[blink] Enable ModuleScript streaming compilation

- Bail out in ScriptStreamer::TryStartStreamingTask if the response
  is not a JavaScript mime type (for CSS and JSON modules)
- Only initiate script streaming from the main thread (for now this
  prevents streaming compilation for workers and worklets)
- Fix trace event ending for streaming compiled module scripts
- Add WPT test with a large CSS module that would previously trigger
  script streaming

Bug: 1061857
Change-Id: I5100e4c12aa3504ea4132b344f7910041270318a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2595299
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#839447}

third_party/blink/renderer/bindings/core/v8/script_streamer.cc

@@ -24,6 +24,7 @@
 #include "third_party/blink/renderer/platform/loader/fetch/cached_metadata.h"
 #include "third_party/blink/renderer/platform/loader/fetch/resource.h"
 #include "third_party/blink/renderer/platform/loader/fetch/response_body_loader.h"
+#include "third_party/blink/renderer/platform/network/mime/mime_type_registry.h"
 #include "third_party/blink/renderer/platform/scheduler/public/post_cross_thread_task.h"
 #include "third_party/blink/renderer/platform/scheduler/public/thread_scheduler.h"
 #include "third_party/blink/renderer/platform/scheduler/public/worker_pool.h"
@@ -524,6 +525,16 @@ bool ScriptStreamer::TryStartStreamingTask() {
   if (!CanStartStreaming())
     return false;
 
+  // Skip non-JS modules based on the mime-type.
+  // TODO(crbug/1132413),TODO(crbug/1061857): Disable streaming for non-JS
+  // based the specific import statements.
+  if (script_resource_->GetScriptType() == mojom::blink::ScriptType::kModule &&
+      !MIMETypeRegistry::IsSupportedJavaScriptMIMEType(
+          script_resource_->GetResponse().HttpContentType())) {
+    SuppressStreaming(NotStreamingReason::kNonJavascriptModule);
+    return false;
+  }
+
   // Even if the first data chunk is small, the script can still be big enough -
   // wait until the next data chunk comes before deciding whether to start the
   // streaming.

third_party/blink/renderer/bindings/core/v8/script_streamer.h

@@ -60,6 +60,7 @@ class CORE_EXPORT ScriptStreamer final
     kModuleScript,
     kNoDataPipe,
     kLoadingCancelled,
+    kNonJavascriptModule,
     kDisabledByFeatureList,
 
     // Pseudo values that should never be seen in reported metrics

third_party/blink/renderer/bindings/core/v8/v8_script_runner.cc

@@ -272,58 +272,58 @@ v8::MaybeLocal<v8::Module> V8ScriptRunner::CompileModule(
                           referrer_info.ToV8HostDefinedOptions(isolate));
 
   v8::Local<v8::String> code = V8String(isolate, params.GetSourceText());
-  if (ScriptStreamer* streamer = params.GetScriptStreamer()) {
+  inspector_compile_script_event::V8CacheResult cache_result;
+  v8::MaybeLocal<v8::Module> script;
+  ScriptStreamer* streamer = params.GetScriptStreamer();
+  if (streamer) {
     // Final compile call for a streamed compilation.
     // Streaming compilation may involve use of code cache.
     // TODO(leszeks): Add compile timer to streaming compilation.
     DCHECK(streamer->IsFinished());
     DCHECK(!streamer->IsStreamingSuppressed());
-    return v8::ScriptCompiler::CompileModule(isolate->GetCurrentContext(),
-                                             streamer->Source(), code, origin);
-  }
-
-  v8::MaybeLocal<v8::Module> script;
-  inspector_compile_script_event::V8CacheResult cache_result;
-
-  switch (compile_options) {
-    case v8::ScriptCompiler::kNoCompileOptions:
-    case v8::ScriptCompiler::kEagerCompile: {
-      v8::ScriptCompiler::Source source(code, origin);
-      script = v8::ScriptCompiler::CompileModule(
-          isolate, &source, compile_options, no_cache_reason);
-      break;
-    }
+    script = v8::ScriptCompiler::CompileModule(
+        isolate->GetCurrentContext(), streamer->Source(), code, origin);
+  } else {
+    switch (compile_options) {
+      case v8::ScriptCompiler::kNoCompileOptions:
+      case v8::ScriptCompiler::kEagerCompile: {
+        v8::ScriptCompiler::Source source(code, origin);
+        script = v8::ScriptCompiler::CompileModule(
+            isolate, &source, compile_options, no_cache_reason);
+        break;
+      }
 
