log: added new module to print fancy tables and use it for histograms as well as periodc stats

config.h

@@ -41,7 +41,8 @@
 #define DEFAULT_NR_HUGEPAGES	100
 
 /** Width of log output in characters */
-#define LOG_WIDTH		132
+#define LOG_WIDTH		80
+#define LOG_HEIGHT		25
 
 /** Socket priority */
 #define SOCKET_PRIO		7

include/villas/log.h

@@ -29,14 +29,17 @@ extern "C" {
 
 #include <stdarg.h>
 #include <time.h>
+#include <sys/ioctl.h>
 
 #include "common.h"
 #include "log_config.h"
 
 #ifdef __GNUC__
   #define INDENT	int __attribute__ ((__cleanup__(log_outdent), unused)) _old_indent = log_indent(1);
+  #define NOINDENT	int __attribute__ ((__cleanup__(log_outdent), unused)) _old_indent = log_noindent();
 #else
   #define INDENT	;
+  #define NOINDENT	;
 #endif
 
 /* The log level which is passed as first argument to print() */
@@ -86,20 +89,16 @@ struct log {
 	enum state state;
 
 	struct timespec epoch;	/**< A global clock used to prefix the log messages. */
+	
+	struct winsize window;	/**< Size of the terminal window. */
 
 	/** Debug level used by the debug() macro.
 	 * It defaults to V (defined by the Makefile) and can be
 	 * overwritten by the 'debug' setting in the configuration file. */
 	int level;
-
-	/** Debug facilities used by the debug() macro. */
-	long facilities;
-
-	/** Path of the log file */
-	const char *path;
-
-	/** Send all log output to this file / stdout / stderr */
-	FILE *file;
+	long facilities;	/**< Debug facilities used by the debug() macro. */
+	const char *path;	/**< Path of the log file. */
+	FILE *file;		/**< Send all log output to this file / stdout / stderr. */
 };
 
 /** The global log instance. */
@@ -122,6 +121,9 @@ int log_destroy(struct log *l);
  */
 int log_indent(int levels);
 
+/** Disable log indention of current thread. */
+int log_noindent();
+
 /** A helper function the restore the previous log indention level.
  *
  * This function is usually called by a __cleanup__ handler (GCC C Extension).
@@ -163,9 +165,6 @@ void log_vprint(struct log *l, const char *lvl, const char *fmt, va_list va);
 void debug(long lvl, const char *fmt, ...)
 	__attribute__ ((format(printf, 2, 3)));
 
-/** Print a horizontal line. */
-void line();
-
 /** Printf alike info message. */
 void info(const char *fmt, ...)
 	__attribute__ ((format(printf, 1, 2)));
@@ -186,6 +185,41 @@ void error(const char *fmt, ...)
 void serror(const char *fmt, ...)
 	__attribute__ ((format(printf, 1, 2)));
 
+/** @addtogroup table Print fancy tables
+ * @{
+ */
+
+struct table_column {
+	int width;	/**< Width of the column. */
+	char *title;	/**< The title as shown in the table header. */
+	char *format;	/**< The format which is used to print the table rows. */
+	char *unit;	/**< An optional unit which will be shown in the table header. */
+
+	enum {
+		TABLE_ALIGN_LEFT,
+		TABLE_ALIGN_RIGHT
+	} align;
+
+	int _width;	/**< The real width of this column. Calculated by table_header() */
+};
+
+struct table {
+	int ncols;
+	int width;
+	struct table_column *cols;
+};
+
+/** Print a table header consisting of \p n columns. */
+void table_header(struct table *t);
+
+/** Print table rows. */
+void table_row(struct table *t, ...);
+
+/** Print the table footer. */
+void table_footer(struct table *t);
+
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif

include/villas/stats.h

@@ -82,6 +82,7 @@ json_t * stats_json(struct stats *s);
 void stats_reset(struct stats *s);
 
 void stats_print_header();
+void stats_print_footer();
 
 void stats_print_periodic(struct stats *s, FILE *f, enum stats_format fmt, int verbose, struct path *p);
 

include/villas/utils.h

@@ -41,12 +41,6 @@
 #endif
 
 /* Some color escape codes for pretty log messages */
-
-/* Alternate character set */
-#define ACS(chr)	"\e(0" chr "\e(B"
-#define ACS_HORIZONTAL	ACS("\x71")
-#define ACS_VERTICAL	ACS("\x78")
-#define ACS_VERTRIGHT	ACS("\x74")
 #define CLR(clr, str)	"\e[" XSTR(clr) "m" str "\e[0m"
 #define CLR_GRY(str)	CLR(30, str) /**< Print str in gray */
 #define CLR_RED(str)	CLR(31, str) /**< Print str in red */
@@ -58,6 +52,29 @@
 #define CLR_WHT(str)	CLR(37, str) /**< Print str in white */
 #define CLR_BLD(str)	CLR( 1, str) /**< Print str in bold */
 
