Handle early pause, cancel for parallel requests.

content/browser/download/parallel_download_job_unittest.cc

 // Copyright 2017 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 "content/browser/download/parallel_download_job.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/memory/ptr_util.h"
@@ skipping 13 matching lines @@
 class MockDownloadRequestHandle : public DownloadRequestHandleInterface {
  public:
   MOCK_CONST_METHOD0(GetWebContents, WebContents*());
   MOCK_CONST_METHOD0(GetDownloadManager, DownloadManager*());
   MOCK_CONST_METHOD0(PauseRequest, void());
   MOCK_CONST_METHOD0(ResumeRequest, void());
   MOCK_CONST_METHOD0(CancelRequest, void());
   MOCK_CONST_METHOD0(DebugString, std::string());
 };
 
+class DownloadWorkerForTest : public DownloadWorker {
+ public:
+  DownloadWorkerForTest(DownloadWorker::Delegate* delegate,
+                        int64_t offset,
+                        int64_t length)
+      : DownloadWorker(delegate, offset, length) {}
+
+  // For passing in a mock request handle.
+  void MakeResponseReady() {
+    UrlDownloader::Delegate* delegate =
+        static_cast<UrlDownloader::Delegate*>(this);
+
+    std::unique_ptr<DownloadCreateInfo> create_info =
+        base::MakeUnique<DownloadCreateInfo>();
+    std::unique_ptr<MockDownloadRequestHandle> mock_handle =
+        base::MakeUnique<MockDownloadRequestHandle>();
+    mock_request_handle_ = mock_handle.get();
+    create_info->request_handle = std::move(mock_handle);
+    delegate->OnUrlDownloaderStarted(
+        std::move(create_info), std::unique_ptr<ByteStreamReader>(),
+        DownloadUrlParameters::OnStartedCallback());
+  }
+
+  MockDownloadRequestHandle* mock_request_handle() const {
+    return mock_request_handle_;
+  }
+
+ private:
+  MockDownloadRequestHandle* mock_request_handle_ = nullptr;
+};
+
 }  // namespace
 
 class ParallelDownloadJobForTest : public ParallelDownloadJob {
  public:
   ParallelDownloadJobForTest(
       DownloadItemImpl* download_item,
       std::unique_ptr<DownloadRequestHandleInterface> request_handle,
       const DownloadCreateInfo& create_info,
       int request_count)
       : ParallelDownloadJob(download_item,
                             std::move(request_handle),
                             create_info),
         request_count_(request_count) {}
 
+  const std::vector<DownloadWorkerForTest*>& mock_workers() {
+    return mock_workers_;
+  }
+
   void CreateRequest(int64_t offset, int64_t length) override {
-    fake_tasks_.push_back(std::pair<int64_t, int64_t>(offset, length));
+    std::unique_ptr<DownloadWorkerForTest> mock_worker =
+        base::MakeUnique<DownloadWorkerForTest>(this, offset, length);
+    mock_workers_.push_back(mock_worker.get());
+
+    DCHECK(workers_.find(offset) == workers_.end());
+    workers_[offset] = std::move(mock_worker);
   }
 
   int GetParallelRequestCount() const override { return request_count_; }
 
-  std::vector<std::pair<int64_t, int64_t>> fake_tasks_;
+ private:
+  std::vector<DownloadWorkerForTest*> mock_workers_;
+  int request_count_;
 
- private:
-  int request_count_;
   DISALLOW_COPY_AND_ASSIGN(ParallelDownloadJobForTest);
 };
 
 class ParallelDownloadJobTest : public testing::Test {
  public:
   void CreateParallelJob(int64_t offset,
                          int64_t content_length,
                          const DownloadItem::ReceivedSlices& slices,
                          int request_count) {
     item_delegate_ = base::MakeUnique<DownloadItemImplDelegate>();
     download_item_ = base::MakeUnique<NiceMock<MockDownloadItemImpl>>(
         item_delegate_.get(), slices);
     DownloadCreateInfo info;
     info.offset = offset;
     info.total_bytes = content_length;
+    std::unique_ptr<MockDownloadRequestHandle> request_handle =
+        base::MakeUnique<MockDownloadRequestHandle>();
+    mock_request_handle_ = request_handle.get();
     job_ = base::MakeUnique<ParallelDownloadJobForTest>(
-        download_item_.get(), base::MakeUnique<MockDownloadRequestHandle>(),
-        info, request_count);
+        download_item_.get(), std::move(request_handle), info, request_count);
   }
 
   void DestroyParallelJob() {
     job_.reset();
     download_item_.reset();
     item_delegate_.reset();
+    mock_request_handle_ = nullptr;
   }
 
