package.lib.cache.IdleFileCachePlugin.js Maven / Gradle / Ivy

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Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.
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/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const Cache = require("../Cache");
const ProgressPlugin = require("../ProgressPlugin");

/** @typedef {import("../Compiler")} Compiler */
/** @typedef {import("./PackFileCacheStrategy")} PackFileCacheStrategy */

const BUILD_DEPENDENCIES_KEY = Symbol();

class IdleFileCachePlugin {
	/**
	 * @param {PackFileCacheStrategy} strategy cache strategy
	 * @param {number} idleTimeout timeout
	 * @param {number} idleTimeoutForInitialStore initial timeout
	 * @param {number} idleTimeoutAfterLargeChanges timeout after changes
	 */
	constructor(
		strategy,
		idleTimeout,
		idleTimeoutForInitialStore,
		idleTimeoutAfterLargeChanges
	) {
		this.strategy = strategy;
		this.idleTimeout = idleTimeout;
		this.idleTimeoutForInitialStore = idleTimeoutForInitialStore;
		this.idleTimeoutAfterLargeChanges = idleTimeoutAfterLargeChanges;
	}

	/**
	 * Apply the plugin
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		let strategy = this.strategy;
		const idleTimeout = this.idleTimeout;
		const idleTimeoutForInitialStore = Math.min(
			idleTimeout,
			this.idleTimeoutForInitialStore
		);
		const idleTimeoutAfterLargeChanges = this.idleTimeoutAfterLargeChanges;
		const resolvedPromise = Promise.resolve();

		let timeSpendInBuild = 0;
		let timeSpendInStore = 0;
		let avgTimeSpendInStore = 0;

		/** @type {Map Promise>} */
		const pendingIdleTasks = new Map();

		compiler.cache.hooks.store.tap(
			{ name: "IdleFileCachePlugin", stage: Cache.STAGE_DISK },
			(identifier, etag, data) => {
				pendingIdleTasks.set(identifier, () =>
					strategy.store(identifier, etag, data)
				);
			}
		);

		compiler.cache.hooks.get.tapPromise(
			{ name: "IdleFileCachePlugin", stage: Cache.STAGE_DISK },
			(identifier, etag, gotHandlers) => {
				const restore = () =>
					strategy.restore(identifier, etag).then(cacheEntry => {
						if (cacheEntry === undefined) {
							gotHandlers.push((result, callback) => {
								if (result !== undefined) {
									pendingIdleTasks.set(identifier, () =>
										strategy.store(identifier, etag, result)
									);
								}
								callback();
							});
						} else {
							return cacheEntry;
						}
					});
				const pendingTask = pendingIdleTasks.get(identifier);
				if (pendingTask !== undefined) {
					pendingIdleTasks.delete(identifier);
					return pendingTask().then(restore);
				}
				return restore();
			}
		);

		compiler.cache.hooks.storeBuildDependencies.tap(
			{ name: "IdleFileCachePlugin", stage: Cache.STAGE_DISK },
			dependencies => {
				pendingIdleTasks.set(BUILD_DEPENDENCIES_KEY, () =>
					Promise.resolve().then(() =>
						strategy.storeBuildDependencies(dependencies)
					)
				);
			}
		);

		compiler.cache.hooks.shutdown.tapPromise(
			{ name: "IdleFileCachePlugin", stage: Cache.STAGE_DISK },
			() => {
				if (idleTimer) {
					clearTimeout(idleTimer);
					idleTimer = undefined;
				}
				isIdle = false;
				const reportProgress = ProgressPlugin.getReporter(compiler);
				const jobs = Array.from(pendingIdleTasks.values());
				if (reportProgress) reportProgress(0, "process pending cache items");
				const promises = jobs.map(fn => fn());
				pendingIdleTasks.clear();
				promises.push(currentIdlePromise);
				const promise = Promise.all(promises);
				currentIdlePromise = promise.then(() => strategy.afterAllStored());
				if (reportProgress) {
					currentIdlePromise = currentIdlePromise.then(() => {
						reportProgress(1, `stored`);
					});
				}
				return currentIdlePromise.then(() => {
					// Reset strategy
					if (strategy.clear) strategy.clear();
				});
			}
		);

