PrismLauncher/launcher/net/MetaCacheSink.cpp
flow ab6e1b112b
change(cache): use cache-specific http headers for their lifetime
This uses the 'Age', 'Cache-Control' and 'Expires' HTTP headers to more
accurately set up the cache lifetime, falling back to a static 1-week
time if they're not present in the response.

Signed-off-by: flow <flowlnlnln@gmail.com>
2022-07-21 19:19:24 -03:00

139 lines
4.5 KiB
C++

// SPDX-License-Identifier: GPL-3.0-only
/*
* PolyMC - Minecraft Launcher
* Copyright (c) 2022 flowln <flowlnlnln@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
* This file incorporates work covered by the following copyright and
* permission notice:
*
* Copyright 2013-2021 MultiMC Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "MetaCacheSink.h"
#include <QFile>
#include <QFileInfo>
#include "Application.h"
namespace Net {
/** Maximum time to hold a cache entry
* = 1 week in seconds
*/
#define MAX_TIME_TO_EXPIRE 1*7*24*60*60
MetaCacheSink::MetaCacheSink(MetaEntryPtr entry, ChecksumValidator * md5sum)
:Net::FileSink(entry->getFullPath()), m_entry(entry), m_md5Node(md5sum)
{
addValidator(md5sum);
}
Task::State MetaCacheSink::initCache(QNetworkRequest& request)
{
if (!m_entry->isStale())
{
return Task::State::Succeeded;
}
// check if file exists, if it does, use its information for the request
QFile current(m_filename);
if(current.exists() && current.size() != 0)
{
if (m_entry->getRemoteChangedTimestamp().size())
{
request.setRawHeader(QString("If-Modified-Since").toLatin1(), m_entry->getRemoteChangedTimestamp().toLatin1());
}
if (m_entry->getETag().size())
{
request.setRawHeader(QString("If-None-Match").toLatin1(), m_entry->getETag().toLatin1());
}
}
return Task::State::Running;
}
Task::State MetaCacheSink::finalizeCache(QNetworkReply & reply)
{
QFileInfo output_file_info(m_filename);
if(wroteAnyData)
{
m_entry->setMD5Sum(m_md5Node->hash().toHex().constData());
}
m_entry->setETag(reply.rawHeader("ETag").constData());
if (reply.hasRawHeader("Last-Modified"))
{
m_entry->setRemoteChangedTimestamp(reply.rawHeader("Last-Modified").constData());
}
m_entry->setLocalChangedTimestamp(output_file_info.lastModified().toUTC().toMSecsSinceEpoch());
{ // Cache lifetime
if (reply.hasRawHeader("Cache-Control")) {
auto cache_control_header = reply.rawHeader("Cache-Control");
// qDebug() << "[MetaCache] Parsing 'Cache-Control' header with" << cache_control_header;
QRegularExpression max_age_expr("max-age=([0-9]+)");
qint64 max_age = max_age_expr.match(cache_control_header).captured(1).toLongLong();
m_entry->setMaximumAge(max_age);
} else if (reply.hasRawHeader("Expires")) {
auto expires_header = reply.rawHeader("Expires");
// qDebug() << "[MetaCache] Parsing 'Expires' header with" << expires_header;
qint64 max_age = QDateTime::fromString(expires_header).toSecsSinceEpoch() - QDateTime::currentSecsSinceEpoch();
m_entry->setMaximumAge(max_age);
} else {
m_entry->setMaximumAge(MAX_TIME_TO_EXPIRE);
}
if (reply.hasRawHeader("Age")) {
auto age_header = reply.rawHeader("Age");
// qDebug() << "[MetaCache] Parsing 'Age' header with" << age_header;
qint64 current_age = age_header.toLongLong();
m_entry->setCurrentAge(current_age);
} else {
m_entry->setCurrentAge(0);
}
}
m_entry->setStale(false);
APPLICATION->metacache()->updateEntry(m_entry);
return Task::State::Succeeded;
}
bool MetaCacheSink::hasLocalData()
{
QFileInfo info(m_filename);
return info.exists() && info.size() != 0;
}
}