   void BuildParallelRequests() { job_->BuildParallelRequests(); }
 
+  // Simulate all workers establishing byte streams.
+  void PushAllByteStream() {
+    for (auto& worker : job_->workers_)
+      job_->OnByteStreamReady(worker.second.get(),
+                              std::unique_ptr<ByteStreamReader>());
+  }
+
+  void VerifyWorker(int64_t offset, int64_t length) const {
+    EXPECT_TRUE(job_->workers_.find(offset) != job_->workers_.end());
+    EXPECT_EQ(offset, job_->workers_[offset]->offset());
+    EXPECT_EQ(length, job_->workers_[offset]->length());
+  }
+
   content::TestBrowserThreadBundle browser_threads_;
   std::unique_ptr<DownloadItemImplDelegate> item_delegate_;
   std::unique_ptr<MockDownloadItemImpl> download_item_;
   std::unique_ptr<ParallelDownloadJobForTest> job_;
+  // Request handle for the original request.
+  MockDownloadRequestHandle* mock_request_handle_;
 };
 
 // Test if parallel requests can be built correctly for a new download.
 TEST_F(ParallelDownloadJobTest, CreateNewDownloadRequests) {
   // Totally 2 requests for 100 bytes.
   // Original request:  Range:0-49, for 50 bytes.
   // Task 1:  Range:50-, for 50 bytes.
   CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2);
   BuildParallelRequests();
-  EXPECT_EQ(1, static_cast<int>(job_->fake_tasks_.size()));
-  EXPECT_EQ(50, job_->fake_tasks_[0].first);
-  EXPECT_EQ(0, job_->fake_tasks_[0].second);
-  job_->fake_tasks_.clear();
+  EXPECT_EQ(1, static_cast<int>(job_->mock_workers().size()));
+  VerifyWorker(50, 0);
   DestroyParallelJob();
 
   // Totally 3 requests for 100 bytes.
   // Original request:  Range:0-32, for 33 bytes.
   // Task 1:  Range:33-65, for 33 bytes.
   // Task 2:  Range:66-, for 34 bytes.
   CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 3);
   BuildParallelRequests();
-  EXPECT_EQ(2, static_cast<int>(job_->fake_tasks_.size()));
-  EXPECT_EQ(33, job_->fake_tasks_[0].first);
-  EXPECT_EQ(33, job_->fake_tasks_[0].second);
-  EXPECT_EQ(66, job_->fake_tasks_[1].first);
-  EXPECT_EQ(0, job_->fake_tasks_[1].second);
-  job_->fake_tasks_.clear();
+  EXPECT_EQ(2, static_cast<int>(job_->mock_workers().size()));
+  VerifyWorker(33, 33);
+  VerifyWorker(66, 0);
   DestroyParallelJob();
 
   // Totally 3 requests for 100 bytes. Start from the 17th byte.
   // Original request:  Range:17-43, for 27 bytes.
   // Task 1:  Range:44-70, for 27 bytes.
   // Task 2:  Range:71-99, for 29 bytes.
   CreateParallelJob(17, 83, DownloadItem::ReceivedSlices(), 3);
   BuildParallelRequests();
-  EXPECT_EQ(2, static_cast<int>(job_->fake_tasks_.size()));
-  EXPECT_EQ(44, job_->fake_tasks_[0].first);
-  EXPECT_EQ(27, job_->fake_tasks_[0].second);
-  EXPECT_EQ(71, job_->fake_tasks_[1].first);
-  EXPECT_EQ(0, job_->fake_tasks_[1].second);
-  job_->fake_tasks_.clear();
+  EXPECT_EQ(2, static_cast<int>(job_->mock_workers().size()));
+  VerifyWorker(44, 27);
+  VerifyWorker(71, 0);
   DestroyParallelJob();
 
   // Less than 2 requests, do nothing.
   CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 1);
   BuildParallelRequests();
-  EXPECT_TRUE(job_->fake_tasks_.empty());
+  EXPECT_TRUE(job_->mock_workers().empty());
   DestroyParallelJob();
 
   CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 0);
   BuildParallelRequests();
-  EXPECT_TRUE(job_->fake_tasks_.empty());
+  EXPECT_TRUE(job_->mock_workers().empty());
   DestroyParallelJob();
 
   // Content-length is 0, do nothing.
   CreateParallelJob(100, 0, DownloadItem::ReceivedSlices(), 3);
   BuildParallelRequests();
-  EXPECT_TRUE(job_->fake_tasks_.empty());
+  EXPECT_TRUE(job_->mock_workers().empty());
   DestroyParallelJob();
 
