Add the ability to cancel prerender reqeusts and tests

components/offline_pages/background/request_coordinator_unittest.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 "components/offline_pages/background/request_coordinator.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 45 matching lines @@
   TriggerConditions const* conditions() const { return &conditions_; }
 
  private:
   bool schedule_called_;
   bool unschedule_called_;
   TriggerConditions conditions_;
 };
 
 class OfflinerStub : public Offliner {
  public:
-  OfflinerStub() : skip_callback_(false) {}
+  OfflinerStub() : request_(kRequestId, kUrl, kClientId, base::Time::Now()),
+                   skip_callback_(false) {}
 
   bool LoadAndSave(const SavePageRequest& request,
                    const CompletionCallback& callback) override {
+    callback_ = callback;
+    request_ = request;
     // Post the callback on the run loop.
     if (!skip_callback_) {
       base::ThreadTaskRunnerHandle::Get()->PostTask(
           FROM_HERE,
           base::Bind(callback, request, Offliner::RequestStatus::SAVED));
     }
     return true;
   }
 
+  // Clears the currently processing request, if any.  Must have called
+  // LoadAndSave first to set the callback and request.
   // Clears the currently processing request, if any.
-  void Cancel() override {}
+  void Cancel() override {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(callback_, request_, Offliner::RequestStatus::CANCELED));
+  }
 
   void set_skip_callback(bool skip) {
     skip_callback_ = skip;
   }
 
  private:
+  CompletionCallback callback_;
+  SavePageRequest request_;
   bool skip_callback_;
 };
 
 class OfflinerFactoryStub : public OfflinerFactory {
  public:
+
+  OfflinerFactoryStub() : offliner_(nullptr) {}
+
   Offliner* GetOffliner(const OfflinerPolicy* policy) override {
     if (offliner_.get() == nullptr) {
       offliner_.reset(new OfflinerStub());
     }
     return offliner_.get();
   }
 
  private:
-  std::unique_ptr<Offliner> offliner_;
+  std::unique_ptr<OfflinerStub> offliner_;
 };
 
 class RequestCoordinatorTest
     : public testing::Test {
  public:
   RequestCoordinatorTest();
   ~RequestCoordinatorTest() override;
 
   void SetUp() override;
 
@@ skipping 27 matching lines @@
                                 Offliner::RequestStatus status);
 
   RequestQueue::GetRequestsResult last_get_requests_result() const {
     return last_get_requests_result_;
   }
 
   const std::vector<SavePageRequest>& last_requests() const {
     return last_requests_;
   }
 
-  void skip_offliner_callback() {
+  void SkipOfflinerCallback() {

[dougarnett, 2016/06/23 17:19:17]

consider whether changing to stub to not auto callback seems attractive - ie,
explicitly control calling the callback with result value for the tests that are
verifying callback values.

[Pete Williamson, 2016/06/23 17:54:54]

Changed to EnableOfflinerCallback(bool enable); Any test that requires the
callback we call it with true, any test that needs the callback to not happen we
call it with false, any test that won't be exercising the callback doesn't call
it at all.

     offliner_->set_skip_callback(true);
   }
 
+  Offliner::RequestStatus last_offlining_status() const {
+    return coordinator_->last_offlining_status_;
+  }
+
  private:
   RequestQueue::GetRequestsResult last_get_requests_result_;
   std::vector<SavePageRequest> last_requests_;
   scoped_refptr<base::TestSimpleTaskRunner> task_runner_;
   base::ThreadTaskRunnerHandle task_runner_handle_;
   std::unique_ptr<RequestCoordinator> coordinator_;
   OfflinerStub* offliner_;
 };
 
 RequestCoordinatorTest::RequestCoordinatorTest()
     : last_get_requests_result_(RequestQueue::GetRequestsResult::STORE_FAILURE),
       task_runner_(new base::TestSimpleTaskRunner),
       task_runner_handle_(task_runner_),
       offliner_(nullptr) {}
 
 RequestCoordinatorTest::~RequestCoordinatorTest() {}
 
 void RequestCoordinatorTest::SetUp() {
   std::unique_ptr<OfflinerPolicy> policy(new OfflinerPolicy());
   std::unique_ptr<OfflinerFactory> factory(new OfflinerFactoryStub());
+  // Save the offliner for use by the tests.
   offliner_ =
       reinterpret_cast<OfflinerStub*>(factory->GetOffliner(policy.get()));
   std::unique_ptr<RequestQueueInMemoryStore>
       store(new RequestQueueInMemoryStore());
   std::unique_ptr<RequestQueue> queue(new RequestQueue(std::move(store)));
   std::unique_ptr<Scheduler> scheduler_stub(new SchedulerStub());
   coordinator_.reset(new RequestCoordinator(
       std::move(policy), std::move(factory), std::move(queue),
       std::move(scheduler_stub)));
 }
 
 void RequestCoordinatorTest::PumpLoop() {
   task_runner_->RunUntilIdle();
 }
 
 void RequestCoordinatorTest::GetRequestsDone(
     RequestQueue::GetRequestsResult result,
     const std::vector<SavePageRequest>& requests) {
   last_get_requests_result_ = result;
   last_requests_ = requests;
 }
 
