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:
npm install --save-dev cache-loader
Add this loader in front of other (expensive) loaders to cache the result on disk.
webpack.config.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
Basic
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.js$/,
use: ['cache-loader', 'babel-loader'],
include: path.resolve('src'),
},
],
},
};
Database Integration
webpack.config.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.