Use HttpMetaCache to minimize network use.

2013-09-08 02:15:20 +02:00
parent 6892c11e9f
commit 6bea4ec988
17 changed files with 698 additions and 274 deletions
--- a/logic/net/CacheDownload.cpp
+++ b/logic/net/CacheDownload.cpp
@ -0,0 +1,122 @@
+#include "MultiMC.h"
+#include "CacheDownload.h"
+#include <pathutils.h>
+
+#include <QCryptographicHash>
+#include <QFileInfo>
+#include <QDateTime>
+#include <QDebug>
+
+CacheDownload::CacheDownload (QUrl url, MetaEntryPtr entry )
+	:Download(), md5sum(QCryptographicHash::Md5)
+{
+	m_url = url;
+	m_entry = entry;
+	m_target_path = entry->getFullPath();
+	m_status = Job_NotStarted;
+	m_opened_for_saving = false;
+}
+
+void CacheDownload::start()
+{
+	if(!m_entry->stale)
+	{
+		emit succeeded(index_within_job);
+		return;
+	}
+	m_output_file.setFileName(m_target_path);
+	// if there already is a file and md5 checking is in effect and it can be opened
+	if(!ensureFilePathExists(m_target_path))
+	{
+		emit failed(index_within_job);
+		return;
+	}
+	qDebug() << "Downloading " << m_url.toString();
+	QNetworkRequest request ( m_url );
+	request.setRawHeader(QString("If-None-Match").toLatin1(), m_entry->etag.toLatin1()); 
+	
+	auto worker = MMC->qnam();
+	QNetworkReply * rep = worker->get ( request );
+	
+	m_reply = QSharedPointer<QNetworkReply> ( rep, &QObject::deleteLater );
+	connect ( rep, SIGNAL ( downloadProgress ( qint64,qint64 ) ), SLOT ( downloadProgress ( qint64,qint64 ) ) );
+	connect ( rep, SIGNAL ( finished() ), SLOT ( downloadFinished() ) );
+	connect ( rep, SIGNAL ( error ( QNetworkReply::NetworkError ) ), SLOT ( downloadError ( QNetworkReply::NetworkError ) ) );
+	connect ( rep, SIGNAL ( readyRead() ), SLOT ( downloadReadyRead() ) );
+}
+
+void CacheDownload::downloadProgress ( qint64 bytesReceived, qint64 bytesTotal )
+{
+	emit progress (index_within_job, bytesReceived, bytesTotal );
+}
+
+void CacheDownload::downloadError ( QNetworkReply::NetworkError error )
+{
+	// error happened during download.
+	// TODO: log the reason why
+	m_status = Job_Failed;
+}
+void CacheDownload::downloadFinished()
+{
+	// if the download succeeded
+	if ( m_status != Job_Failed )
+	{
+		
+		// nothing went wrong...
+		m_status = Job_Finished;
+		if(m_opened_for_saving)
+		{
+			// save the data to the downloadable if we aren't saving to file
+			m_output_file.close();
+			m_entry->md5sum = md5sum.result().toHex().constData();
+		}
+		else
+		{
+			if ( m_output_file.open ( QIODevice::ReadOnly ) )
+			{
+				m_entry->md5sum = QCryptographicHash::hash ( m_output_file.readAll(), QCryptographicHash::Md5 ).toHex().constData();
+				m_output_file.close();
+			}
+		}
+		QFileInfo output_file_info(m_target_path);
+		
+		
+		m_entry->etag = m_reply->rawHeader("ETag").constData();
+		m_entry->last_changed_timestamp = output_file_info.lastModified().toUTC().toMSecsSinceEpoch();
+		m_entry->stale = false;
+		MMC->metacache()->updateEntry(m_entry);
+		
+		m_reply.clear();
+		emit succeeded(index_within_job);
+		return;
+	}
+	// else the download failed
+	else
+	{
+		m_output_file.close();
+		m_output_file.remove();
+		m_reply.clear();
+		emit failed(index_within_job);
+		return;
+	}
+}
+
+void CacheDownload::downloadReadyRead()
+{
+	if(!m_opened_for_saving)
+	{
+		if ( !m_output_file.open ( QIODevice::WriteOnly ) )
+		{
+			/*
+			* Can't open the file... the job failed
+			*/
+			m_reply->abort();
+			emit failed(index_within_job);
+			return;
+		}
+		m_opened_for_saving = true;
+	}
+	QByteArray ba = m_reply->readAll();
+	md5sum.addData(ba);
+	m_output_file.write ( ba );
+}