+/* Alternate character set
+ *
+ * The suffixed of the BOX_ macro a constructed by
+ * combining the following letters in the written order:
+ *   - U for a line facing upwards
+ *   - D for a line facing downwards
+ *   - L for a line facing leftwards
+ *   - R for a line facing rightwards
+ *
+ * E.g. a cross can be constructed by combining all line fragments:
+ *    BOX_UDLR
+ */
+#define BOX(chr)	"\e(0" chr "\e(B"
+#define BOX_LR		BOX("\x71") /**< Boxdrawing: ─ */
+#define BOX_UD		BOX("\x78") /**< Boxdrawing: │ */
+#define BOX_UDR		BOX("\x74") /**< Boxdrawing: ├ */
+#define BOX_UDLR	BOX("\x6E") /**< Boxdrawing: ┼ */
+#define BOX_UDL		BOX("\x75") /**< Boxdrawing: ┤ */
+#define BOX_ULR		BOX("\x76") /**< Boxdrawing: ┴ */
+#define BOX_UL		BOX("\x6A") /**< Boxdrawing: ┘ */
+#define BOX_DLR		BOX("\x77") /**< Boxdrawing: ┘ */
+#define BOX_DL		BOX("\x6B") /**< Boxdrawing: ┘ */
+
 /* CPP stringification */
 #define XSTR(x)		STR(x)
 #define  STR(x)		#x

lib/Makefile.villas-ext.inc

@@ -26,7 +26,7 @@ LIBEXT = $(BUILDDIR)/$(LIBEXT_NAME).so.$(LIBEXT_ABI_VERSION)
 
 LIBEXT_SRCS += $(addprefix lib/, sample.c queue.c queue_signalled.c \
                  memory.c log.c shmem.c utils.c kernel/kernel.c list.c \
-                 timing.c pool.c \
+                 timing.c pool.c log_helper.c \
                )
 
 LIBEXT_LDFLAGS = -shared

lib/Makefile.villas.inc

@@ -31,7 +31,7 @@ LIB_SRCS += $(addprefix lib/nodes/, file.c cbuilder.c shmem.c signal.c) 		\
                log.c log_config.c utils.c super_node.c hist.c timing.c pool.c	\
                list.c queue.c queue_signalled.c memory.c advio.c web.c api.c	\
                plugin.c node_type.c stats.c mapping.c sample_io.c shmem.c \
-               json.c crypt.c compat.c \
+               json.c crypt.c compat.c log_table.c log_helper.c \
             )
 
 LIB_LDFLAGS = -shared

lib/hist.c

@@ -166,27 +166,36 @@ void hist_plot(struct hist *h)
 		if (h->data[i] > max)
 			max = h->data[i];
 	}
+	
+	struct table_column cols[] = {
+		{ -9, "Value", "%+9.3g", NULL,         TABLE_ALIGN_RIGHT },
+		{ -6, "Count", "%6ju",   NULL,         TABLE_ALIGN_RIGHT },
+		{  0, "Plot",  "%s",     "occurences", TABLE_ALIGN_LEFT  }
+	};
+	
+	struct table table = {
+		.ncols = ARRAY_LEN(cols),
+		.cols = cols
+	};
 
 	/* Print plot */
-	stats("%9s | %5s | %s", "Value", "Count", "Plot");
-	line();
+	table_header(&table);
 
 	for (int i = 0; i < h->length; i++) {
 		double value = VAL(h, i);
 		hist_cnt_t cnt = h->data[i];
-		int bar = HIST_HEIGHT * ((double) cnt / max);
-
-		char *buf = 0;
-		buf = strcatf(&buf, "%+9.3g | %5ju | ", value, cnt);
-
+		int bar = cols[2]._width * ((double) cnt / max);
+		
+		char *buf = strf("%s", "");
 		for (int i = 0; i < bar; i++)
 			buf = strcatf(&buf, "\u2588");
 