-
 void RequestCoordinatorTest::AddRequestDone(
     RequestQueue::AddRequestResult result,
     const SavePageRequest& request) {}
 
 void RequestCoordinatorTest::SendOfflinerDoneCallback(
     const SavePageRequest& request, Offliner::RequestStatus status) {
   // Using the fact that the test class is a friend, call to the callback
   coordinator_->OfflinerDoneCallback(request, status);
 }
 
-
 TEST_F(RequestCoordinatorTest, StartProcessingWithNoRequests) {
   DeviceConditions device_conditions(false, 75,
                                      net::NetworkChangeNotifier::CONNECTION_3G);
   base::Callback<void(bool)> callback =
       base::Bind(
           &RequestCoordinatorTest::EmptyCallbackFunction,
           base::Unretained(this));
   EXPECT_TRUE(coordinator()->StartProcessing(device_conditions, callback));
 }
 
 TEST_F(RequestCoordinatorTest, StartProcessingWithRequestInProgress) {
   // Put the request on the queue.
   EXPECT_TRUE(coordinator()->SavePageLater(kUrl, kClientId));
 
   // Set up for the call to StartProcessing by building arguments.
   DeviceConditions device_conditions(false, 75,
                                      net::NetworkChangeNotifier::CONNECTION_3G);
   base::Callback<void(bool)> callback =
       base::Bind(&RequestCoordinatorTest::EmptyCallbackFunction,
                  base::Unretained(this));
 
   // Ensure that the forthcoming request does not finish - we simulate it being
   // in progress by asking it to skip making the completion callback.
-  skip_offliner_callback();
+  SkipOfflinerCallback();
 
   // Sending the request to the offliner should make it busy.
   EXPECT_TRUE(coordinator()->StartProcessing(device_conditions, callback));
   PumpLoop();
   EXPECT_TRUE(is_busy());
 
   // Now trying to start processing on another request should return false.
   EXPECT_FALSE(coordinator()->StartProcessing(device_conditions, callback));
 }
 
@@ skipping 83 matching lines @@
   coordinator()->queue()->GetRequests(
       base::Bind(&RequestCoordinatorTest::GetRequestsDone,
                  base::Unretained(this)));
   PumpLoop();
 
   // Still one request in the queue.
   EXPECT_EQ(1UL, last_requests().size());
   // TODO(dougarnett): Verify retry count gets incremented.
 }
 
+// This tests a StopProcessing call before we have actually started the
+// prerenderer.
+TEST_F(RequestCoordinatorTest, StartProcessingThenStopProcessingImmediately) {
+  // Add a request to the queue, wait for callbacks to finish.
+  offline_pages::SavePageRequest request(
+      kRequestId, kUrl, kClientId, base::Time::Now());
+  coordinator()->queue()->AddRequest(
+      request,
+      base::Bind(&RequestCoordinatorTest::AddRequestDone,
+                 base::Unretained(this)));
+  PumpLoop();
+
+  DeviceConditions device_conditions(false, 75,
+                                     net::NetworkChangeNotifier::CONNECTION_3G);
+  base::Callback<void(bool)> callback =
+      base::Bind(
+          &RequestCoordinatorTest::EmptyCallbackFunction,
+          base::Unretained(this));
+  EXPECT_TRUE(coordinator()->StartProcessing(device_conditions, callback));
+
+  // Now, quick, before it can do much (we haven't called PumpLoop), cancel it.
+  coordinator()->StopProcessing();
+
+  // Let the async callbacks in the request coordinator run.
+  PumpLoop();
+
+  // OfflinerDoneCallback will not end up getting called with status SAVED,
+  // Since we cancelled the event before it called offliner_->LoadAndSave().
+  EXPECT_NE(Offliner::RequestStatus::SAVED, last_offlining_status());
+}
+
+// This tests a StopProcessing call after the prerenderer has been started.
+TEST_F(RequestCoordinatorTest, StartProcessingThenStopProcessingLater) {
+  // Add a request to the queue, wait for callbacks to finish.
+  offline_pages::SavePageRequest request(
+      kRequestId, kUrl, kClientId, base::Time::Now());
+  coordinator()->queue()->AddRequest(
+      request,
+      base::Bind(&RequestCoordinatorTest::AddRequestDone,
+                 base::Unretained(this)));
+  PumpLoop();
+
+  // Ensure the start processing request stops before the completion callback.
+  SkipOfflinerCallback();
+
+  DeviceConditions device_conditions(false, 75,
+                                     net::NetworkChangeNotifier::CONNECTION_3G);
+  base::Callback<void(bool)> callback =
+      base::Bind(
+          &RequestCoordinatorTest::EmptyCallbackFunction,
+          base::Unretained(this));
+  EXPECT_TRUE(coordinator()->StartProcessing(device_conditions, callback));
+
+  // Let all the async parts of the start processing pipeline run to completion.
+  PumpLoop();
+
+  // Now we cancel it while the prerenderer is busy.
+  coordinator()->StopProcessing();
+
+  // Let the async callbacks in the cancel run.
+  PumpLoop();
+
+  // OfflinerDoneCallback will not end up getting called with status SAVED,
+  // Since we cancelled the event before it called offliner_->LoadAndSave().
+  EXPECT_EQ(Offliner::RequestStatus::CANCELED, last_offlining_status());
+}
+
 }  // namespace offline_pages