[Offline pages] Adding capability to free up space used by Offline pages

components/offline_pages/offline_page_model.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/offline_pages/offline_page_model.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/sequenced_task_runner.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/bookmarks/browser/bookmark_node.h"
 #include "components/offline_pages/offline_page_item.h"
 #include "components/offline_pages/offline_page_metadata_store.h"
 #include "url/gurl.h"
 
 using ArchiverResult = offline_pages::OfflinePageArchiver::ArchiverResult;
 using SavePageResult = offline_pages::OfflinePageModel::SavePageResult;
 
 namespace offline_pages {
 
 namespace {
 
+// Threshold for how old offline copy of a page should be before we offer to
+// delete it to free up space.
+const base::TimeDelta kPageCleanUpThreshold = base::TimeDelta::FromDays(30);
+
 SavePageResult ToSavePageResult(ArchiverResult archiver_result) {
   SavePageResult result;
   switch (archiver_result) {
     case ArchiverResult::SUCCESSFULLY_CREATED:
       result = SavePageResult::SUCCESS;
       break;
     case ArchiverResult::ERROR_DEVICE_FULL:
       result = SavePageResult::DEVICE_FULL;
       break;
     case ArchiverResult::ERROR_CONTENT_UNAVAILABLE:
@@ skipping 108 matching lines @@
 }
 
 const std::vector<OfflinePageItem> OfflinePageModel::GetAllPages() const {
   DCHECK(is_loaded_);
   std::vector<OfflinePageItem> offline_pages;
   for (const auto& id_page_pair : offline_pages_)
     offline_pages.push_back(id_page_pair.second);
   return offline_pages;
 }
 
+const std::vector<OfflinePageItem> OfflinePageModel::GetPagesToCleanUp() const {
+  DCHECK(is_loaded_);
+  std::vector<OfflinePageItem> offline_pages;
+  base::Time now = base::Time::Now();
+  for (const auto& id_page_pair : offline_pages_) {
+    if (now - id_page_pair.second.creation_time > kPageCleanUpThreshold)
+      offline_pages.push_back(id_page_pair.second);
+  }
+  return offline_pages;
+}
+
 bool OfflinePageModel::GetPageByBookmarkId(
     int64 bookmark_id,
     OfflinePageItem* offline_page) const {
   DCHECK(offline_page);
 
   const auto iter = offline_pages_.find(bookmark_id);
   if (iter != offline_pages_.end()) {
     *offline_page = iter->second;
     return true;
   }
@@ skipping 141 matching lines @@
   for (int64 bookmark_id : bookmark_ids)
     offline_pages_.erase(bookmark_id);
   // Deleting multiple pages always succeeds when it gets to this point.
   if (success || bookmark_ids.size() > 1)
     callback.Run(DeletePageResult::SUCCESS);
   else
     callback.Run(DeletePageResult::STORE_FAILURE);
 }
 
 }  // namespace offline_pages