Implement DownloadUpdateTask

Installing updates is not implemented yet. That's next.

1 files changed, 182 insertions, 0 deletions

diff --git a/logic/updater/DownloadUpdateTask.h b/logic/updater/DownloadUpdateTask.h
new file mode 100644
index 00000000..6fb745ab
--- /dev/null
+++ b/logic/updater/DownloadUpdateTask.h
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+/* Copyright 2013 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.
+ */
+
+#pragma once
+
+#include "logic/tasks/Task.h"
+#include "logic/net/NetJob.h"
+
+/*!
+ * The DownloadUpdateTask is a task that takes a given version ID and repository URL,
+ * downloads that version's files from the repository, and prepares to install them.
+ */
+class DownloadUpdateTask : public Task
+{
+	Q_OBJECT
+
+public:
+	explicit DownloadUpdateTask(QString repoUrl, int versionId, QObject* parent=0);
+	
+protected:
+	// TODO: We should probably put these data structures into a separate header...
+
+	/*!
+	 * Struct that describes an entry in a VersionFileEntry's `Sources` list.
+	 */
+	struct FileSource
+	{
+		FileSource(QString type, QString url, QString compression="")
+		{
+			this->type = type;
+			this->url = url;
+			this->compressionType = compression;
+		}
+
+		QString type;
+		QString url;
+		QString compressionType;
+	};
+
+	typedef QList<FileSource> FileSourceList;
+
+	/*!
+	 * Structure that describes an entry in a GoUpdate version's `Files` list.
+	 */
+	struct VersionFileEntry
+	{
+		QString path;
+		bool isExecutable;
+		FileSourceList sources;
+		QString md5;
+	};
+
+	typedef QList<VersionFileEntry> VersionFileList;
+
+
+	/*!
+	 * Structure that describes an operation to perform when installing updates.
+	 */
+	struct UpdateOperation
+	{
+		static UpdateOperation CopyOp(QString fsource, QString fdest) { return UpdateOperation{OP_COPY, fsource, fdest, 644}; }
+		static UpdateOperation MoveOp(QString fsource, QString fdest) { return UpdateOperation{OP_MOVE, fsource, fdest, 644}; }
+		static UpdateOperation DeleteOp(QString file) { return UpdateOperation{OP_DELETE, file, "", 644}; }
+		static UpdateOperation ChmodOp(QString file, int fmode) { return UpdateOperation{OP_CHMOD, file, "", fmode}; }
+
+		//! Specifies the type of operation that this is.
+		enum Type
+		{
+			OP_COPY,
+			OP_DELETE,
+			OP_MOVE,
+			OP_CHMOD,
+		} type;
+
+		//! The source file. If this is a DELETE or CHMOD operation, this is the file that will be modified.
+		QString source;
+
+		//! The destination file. If this is a DELETE or CHMOD operation, this field will be ignored.
+		QString dest;
+
+		//! The mode to change the source file to. Ignored if this isn't a CHMOD operation.
+		int mode;
+
+		// Yeah yeah, polymorphism blah blah inheritance, blah blah object oriented. I'm lazy, OK?
+	};
+
+	typedef QList<UpdateOperation> UpdateOperationList;
+
+	/*!
+	 * Used for arguments to parseVersionInfo and friends to specify which version info file to parse.
+	 */
+	enum VersionInfoFileEnum { NEW_VERSION, CURRENT_VERSION };
+
+
+	//! Entry point for tasks.
+	virtual void executeTask();
+
+	/*!
+	 * Attempts to find the version ID and repository URL for the current version.
+	 * The function will look up the repository URL in the UpdateChecker's channel list.
+	 * If the repository URL can't be found, this function will return false.
+	 */
+	virtual void findCurrentVersionInfo();
+
+	/*!
+	 * Downloads the version info files from the repository.
+	 * The files for both the current build, and the build that we're updating to need to be downloaded.
+	 * If the current version's info file can't be found, MultiMC will not delete files that 
+	 * were removed between versions. It will still replace files that have changed, however.
+	 * Note that although the repository URL for the current version is not given to the update task,
+	 * the task will attempt to look it up in the UpdateChecker's channel list.
+	 * If an error occurs here, the function will call emitFailed and return false.
+	 */
+	virtual void loadVersionInfo();
+
+	/*!
+	 * This function is called when version information is finished downloading.
+	 * This handles parsing the JSON downloaded by the version info network job and then calls processFileLists.
+	 * Note that this function will sometimes be called even if the version info download emits failed. If
+	 * we couldn't download the current version's info file, we can still update. This will be called even if the 
+	 * current version's info file fails to download, as long as the new version's info file succeeded.
+	 */
+	virtual void parseDownloadedVersionInfo();
+
+	/*!
+	 * Loads the file list from the given version info JSON object into the given list.
+	 */
+	virtual void parseVersionInfo(VersionInfoFileEnum vfile, VersionFileList* list);
+
+	/*!
+	 * Takes a list of file entries for the current version's files and the new version's files
+	 * and populates the downloadList and operationList with information about how to download and install the update.
+	 */
+	virtual void processFileLists();
+
+	VersionFileList m_downloadList;
+	UpdateOperationList m_operationList;
+
+	VersionFileList m_nVersionFileList;
+	VersionFileList m_cVersionFileList;
+
+	//! Network job for downloading version info files.
+	NetJobPtr m_vinfoNetJob;
+	
+	//! Network job for downloading update files.
+	NetJobPtr m_filesNetJob;
+
+	// Version ID and repo URL for the new version.
+	int m_nVersionId;
+	QString m_nRepoUrl;
+
+	// Version ID and repo URL for the currently installed version.
+	int m_cVersionId;
+	QString m_cRepoUrl;
+
+	/*!
+	 * Temporary directory to store update files in.
+	 * This will be set to not auto delete. Task will fail if this fails to be created.
+	 */
+	QTemporaryDir m_updateFilesDir;
+
+protected slots:
+	void vinfoDownloadFinished();
+	void vinfoDownloadFailed();
+
+	void fileDownloadFinished();
+	void fileDownloadFailed();
+	void fileDownloadProgressChanged(qint64 current, qint64 total);
+};
+