GH-1060 implement very basic updater (only linux and maybe osx right now)

8 files changed, 170 insertions, 116 deletions

diff --git a/application/MainWindow.cpp b/application/MainWindow.cpp
index 933c4dbc..8c827806 100644
--- a/application/MainWindow.cpp
+++ b/application/MainWindow.cpp
@@ -992,7 +992,7 @@ void MainWindow::downloadUpdates(GoUpdate::Status status)
 	// If the task succeeds, install the updates.
 	if (updateDlg.exec(&updateTask))
 	{
-		MMC->installUpdates(updateTask.updateFilesDir());
+		MMC->installUpdates(updateTask.updateFilesDir(), updateTask.operations());
 	}
 	else
 	{
diff --git a/application/MultiMC.cpp b/application/MultiMC.cpp
index 67b50b40..a21455f0 100644
--- a/application/MultiMC.cpp
+++ b/application/MultiMC.cpp
@@ -583,7 +583,69 @@ std::shared_ptr<JavaVersionList> MultiMC::javalist()
 	return m_javalist;
 }
 
-void MultiMC::installUpdates(const QString updateFilesDir)
+// from <sys/stat.h>
+#ifndef S_IRUSR
+#define __S_IREAD 0400         /* Read by owner.  */
+#define __S_IWRITE 0200        /* Write by owner.  */
+#define __S_IEXEC 0100         /* Execute by owner.  */
+#define S_IRUSR __S_IREAD      /* Read by owner.  */
+#define S_IWUSR __S_IWRITE     /* Write by owner.  */
+#define S_IXUSR __S_IEXEC      /* Execute by owner.  */
+
+#define S_IRGRP (S_IRUSR >> 3) /* Read by group.  */
+#define S_IWGRP (S_IWUSR >> 3) /* Write by group.  */
+#define S_IXGRP (S_IXUSR >> 3) /* Execute by group.  */
+
+#define S_IROTH (S_IRGRP >> 3) /* Read by others.  */
+#define S_IWOTH (S_IWGRP >> 3) /* Write by others.  */
+#define S_IXOTH (S_IXGRP >> 3) /* Execute by others.  */
+#endif
+static QFile::Permissions unixModeToPermissions(const int mode)
+{
+	QFile::Permissions perms;
+
+	if (mode & S_IRUSR)
+	{
+		perms |= QFile::ReadUser;
+	}
+	if (mode & S_IWUSR)
+	{
+		perms |= QFile::WriteUser;
+	}
+	if (mode & S_IXUSR)
+	{
+		perms |= QFile::ExeUser;
+	}
+
+	if (mode & S_IRGRP)
+	{
+		perms |= QFile::ReadGroup;
+	}
+	if (mode & S_IWGRP)
+	{
+		perms |= QFile::WriteGroup;
+	}
+	if (mode & S_IXGRP)
+	{
+		perms |= QFile::ExeGroup;
+	}
+
+	if (mode & S_IROTH)
+	{
+		perms |= QFile::ReadOther;
+	}
+	if (mode & S_IWOTH)
+	{
+		perms |= QFile::WriteOther;
+	}
+	if (mode & S_IXOTH)
+	{
+		perms |= QFile::ExeOther;
+	}
+	return perms;
+}
+
+void MultiMC::installUpdates(const QString updateFilesDir, GoUpdate::OperationList operations)
 {
 	qDebug() << "Installing updates.";
 #ifdef WINDOWS
@@ -596,14 +658,96 @@ void MultiMC::installUpdates(const QString updateFilesDir)
 #error Unsupported operating system.
 #endif
 