-    case v8::ScriptCompiler::kConsumeCodeCache: {
-      // Compile a script, and consume a V8 cache that was generated previously.
-      SingleCachedMetadataHandler* cache_handler = params.CacheHandler();
-      DCHECK(cache_handler);
-      v8::ScriptCompiler::CachedData* cached_data =
-          V8CodeCache::CreateCachedData(cache_handler);
-      v8::ScriptCompiler::Source source(code, origin, cached_data);
-      script = v8::ScriptCompiler::CompileModule(
-          isolate, &source, compile_options, no_cache_reason);
-      if (cached_data->rejected) {
-        cache_handler->ClearCachedMetadata(
-            CachedMetadataHandler::kClearPersistentStorage);
-      } else if (InDiscardExperiment()) {
-        // Experimentally free code cache from memory after first use. See
-        // http://crbug.com/1045052.
-        cache_handler->ClearCachedMetadata(
-            CachedMetadataHandler::kDiscardLocally);
+      case v8::ScriptCompiler::kConsumeCodeCache: {
+        // Compile a script, and consume a V8 cache that was generated
+        // previously.
+        SingleCachedMetadataHandler* cache_handler = params.CacheHandler();
+        DCHECK(cache_handler);
+        v8::ScriptCompiler::CachedData* cached_data =
+            V8CodeCache::CreateCachedData(cache_handler);
+        v8::ScriptCompiler::Source source(code, origin, cached_data);
+        script = v8::ScriptCompiler::CompileModule(
+            isolate, &source, compile_options, no_cache_reason);
+        if (cached_data->rejected) {
+          cache_handler->ClearCachedMetadata(
+              CachedMetadataHandler::kClearPersistentStorage);
+        } else if (InDiscardExperiment()) {
+          // Experimentally free code cache from memory after first use. See
+          // http://crbug.com/1045052.
+          cache_handler->ClearCachedMetadata(
+              CachedMetadataHandler::kDiscardLocally);
+        }
+        cache_result.consume_result = base::make_optional(
+            inspector_compile_script_event::V8CacheResult::ConsumeResult(
+                compile_options, cached_data->length, cached_data->rejected));
+        break;
       }
-      cache_result.consume_result = base::make_optional(
-          inspector_compile_script_event::V8CacheResult::ConsumeResult(
-              compile_options, cached_data->length, cached_data->rejected));
-      break;
     }
   }
 
   TRACE_EVENT_END1(kTraceEventCategoryGroup, "v8.compileModule", "data",
                    inspector_compile_script_event::Data(
-                       file_name, start_position, cache_result, false,
-                       ScriptStreamer::NotStreamingReason::kModuleScript));
-
+                       file_name, start_position, cache_result, streamer,
+                       params.NotStreamingReason()));
   return script;
 }
 

third_party/blink/renderer/core/inspector/inspector_trace_events.cc

@@ -433,6 +433,8 @@ const char* NotStreamedReasonString(ScriptStreamer::NotStreamingReason reason) {
       return "no data pipe received";
     case ScriptStreamer::NotStreamingReason::kDisabledByFeatureList:
       return "streaming disabled from the feature list";
+    case ScriptStreamer::NotStreamingReason::kNonJavascriptModule:
+      return "not a javascript module";
     case ScriptStreamer::NotStreamingReason::kLoadingCancelled:
       return "loading was cancelled";
     case ScriptStreamer::NotStreamingReason::kDidntTryToStartStreaming:

third_party/blink/renderer/core/loader/modulescript/document_module_script_fetcher.cc

@@ -28,9 +28,13 @@ void DocumentModuleScriptFetcher::Fetch(
   DCHECK(fetch_client_settings_object_fetcher);
   DCHECK(!client_);
   client_ = client;
-  // TODO(crbug.com/1061857): Enable streaming.
+  // Streaming can currently only be triggered from the main thread. This
+  // currently happens only for dynamic imports in worker modules.
+  ScriptResource::StreamingAllowed streaming_allowed =
+                        IsMainThread() ? ScriptResource::kAllowStreaming
+                                       : ScriptResource::kNoStreaming;
   ScriptResource::Fetch(fetch_params, fetch_client_settings_object_fetcher,
-                        this, ScriptResource::kNoStreaming);
+                        this, streaming_allowed);
 }
 
 void DocumentModuleScriptFetcher::NotifyFinished(Resource* resource) {

third_party/blink/renderer/core/loader/modulescript/module_script_creation_params.h

