Add pause/resume functionality to precache

components/precache/core/precache_database.cc

 // Copyright 2013 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/precache/core/precache_database.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/history/core/browser/history_constants.h"
+#include "components/precache/core/proto/unfinished_work.pb.h"
 #include "sql/connection.h"
 #include "sql/transaction.h"
 #include "url/gurl.h"
 
 namespace {
 
 // The number of days old that an entry in the precache URL table can be before
 // it is considered "old" and is removed from the table.
 const int kPrecacheHistoryExpiryPeriodDays = 60;
 
@@ skipping 19 matching lines @@
 
   db_.reset(new sql::Connection());
   db_->set_histogram_tag("Precache");
 
   if (!db_->Open(db_path)) {
     // Don't initialize the URL table if unable to access
     // the database.
     return false;
   }
 
-  if (!precache_url_table_.Init(db_.get())) {
+  if (!precache_url_table_.Init(db_.get()) ||
+      !precache_session_table_.Init(db_.get())) {
     // Raze and close the database connection to indicate that it's not usable,
     // and so that the database will be created anew next time, in case it's
     // corrupted.
     db_->RazeAndClose();
     return false;
   }
   return true;
 }
 
 void PrecacheDatabase::DeleteExpiredPrecacheHistory(
@@ skipping 187 matching lines @@
   // Post a delayed task to flush the buffer in 1 second, so that multiple
   // database writes can be buffered up and flushed together in the same
   // transaction.
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, base::Bind(&PrecacheDatabase::PostedFlush,
                             weak_factory_.GetWeakPtr()),
       base::TimeDelta::FromSeconds(1));
   is_flush_posted_ = true;
 }
 
+std::unique_ptr<PrecacheUnfinishedWork>
+PrecacheDatabase::GetUnfinishedWork() {
+  std::unique_ptr<PrecacheUnfinishedWork> unfinished_work =
+      precache_session_table_.GetUnfinishedWork();
+  precache_session_table_.DeleteUnfinishedWork();
+  return unfinished_work;
+}
+
+void PrecacheDatabase::SaveUnfinishedWork(
+    std::unique_ptr<PrecacheUnfinishedWork> unfinished_work) {
+  precache_session_table_.SaveUnfinishedWork(
+      std::move(unfinished_work));
+}
+
+void PrecacheDatabase::DeleteUnfinishedWork() {
+  precache_session_table_.DeleteUnfinishedWork();
+}
+
+base::WeakPtr<PrecacheDatabase> PrecacheDatabase::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
 }  // namespace precache