-	QStringList args;
-	args << "--install-dir" << root();
-	args << "--package-dir" << updateFilesDir;
-	args << "--script" << PathCombine(updateFilesDir, "file_list.xml");
-	args << "--wait" << QString::number(applicationPid());
-	args << "--finish-cmd" << finishCmd;
-	args << "--finish-dir" << dataPath;
-	qDebug() << "Running updater with args" << args.join(" ");
+	QString backupPath = PathCombine(root(), "update-backup");
+	QString trashPath = PathCombine(root(), "update-trash");
+	if(!ensureFolderPathExists(backupPath))
+	{
+		qWarning() << "couldn't create folder" << backupPath;
+		return;
+	}
+	if(!ensureFolderPathExists(trashPath))
+	{
+		qWarning() << "couldn't create folder" << trashPath;
+		return;
+	}
+	struct BackupEntry
+	{
+		QString orig;
+		QString backup;
+	};
+	QList <BackupEntry> backups;
+	QList <BackupEntry> trashcan;
+	for(auto op: operations)
+	{
+		switch(op.type)
+		{
+			case GoUpdate::Operation::OP_COPY:
+			{
+				QFileInfo replaced (PathCombine(root(), op.dest));
+				if(replaced.exists())
+				{
+					QString backupFilePath = PathCombine(backupPath, replaced.completeBaseName());
+					QFile::rename(replaced.absoluteFilePath(), backupFilePath);
+					BackupEntry be;
+					be.orig = replaced.absoluteFilePath();
+					be.backup = backupFilePath;
+					backups.append(be);
+				}
+				QFile::copy(op.file, replaced.absoluteFilePath());
+				QFile::setPermissions(replaced.absoluteFilePath(), unixModeToPermissions(op.mode));
+			}
+			break;
+			case GoUpdate::Operation::OP_DELETE:
+			{
+				QString trashFilePath = PathCombine(backupPath, op.file);
+				QString origFilePath = PathCombine(root(), op.file);
+				if(QFile::exists(origFilePath))
+				{
+					QFile::rename(origFilePath, trashFilePath);
+					BackupEntry be;
+					be.orig = origFilePath;
+					be.backup = trashFilePath;
+					trashcan.append(be);
+				}
+			}
+			break;
+		}
+	}
+
+	// try to start the new binary
+	qint64 pid = -1;
+	auto args = qApp->arguments();
+	args.removeFirst();
+	QProcess::startDetached(finishCmd, args, QDir::currentPath(), &pid);
+	// failed to start... ?
+	if(pid == -1)
+	{
+		goto FAILED;
+	}
+	// now clean up the backed up stuff.
+	for(auto backup:backups)
+	{
+		QFile::remove(backup.backup);
+	}
+	for(auto backup:trashcan)
+	{
+		QFile::remove(backup.backup);
+	}
+	qApp->quit();
+	return;
+
+FAILED:
+	// if the above failed, roll back changes
+	for(auto backup:backups)
+	{
+		QFile::remove(backup.orig);
+		QFile::rename(backup.backup, backup.orig);
+	}
+	for(auto backup:trashcan)
+	{
+		QFile::rename(backup.backup, backup.orig);
+	}
+	// and do nothing
 }
 
 void MultiMC::setIconTheme(const QString& name)
diff --git a/application/MultiMC.h b/application/MultiMC.h
index f815b8e4..9edf0596 100644
--- a/application/MultiMC.h
+++ b/application/MultiMC.h
@@ -6,6 +6,7 @@
 #include <QFlag>
 #include <QIcon>
 #include <QDateTime>
+#include <updater/GoUpdate.h>
 
 class QFile;
 class MinecraftVersionList;
@@ -105,7 +106,7 @@ public:
 	}
 
 	// APPLICATION ONLY
-	void installUpdates(const QString updateFilesDir);
+	void installUpdates(const QString updateFilesDir, GoUpdate::OperationList operations);
 
 	/*!
 	 * Opens a json file using either a system default editor, or, if note empty, the editor
diff --git a/logic/updater/DownloadTask.cpp b/logic/updater/DownloadTask.cpp
index 352f1f0d..4a42f583 100644
--- a/logic/updater/DownloadTask.cpp
+++ b/logic/updater/DownloadTask.cpp
@@ -89,7 +89,6 @@ void DownloadTask::processDownloadedVersionInfo()
 {
 	VersionFileList m_currentVersionFileList;
 	VersionFileList m_newVersionFileList;
-	OperationList operationList;
 
 	setStatus(tr("Reading file list for new version..."));
 	qDebug() << "Reading file list for new version...";
@@ -125,19 +124,12 @@ void DownloadTask::processDownloadedVersionInfo()
 	NetJobPtr netJob (new NetJob("Update Files"));
 
 	// fill netJob and operationList
-	if (!processFileLists(m_currentVersionFileList, m_newVersionFileList, m_status.rootPath, m_updateFilesDir.path(), netJob, operationList))
+	if (!processFileLists(m_currentVersionFileList, m_newVersionFileList, m_status.rootPath, m_updateFilesDir.path(), netJob, m_operations))
 	{
 		emitFailed(tr("Failed to process update lists..."));
 		return;
 	}
 
-	// write the instruction file for the file swapper
-	if(!writeInstallScript(operationList, PathCombine(m_updateFilesDir.path(), "file_list.xml")))
-	{
-		emitFailed(tr("Failed to write update script file."));
-		return;
-	}
-
 	// Now start the download.
 	QObject::connect(netJob.get(), &NetJob::succeeded, this, &DownloadTask::fileDownloadFinished);
 	QObject::connect(netJob.get(), &NetJob::progress, this, &DownloadTask::fileDownloadProgressChanged);
@@ -170,4 +162,9 @@ QString DownloadTask::updateFilesDir()
 	return m_updateFilesDir.path();
 }
 
+OperationList DownloadTask::operations()
+{
+	return m_operations;
+}
+
 }
\ No newline at end of file
diff --git a/logic/updater/DownloadTask.h b/logic/updater/DownloadTask.h
index 197aa3e6..3bc504fc 100644
--- a/logic/updater/DownloadTask.h
+++ b/logic/updater/DownloadTask.h
@@ -35,6 +35,9 @@ public:
 	/// Get the directory that will contain the update files.
 	QString updateFilesDir();
 
+	/// Get the list of operations that should be done
+	OperationList operations();
+
 	/// set updater download behavior
 	void setUseLocalUpdater(bool useLocal);
 
@@ -61,6 +64,8 @@ protected:
 
 	Status m_status;
 
