+
+/*******************************************************************************
+
+ Copyright (c) 2009, Charles McGarvey
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+*******************************************************************************/
+
+#ifndef _MOOF_LOG_H_
+#define _MOOF_LOG_H_
+
+/**
+ * @file log.h
+ * Functions related to logging the process.
+ * The logging functions are logError(), logWarning(), logInfo(), and
+ * logDebug(), listed from most critical to least critical.
+ */
+
+#include <cstdlib> // exit
+#include <cerrno> // errno
+#include <cstring> // strerror
+
+
+namespace Mf {
+
+
+/**
+ * Macro which tests an assertion and issues an logError() and exits if false.
+ * This differs from the standard assert() in that this is a runtime assertion
+ * test and will always be compiled in.
+ * @param X test to perform
+ */
+
+#define ASSERT(X) if (!(X)) logError("false assertion at %s:%d, " #X \
+ " (errno: %d, %s)", __FILE__, __LINE__, errno, strerror(errno)), exit(1)
+
+
+/**
+ * Possible values used for setting the log level using LogLevel(). Log
+ * messages of lesser importance than the level specified are ignored.
+ * @see LogLevel()
+ */
+
+typedef enum {
+ NONE = -1, ///< Disable all logging.
+ ERROR = 1, ///< Log only errors.
+ WARNING = 2, ///< Log warnings and errors.
+ INFO = 3, ///< Log info, warnings, errors.
+ DEBUGGING = 4 ///< Log all messages.
+} LogLevel;
+
+
+/**
+ * Set and/or get the level of logs which will be logged. If not called,
+ * defaults to WARNING
+ * @param level LOG_LEVEL_* constant or 0 for no change.
+ * @return The currently set log level.
+ */
+
+LogLevel setLogLevel(LogLevel level);
+
+
+/**
+ * Log an error.
+ * @param fmt Log format string.
+ * @param ... Extra format arguments.
+ */
+
+void logError(const char* fmt, ...);
+
+/**
+ * Log a warning.
+ * @param fmt Log format string.
+ * @param ... Extra format arguments.
+ */
+
+void logWarning(const char* fmt, ...);
+
+/**
+ * Log a message.
+ * @param fmt Log format string.
+ * @param ... Extra format arguments.
+ */
+
+void logInfo(const char* fmt, ...);
+
+/**
+ * Log a debug message.
+ * @param fmt Log format string.
+ * @param ... Extra format arguments.
+ */
+
+void logDebug(const char* fmt, ...);
+
+
+} // namespace Mf
+
+#endif // _MOOF_LOG_H_
+