-		stats("%s", buf);
+		table_row(&table, value, cnt, buf);
+
 		free(buf);
 	}
-
-	line();
+	
+	table_footer(&table);
 }
 
 char * hist_dump(struct hist *h)

lib/hooks/stats_collect.c

@@ -110,8 +110,7 @@ static int stats_collect_periodic(struct hook *h)
 {
 	struct stats_collect *p = h->_vd;
 
-	if (h->path->state == STATE_STARTED)
-		stats_print_periodic(&p->stats, p->output, p->format, p->verbose, h->path);
+	stats_print_periodic(&p->stats, p->output, p->format, p->verbose, h->path);
 
 	return 0;
 }

lib/log.c

@@ -22,9 +22,10 @@
 
 #include <stdio.h>
 #include <stdbool.h>
+#include <stdarg.h>
 #include <string.h>
 #include <time.h>
-#include <errno.h>
+#include <unistd.h>
 
 #include "config.h"
 #include "log.h"
@@ -45,7 +46,11 @@ struct log default_log = {
 	.facilities = LOG_ALL,
 	.file = NULL,
 	.path = NULL,
-	.epoch = { -1 , -1 }
+	.epoch = { -1 , -1 },
+	.window = {
+		.ws_row = LOG_HEIGHT,
+		.ws_col = LOG_WIDTH
+	}
 };
 
 /** List of debug facilities as strings */
@@ -80,8 +85,41 @@ static const char *facilities_strs[] = {
 /** The current log indention level (per thread!). */
 static __thread int indent = 0;
 
+int log_indent(int levels)
+{
+	int old = indent;
+	indent += levels;
+	return old;
+}
+
+int log_noindent()
+{
+	int old = indent;
+	indent = 0;
+	return old;
+}
+
+void log_outdent(int *old)
+{
+	indent = *old;
+}
+#endif
+
+static void log_resize(int signal, siginfo_t *sinfo, void *ctx)
+{
+	int ret;
+
+	ret = ioctl(STDOUT_FILENO, TIOCGWINSZ, &global_log->window);
+	if (ret)
+		return;
+	
+	debug(LOG_LOG | 15, "New terminal size: %dx%x", global_log->window.ws_row, global_log->window.ws_col);
+}
+
 int log_init(struct log *l, int level, long facilitites)
 {
+	int ret;
+
 	/* Register this log instance globally */
 	global_log = l;
 
@@ -89,6 +127,26 @@ int log_init(struct log *l, int level, long facilitites)
 	l->facilities = facilitites;
 	l->file = stderr;
 	l->path = NULL;
+	l->window.ws_col = LOG_WIDTH;
+	l->window.ws_row = LOG_HEIGHT;
+	
+	/* Register signal handler which is called whenever the
+	 * terminal size changes. */
+	if (l->file == stderr) {
+		struct sigaction sa_resize = {
+			.sa_flags = SA_SIGINFO,
+			.sa_sigaction = log_resize
+		};
+	
+		sigemptyset(&sa_resize.sa_mask);
+	
+		ret = sigaction(SIGWINCH, &sa_resize, NULL);
+		if (ret)
+			return ret;
+	
+		/* Try to get initial window size */
+		ioctl(STDERR_FILENO, TIOCGWINSZ, &global_log->window);
+	}
 
 	l->state = STATE_INITIALIZED;
 
@@ -135,19 +193,6 @@ int log_destroy(struct log *l)
 	return 0;
 }
 
-int log_indent(int levels)
-{
-	int old = indent;
-	indent += levels;
-	return old;
-}
-
-void log_outdent(int *old)
-{
-	indent = *old;
-}
-#endif
-
 int log_set_facility_expression(struct log *l, const char *expression)
 {
 	bool negate;
@@ -212,18 +257,15 @@ void log_vprint(struct log *l, const char *lvl, const char *fmt, va_list ap)
 	struct timespec ts = time_now();
 	char *buf = alloc(512);
 