   CreateParallelJob(0, 0, DownloadItem::ReceivedSlices(), 3);
   BuildParallelRequests();
-  EXPECT_TRUE(job_->fake_tasks_.empty());
+  EXPECT_TRUE(job_->mock_workers().empty());
   DestroyParallelJob();
 
   // 2 bytes left for 3 additional requests. Only 1 are built.
   // Original request:  Range:98-98, for 1 byte.
   // Task 1:  Range:99-, for 1 byte.
   CreateParallelJob(98, 2, DownloadItem::ReceivedSlices(), 4);
   BuildParallelRequests();
-  EXPECT_EQ(1, static_cast<int>(job_->fake_tasks_.size()));
-  EXPECT_EQ(99, job_->fake_tasks_[0].first);
-  EXPECT_EQ(0, job_->fake_tasks_[0].second);
-  job_->fake_tasks_.clear();
+  EXPECT_EQ(1, static_cast<int>(job_->mock_workers().size()));
+  VerifyWorker(99, 0);
   DestroyParallelJob();
 }
 
+// Pause, cancel, resume can be called before or after the worker establish
+// the byte stream.
+// These tests ensure the states consistency between the job and workers.
+
+// Ensure cancel before building the requests will result in workers being
+// canceled.
+TEST_F(ParallelDownloadJobTest, EarlyCancelBeforeBuildRequests) {
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2);
+  EXPECT_CALL(*mock_request_handle_, CancelRequest());
+
+  // Job is canceled before building parallel requests.
+  job_->Cancel(true);
+  EXPECT_TRUE(job_->is_canceled());
+
+  BuildParallelRequests();
+  VerifyWorker(50, 0);
+  for (auto* worker : job_->mock_workers()) {
+    worker->MakeResponseReady();
+    EXPECT_CALL(*worker->mock_request_handle(), CancelRequest());
+  }
+  PushAllByteStream();
+  DestroyParallelJob();
+}
+
+// Ensure cancel before adding the byte stream will result in workers being
+// canceled.
+TEST_F(ParallelDownloadJobTest, EarlyCancelBeforeByteStreamReady) {
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2);
+  EXPECT_CALL(*mock_request_handle_, CancelRequest());
+
+  BuildParallelRequests();
+  VerifyWorker(50, 0);
+
+  // Job is canceled after building parallel requests and before byte streams
+  // are added to the file sink.
+  job_->Cancel(true);
+  EXPECT_TRUE(job_->is_canceled());
+
+  for (auto* worker : job_->mock_workers()) {
+    worker->MakeResponseReady();
+    EXPECT_CALL(*worker->mock_request_handle(), CancelRequest());
+  }
+  PushAllByteStream();
+  DestroyParallelJob();
+}
+
+// Ensure pause before building the requests will result in workers being
+// paused.
+TEST_F(ParallelDownloadJobTest, EarlyPauseBeforeBuildRequests) {
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2);
+  EXPECT_CALL(*mock_request_handle_, PauseRequest());
+
+  // Job is paused before building parallel requests.
+  job_->Pause();
+  EXPECT_TRUE(job_->is_paused());
+
+  BuildParallelRequests();
+  VerifyWorker(50, 0);
+  for (auto* worker : job_->mock_workers()) {
+    worker->MakeResponseReady();
+    EXPECT_CALL(*worker->mock_request_handle(), PauseRequest());
+    // MockDownloadItemImpl doesn't have DownloadFile, so the worker will call
+    // cancel after failed to add the byte stream to file sink.
+    // TODO(xingliu): Consider pass a mock download file into this test.
+    EXPECT_CALL(*worker->mock_request_handle(), CancelRequest());
+  }
+
+  PushAllByteStream();
+  DestroyParallelJob();
+}
+
+// Ensure pause before adding the byte stream will result in workers being
+// paused.
+TEST_F(ParallelDownloadJobTest, EarlyPauseBeforeByteStreamReady) {
+  CreateParallelJob(0, 100, DownloadItem::ReceivedSlices(), 2);
+  EXPECT_CALL(*mock_request_handle_, PauseRequest());
+
+  BuildParallelRequests();
+  VerifyWorker(50, 0);
+
+  // Job is paused after building parallel requests and before adding the byte
+  // stream to the file sink.
+  job_->Pause();
+  EXPECT_TRUE(job_->is_paused());
+
+  for (auto* worker : job_->mock_workers()) {
+    worker->MakeResponseReady();
+    EXPECT_CALL(*worker->mock_request_handle(), PauseRequest());
+    EXPECT_CALL(*worker->mock_request_handle(), CancelRequest());
+  }
+
+  PushAllByteStream();
+  DestroyParallelJob();
+}
+
 }  // namespace content