[browser] wasm memory snapshot into browser cache

src/mono/wasm/runtime/assets.ts

@@ -46,35 +46,8 @@ const skipInstantiateByAssetTypes: {
     "dotnetwasm": true,
 };
 
-export function get_preferred_icu_asset(): string | null {
-    if (!runtimeHelpers.config.assets)
-        return null;
-
-    // By setting <WasmIcuDataFileName> user can define what ICU source file they want to load.
-    // There is no need to check application's culture when <WasmIcuDataFileName> is set.
-    // If it was not set, then we have 3 "icu" assets in config and we should choose
-    // only one for loading, the one that matches the application's locale.
-    const icuAssets = runtimeHelpers.config.assets.filter(a => a["behavior"] == "icu");
-    if (icuAssets.length === 1)
-        return icuAssets[0].name;
-
-    // reads the browsers locale / the OS's locale
-    const preferredCulture = ENVIRONMENT_IS_WEB ? navigator.language : Intl.DateTimeFormat().resolvedOptions().locale;
-    const prefix = preferredCulture.split("-")[0];
-    const CJK = "icudt_CJK.dat";
-    const EFIGS = "icudt_EFIGS.dat";
-    const OTHERS = "icudt_no_CJK.dat";
-
-    // not all "fr-*", "it-*", "de-*", "es-*" are in EFIGS, only the one that is mostly used
-    if (prefix == "en" || ["fr", "fr-FR", "it", "it-IT", "de", "de-DE", "es", "es-ES"].includes(preferredCulture))
-        return EFIGS;
-    if (["zh", "ko", "ja"].includes(prefix))
-        return CJK;
-    return OTHERS;
-}
-
-export function shouldLoadIcuAsset(asset: AssetEntryInternal, preferredIcuAsset: string | null): boolean {
-    return !(asset.behavior == "icu" && asset.name != preferredIcuAsset);
+export function shouldLoadIcuAsset(asset: AssetEntryInternal): boolean {
+    return !(asset.behavior == "icu" && asset.name != runtimeHelpers.preferredIcuAsset);
 }
 
 export function resolve_asset_path(behavior: AssetBehaviours) {
@@ -86,7 +59,11 @@ export function resolve_asset_path(behavior: AssetBehaviours) {
     return asset;
 }
 export async function mono_download_assets(): Promise<void> {
-    const preferredIcuAsset = get_preferred_icu_asset();
+    if (runtimeHelpers.memoryIsLoaded) {
+        allAssetsInMemory.promise_control.resolve();
+        return;
+    }
+
     if (runtimeHelpers.diagnosticTracing) console.debug("MONO_WASM: mono_download_assets");
     runtimeHelpers.maxParallelDownloads = runtimeHelpers.config.maxParallelDownloads || runtimeHelpers.maxParallelDownloads;
     runtimeHelpers.enableDownloadRetry = runtimeHelpers.config.enableDownloadRetry || runtimeHelpers.enableDownloadRetry;
@@ -101,10 +78,10 @@ export async function mono_download_assets(): Promise<void> {
             mono_assert(!asset.resolvedUrl || typeof asset.resolvedUrl === "string", "asset resolvedUrl could be string");
             mono_assert(!asset.hash || typeof asset.hash === "string", "asset resolvedUrl could be string");
             mono_assert(!asset.pendingDownload || typeof asset.pendingDownload === "object", "asset pendingDownload could be object");
-            if (!skipInstantiateByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset, preferredIcuAsset)) {
+            if (!skipInstantiateByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset)) {
                 expected_instantiated_assets_count++;
             }
-            if (!skipDownloadsByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset, preferredIcuAsset)) {
+            if (!skipDownloadsByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset)) {
                 expected_downloaded_assets_count++;
                 promises_of_assets.push(start_asset_download(asset));
             }
@@ -132,10 +109,10 @@ export async function mono_download_assets(): Promise<void> {
                     const headersOnly = skipBufferByAssetTypes[asset.behavior];
                     if (!headersOnly) {
                         mono_assert(asset.isOptional, "Expected asset to have the downloaded buffer");
-                        if (!skipDownloadsByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset, preferredIcuAsset)) {
+                        if (!skipDownloadsByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset)) {
                             expected_downloaded_assets_count--;
                         }
-                        if (!skipInstantiateByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset, preferredIcuAsset)) {
+                        if (!skipInstantiateByAssetTypes[asset.behavior] && shouldLoadIcuAsset(asset)) {
                             expected_instantiated_assets_count--;
                         }
                     } else {

