Initial commit

backends/log/log.cpp

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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, 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 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "backends/log/log.h"
+
+#include "common/stream.h"
+#include "common/str.h"
+#include "common/system.h"
+
+#include "base/version.h"
+
+namespace Backends {
+namespace Log {
+
+Log::Log(OSystem *system)
+	: _system(system), _stream(nullptr), _startOfLine(true) {
+	assert(system);
+}
+
+void Log::open(Common::WriteStream *stream) {
+	// Close the previous log
+	close();
+
+	_stream = stream;
+
+	// Output information about the ScummVM version at the start of the log
+	// file
+	print(gScummVMFullVersion);
+	print("\n");
+	print(gScummVMFeatures);
+	print("\n");
+	print("--- Log opened.\n");
+	_startOfLine = true;
+}
+
+void Log::close() {
+	if (_stream) {
+		// Output a message to indicate that the log was closed successfully
+		print("--- Log closed successfully.\n");
+
+		// This avoids a segfault if a warning is issued when deleting the stream
+		Common::WriteStream *stream = _stream;
+		_stream = nullptr;
+
+		delete stream;
+	}
+}
+
+void Log::print(const char *message, const bool printTime) {
+	if (!_stream)
+		return;
+
+	while (*message) {
+		if (_startOfLine) {
+			_startOfLine = false;
+			if (printTime)
+				printTimeStamp();
+		}
+
+		const char *msgStart = message;
+		// scan for end of line/string
+		while (*message && *message != '\n')
+			++message;
+
+		if (*message == '\n') {
+			++message;
+			_startOfLine = true;
+		}
+
+		// TODO: It might be wise to check for write errors and/or incomplete
+		// writes here, since losing certain bits of the log is not nice.
+		_stream->write(msgStart, message - msgStart);
+	}
+
+	_stream->flush();
+}
+
+void Log::printTimeStamp() {
+	TimeDate date;
+	int curMonth;
+	_system->getTimeAndDate(date, true);
+	curMonth = date.tm_mon + 1; // month is base 0, we need base 1 (1 = january and so on)
+
+	_stream->writeString(Common::String::format("[%d-%02d-%02d %02d:%02d:%02d] ",
+	                     date.tm_year + 1900, curMonth, date.tm_mday,
+	                     date.tm_hour, date.tm_min, date.tm_sec));
+}
+
+} // End of namespace Log
+} // End of namespace Backends

backends/log/log.h

@@ -0,0 +1,127 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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, 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 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef BACKENDS_LOG_LOG_H
+#define BACKENDS_LOG_LOG_H
+
+#include "common/scummsys.h"
+
+class OSystem;
+
+namespace Common {
+class WriteStream;
+} // End of namespace Common
+
+namespace Backends {
+namespace Log {
+
+/**
+ * Log file writer.
+ *
+ * This can be used by the backends to implement file logging functionality.
+ */
+class Log {
+public:
+	/**
+	 * Constructor for the logger object.
+	 *
+	 * @param system The OSystem instance to use. Must be non-null.
+	 */
+	Log(OSystem *system);
+	~Log() { close(); }
+
+	/**
+	 * Opens a new log file.
+	 *
+	 * The previous log, which was handled by this logger, will be closed
+	 * before the new stream is associated.
+	 *
+	 * The current implemention will always call flush after data is written
+	 * to the log file. It might thus be wise to pass an unbuffered write
+	 * stream here to avoid unnecessary overhead.
+	 * @see Common::WriteStream::flush
+	 *
+	 * Calling open with stream being 0 is valid and will result in the same
+	 * behavior as calling close, but it may have additional overhead.
+	 * @see close
+	 *
+	 * This function will output information about the ScummVM version and
+	 * the features built into ScummVM automatically. It will also add a short
+	 * notice to indicate that the log was opened successfully.
+	 *
+	 * @param stream Stream where to output the log contents.
+	 *               Note that the stream will be deleted by the logger.
+	 */
+	void open(Common::WriteStream *stream);
+
+	/**
+	 * Closes the current log file.
+	 *
+	 * This function will output a line saying that the log was closed
+	 * successfully. This can be used to check whether a log is incomplete
+	 * because of whatever reasons.
+	 */
+	void close();
+
+	/**
+	 * Prints a message to the log stream.
+	 *
+	 * This has optional support to output a timestamp on every new line.
+	 * The timestamp will look like: "[YYYY-MM-DD HH:MM:SS] ".
+	 * Printing of a timestamp is done by default.
+	 *
+	 * It might be noteworthy that this function does not append a new line
+	 * to the given message.
+	 *
+	 * In case no stream is associated with this logger, this function will
+	 * quit immediately.
+	 *
+	 * @param message            The message to write.
+	 * @param printTimeOnNewline Whether to print a timestamp on the start of
+	 *                           a new line.
+	 */
+	void print(const char *message, const bool printTimeOnNewline = true);
+private:
+	/**
+	 * Prints a time stamp in the form: "[YYYY-MM-DD HH:MM:SS] ".
+	 */
+	void printTimeStamp();
+
+	/**
+	 * The OSystem instance used to query data like the time.
+	 */
+	OSystem *_system;
+
+	/**
+	 * Where to write the output too.
+	 */
+	Common::WriteStream *_stream;
+
+	/**
+	 * Whether we are at the start of a line.
+	 */
+	bool _startOfLine;
+};
+
+} // End of namespace Log
+} // End of namespace Backends
+
+#endif