Cross Device Promo - Main Eligibility Flow

components/signin/core/browser/device_activity_fetcher.cc

+// Copyright 2015 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 "components/signin/core/browser/device_activity_fetcher.h"
+
+#include "base/strings/stringprintf.h"
+#include "components/signin/core/browser/signin_client.h"
+#include "google_apis/gaia/gaia_auth_fetcher.h"
+#include "google_apis/gaia/gaia_constants.h"
+#include "google_apis/gaia/gaia_urls.h"
+#include "google_apis/gaia/google_service_auth_error.h"
+#include "net/http/http_status_code.h"
+#include "net/url_request/url_fetcher.h"
+
+namespace {
+
+const char* kSyncListDevicesScope =
+    "https://www.googleapis.com/auth/chromesynclistdevices";
+const char* kChromeDomain = "http://www.chrome.com";
+const char* kListDevicesEndpoint = "http://127.0.0.1";
+// Template for optional authorization header when using an OAuth access token.
+const char kAuthorizationHeader[] = "Authorization: Bearer %s";
+
+// In case of an error while fetching using the GaiaAuthFetcher, retry with
+// exponential backoff. Try up to 9 times within 10 minutes.
+const net::BackoffEntry::Policy kBackoffPolicy = {
+  // Number of initial errors (in sequence) to ignore before applying
+  // exponential back-off rules.
+  0,
+  // Initial delay for exponential backoff in ms.
+  1000,
+  // Factor by which the waiting time will be multiplied.
+  2,
+  // Fuzzing percentage. ex: 10% will spread requests randomly
+  // between 90%-100% of the calculated time.
+  0.1, // 20%

[anthonyvd, 2015/05/14 18:24:20]

Seems like the comment is off here. Should be 10%

[Mike Lerman, 2015/05/14 20:25:33]

Done.

+  // Maximum amount of time we are willing to delay our request in ms.
+  1000 * 15, // 15 minutes.

[anthonyvd, 2015/05/14 18:24:20]

That seems like 15 seconds, not 15 minutes.

[Mike Lerman, 2015/05/14 20:25:33]

*60. Done.

+  // Time to keep an entry from being discarded even when it
+  // has no significant state, -1 to never discard.
+  -1,
+  // Don't use initial delay unless the last request was an error.
+  false,
+};
+
+const int kMaxFetcherRetries = 9;
+
+bool IsTransientError(const GoogleServiceAuthError& error) {
+  return error.state() == GoogleServiceAuthError::CONNECTION_FAILED ||

[anthonyvd, 2015/05/14 18:24:20]

There's a GoogleServiceAuthError::IsTransientError method that could maybe
replace this, although it doesn't include REQUEST_CANCELED.

I'd still prefer return error.IsTransientError() || error.state() ==
GoogleServiceAuthError::REQUEST_CANCELED; if we treat REQUEST_CANCELED as
transient.

[Mike Lerman, 2015/05/14 20:25:33]

Didn't know about it! Thanks. Done.

+      error.state() == GoogleServiceAuthError::SERVICE_UNAVAILABLE ||
+      error.state() == GoogleServiceAuthError::REQUEST_CANCELED;
+}
+
+}  // namespace
+
+DeviceActivityFetcher::DeviceActivityFetcher(
+    SigninClient* signin_client,
+    DeviceActivityFetcher::Observer* observer)
+    : fetcher_backoff_(&kBackoffPolicy),
+      fetcher_retries_(0),
+      signin_client_(signin_client),
+      observer_(observer) {}
+
+DeviceActivityFetcher::~DeviceActivityFetcher() {
+}
+
+void DeviceActivityFetcher::Start() {
+  fetcher_retries_ = 0;
+  login_hint_ = std::string();
+  StartFetchingListIdpSessions();
+}
+
+void DeviceActivityFetcher::StartFetchingListIdpSessions() {
+  gaia_auth_fetcher_.reset(new GaiaAuthFetcher(this,
+    GaiaConstants::kChromeSource, signin_client_->GetURLRequestContext()));
+  gaia_auth_fetcher_->StartListIDPSessions(kSyncListDevicesScope,
+                                           kChromeDomain);
+}
+
+void DeviceActivityFetcher::StartFetchingGetTokenResponse() {
+  gaia_auth_fetcher_.reset(new GaiaAuthFetcher(this,
+    GaiaConstants::kChromeSource, signin_client_->GetURLRequestContext()));
+  gaia_auth_fetcher_->StartGetTokenResponse(kSyncListDevicesScope,
+                                            kChromeDomain,
+                                            login_hint_);
+}
+
+void DeviceActivityFetcher::StartFetchingListDevices() {
+  // Call the Sync Endpoint.
+  url_fetcher_ = net::URLFetcher::Create(GURL(kListDevicesEndpoint),
+                                         net::URLFetcher::GET,
+                                         this);
+  url_fetcher_->SetRequestContext(signin_client_->GetURLRequestContext());
+  if (!access_token_.empty()) {
+    url_fetcher_->SetExtraRequestHeaders(
+        base::StringPrintf(kAuthorizationHeader, access_token_.c_str()));
+  }
+  url_fetcher_->Start();
+}
+
+void DeviceActivityFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
+  // TODO(mlerman): Uncomment the code below once we have a working proto.
+
+  // std::string response_string;
+  // ListDevices list_devices;
+
+  // if (!source->GetStatus().is_success()) {
+  //   VLOG(1) << "Failed to fetch listdevices response. Retrying.";
+  //   if (++fetcher_retries_ < kMaxFetcherRetries) {
+  //     fetcher_backoff_.InformOfRequest(false);
+  //     fetcher_timer_.Start(
+  //         FROM_HERE, fetcher_backoff_.GetTimeUntilRelease(), this,
+  //         &DeviceActivityFetcher::StartFetchingListDevices);
+  //     return;
+  //   } else {
+  //     observer_->OnFetchDeviceActivityFailure();
+  //   }
+  // }
+
+  // net::HttpStatusCode response_status = static_cast<net::HttpStatusCode>(
+  //     source->GetResponseCode());
+  // if (response_status == net::HTTP_BAD_REQUEST ||
+  //     response_status == net::HTTP_UNAUTHORIZED) {
+  //   // BAD_REQUEST indicates that the request was malformed.
+  //   // UNAUTHORIZED indicates that security token didn't match the id.
+  //   VLOG(1) << "No point retrying the checkin with status: "
+  //              << response_status << ". Checkin failed.";
+  //   CheckinRequestStatus status = response_status == net::HTTP_BAD_REQUEST ?
+  //       HTTP_BAD_REQUEST : HTTP_UNAUTHORIZED;
+  //   RecordCheckinStatusAndReportUMA(status, recorder_, false);
+  //   callback_.Run(response_proto);
+  //   return;
+  // }
+
+  // if (response_status != net::HTTP_OK ||
+  //     !source->GetResponseAsString(&response_string) ||
+  //     !list_devices.ParseFromString(response_string)) {
+  //   LOG(ERROR) << "Failed to get list devices response. HTTP Status: "
+  //              << response_status;
+  //   if (++fetcher_retries_ < kMaxFetcherRetries) {
+  //     fetcher_backoff_.InformOfRequest(false);
+  //     fetcher_timer_.Start(
+  //         FROM_HERE, fetcher_backoff_.GetTimeUntilRelease(), this,
+  //         &DeviceActivityFetcher::StartFetchingListDevices);
+  //     return;
+  //   } else {
+  //     observer_->OnFetchDeviceActivityFailure();

