[Offline Pages] Implement OfflinePageStorageManager.

components/offline_pages/offline_page_storage_manager.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/offline_page_storage_manager.h"
+
+#include "base/bind.h"
+#include "components/offline_pages/client_policy_controller.h"
+#include "components/offline_pages/offline_page_client_policy.h"
+#include "components/offline_pages/offline_page_item.h"
+#include "components/offline_pages/offline_page_model.h"
+
+using DeletePageResult = offline_pages::OfflinePageModel::DeletePageResult;
+using MultipleOfflinePageItemResult =
+    offline_pages::OfflinePageModel::MultipleOfflinePageItemResult;
+
+namespace offline_pages {
+
+OfflinePageStorageManager::OfflinePageStorageManager(OfflinePageModel* model)
+    : model_(model),
+      policy_controller_(model->GetPolicyController()),
+      in_progress_(false),
+      weak_ptr_factory_(this) {}
+
+OfflinePageStorageManager::~OfflinePageStorageManager() {
+}
+
+void OfflinePageStorageManager::ClearPagesIfNeeded(
+    const ClearPageCallback& callback) {
+  if (!ShouldClearPages())
+    return;
+  in_progress_ = true;
+  model_->GetAllPages(base::Bind(&OfflinePageStorageManager::ClearExpiredPages,
+                                 weak_ptr_factory_.GetWeakPtr(), callback));
+}
+
+void OfflinePageStorageManager::ClearExpiredPages(
+    const ClearPageCallback& callback,
+    const MultipleOfflinePageItemResult& pages) {
+  DCHECK(in_progress_);
+  std::vector<int64_t> offline_ids;
+  GetExpiredPageIds(pages, offline_ids);
+  model_->DeletePagesByOfflineId(
+      offline_ids,
+      base::Bind(&OfflinePageStorageManager::OnExpiredPagesDeleted,
+                 weak_ptr_factory_.GetWeakPtr(), callback, offline_ids.size()));
+}
+
+void OfflinePageStorageManager::GetExpiredPageIds(
+    const MultipleOfflinePageItemResult& pages,
+    std::vector<int64_t>& offline_ids) {
+  for (const auto& page : pages) {
+    if (IsPageExpired(page))
+      offline_ids.push_back(page.offline_id);
+  }
+}
+
+void OfflinePageStorageManager::OnExpiredPagesDeleted(
+    const ClearPageCallback& callback,
+    int pages_cleared,
+    DeletePageResult result) {
+  in_progress_ = false;
+  callback.Run(pages_cleared, result);
+}
+
+bool OfflinePageStorageManager::ShouldClearPages() {
+  return !in_progress_ && model_->is_loaded();
+}
+
+bool OfflinePageStorageManager::IsPageExpired(const OfflinePageItem& page) {
+  base::Time now = base::Time::Now();
+  const LifetimePolicy& policy =
+      policy_controller_->GetPolicy(page.client_id.name_space).lifetime_policy;
+  return now - page.last_access_time > policy.expiration_period;
+}
+
+}  // namespace offline_pages