		/** @type {Promise} */
		let currentIdlePromise = resolvedPromise;
		let isIdle = false;
		let isInitialStore = true;
		const processIdleTasks = () => {
			if (isIdle) {
				const startTime = Date.now();
				if (pendingIdleTasks.size > 0) {
					const promises = [currentIdlePromise];
					const maxTime = startTime + 100;
					let maxCount = 100;
					for (const [filename, factory] of pendingIdleTasks) {
						pendingIdleTasks.delete(filename);
						promises.push(factory());
						if (maxCount-- <= 0 || Date.now() > maxTime) break;
					}
					currentIdlePromise = Promise.all(promises);
					currentIdlePromise.then(() => {
						timeSpendInStore += Date.now() - startTime;
						// Allow to exit the process between
						idleTimer = setTimeout(processIdleTasks, 0);
						idleTimer.unref();
					});
					return;
				}
				currentIdlePromise = currentIdlePromise
					.then(async () => {
						await strategy.afterAllStored();
						timeSpendInStore += Date.now() - startTime;
						avgTimeSpendInStore =
							Math.max(avgTimeSpendInStore, timeSpendInStore) * 0.9 +
							timeSpendInStore * 0.1;
						timeSpendInStore = 0;
						timeSpendInBuild = 0;
					})
					.catch(err => {
						const logger = compiler.getInfrastructureLogger(
							"IdleFileCachePlugin"
						);
						logger.warn(`Background tasks during idle failed: ${err.message}`);
						logger.debug(err.stack);
					});
				isInitialStore = false;
			}
		};
		/** @type {ReturnType | undefined} */
		let idleTimer = undefined;
		compiler.cache.hooks.beginIdle.tap(
			{ name: "IdleFileCachePlugin", stage: Cache.STAGE_DISK },
			() => {
				const isLargeChange = timeSpendInBuild > avgTimeSpendInStore * 2;
				if (isInitialStore && idleTimeoutForInitialStore < idleTimeout) {
					compiler
						.getInfrastructureLogger("IdleFileCachePlugin")
						.log(
							`Initial cache was generated and cache will be persisted in ${
								idleTimeoutForInitialStore / 1000
							}s.`
						);
				} else if (
					isLargeChange &&
					idleTimeoutAfterLargeChanges < idleTimeout
				) {
					compiler
						.getInfrastructureLogger("IdleFileCachePlugin")
						.log(
							`Spend ${Math.round(timeSpendInBuild) / 1000}s in build and ${
								Math.round(avgTimeSpendInStore) / 1000
							}s in average in cache store. This is considered as large change and cache will be persisted in ${
								idleTimeoutAfterLargeChanges / 1000
							}s.`
						);
				}
				idleTimer = setTimeout(
					() => {
						idleTimer = undefined;
						isIdle = true;
						resolvedPromise.then(processIdleTasks);
					},
					Math.min(
						isInitialStore ? idleTimeoutForInitialStore : Infinity,
						isLargeChange ? idleTimeoutAfterLargeChanges : Infinity,
						idleTimeout
					)
				);
				idleTimer.unref();
			}
		);
		compiler.cache.hooks.endIdle.tap(
			{ name: "IdleFileCachePlugin", stage: Cache.STAGE_DISK },
			() => {
				if (idleTimer) {
					clearTimeout(idleTimer);
					idleTimer = undefined;
				}
				isIdle = false;
			}
		);
		compiler.hooks.done.tap("IdleFileCachePlugin", stats => {
			// 10% build overhead is ignored, as it's not cacheable
			timeSpendInBuild *= 0.9;
			timeSpendInBuild +=
				/** @type {number} */ (stats.endTime) -
				/** @type {number} */ (stats.startTime);
		});
	}
}

module.exports = IdleFileCachePlugin;