src/mono/wasm/runtime/dotnet.d.ts

@@ -18,6 +18,7 @@ interface DotnetHostBuilder {
     withDebugging(level: number): DotnetHostBuilder;
     withMainAssembly(mainAssemblyName: string): DotnetHostBuilder;
     withApplicationArgumentsFromQuery(): DotnetHostBuilder;
+    withMemoryCache(value: boolean): DotnetHostBuilder;
     create(): Promise<RuntimeAPI>;
     run(): Promise<number>;
 }
@@ -132,6 +133,10 @@ type MonoConfig = {
      * initial number of workers to add to the emscripten pthread pool
      */
     pthreadPoolSize?: number;
+    /**
+     * If true, the snapshot of runtime's memory will be stored in the browser and used for faster startup next time. Default is true.
+     */
+    cacheMemory?: boolean;
     /**
      * hash of assets
      */

src/mono/wasm/runtime/icu.ts

@@ -50,3 +50,29 @@ export function mono_wasm_globalization_init(): void {
     }
 }
 
+export function get_preferred_icu_asset(): string | null {
+    if (!runtimeHelpers.config.assets)
+        return null;
+
+    // By setting <WasmIcuDataFileName> user can define what ICU source file they want to load.
+    // There is no need to check application's culture when <WasmIcuDataFileName> is set.
+    // If it was not set, then we have 3 "icu" assets in config and we should choose
+    // only one for loading, the one that matches the application's locale.
+    const icuAssets = runtimeHelpers.config.assets.filter(a => a["behavior"] == "icu");
+    if (icuAssets.length === 1)
+        return icuAssets[0].name;
+
+    // reads the browsers locale / the OS's locale
+    const preferredCulture = ENVIRONMENT_IS_WEB ? navigator.language : Intl.DateTimeFormat().resolvedOptions().locale;
+    const prefix = preferredCulture.split("-")[0];
+    const CJK = "icudt_CJK.dat";
+    const EFIGS = "icudt_EFIGS.dat";
+    const OTHERS = "icudt_no_CJK.dat";
+
+    // not all "fr-*", "it-*", "de-*", "es-*" are in EFIGS, only the one that is mostly used
+    if (prefix == "en" || ["fr", "fr-FR", "it", "it-IT", "de", "de-DE", "es", "es-ES"].includes(preferredCulture))
+        return EFIGS;
+    if (["zh", "ko", "ja"].includes(prefix))
+        return CJK;
+    return OTHERS;
+}

src/mono/wasm/runtime/imports.ts

@@ -10,6 +10,7 @@ import type { EmscriptenModule } from "./types/emscripten";
 
 // these are our public API (except internal)
 export let Module: EmscriptenModule & DotnetModule;
+export let anyModule: any = undefined;
 export let INTERNAL: any;
 export let IMPORTS: any;
 
@@ -29,7 +30,7 @@ export function set_imports_exports(
 ): void {
     INTERNAL = exports.internal;
     IMPORTS = exports.marshaled_imports;
-    Module = exports.module;
+    anyModule = Module = exports.module;
 
     ENVIRONMENT_IS_NODE = imports.isNode;
     ENVIRONMENT_IS_SHELL = imports.isShell;

src/mono/wasm/runtime/managed-exports.ts

@@ -3,14 +3,13 @@
 
 import { GCHandle, MarshalerToCs, MarshalerToJs, MonoMethod, mono_assert } from "./types";
 import cwraps from "./cwraps";
-import { Module, runtimeHelpers, ENVIRONMENT_IS_PTHREAD } from "./imports";
+import { runtimeHelpers, ENVIRONMENT_IS_PTHREAD, anyModule } from "./imports";
 import { alloc_stack_frame, get_arg, get_arg_gc_handle, MarshalerType, set_arg_type, set_gc_handle } from "./marshal";
 import { invoke_method_and_handle_exception } from "./invoke-cs";
 import { marshal_array_to_cs_impl, marshal_exception_to_cs, marshal_intptr_to_cs } from "./marshal-to-cs";
 import { marshal_int32_to_js, marshal_string_to_js, marshal_task_to_js } from "./marshal-to-js";
 
 export function init_managed_exports(): void {
-    const anyModule = Module as any;
     const exports_fqn_asm = "System.Runtime.InteropServices.JavaScript";
     runtimeHelpers.runtime_interop_module = cwraps.mono_wasm_assembly_load(exports_fqn_asm);
     if (!runtimeHelpers.runtime_interop_module)

