webpack/lib/wasm/WasmMainTemplatePlugin.js

342 lines
10 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const Template = require("../Template");
const WebAssemblyUtils = require("./WebAssemblyUtils");
/** @typedef {import("../Module")} Module */
/** @typedef {import("../MainTemplate")} MainTemplate */
// Get all wasm modules
const getAllWasmModules = chunk => {
const wasmModules = chunk.getAllAsyncChunks();
const array = [];
for (const chunk of wasmModules) {
for (const m of chunk.modulesIterable) {
if (m.type.startsWith("webassembly")) {
array.push(m);
}
}
}
return array;
};
/**
* generates the import object function for a module
* @param {Module} module the module
* @param {boolean} mangle mangle imports
* @returns {string} source code
*/
const generateImportObject = (module, mangle) => {
const waitForInstances = new Map();
const properties = [];
const usedWasmDependencies = WebAssemblyUtils.getUsedDependencies(
module,
mangle
);
for (const usedDep of usedWasmDependencies) {
const dep = usedDep.dependency;
const importedModule = dep.module;
const exportName = dep.name;
const usedName = importedModule && importedModule.isUsed(exportName);
const description = dep.description;
const direct = dep.onlyDirectImport;
const module = usedDep.module;
const name = usedDep.name;
if (direct) {
const instanceVar = `m${waitForInstances.size}`;
waitForInstances.set(instanceVar, importedModule.id);
properties.push({
module,
name,
value: `${instanceVar}[${JSON.stringify(usedName)}]`
});
} else {
const params = description.signature.params.map(
(param, k) => "p" + k + param.valtype
);
const mod = `installedModules[${JSON.stringify(importedModule.id)}]`;
const func = `${mod}.exports[${JSON.stringify(usedName)}]`;
properties.push({
module,
name,
value: Template.asString([
(importedModule.type.startsWith("webassembly")
? `${mod} ? ${func} : `
: "") + `function(${params}) {`,
Template.indent([`return ${func}(${params});`]),
"}"
])
});
}
}
let importObject;
if (mangle) {
importObject = [
"return {",
Template.indent([
properties.map(p => `${JSON.stringify(p.name)}: ${p.value}`).join(",\n")
]),
"};"
];
} else {
const propertiesByModule = new Map();
for (const p of properties) {
let list = propertiesByModule.get(p.module);
if (list === undefined) {
propertiesByModule.set(p.module, (list = []));
}
list.push(p);
}
importObject = [
"return {",
Template.indent([
Array.from(propertiesByModule, ([module, list]) => {
return Template.asString([
`${JSON.stringify(module)}: {`,
Template.indent([
list.map(p => `${JSON.stringify(p.name)}: ${p.value}`).join(",\n")
]),
"}"
]);
}).join(",\n")
]),
"};"
];
}
if (waitForInstances.size === 1) {
const moduleId = Array.from(waitForInstances.values())[0];
const promise = `installedWasmModules[${JSON.stringify(moduleId)}]`;
const variable = Array.from(waitForInstances.keys())[0];
return Template.asString([
`${JSON.stringify(module.id)}: function() {`,
Template.indent([
`return promiseResolve().then(function() { return ${promise}; }).then(function(${variable}) {`,
Template.indent(importObject),
"});"
]),
"},"
]);
} else if (waitForInstances.size > 0) {
const promises = Array.from(
waitForInstances.values(),
id => `installedWasmModules[${JSON.stringify(id)}]`
).join(", ");
const variables = Array.from(
waitForInstances.keys(),
(name, i) => `${name} = array[${i}]`
).join(", ");
return Template.asString([
`${JSON.stringify(module.id)}: function() {`,
Template.indent([
`return promiseResolve().then(function() { return Promise.all([${promises}]); }).then(function(array) {`,
Template.indent([`var ${variables};`, ...importObject]),
"});"
]),
"},"
]);
} else {
return Template.asString([
`${JSON.stringify(module.id)}: function() {`,
Template.indent(importObject),
"},"
]);
}
};
class WasmMainTemplatePlugin {
constructor({ generateLoadBinaryCode, supportsStreaming, mangleImports }) {
this.generateLoadBinaryCode = generateLoadBinaryCode;
this.supportsStreaming = supportsStreaming;
this.mangleImports = mangleImports;
}
/**
* @param {MainTemplate} mainTemplate main template
* @returns {void}
*/
apply(mainTemplate) {
mainTemplate.hooks.localVars.tap(
"WasmMainTemplatePlugin",
(source, chunk) => {
const wasmModules = getAllWasmModules(chunk);
if (wasmModules.length === 0) return source;
const importObjects = wasmModules.map(module => {
return generateImportObject(module, this.mangleImports);
});
return Template.asString([
source,
"",
"// object to store loaded and loading wasm modules",
"var installedWasmModules = {};",
"",
// This function is used to delay reading the installed wasm module promises
// by a microtask. Sorting them doesn't help because there are egdecases where
// sorting is not possible (modules splitted into different chunks).