-	/* Timestamp */
-	strcatf(&buf, "%10.3f ", time_delta(&l->epoch, &ts));
-
-	/* Severity */
-	strcatf(&buf, "%5s ", lvl);
+	/* Timestamp & Severity */
+	strcatf(&buf, "%10.3f %5s ", time_delta(&l->epoch, &ts), lvl);
 
 	/* Indention */
 #ifdef __GNUC__
 	for (int i = 0; i < indent; i++)
-		strcatf(&buf, ACS_VERTICAL " ");
+		strcatf(&buf, "%s ", BOX_UD);
 
-	strcatf(&buf, ACS_VERTRIGHT " ");
+	strcatf(&buf, "%s ", BOX_UDR);
 #endif
 
 	/* Format String */
@@ -234,92 +276,6 @@ void log_vprint(struct log *l, const char *lvl, const char *fmt, va_list ap)
 	OpalPrint("VILLASnode: %s\n", buf);
 #endif
 	fprintf(l->file ? l->file : stderr, "\33[2K\r%s\n", buf);
-	free(buf);
-}
-
-void line()
-{
-	char buf[LOG_WIDTH];
-	memset(buf, 0x71, sizeof(buf));
-
-	log_print(global_log, "", "\b" ACS("%.*s"), LOG_WIDTH, buf);
-}
-
-void debug(long class, const char *fmt, ...)
-{
-	va_list ap;
-
-	struct log *l = global_log ? global_log : &default_log;
-
-	int lvl = class &  0xFF;
-	int fac = class & ~0xFF;
-
-	if (((fac == 0) || (fac & l->facilities)) && (lvl <= l->level)) {
-		va_start(ap, fmt);
-		log_vprint(l, LOG_LVL_DEBUG, fmt, ap);
-		va_end(ap);
-	}
-}
-
-void info(const char *fmt, ...)
-{
-	va_list ap;
-
-	struct log *l = global_log ? global_log : &default_log;
-
-	va_start(ap, fmt);
-	log_vprint(l, LOG_LVL_INFO, fmt, ap);
-	va_end(ap);
-}
-
-void warn(const char *fmt, ...)
-{
-	va_list ap;
-
-	struct log *l = global_log ? global_log : &default_log;
-
-	va_start(ap, fmt);
-	log_vprint(l, LOG_LVL_WARN, fmt, ap);
-	va_end(ap);
-}
-
-void stats(const char *fmt, ...)
-{
-	va_list ap;
-
-	struct log *l = global_log ? global_log : &default_log;
-
-	va_start(ap, fmt);
-	log_vprint(l, LOG_LVL_STATS, fmt, ap);
-	va_end(ap);
-}
-
-void error(const char *fmt, ...)
-{
-	va_list ap;
-
-	struct log *l = global_log ? global_log : &default_log;
-
-	va_start(ap, fmt);
-	log_vprint(l, LOG_LVL_ERROR, fmt, ap);
-	va_end(ap);
-
-	die();
-}
-
-void serror(const char *fmt, ...)
-{
-	va_list ap;
-	char *buf = NULL;
-
-	struct log *l = global_log ? global_log : &default_log;
-
-	va_start(ap, fmt);
-	vstrcatf(&buf, fmt, ap);
-	va_end(ap);
-
-	log_print(l, LOG_LVL_ERROR, "%s: %m (%u)", buf, errno);
 