src/mono/wasm/runtime/marshal.ts

@@ -2,7 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 import { js_owned_gc_handle_symbol, teardown_managed_proxy } from "./gc-handles";
-import { Module, runtimeHelpers } from "./imports";
+import { anyModule, Module, runtimeHelpers } from "./imports";
 import { getF32, getF64, getI16, getI32, getI64Big, getU16, getU32, getU8, setF32, setF64, setI16, setI32, setI64Big, setU16, setU32, setU8 } from "./memory";
 import { mono_wasm_new_external_root } from "./roots";
 import { mono_assert, GCHandle, JSHandle, MonoObject, MonoString, GCHandleNull, JSMarshalerArguments, JSFunctionSignature, JSMarshalerType, JSMarshalerArgument, MarshalerToJs, MarshalerToCs, WasmRoot } from "./types";
@@ -41,7 +41,6 @@ export const JSMarshalerTypeSize = 32;
 export const JSMarshalerSignatureHeaderSize = 4 + 4; // without Exception and Result
 
 export function alloc_stack_frame(size: number): JSMarshalerArguments {
-    const anyModule = Module as any;
     const args = anyModule.stackAlloc(JavaScriptMarshalerArgSize * size);
     mono_assert(args && (<any>args) % 8 == 0, "Arg alignment");
     const exc = get_arg(args, 0);

src/mono/wasm/runtime/polyfills.ts

@@ -3,7 +3,7 @@
 
 import BuildConfiguration from "consts:configuration";
 import MonoWasmThreads from "consts:monoWasmThreads";
-import { ENVIRONMENT_IS_NODE, ENVIRONMENT_IS_SHELL, ENVIRONMENT_IS_WEB, ENVIRONMENT_IS_WORKER, INTERNAL, Module, runtimeHelpers } from "./imports";
+import { anyModule, ENVIRONMENT_IS_NODE, ENVIRONMENT_IS_SHELL, ENVIRONMENT_IS_WEB, ENVIRONMENT_IS_WORKER, INTERNAL, Module, runtimeHelpers } from "./imports";
 import { afterUpdateGlobalBufferAndViews } from "./memory";
 import { replaceEmscriptenPThreadLibrary } from "./pthreads/shared/emscripten-replacements";
 import { DotnetModuleConfigImports, EarlyReplacements } from "./types";
@@ -13,7 +13,6 @@ let node_fs: any | undefined = undefined;
 let node_url: any | undefined = undefined;
 
 export function init_polyfills(replacements: EarlyReplacements): void {
-    const anyModule = Module as any;
 
     // performance.now() is used by emscripten and doesn't work in JSC
     if (typeof globalThis.performance === "undefined") {
@@ -177,7 +176,7 @@ export function init_polyfills(replacements: EarlyReplacements): void {
 
     // memory
     const originalUpdateGlobalBufferAndViews = replacements.updateGlobalBufferAndViews;
-    replacements.updateGlobalBufferAndViews = (buffer: ArrayBufferLike) => {
+    runtimeHelpers.updateGlobalBufferAndViews = replacements.updateGlobalBufferAndViews = (buffer: ArrayBufferLike) => {
         originalUpdateGlobalBufferAndViews(buffer);
         afterUpdateGlobalBufferAndViews(buffer);
     };

src/mono/wasm/runtime/run-outer.ts

@@ -18,6 +18,7 @@ export interface DotnetHostBuilder {
     withDebugging(level: number): DotnetHostBuilder
     withMainAssembly(mainAssemblyName: string): DotnetHostBuilder
     withApplicationArgumentsFromQuery(): DotnetHostBuilder
+    withMemoryCache(value: boolean): DotnetHostBuilder
     create(): Promise<RuntimeAPI>
     run(): Promise<number>
 }
@@ -137,6 +138,19 @@ class HostBuilder implements DotnetHostBuilder {
         }
     }
 
+    withMemoryCache(value: boolean): DotnetHostBuilder {
+        try {
+            const configInternal: MonoConfigInternal = {
+                cacheMemory: value
+            };
+            Object.assign(this.moduleConfig.config!, configInternal);
+            return this;
+        } catch (err) {
+            mono_exit(1, err);
+            throw err;
+        }
+    }
+
     withConfig(config: MonoConfig): DotnetHostBuilder {
         try {
             const providedConfig = { ...config };