Reporting: Implement uploader.

net/reporting/reporting_uploader.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/reporting/reporting_uploader.h"
+
+#include "base/callback_helpers.h"
+#include "base/memory/ptr_util.h"
+#include "base/metrics/histogram_macros.h"
+#include "net/base/elements_upload_data_stream.h"
+#include "net/base/load_flags.h"
+#include "net/base/upload_bytes_element_reader.h"
+#include "net/http/http_response_headers.h"
+#include "net/url_request/redirect_info.h"
+#include "net/url_request/url_request_context.h"
+
+namespace net {
+
+namespace {
+
+ReportingUploader::Outcome ResponseCodeToOutcome(int response_code) {
+  if (response_code >= 200 && response_code <= 299)
+    return ReportingUploader::SUCCESS;
+  if (response_code == 410)
+    return ReportingUploader::REMOVE_ENDPOINT;
+  return ReportingUploader::FAILURE;
+}
+
+class ReportingUploaderImpl : public ReportingUploader, URLRequest::Delegate {

[shivanisha, 2017/03/28 19:57:14]

Why is this class definition inside the anonymous namespace inside net? Can this
be put directly in net namespace?

[Julia Tuttle, 2017/03/28 20:36:34]

It could, but I consider it an implementation detail, so I wanted to keep it in
the anonymous namespace.

+ public:
+  ReportingUploaderImpl(const URLRequestContext* context) : context_(context) {
+    DCHECK(context_);
+  }
+
+  ~ReportingUploaderImpl() override {
+    for (auto& it : uploads_) {
+      base::ResetAndReturn(&it.second->second).Run(FAILURE);
+      it.second->first->Cancel();
+    }
+    uploads_.clear();
+  }
+
+  void StartUpload(const GURL& url,
+                   const std::string& json,
+                   const Callback& callback) override {
+    std::unique_ptr<URLRequest> request =
+        context_->CreateRequest(url, IDLE, this);
+
+    request->set_method("POST");
+
+    request->SetLoadFlags(LOAD_DISABLE_CACHE | LOAD_DO_NOT_SAVE_COOKIES |
+                          LOAD_DO_NOT_SEND_COOKIES);
+
+    request->SetExtraRequestHeaderByName(HttpRequestHeaders::kContentType,
+                                         kUploadContentType, true);
+
+    std::vector<char> json_data(json.begin(), json.end());
+    std::unique_ptr<UploadElementReader> reader(
+        new UploadOwnedBytesElementReader(&json_data));
+    request->set_upload(
+        ElementsUploadDataStream::CreateWithReader(std::move(reader), 0));
+
+    // This inherently sets mode = "no-cors", but that doesn't matter, because
+    // the origins that are included in the upload don't actually get to see
+    // the response.
+    //
+    // This inherently skips Service Worker, too.

[shivanisha, 2017/03/28 19:57:14]

This question is for my own understanding: what is the significance of the
servive worker related comment here?

[Julia Tuttle, 2017/03/28 20:36:34]

The Reporting spec requires report delivery requests to skip Service Worker.

+    request->Start();
+
+    // Have to grab the unique_ptr* first to ensure request.get() happens
+    // before std::move(request).
+    std::unique_ptr<Upload>* upload = &uploads_[request.get()];
+    *upload = base::MakeUnique<Upload>(std::move(request), callback);
+  }
+
+  // URLRequest::Delegate implementation:

[shivanisha, 2017/03/28 19:57:14]

new line after this comment as it applies to all the below functions.

[Julia Tuttle, 2017/03/28 20:36:34]

Done.

+  void OnReceivedRedirect(URLRequest* request,
+                          const RedirectInfo& redirect_info,
+                          bool* defer_redirect) override {
+    if (!redirect_info.new_url.SchemeIsCryptographic()) {
+      request->Cancel();
+      return;
+    }
+  }
+
+  void OnAuthRequired(URLRequest* request,
+                      AuthChallengeInfo* auth_info) override {
+    request->Cancel();
+  }
+
+  void OnCertificateRequested(URLRequest* request,
+                              SSLCertRequestInfo* cert_request_info) override {
+    request->Cancel();
+  }

[shivanisha, 2017/03/28 19:57:14]

Implementation of URLRequest::Delegate::OnSSLCertificateError?

[Julia Tuttle, 2017/03/28 20:36:34]

Done.

+
+  void OnResponseStarted(URLRequest* request, int net_error) override {
+    // Grab Upload from map, and hold on to it in a local unique_ptr so it's
+    // removed at the end of the method.
+    UploadMap::iterator it = uploads_.find(request);
+    DCHECK(it != uploads_.end());
+    std::unique_ptr<Upload> upload = std::move(it->second);
+    uploads_.erase(it);
+
+    // request->GetResponseCode() should work, but doesn't in the cases above
+    // where the request was canceled, so get the response code by hand.
+    // TODO(juliatuttle): Check if mmenke fixed this yet.
+    HttpResponseHeaders* headers = request->response_headers();
+    int response_code = headers ? headers->response_code() : 0;
+    Outcome outcome = ResponseCodeToOutcome(response_code);
+
+    upload->second.Run(outcome);
+
+    request->Cancel();
+  }
+
+  void OnReadCompleted(URLRequest* request, int bytes_read) override {
+    // Reporting doesn't need anything in the body of the response, so it
+    // doesn't read it, so it should never get OnReadCompleted calls.
+    NOTREACHED();
+  }
+
+ private:
+  using Upload = std::pair<std::unique_ptr<URLRequest>, Callback>;
+  using UploadMap = std::map<const URLRequest*, std::unique_ptr<Upload>>;
+
+  const URLRequestContext* context_;
+  UploadMap uploads_;
+};
+
+}  // namespace
+
+// static
+const char ReportingUploader::kUploadContentType[] = "application/report";
+
+ReportingUploader::~ReportingUploader() {}
+
+// static
+std::unique_ptr<ReportingUploader> ReportingUploader::Create(
+    const URLRequestContext* context) {
+  return base::MakeUnique<ReportingUploaderImpl>(context);
+}
+
+}  // namespace net