 	free(buf);
-	die();
-}
+}

lib/log_helper.c

@@ -0,0 +1,105 @@
+/** Logging and debugging routines
+ *
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2017, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * 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
+ * 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 <errno.h>
+
+#include "utils.h"
+#include "log.h"
+
+void debug(long class, const char *fmt, ...)
+{
+	va_list ap;
+
+	struct log *l = global_log ? global_log : &default_log;
+
+	int lvl = class &  0xFF;
+	int fac = class & ~0xFF;
+
+	if (((fac == 0) || (fac & l->facilities)) && (lvl <= l->level)) {
+		va_start(ap, fmt);
+		log_vprint(l, LOG_LVL_DEBUG, fmt, ap);
+		va_end(ap);
+	}
+}
+
+void info(const char *fmt, ...)
+{
+	va_list ap;
+
+	struct log *l = global_log ? global_log : &default_log;
+
+	va_start(ap, fmt);
+	log_vprint(l, LOG_LVL_INFO, fmt, ap);
+	va_end(ap);
+}
+
+void warn(const char *fmt, ...)
+{
+	va_list ap;
+
+	struct log *l = global_log ? global_log : &default_log;
+
+	va_start(ap, fmt);
+	log_vprint(l, LOG_LVL_WARN, fmt, ap);
+	va_end(ap);
+}
+
+void stats(const char *fmt, ...)
+{
+	va_list ap;
+
+	struct log *l = global_log ? global_log : &default_log;
+
+	va_start(ap, fmt);
+	log_vprint(l, LOG_LVL_STATS, fmt, ap);
+	va_end(ap);
+}
+
+void error(const char *fmt, ...)
+{
+	va_list ap;
+
+	struct log *l = global_log ? global_log : &default_log;
+
+	va_start(ap, fmt);
+	log_vprint(l, LOG_LVL_ERROR, fmt, ap);
+	va_end(ap);
+
+	killme(SIGALRM);
+}
+
+void serror(const char *fmt, ...)
+{
+	va_list ap;
+	char *buf = NULL;
+
+	struct log *l = global_log ? global_log : &default_log;
+
+	va_start(ap, fmt);
+	vstrcatf(&buf, fmt, ap);
+	va_end(ap);
+
+	log_print(l, LOG_LVL_ERROR, "%s: %m (%u)", buf, errno);
+
+	free(buf);
+	killme(SIGALRM);
+}

lib/log_table.c

@@ -0,0 +1,170 @@
+/** Print fancy tables.
+ *
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2017, Institute for Automation of Complex Power Systems, EONERC
+ * @license GNU General Public License (version 3)
+ *
+ * VILLASnode
+ *
+ * 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
+ * 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 <stdlib.h>
+#include <string.h>
+
+#include "utils.h"
+#include "log.h"
+
+static int table_resize(struct table *t, int width)
+{
+	int norm, flex, fixed, total;
+
+	t->width = width;
+	
+	norm  = 0;
+	flex  = 0;
+	fixed = 0;
+	total = t->width - t->ncols * 2;
+
+	/* Normalize width */
+	for (int i = 0; i < t->ncols; i++) {
+		if (t->cols[i].width > 0)
+			norm += t->cols[i].width;
+		if (t->cols[i].width == 0)
+			flex++;
+		if (t->cols[i].width < 0)
+			fixed += -1 * t->cols[i].width;
+	}
+
+	for (int i = 0; i < t->ncols; i++) {
+		if (t->cols[i].width > 0)
+			t->cols[i]._width = t->cols[i].width * (float) (total - fixed) / norm;
+		if (t->cols[i].width == 0)
+			t->cols[i]._width = (float) (total - fixed) / flex;
+		if (t->cols[i].width < 0)
+			t->cols[i]._width = -1 * t->cols[i].width;
+	}
+
+	return 0;
+}
+
+void table_header(struct table *t)
+{ NOINDENT
+	struct log *l = global_log ? global_log : &default_log;
+
+	if (t->width != l->window.ws_col - 24)
+		table_resize(t, l->window.ws_col - 24);
+
+	char *line1 = strf("\b\b" BOX_UD);
+	char *line0 = strf("\b");
+	char *line2 = strf("\b");
+	
+	for (int i = 0; i < t->ncols; i++) {
+		char *col = strf(CLR_BLD("%s"), t->cols[i].title);
+		
+		if (t->cols[i].unit)
+			strcatf(&col, " (" CLR_YEL("%s") ")", t->cols[i].unit);
+		
+		int l = strlenp(col);
+		int r = strlen(col);
+		int w = t->cols[i]._width + r - l;
+
+		if (t->cols[i].align == TABLE_ALIGN_LEFT)
+			strcatf(&line1, " %-*.*s " BOX_UD, w, w, col);
+		else
+			strcatf(&line1, " %*.*s " BOX_UD, w, w, col);
+
+		for (int j = 0; j < t->cols[i]._width + 2; j++) {
+			strcatf(&line0, "%s", BOX_LR);
+			strcatf(&line2, "%s", BOX_LR);
+		}
+
+		if (i == t->ncols - 1) {
+			strcatf(&line0, "%s", BOX_DL);
+			strcatf(&line2, "%s", BOX_UDL);
+		}
+		else {
+			strcatf(&line0, "%s", BOX_DLR);
+			strcatf(&line2, "%s", BOX_UDLR);
+		}
+		
+		free(col);
+	}
+
+	stats(line0);
+	stats(line1);
+	stats(line2);
+	
+	free(line0);
+	free(line1);
+	free(line2);
+}
+
+void table_row(struct table *t, ...)
+{ NOINDENT
+	struct log *l = global_log ? global_log : &default_log;
+
+	if (t->width != l->window.ws_col - 24) {
+		table_resize(t, l->window.ws_col - 24);
+		table_header(t);
+	}
+
+	va_list args;
+	va_start(args, t);
+
+	char *line = strf("\b\b" BOX_UD);
+
+	for (int i = 0; i < t->ncols; ++i) {
+		char *col = vstrf(t->cols[i].format, args);
+		
+		int l = strlenp(col);
+		int r = strlen(col);
+		int w = t->cols[i]._width + r - l;
+
+		if (t->cols[i].align == TABLE_ALIGN_LEFT)
+			strcatf(&line, " %-*.*s " BOX_UD, w, w, col);
+		else
+			strcatf(&line, " %*.*s " BOX_UD, w, w, col);
+
+		free(col);
+	}
+
+	va_end(args);
+	
+	stats(line);
+	free(line);
+}
+
+void table_footer(struct table *t)
+{ NOINDENT
+	struct log *l = global_log ? global_log : &default_log;
+
+	if (t->width != l->window.ws_col - 24)
+		table_resize(t, l->window.ws_col - 24);
+	
+	char *line = strf("\b");
+	
+	for (int i = 0; i < t->ncols; i++) {
+		for (int j = 0; j < t->cols[i]._width + 2; j++)
+			strcatf(&line, BOX_LR);
+		
+		if (i == t->ncols - 1)
+			strcatf(&line, "%s", BOX_UL);
+		else
+			strcatf(&line, "%s", BOX_ULR);
+	}
+	
+	stats(line);
+	free(line);
+}

