: "[ 200, 401 ]"	[ 200 ]
expire	Time to live (in seconds) of the cached route.	number	expire: 60	86400 (1 day)
rules	Array containing all the rules to cache the routes.	object[]		[]

Rules properties