/*************************************************************************
*    UrBackup - Client/Server backup system
*    Copyright (C) 2011-2016 Martin Raiber
*
*    This program is free software: you can redistribute it and/or modify
*    it under the terms of the GNU Affero General Public License as published by
*    the Free Software Foundation, either version 3 of the License, or
*    (at your option) any later version.
*
*    This program is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU Affero General Public License for more details.
*
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
**************************************************************************/

#include "WalCheckpointThread.h"
#include "../urbackupcommon/os_functions.h"
#include "../Interface/File.h"
#include "../Interface/Server.h"
#include "database.h"
#include "../Interface/Database.h"
#include <memory>

WalCheckpointThread::WalCheckpointThread()
	: last_checkpoint_wal_size(0)
{
}

void WalCheckpointThread::checkpoint()
{
	int mode = MODE_READ;
#ifdef _WIN32
	mode=MODE_READ_DEVICE;
#endif
	std::auto_ptr<IFile> wal_file(Server->openFile("urbackup" + os_file_sep() + "backup_server_files.db-wal", mode));

	if(wal_file.get()!=NULL)
	{
		int64 wal_size = wal_file->Size();
		if (wal_size > 1 * 1024 * 1024 * 1024) //>1GiB
		{
			wal_file.reset();

			passive_checkpoint();

			Server->Log("Files WAL file greater than 1GiB. Doing full WAL checkpoint...", LL_INFO);

			IDatabase* db = Server->getDatabase(Server->getThreadID(), URBACKUPDB_SERVER_FILES);
			db->lockForSingleUse();
			db->Write("PRAGMA wal_checkpoint(TRUNCATE)");
			db->unlockForSingleUse();

			last_checkpoint_wal_size = 0;
		}
		else if (wal_size - last_checkpoint_wal_size > 100 * 1024 * 1024) //100MB
		{
			last_checkpoint_wal_size = wal_size;

			wal_file.reset();

			passive_checkpoint();
		}
		else if (wal_size < last_checkpoint_wal_size)
		{
			last_checkpoint_wal_size = 0;
		}
	}
	else
	{
		Server->Log("Could not open WAL file (wal checkpoint thread)", LL_WARNING);
	}
}

void WalCheckpointThread::operator()()
{
	while(true)
	{
		Server->wait(10000); //every 10s
		checkpoint();
	}
}

void WalCheckpointThread::passive_checkpoint()
{
	IDatabase* db = Server->getDatabase(Server->getThreadID(), URBACKUPDB_SERVER_FILES);
	db_results res = db->Read("PRAGMA wal_checkpoint(PASSIVE)");
	if (!res.empty())
	{
		Server->Log("Passive WAL checkpoint completed busy=" + res[0]["busy"] + " checkpointed=" + res[0]["checkpointed"] + " log=" + res[0]["log"]);
	}	
}