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diff --git a/node_modules/keyv/README.md b/node_modules/keyv/README.md new file mode 100644 index 0000000..1829d09 --- /dev/null +++ b/node_modules/keyv/README.md @@ -0,0 +1,288 @@ +<h1 align="center"> + <img width="250" src="https://rawgit.com/lukechilds/keyv/master/media/logo.svg" alt="keyv"> + <br> + <br> +</h1> + +> Simple key-value storage with support for multiple backends + +[](https://travis-ci.org/lukechilds/keyv) +[](https://coveralls.io/github/lukechilds/keyv?branch=master) +[](https://www.npmjs.com/package/keyv) +[](https://www.npmjs.com/package/keyv) + +Keyv provides a consistent interface for key-value storage across multiple backends via storage adapters. It supports TTL based expiry, making it suitable as a cache or a persistent key-value store. + +## Features + +There are a few existing modules similar to Keyv, however Keyv is different because it: + +- Isn't bloated +- Has a simple Promise based API +- Suitable as a TTL based cache or persistent key-value store +- [Easily embeddable](#add-cache-support-to-your-module) inside another module +- Works with any storage that implements the [`Map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) API +- Handles all JSON types plus `Buffer` +- Supports namespaces +- Wide range of [**efficient, well tested**](#official-storage-adapters) storage adapters +- Connection errors are passed through (db failures won't kill your app) +- Supports the current active LTS version of Node.js or higher + +## Usage + +Install Keyv. + +``` +npm install --save keyv +``` + +By default everything is stored in memory, you can optionally also install a storage adapter. + +``` +npm install --save @keyv/redis +npm install --save @keyv/mongo +npm install --save @keyv/sqlite +npm install --save @keyv/postgres +npm install --save @keyv/mysql +``` + +Create a new Keyv instance, passing your connection string if applicable. Keyv will automatically load the correct storage adapter. + +```js +const Keyv = require('keyv'); + +// One of the following +const keyv = new Keyv(); +const keyv = new Keyv('redis://user:pass@localhost:6379'); +const keyv = new Keyv('mongodb://user:pass@localhost:27017/dbname'); +const keyv = new Keyv('sqlite://path/to/database.sqlite'); +const keyv = new Keyv('postgresql://user:pass@localhost:5432/dbname'); +const keyv = new Keyv('mysql://user:pass@localhost:3306/dbname'); + +// Handle DB connection errors +keyv.on('error', err => console.log('Connection Error', err)); + +await keyv.set('foo', 'expires in 1 second', 1000); // true +await keyv.set('foo', 'never expires'); // true +await keyv.get('foo'); // 'never expires' +await keyv.delete('foo'); // true +await keyv.clear(); // undefined +``` + +### Namespaces + +You can namespace your Keyv instance to avoid key collisions and allow you to clear only a certain namespace while using the same database. + +```js +const users = new Keyv('redis://user:pass@localhost:6379', { namespace: 'users' }); +const cache = new Keyv('redis://user:pass@localhost:6379', { namespace: 'cache' }); + +await users.set('foo', 'users'); // true +await cache.set('foo', 'cache'); // true +await users.get('foo'); // 'users' +await cache.get('foo'); // 'cache' +await users.clear(); // undefined +await users.get('foo'); // undefined +await cache.get('foo'); // 'cache' +``` + +### Custom Serializers + +Keyv uses [`json-buffer`](https://github.com/dominictarr/json-buffer) for data serialization to ensure consistency across different backends. + +You can optionally provide your own serialization functions to support extra data types or to serialize to something other than JSON. + +```js +const keyv = new Keyv({ serialize: JSON.stringify, deserialize: JSON.parse }); +``` + +**Warning:** Using custom serializers means you lose any guarantee of data consistency. You should do extensive testing with your serialisation functions and chosen storage engine. + +## Official Storage Adapters + +The official storage adapters are covered by [over 150 integration tests](https://travis-ci.org/lukechilds/keyv/jobs/260418145) to guarantee consistent behaviour. They are lightweight, efficient wrappers over the DB clients making use of indexes and native TTLs where available. + +Database | Adapter | Native TTL | Status +---|---|---|--- +Redis | [@keyv/redis](https://github.com/lukechilds/keyv-redis) | Yes | [](https://travis-ci.org/lukechilds/keyv-redis) [](https://coveralls.io/github/lukechilds/keyv-redis?branch=master) +MongoDB | [@keyv/mongo](https://github.com/lukechilds/keyv-mongo) | Yes | [](https://travis-ci.org/lukechilds/keyv-mongo) [](https://coveralls.io/github/lukechilds/keyv-mongo?branch=master) +SQLite | [@keyv/sqlite](https://github.com/lukechilds/keyv-sqlite) | No | [](https://travis-ci.org/lukechilds/keyv-sqlite) [](https://coveralls.io/github/lukechilds/keyv-sqlite?branch=master) +PostgreSQL | [@keyv/postgres](https://github.com/lukechilds/keyv-postgres) | No | [](https://travis-ci.org/lukechildskeyv-postgreskeyv) [](https://coveralls.io/github/lukechilds/keyv-postgres?branch=master) +MySQL | [@keyv/mysql](https://github.com/lukechilds/keyv-mysql) | No | [](https://travis-ci.org/lukechilds/keyv-mysql) [](https://coveralls.io/github/lukechilds/keyv-mysql?branch=master) + +## Third-party Storage Adapters + +You can also use third-party storage adapters or build your own. Keyv will wrap these storage adapters in TTL functionality and handle complex types internally. + +```js +const Keyv = require('keyv'); +const myAdapter = require('./my-storage-adapter'); + +const keyv = new Keyv({ store: myAdapter }); +``` + +Any store that follows the [`Map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map) api will work. + +```js +new Keyv({ store: new Map() }); +``` + +For example, [`quick-lru`](https://github.com/sindresorhus/quick-lru) is a completely unrelated module that implements the Map API. + +```js +const Keyv = require('keyv'); +const QuickLRU = require('quick-lru'); + +const lru = new QuickLRU({ maxSize: 1000 }); +const keyv = new Keyv({ store: lru }); +``` + +The following are third-party storage adapters compatible with Keyv: + +- [quick-lru](https://github.com/sindresorhus/quick-lru) - Simple "Least Recently Used" (LRU) cache +- [keyv-file](https://github.com/zaaack/keyv-file) - File system storage adapter for Keyv +- [keyv-dynamodb](https://www.npmjs.com/package/keyv-dynamodb) - DynamoDB storage adapter for Keyv +- [keyv-firestore ](https://github.com/goto-bus-stop/keyv-firestore) – Firebase Cloud Firestore adapter for Keyv +- [keyv-mssql](https://github.com/pmorgan3/keyv-mssql) - Microsoft Sql Server adapter for Keyv +- [keyv-memcache](https://github.com/jaredwray/keyv-memcache) - Memcache storage adapter for Keyv + +## Add Cache Support to your Module + +Keyv is designed to be easily embedded into other modules to add cache support. The recommended pattern is to expose a `cache` option in your modules options which is passed through to Keyv. Caching will work in memory by default and users have the option to also install a Keyv storage adapter and pass in a connection string, or any other storage that implements the `Map` API. + +You should also set a namespace for your module so you can safely call `.clear()` without clearing unrelated app data. + +Inside your module: + +```js +class AwesomeModule { + constructor(opts) { + this.cache = new Keyv({ + uri: typeof opts.cache === 'string' && opts.cache, + store: typeof opts.cache !== 'string' && opts.cache, + namespace: 'awesome-module' + }); + } +} +``` + +Now it can be consumed like this: + +```js +const AwesomeModule = require('awesome-module'); + +// Caches stuff in memory by default +const awesomeModule = new AwesomeModule(); + +// After npm install --save keyv-redis +const awesomeModule = new AwesomeModule({ cache: 'redis://localhost' }); + +// Some third-party module that implements the Map API +const awesomeModule = new AwesomeModule({ cache: some3rdPartyStore }); +``` + +## API + +### new Keyv([uri], [options]) + +Returns a new Keyv instance. + +The Keyv instance is also an `EventEmitter` that will emit an `'error'` event if the storage adapter connection fails. + +### uri + +Type: `String`<br> +Default: `undefined` + +The connection string URI. + +Merged into the options object as options.uri. + +### options + +Type: `Object` + +The options object is also passed through to the storage adapter. Check your storage adapter docs for any extra options. + +#### options.namespace + +Type: `String`<br> +Default: `'keyv'` + +Namespace for the current instance. + +#### options.ttl + +Type: `Number`<br> +Default: `undefined` + +Default TTL. Can be overridden by specififying a TTL on `.set()`. + +#### options.serialize + +Type: `Function`<br> +Default: `JSONB.stringify` + +A custom serialization function. + +#### options.deserialize + +Type: `Function`<br> +Default: `JSONB.parse` + +A custom deserialization function. + +#### options.store + +Type: `Storage adapter instance`<br> +Default: `new Map()` + +The storage adapter instance to be used by Keyv. + +#### options.adapter + +Type: `String`<br> +Default: `undefined` + +Specify an adapter to use. e.g `'redis'` or `'mongodb'`. + +### Instance + +Keys must always be strings. Values can be of any type. + +#### .set(key, value, [ttl]) + +Set a value. + +By default keys are persistent. You can set an expiry TTL in milliseconds. + +Returns a promise which resolves to `true`. + +#### .get(key, [options]) + +Returns a promise which resolves to the retrieved value. + +##### options.raw + +Type: `Boolean`<br> +Default: `false` + +If set to true the raw DB object Keyv stores internally will be returned instead of just the value. + +This contains the TTL timestamp. + +#### .delete(key) + +Deletes an entry. + +Returns a promise which resolves to `true` if the key existed, `false` if not. + +#### .clear() + +Delete all entries in the current namespace. + +Returns a promise which is resolved when the entries have been cleared. + +## License + +MIT © Luke Childs |