@@ -110,6 +110,9 @@ class ModuleScriptCreationParams {
   }
 
   ScriptStreamer* GetScriptStreamer() const { return script_streamer_; }
+  ScriptStreamer::NotStreamingReason NotStreamingReason() const {
+    return not_streaming_reason_;
+  }
 
  private:
   // Creates an isolated copy.

third_party/blink/web_tests/external/wpt/html/semantics/scripting-1/the-script-element/css-module/import-css-module-basic.html

@@ -18,6 +18,20 @@
             document.body.appendChild(iframe);
         }, "A CSS Module should load");
 
+        async_test(function (test) {
+            // This tests potential streaming compilation of modules in
+            // Chromium that is triggered only for large (32>KiB) files in older
+            // versions.
+            const iframe = document.createElement("iframe");
+            iframe.src = "resources/css-module-basic-large-iframe.html";
+            iframe.onload = test.step_func_done(function () {
+                assert_equals(getComputedStyle(iframe.contentDocument.querySelector('#test'))
+                    .backgroundColor, "rgb(255, 0, 0)",
+                    "CSS module import should succeed");
+            });
+            document.body.appendChild(iframe);
+        }, "A large CSS Module should load");
+
         async_test(function (test) {
             const iframe = document.createElement("iframe");
             iframe.src = "resources/css-module-at-import-iframe.html";
@@ -41,4 +55,4 @@
             document.body.appendChild(iframe);
         }, "Malformed CSS should not load");
     </script>
-</body>
+</body>
\ No newline at end of file

third_party/blink/web_tests/external/wpt/html/semantics/scripting-1/the-script-element/css-module/resources/css-module-basic-large-iframe.html

+<!DOCTYPE html>
+<body>
+    <script>
+        window.onerror = function (errorMsg, url, lineNumber, column, errorObj)
+        {
+            document.load_error = errorObj.name;
+            return true;
+        };
+    </script>
+    <script type="module">
+        import v from "./basic-large.css";
+        document.adoptedStyleSheets = [v];
+    </script>
+
+    <div id="test">
+        I am a test div.
+    </div>
+</body>

third_party/blink/web_tests/http/tests/devtools/isolated-code-cache/same-origin-module-test-expected.txt

@@ -6,7 +6,7 @@ v8.compileModule Properties:
     data : {
         columnNumber : 1
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "script too small"
         streamed : <boolean>
         url : .../devtools/resources/v8-cache-script.cgi
     }
@@ -20,7 +20,7 @@ v8.compileModule Properties:
     data : {
         columnNumber : 1
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "already used streamed data"
         streamed : <boolean>
         url : .../devtools/resources/v8-cache-script.cgi
     }
@@ -52,7 +52,7 @@ v8.compileModule Properties:
         columnNumber : 1
         consumedCacheSize : <number>
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "already used streamed data"
         streamed : <boolean>
         url : .../devtools/resources/v8-cache-script.cgi
     }
@@ -66,7 +66,7 @@ v8.compileModule Properties:
     data : {
         columnNumber : 1
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "script too small"
         streamed : <boolean>
         url : .../devtools/resources/v8-cache-script.cgi
     }
@@ -83,7 +83,7 @@ v8.compileModule Properties:
         columnNumber : 1
         consumedCacheSize : <number>
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "already used streamed data"
         streamed : <boolean>
         url : .../devtools/resources/v8-cache-script.cgi
     }
@@ -100,7 +100,7 @@ v8.compileModule Properties:
         columnNumber : 1
         consumedCacheSize : <number>
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "script too small"
         streamed : <boolean>
         url : .../devtools/resources/v8-cache-script.cgi
     }

third_party/blink/web_tests/http/tests/devtools/tracing/timeline-script-module-expected.txt

@@ -5,7 +5,7 @@ v8.compileModule Properties:
     data : {
         columnNumber : 1
         lineNumber : 1
-        notStreamedReason : "module script"
+        notStreamedReason : "already disabled streaming"
         streamed : <boolean>
         url : .../devtools/resources/inspected-page.html
     }