[![npm][npm]][npm-url]
[![node][node]][node-url]
[![deps][deps]][deps-url]
[![tests][tests]][tests-url]
[![coverage][cover]][cover-url]
[![chat][chat]][chat-url]
[![size][size]][size-url]

cache-loader

The cache-loader allow to Caches the result of following loaders on disk (default) or in the database.

Getting Started

To begin, you'll need to install cache-loader:

``console
npm install --save-dev cache-loader
`

Add this loader in front of other (expensive) loaders to cache the result on disk.

webpack.config.js

`js
module.exports = {
module: {
rules: [
{
test: /\.ext$/,
use: ['cache-loader', ...loaders],
include: path.resolve('src'),
},
],
},
};
`

> ⚠️ Note that there is an overhead for saving the reading and saving the cache file, so only use this loader to cache expensive loaders.

Options

| Name | Type | n Default | Description |
| :-------------------: | :----------------------------------------------: | :-----------------------------------------------------: | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| cacheContext | {String} | undefined | Allows you to override the default cache context in order to generate the cache relatively to a path. By default it will use absolute paths |
| cacheKey | {Function(options, request) -> {String}} | undefined | Allows you to override default cache key generator |
| cacheDirectory | {String} | findCacheDir({ name: 'cache-loader' }) or os.tmpdir() | Provide a cache directory where cache items should be stored (used for default read/write implementation) |
| cacheIdentifier | {String} | cache-loader:{version} {process.env.NODE_ENV} | Provide an invalidation identifier which is used to generate the hashes. You can use it for extra dependencies of loaders (used for default read/write implementation) |
| compare | {Function(stats, dep) -> {Boolean}} | undefined | Allows you to override default comparison function between the cached dependency and the one is being read. Return true to use the cached resource |
| precision | {Number} | 0 | Round mtime by this number of milliseconds both for stats and dep before passing those params to the comparing function |
| read | {Function(cacheKey, callback) -> {void}} | undefined | Allows you to override default read cache data from file |
| readOnly | {Boolean} | false | Allows you to override default value and make the cache read only (useful for some environments where you don't want the cache to be updated, only read from it) |
| write | {Function(cacheKey, data, callback) -> {void}} | undefined | Allows you to override default write cache data to file (e.g. Redis, memcached) |

Examples

$3

webpack.config.js

`js
module.exports = {
module: {
rules: [
{
test: /\.js$/,
use: ['cache-loader', 'babel-loader'],
include: path.resolve('src'),
},
],
},
};
`

$3

webpack.config.js

`js
// Or different database client - memcached, mongodb, ...
const redis = require('redis');
const crypto = require('crypto');

// ...
// connect to client
// ...

const BUILD_CACHE_TIMEOUT = 24 * 3600; // 1 day

function digest(str) {
return crypto
.createHash('md5')
.update(str)
.digest('hex');
}

// Generate own cache key
function cacheKey(options, request) {
return build:cache:${digest(request)};
}

// Read data from database and parse them
function read(key, callback) {
client.get(key, (err, result) => {
if (err) {
return callback(err);
}

if (!result) {
return callback(new Error(Key ${key} not found));
}

try {
let data = JSON.parse(result);
callback(null, data);
} catch (e) {
callback(e);
}
});
}

// Write data to database under cacheKey
function write(key, data, callback) {
client.set(key, JSON.stringify(data), 'EX', BUILD_CACHE_TIMEOUT, callback);
}

module.exports = {
module: {
rules: [
{
test: /\.js$/,
use: [
{
loader: 'cache-loader',
options: {
cacheKey,
read,
write,
},
},
'babel-loader',
],
include: path.resolve('src'),
},
],
},
};
``

Contributing

Please take a moment to read our contributing guidelines if you haven't yet done so.

CONTRIBUTING

License

MIT

[npm]: https://img.shields.io/npm/v/cache-loader.svg
[npm-url]: https://npmjs.com/package/cache-loader
[node]: https://img.shields.io/node/v/cache-loader.svg
[node-url]: https://nodejs.org
[deps]: https://david-dm.org/webpack-contrib/cache-loader.svg
[deps-url]: https://david-dm.org/webpack-contrib/cache-loader
[tests]: https://dev.azure.com/webpack-contrib/cache-loader/_apis/build/status/webpack-contrib.cache-loader?branchName=master
[tests-url]: https://dev.azure.com/webpack-contrib/cache-loader/_build/latest?definitionId=4&branchName=master
[cover]: https://codecov.io/gh/webpack-contrib/cache-loader/branch/master/graph/badge.svg
[cover-url]: https://codecov.io/gh/webpack-contrib/cache-loader
[chat]: https://badges.gitter.im/webpack/webpack.svg
[chat-url]: https://gitter.im/webpack/webpack
[size]: https://packagephobia.now.sh/badge?p=cache-loader
[size-url]: https://packagephobia.now.sh/result?p=cache-loader