/** \file debug.h * A C library for generating and controlling debug output */ #ifndef __CMYTH_DEBUG_H #define __CMYTH_DEBUG_H #include #include #include typedef struct { char *name; int cur_level; int (*selector)(int plevel, int slevel); void (*msg_callback)(int level, char *msg); } cmyth_debug_ctx_t; /** * Make a static initializer for an cmyth_debug_ctx_t which provides a debug * context for a subsystem. This is a macro. * \param n subsystem name (a static string is fine) * \param l initial debug level for the subsystem * \param s custom selector function pointer (NULL is okay) */ #define CMYTH_DEBUG_CTX_INIT(n,l,s) { n, l, s, NULL } /** * Set the debug level to be used for the subsystem * \param ctx the subsystem debug context to use * \param level the debug level for the subsystem * \return an integer subsystem id used for future interaction */ static inline void __cmyth_dbg_setlevel(cmyth_debug_ctx_t *ctx, int level) { if (ctx != NULL) { ctx->cur_level = level; } } /** * Generate a debug message at a given debug level * \param ctx the subsystem debug context to use * \param level the debug level of the debug message * \param fmt a printf style format string for the message * \param ... arguments to the format */ static inline void __cmyth_dbg(cmyth_debug_ctx_t *ctx, int level, char *fmt, va_list ap) { char msg[4096]; int len; if (!ctx) { return; } if ((ctx->selector && ctx->selector(level, ctx->cur_level)) || (!ctx->selector && (level < ctx->cur_level))) { len = snprintf(msg, sizeof(msg), "(%s)", ctx->name); vsnprintf(msg + len, sizeof(msg)-len, fmt, ap); if (ctx->msg_callback) { ctx->msg_callback(level, msg); } else { fwrite(msg, strlen(msg), 1, stdout); } } } #endif /* __CMYTH_DEBUG_H */