webpack/lib/node/ReadFileCompileAsyncWasmPlugin.js

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.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const { WEBASSEMBLY_MODULE_TYPE_ASYNC } = require("../ModuleTypeConstants");
const RuntimeGlobals = require("../RuntimeGlobals");
const Template = require("../Template");
const AsyncWasmCompileRuntimeModule = require("../wasm-async/AsyncWasmCompileRuntimeModule");
const AsyncWasmLoadingRuntimeModule = require("../wasm-async/AsyncWasmLoadingRuntimeModule");

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

/**
 * Defines the read file compile async wasm plugin options type used by this module.
 * @typedef {object} ReadFileCompileAsyncWasmPluginOptions
 * @property {boolean=} import use import?
 */

const PLUGIN_NAME = "ReadFileCompileAsyncWasmPlugin";

class ReadFileCompileAsyncWasmPlugin {
	/**
	 * Creates an instance of ReadFileCompileAsyncWasmPlugin.
	 * @param {ReadFileCompileAsyncWasmPluginOptions=} options options object
	 */
	constructor({ import: useImport = false } = {}) {
		/** @type {boolean} */
		this._import = useImport;
	}

	/**
	 * Applies the plugin by registering its hooks on the compiler.
	 * @param {Compiler} compiler the compiler instance
	 * @returns {void}
	 */
	apply(compiler) {
		compiler.hooks.thisCompilation.tap(PLUGIN_NAME, (compilation) => {
			const globalWasmLoading = compilation.outputOptions.wasmLoading;
			/**
			 * Checks whether this read file compile async wasm plugin is enabled for chunk.
			 * @param {Chunk} chunk chunk
			 * @returns {boolean} true, if wasm loading is enabled for the chunk
			 */
			const isEnabledForChunk = (chunk) => {
				const options = chunk.getEntryOptions();
				const wasmLoading =
					options && options.wasmLoading !== undefined
						? options.wasmLoading
						: globalWasmLoading;
				return wasmLoading === "async-node";
			};

			/**
			 * @type {(path: string) => string} callback to generate code to load the wasm file
			 */
			const generateLoadBinaryCode = this._import
				? (path) =>
						Template.asString([
							"Promise.all([import('fs'), import('url')]).then(([{ readFile }, { URL }]) => new Promise((resolve, reject) => {",
							Template.indent([
								`readFile(new URL(${path}, ${compilation.outputOptions.importMetaName}.url), (err, buffer) => {`,
								Template.indent([
									"if (err) return reject(err);",
									"",
									"// Fake fetch response",
									"resolve({",
									Template.indent(["arrayBuffer() { return buffer; }"]),
									"});"
								]),
								"});"
							]),
							"}))"
						])
				: (path) =>
						Template.asString([
							"new Promise(function (resolve, reject) {",
							Template.indent([
								"try {",
								Template.indent([
									`var { readFile } = require(${compilation.runtimeTemplate.renderNodePrefixForCoreModule("fs")});`,
									`var { join } = require(${compilation.runtimeTemplate.renderNodePrefixForCoreModule("path")});`,
									"",
									`readFile(join(__dirname, ${path}), function(err, buffer){`,
									Template.indent([
										"if (err) return reject(err);",
										"",
										"// Fake fetch response",
										"resolve({",
										Template.indent(["arrayBuffer() { return buffer; }"]),
										"});"
									]),
									"});"
								]),
								"} catch (err) { reject(err); }"
							]),
							"})"
						]);

			compilation.hooks.runtimeRequirementInTree
				.for(RuntimeGlobals.instantiateWasm)
				.tap(PLUGIN_NAME, (chunk, set, { chunkGraph }) => {
					if (!isEnabledForChunk(chunk)) return;
					if (
						!chunkGraph.hasModuleInGraph(
							chunk,
							(m) => m.type === WEBASSEMBLY_MODULE_TYPE_ASYNC
						)
					) {
						return;
					}
					compilation.addRuntimeModule(
						chunk,
						new AsyncWasmLoadingRuntimeModule({
							generateLoadBinaryCode,
							supportsStreaming: false
						})
					);
				});

			compilation.hooks.runtimeRequirementInTree
				.for(RuntimeGlobals.compileWasm)
				.tap(PLUGIN_NAME, (chunk, set, { chunkGraph }) => {
					if (!isEnabledForChunk(chunk)) return;
					if (
						!chunkGraph.hasModuleInGraph(
							chunk,
							(m) => m.type === WEBASSEMBLY_MODULE_TYPE_ASYNC
						)
					) {
						return;
					}
					compilation.addRuntimeModule(
						chunk,
						new AsyncWasmCompileRuntimeModule({
							generateLoadBinaryCode,
							supportsStreaming: false
						})
					);
				});
		});
	}
}

module.exports = ReadFileCompileAsyncWasmPlugin;