webpack/lib/wasm-async/AsyncWasmLoadingRuntimeModule.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support 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 RuntimeGlobals = require("../RuntimeGlobals");
const RuntimeModule = require("../RuntimeModule");
const Template = require("../Template");

class AsyncWasmLoadingRuntimeModule extends RuntimeModule {
	constructor({ generateLoadBinaryCode, supportsStreaming }) {
		super("wasm loading", RuntimeModule.STAGE_NORMAL);
		this.generateLoadBinaryCode = generateLoadBinaryCode;
		this.supportsStreaming = supportsStreaming;
	}

	/**
	 * @returns {string} runtime code
	 */
	generate() {
		const { compilation, chunk } = this;
		const { outputOptions, runtimeTemplate } = compilation;
		const fn = RuntimeGlobals.instantiateWasm;
		const wasmModuleSrcPath = compilation.getPath(
			JSON.stringify(outputOptions.webassemblyModuleFilename),
			{
				hash: `" + ${RuntimeGlobals.getFullHash}() + "`,
				hashWithLength: length =>
					`" + ${RuntimeGlobals.getFullHash}}().slice(0, ${length}) + "`,
				module: {
					id: '" + wasmModuleId + "',
					hash: `" + wasmModuleHash + "`,
					hashWithLength(length) {
						return `" + wasmModuleHash.slice(0, ${length}) + "`;
					}
				},
				runtime: chunk.runtime
			}
		);
		return `${fn} = ${runtimeTemplate.basicFunction(
			"exports, wasmModuleId, wasmModuleHash, importsObj",
			[
				`var req = ${this.generateLoadBinaryCode(wasmModuleSrcPath)};`,
				this.supportsStreaming
					? Template.asString([
							"if (typeof WebAssembly.instantiateStreaming === 'function') {",
							Template.indent([
								"return WebAssembly.instantiateStreaming(req, importsObj)",
								Template.indent([
									`.then(${runtimeTemplate.returningFunction(
										"Object.assign(exports, res.instance.exports)",
										"res"
									)});`
								])
							]),
							"}"
					  ])
					: "// no support for streaming compilation",
				"return req",
				Template.indent([
					`.then(${runtimeTemplate.returningFunction("x.arrayBuffer()", "x")})`,
					`.then(${runtimeTemplate.returningFunction(
						"WebAssembly.instantiate(bytes, importsObj)",
						"bytes"
					)})`,
					`.then(${runtimeTemplate.returningFunction(
						"Object.assign(exports, res.instance.exports)",
						"res"
					)});`
				])
			]
		)};`;
	}
}

module.exports = AsyncWasmLoadingRuntimeModule;