[anthonyvd, 2015/05/14 18:24:20]

It seems like the observers could be notified twice. Let's say
source->GetStatus().is_success() at line 108 returns false, response_status
would be net::RESPONSE_CODE_INVALID so if the max retry count was reached, both
the OnFetchDeviceActivityFailure calls would be made.

[Mike Lerman, 2015/05/14 20:25:33]

True. Added some returns.

+  //   }
+  // }
+
+  std::vector<DeviceActivity> devices;
+  // TODO(mlerman): Fill |devices| from the proto in |source|.
+
+  observer_->OnFetchDeviceActivitySuccess(devices);
+}
+
+
+void DeviceActivityFetcher::OnListIdpSessionsSuccess(
+    const std::string& login_hint) {
+  fetcher_backoff_.InformOfRequest(true);
+  login_hint_ = login_hint;
+  access_token_ = std::string();
+  StartFetchingGetTokenResponse();
+}
+
+void DeviceActivityFetcher::OnListIdpSessionsError(
+    const GoogleServiceAuthError& error) {
+  if (++fetcher_retries_ < kMaxFetcherRetries &&

[anthonyvd, 2015/05/14 18:24:20]

Is it expected that fetcher_retries_ represents the retries across all fetches?
I was expecting at most kMaxFetcherRetries retries for each fetch operations but
the way the code is at the moment the count is never reset when a fetch
succeeds.

[Mike Lerman, 2015/05/14 20:25:33]

It is supposed to be across all fetches. The fetches happen one after the other,
so logically are a single operation. That's why we have a single backoff
instance and we InformOfRequest() on the same instance for all fetches. The
count is reset when the whole process kicks off in Start().

[anthonyvd, 2015/05/19 15:07:37]

Makes total sense, thanks for the info :)

+      IsTransientError(error)) {
+    fetcher_backoff_.InformOfRequest(false);
+    fetcher_timer_.Start(
+        FROM_HERE, fetcher_backoff_.GetTimeUntilRelease(), this,
+        &DeviceActivityFetcher::StartFetchingListIdpSessions);
+    return;
+  }
+  observer_->OnFetchDeviceActivityFailure();
+}
+
+void DeviceActivityFetcher::OnGetTokenResponseSuccess(
+    const ClientOAuthResult& result) {
+  fetcher_backoff_.InformOfRequest(true);
+  access_token_ = result.access_token;
+  StartFetchingListDevices();
+}
+
+void DeviceActivityFetcher::OnGetTokenResponseError(
+    const GoogleServiceAuthError& error) {
+  if (++fetcher_retries_ < kMaxFetcherRetries &&
+      IsTransientError(error)) {

[anthonyvd, 2015/05/14 18:24:20]

nit: I think this condition fits on a single line.

[Mike Lerman, 2015/05/14 20:25:33]

I think you're right.

+    fetcher_backoff_.InformOfRequest(false);
+    fetcher_timer_.Start(
+        FROM_HERE, fetcher_backoff_.GetTimeUntilRelease(), this,
+        &DeviceActivityFetcher::StartFetchingGetTokenResponse);
+    return;
+  }
+  observer_->OnFetchDeviceActivityFailure();
+}