better logging (maybe) and exception handling

[chaz/yoink] / src / Moof / Log.hh

diff --git a/src/Moof/Log.hh b/src/Moof/Log.hh
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+++ b/src/Moof/Log.hh
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+
+/*******************************************************************************
+
+ 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_
+