A straightforward Least Recently Used (LRU) cache implementation using the native Map object in Node.js. Bundled with Polka HTTP server for easy access.
git clone https://github.com/cgatno/least-recently-used.git
cd least-recently-used
npm install
npm start
See the HTTP interface specs below for info on using the cache.
This LRU caching app implements the following functionality:
- Finite and hold up to a maximum number of elements
- Supports ‘get,’ ‘put,’ and ‘delete' operations
- Discards the least recently used elements first
- Accessible using HTTP
You can access the cache using any HTTP client (or web browser for GET requests). I recommend Postman or httpie.
See below for a list of app endpoints.
By default, the app listens at http://localhost:8080. The port can be overriden using the PORT environment variable. (E.g. PORT=4343 npm start)
| Endpoint | Request Type | Input (application/json) | Response Code | Response Description |
|---|---|---|---|---|
/ |
GET | N/A | 200 | Friendly, descriptive welcome message 😊 |
/cache |
GET | N/A | 200 | JSON array of form [<key>, <value>] for most recently used pair |
| POST | {key: string?, value: string?} |
200 | JSON array of form [<new key>, <new value>] |
|
| 500 | Add pair error message - stack trace logged to Node console | |||
/cache/{key} |
GET | N/A | 200 | Plaintext value for the given key |
| 404 | Key not found message | |||
| DELETE | N/A | 200 | Key deleted message | |
| 404 | Key not found message | |||
| PUT | {value: string?} |
200 | JSON array of form [<key>, <new value>] |
|
| 500 | Key update error message - stack trace logged to Node console |
- Outfit toolchain with nodemon to automatically reload in dev environment
- Test performance of JavaScript Map to see if more performant implementation is necessary
- Build UI for interacting with the Express API and underlying cache
- Add persist/load functions to LRU cache
- Promisify LRUCache.js for async operations