// So we not even trying and solve this by a microtask delay.
"function promiseResolve() { return Promise.resolve(); }",
"",
"var wasmImportObjects = {",
Template.indent(importObjects),
"};"
]);
}
);
mainTemplate.hooks.requireEnsure.tap(
"WasmMainTemplatePlugin",
(source, chunk, hash) => {
const webassemblyModuleFilename =
mainTemplate.outputOptions.webassemblyModuleFilename;
const chunkModuleMaps = chunk.getChunkModuleMaps(m =>
m.type.startsWith("webassembly")
);
if (Object.keys(chunkModuleMaps.id).length === 0) return source;
const wasmModuleSrcPath = mainTemplate.getAssetPath(
JSON.stringify(webassemblyModuleFilename),
{
hash: `" + ${mainTemplate.renderCurrentHashCode(hash)} + "`,
hashWithLength: length =>
`" + ${mainTemplate.renderCurrentHashCode(hash, length)} + "`,
module: {
id: '" + wasmModuleId + "',
hash: `" + ${JSON.stringify(
chunkModuleMaps.hash
)}[wasmModuleId] + "`,
hashWithLength(length) {
const shortChunkHashMap = Object.create(null);
for (const wasmModuleId of Object.keys(chunkModuleMaps.hash)) {
if (typeof chunkModuleMaps.hash[wasmModuleId] === "string") {
shortChunkHashMap[wasmModuleId] = chunkModuleMaps.hash[
wasmModuleId
].substr(0, length);
}
}
return `" + ${JSON.stringify(
shortChunkHashMap
)}[wasmModuleId] + "`;
}
}
}
);
const createImportObject = content =>
this.mangleImports
? `{ ${JSON.stringify(
WebAssemblyUtils.MANGLED_MODULE
)}: ${content} }`
: content;
return Template.asString([
source,
"",
"// Fetch + compile chunk loading for webassembly",
"",
`var wasmModules = ${JSON.stringify(
chunkModuleMaps.id
)}[chunkId] || [];`,
"",
"wasmModules.forEach(function(wasmModuleId) {",
Template.indent([
"var installedWasmModuleData = installedWasmModules[wasmModuleId];",
"",
'// a Promise means "currently loading" or "already loaded".',
"if(installedWasmModuleData)",
Template.indent(["promises.push(installedWasmModuleData);"]),
"else {",
Template.indent([
`var importObject = wasmImportObjects[wasmModuleId]();`,
`var req = ${this.generateLoadBinaryCode(wasmModuleSrcPath)};`,
"var promise;",
this.supportsStreaming
? Template.asString([
"if(importObject instanceof Promise && typeof WebAssembly.compileStreaming === 'function') {",
Template.indent([
"promise = Promise.all([WebAssembly.compileStreaming(req), importObject]).then(function(items) {",
Template.indent([
`return WebAssembly.instantiate(items[0], ${createImportObject(
"items[1]"
)});`
]),
"});"
]),
"} else if(typeof WebAssembly.instantiateStreaming === 'function') {",
Template.indent([
`promise = WebAssembly.instantiateStreaming(req, ${createImportObject(
"importObject"
)});`
])
])
: Template.asString([
"if(importObject instanceof Promise) {",
Template.indent([
"var bytesPromise = req.then(function(x) { return x.arrayBuffer(); });",
"promise = Promise.all([",
Template.indent([
"bytesPromise.then(function(bytes) { return WebAssembly.compile(bytes); }),",
"importObject"
]),
"]).then(function(items) {",
Template.indent([
`return WebAssembly.instantiate(items[0], ${createImportObject(
"items[1]"
)});`
]),
"});"
])
]),
"} else {",
Template.indent([
"var bytesPromise = req.then(function(x) { return x.arrayBuffer(); });",
"promise = bytesPromise.then(function(bytes) {",
Template.indent([
`return WebAssembly.instantiate(bytes, ${createImportObject(
"importObject"
)});`
]),
"});"
]),
"}",
"promises.push(installedWasmModules[wasmModuleId] = promise.then(function(res) {",
Template.indent([
`return ${mainTemplate.requireFn}.w[wasmModuleId] = (res.instance || res).exports;`
]),
"}));"
]),
"}"
]),
"});"
]);
}
);
mainTemplate.hooks.requireExtensions.tap(
"WasmMainTemplatePlugin",
(source, chunk) => {
if (!chunk.hasModuleInGraph(m => m.type.startsWith("webassembly"))) {
return source;
}
return Template.asString([
source,
"",
"// object with all WebAssembly.instance exports",
`${mainTemplate.requireFn}.w = {};`
]);
}
);
mainTemplate.hooks.hash.tap("WasmMainTemplatePlugin", hash => {
hash.update("WasmMainTemplatePlugin");
hash.update("2");
});
}
}
module.exports = WasmMainTemplatePlugin;