Reconcile the request queue on startup.

components/offline_pages/core/background/reconcile_task.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/core/background/reconcile_task.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "components/offline_pages/core/background/offliner_policy.h"
+#include "components/offline_pages/core/background/request_coordinator_event_logger.h"
+#include "components/offline_pages/core/background/request_notifier.h"
+#include "components/offline_pages/core/background/request_queue_store.h"
+#include "components/offline_pages/core/background/save_page_request.h"
+
+namespace offline_pages {
+
+ReconcileTask::ReconcileTask(RequestQueueStore* store,
+                             const RequestQueueStore::UpdateCallback& callback)
+    : store_(store), callback_(callback), weak_ptr_factory_(this) {}
+
+ReconcileTask::~ReconcileTask() {}
+
+void ReconcileTask::Run() {
+  GetRequests();
+}
+
+void ReconcileTask::GetRequests() {
+  // Get all the requests from the queue, we will reconcile them in the
+  // callback.
+  store_->GetRequests(
+      base::Bind(&ReconcileTask::Reconcile, weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ReconcileTask::Reconcile(
+    bool success,
+    std::vector<std::unique_ptr<SavePageRequest>> requests) {
+  // If there is nothing to do, return right away, no need to call the callback,
+  // since the state of the notifications did not change.
+  if (requests.empty()) {
+    TaskComplete();
+    return;
+  }
+
+  // Check for tasks in the OFFLINING state, and change the state back to
+  // AVAILABLE.
+  std::vector<SavePageRequest> items_to_update;
+  for (auto& request : requests) {
+    if (request->request_state() == SavePageRequest::RequestState::OFFLINING) {
+      request->set_request_state(SavePageRequest::RequestState::AVAILABLE);
+      items_to_update.push_back(*request.get());
+      // TODO(petewil): Consider adding UMA to see how often chrome gets killed
+      // while processing a request.
+    }
+  }
+
+  // If there is no work (most common case), just return, no need for a
+  // callback.
+  if (items_to_update.empty()) {
+    TaskComplete();
+    return;
+  }
+
+  store_->UpdateRequests(items_to_update,
+                         base::Bind(&ReconcileTask::UpdateCompleted,
+                                    weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ReconcileTask::UpdateCompleted(
+    std::unique_ptr<UpdateRequestsResult> update_result) {
+  // Send a notification to the UI that these items have updated.
+  callback_.Run(std::move(update_result));
+  TaskComplete();
+}
+
+}  // namespace offline_pages