Chromium 中js Fetch API接口c++代码实现（二）

Chromium 中JavaScript Fetch API接口c++代码实现（一）-CSDN博客

接着上一篇继续介绍调用，上函数堆栈。

1、打开http://192.168.8.1/chfs/shared/test/test02.html

此标签进程ID12484，

2、打开vs附加上此进程ID12484

3、点击页面测试按钮调转到c++代码

F:\code\google\src\third_party\blink\renderer\core\fetch\fetch_manager.cc

ScriptPromise FetchManager::Fetch(ScriptState* script_state,FetchRequestData* request,AbortSignal* signal,ExceptionState& exception_state) {DCHECK(signal);if (signal->aborted()) {exception_state.RethrowV8Exception(signal->reason(script_state).V8Value());return ScriptPromise();}request->SetDestination(network::mojom::RequestDestination::kEmpty);auto* resolver = MakeGarbageCollected<ScriptPromiseResolver>(script_state, exception_state.GetContext());ScriptPromise promise = resolver->Promise();auto* loader = MakeGarbageCollected<Loader>(GetExecutionContext(), this, resolver, request, script_state, signal);loaders_.insert(loader);// TODO(ricea): Reject the Response body with AbortError, not TypeError.loader->Start(exception_state);return promise;
}

可以看到已经进入fetch函数

4、response响应堆栈：

third_party\blink\renderer\platform\loader\fetch\url_loader\background_url_loader.cc

5、third_party\blink\renderer\platform\loader\fetch\resource_loader.h 资源加载响应

\third_party\blink\renderer\platform\loader\fetch\resource_loader.cc

//通知body 响应response.json()函数

  // FrameType never changes during the lifetime of a request.if (auto* observer = fetcher_->GetResourceLoadObserver()) {ResourceRequest request_for_obserber(initial_request);// TODO(yoichio): Have DidReceiveResponse take a ResourceResponseHead, not// ResourceRequest.observer->DidReceiveResponse(resource_->InspectorId(), request_for_obserber, response, resource_,ResourceLoadObserver::ResponseSource::kNotFromMemoryCache);}

6、src\out\Debug\gen\third_party\blink\renderer\bindings\core\v8\v8_response.cc

void JsonOperationCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {RUNTIME_CALL_TIMER_SCOPE_DISABLED_BY_DEFAULT(info.GetIsolate(), "Blink_Response_json");
BLINK_BINDINGS_TRACE_EVENT("Response.json");// Promise returning function: Convert a TypeError to a reject promise.
v8::Isolate* isolate = info.GetIsolate();
v8::Local<v8::Object> v8_receiver = info.This();
const ExceptionContextType exception_context_type = ExceptionContextType::kOperationInvoke;
const char* const class_like_name = "Response";
const char* const property_name = "json";
ExceptionState exception_state(isolate, exception_context_type, class_like_name, property_name);
ExceptionToRejectPromiseScope reject_promise_scope(info, exception_state);
if (!V8Response::HasInstance(isolate, v8_receiver)) {exception_state.ThrowTypeError("Illegal invocation");
return;
}Response* blink_receiver = V8Response::ToWrappableUnsafe(isolate, v8_receiver);
v8::Local<v8::Context> receiver_context = v8_receiver->GetCreationContextChecked();
ScriptState* receiver_script_state = ScriptState::From(receiver_context);
ScriptState* script_state = receiver_script_state;
auto&& return_value = blink_receiver->json(script_state, exception_state);
if (UNLIKELY(exception_state.HadException())) {return;
}
bindings::V8SetReturnValue(info, return_value);
}

7、src\third_party\blink\renderer\core\fetch\body.cc

Response.json 响应

ScriptPromise Body::json(ScriptState* script_state,ExceptionState& exception_state) {auto on_no_body = [script_state](ScriptPromiseResolver* resolver) {resolver->Reject(V8ThrowException::CreateSyntaxError(script_state->GetIsolate(), "Unexpected end of input"));};return LoadAndConvertBody<BodyJsonConsumer>(script_state, &CreateLoaderAsStringWithUTF8Decode, on_no_body,exception_state);
}