+	OperationList m_operations;
+
 	/*!
 	 * Temporary directory to store update files in.
 	 * This will be set to not auto delete. Task will fail if this fails to be created.
diff --git a/logic/updater/GoUpdate.cpp b/logic/updater/GoUpdate.cpp
index d85f00d6..a43c5e7c 100644
--- a/logic/updater/GoUpdate.cpp
+++ b/logic/updater/GoUpdate.cpp
@@ -213,78 +213,4 @@ bool fixPathForOSX(QString &path)
 		return false;
 	}
 }
-
-bool writeInstallScript(OperationList &opsList, QString scriptFile)
-{
-	// Build the base structure of the XML document.
-	QDomDocument doc;
-
-	QDomElement root = doc.createElement("update");
-	root.setAttribute("version", "3");
-	doc.appendChild(root);
-
-	QDomElement installFiles = doc.createElement("install");
-	root.appendChild(installFiles);
-
-	QDomElement removeFiles = doc.createElement("uninstall");
-	root.appendChild(removeFiles);
-
-	// Write the operation list to the XML document.
-	for (Operation op : opsList)
-	{
-		QDomElement file = doc.createElement("file");
-
-		switch (op.type)
-		{
-		case Operation::OP_COPY:
-		{
-			// Install the file.
-			QDomElement name = doc.createElement("source");
-			QDomElement path = doc.createElement("dest");
-			QDomElement mode = doc.createElement("mode");
-			name.appendChild(doc.createTextNode(op.file));
-			path.appendChild(doc.createTextNode(op.dest));
-			// We need to add a 0 at the beginning here, because Qt doesn't convert to octal
-			// correctly.
-			mode.appendChild(doc.createTextNode("0" + QString::number(op.mode, 8)));
-			file.appendChild(name);
-			file.appendChild(path);
-			file.appendChild(mode);
-			installFiles.appendChild(file);
-			qDebug() << "Will install file " << op.file << " to " << op.dest;
-		}
-		break;
-
-		case Operation::OP_DELETE:
-		{
-			// Delete the file.
-			file.appendChild(doc.createTextNode(op.file));
-			removeFiles.appendChild(file);
-			qDebug() << "Will remove file" << op.file;
-		}
-		break;
-
-		default:
-			qWarning() << "Can't write update operation of type" << op.type
-						<< "to file. Not implemented.";
-			continue;
-		}
-	}
-
-	// Write the XML document to the file.
-	QFile outFile(scriptFile);
-
-	if (outFile.open(QIODevice::WriteOnly))
-	{
-		outFile.write(doc.toByteArray());
-	}
-	else
-	{
-		return false;
-	}
-
-	return true;
-}
-
-
 }
\ No newline at end of file
diff --git a/logic/updater/GoUpdate.h b/logic/updater/GoUpdate.h
index 941c4e3a..21976f8f 100644
--- a/logic/updater/GoUpdate.h
+++ b/logic/updater/GoUpdate.h
@@ -88,23 +88,18 @@ struct Operation
 		OP_DELETE,
 	} type;
 
-	//! The file to operate on. If this is a DELETE or CHMOD operation, this is the file that will be modified.
+	//! The file to operate on.
 	QString file;
 
-	//! The destination file. If this is a DELETE or CHMOD operation, this field will be ignored.
+	//! The destination file.
 	QString dest;
 
-	//! The mode to change the source file to. Ignored if this isn't a CHMOD operation.
+	//! The mode to change the source file to.
 	int mode;
 };
 typedef QList<Operation> OperationList;
 
 /**
- * Takes the @OperationList list and writes an install script for the updater to the update files directory.
- */
-bool writeInstallScript(OperationList& opsList, QString scriptFile);
-
-/**
  * Loads the file list from the given version info JSON object into the given list.
  */
 bool parseVersionInfo(const QByteArray &data, VersionFileList& list, QString &error);
diff --git a/tests/tst_DownloadTask.cpp b/tests/tst_DownloadTask.cpp
index 289aa195..eb58762b 100644
--- a/tests/tst_DownloadTask.cpp
+++ b/tests/tst_DownloadTask.cpp
@@ -69,20 +69,6 @@ slots:
 	{
 	}
 
-	void test_writeInstallScript()
-	{
-		OperationList ops;
-
-		ops << Operation::CopyOp("sourceOne", "destOne", 0777)
-			<< Operation::CopyOp("MultiMC.exe", "M/u/l/t/i/M/C/e/x/e")
-			<< Operation::DeleteOp("toDelete.abc");
-		auto testFile = "tests/data/tst_DownloadTask-test_writeInstallScript.xml";
-		const QString script = QDir::temp().absoluteFilePath("MultiMCUpdateScript.xml");
-		QVERIFY(writeInstallScript(ops, script));
-		QCOMPARE(TestsInternal::readFileUtf8(script).replace(QRegExp("[\r\n]+"), "\n"),
-				 MULTIMC_GET_TEST_FILE_UTF8(testFile).replace(QRegExp("[\r\n]+"), "\n"));
-	}
-
 	void test_parseVersionInfo_data()
 	{
 		QTest::addColumn<QByteArray>("data");