lib/stats.c

@@ -34,7 +34,7 @@ static struct stats_desc {
 	const char *unit;
 	const char *desc;
 	int hist_buckets;
-} stats_table[] = {
+} stats_metrics[] = {
 	{ "skipped",	  "samples",	"skipped samples by hooks",						25 },
 	{ "reorderd",	  "samples",	"reordered samples",							25 },
 	{ "gap_sample",	  "seconds",	"inter message timestamps (as sent by remote)",				25 },
@@ -116,7 +116,7 @@ json_t * stats_json(struct stats *s)
 	json_t *obj = json_object();
 
 	for (int i = 0; i < STATS_COUNT; i++) {
-		struct stats_desc *desc = &stats_table[i];
+		struct stats_desc *desc = &stats_metrics[i];
 
 		json_t *stats = hist_json(&s->histograms[i]);
 
@@ -145,19 +145,36 @@ void stats_reset(struct stats *s)
 	}
 }
 
+static struct table_column stats_cols[] = {
+	{ 35, "Path", "%s", NULL,   TABLE_ALIGN_LEFT },
+	{ 10, "Cnt",  "%ju", "p",   TABLE_ALIGN_RIGHT },
+	{ 10, "OWD",  "%f",  "S",   TABLE_ALIGN_RIGHT },
+	{ 10, "Rate", "%f",  "p/S", TABLE_ALIGN_RIGHT },
+	{ 10, "Drop", "%ju", "p",   TABLE_ALIGN_RIGHT },
+	{ 10, "Skip", "%ju", "p",   TABLE_ALIGN_RIGHT }
+};
+
+static struct table stats_table = {
+	.ncols = ARRAY_LEN(stats_cols),
+	.cols = stats_cols
+};
+
 void stats_print_header(enum stats_format fmt)
 {
-	#define UNIT(u)	"(" YEL(u) ")"
-
 	switch (fmt) {
 		case STATS_FORMAT_HUMAN:
-			stats("%-40s|%19s|%19s|%19s|%19s|", "Source " MAG("=>") " Destination",
-				"OWD"	UNIT("S") " ",
-				"Rate"	UNIT("p/S") " ",
-				"Drop"	UNIT("p") " ",
-				"Skip"	UNIT("p") " "
-			);
-			line();
+			table_header(&stats_table);
+			break;
+
+		default: { }
+	}
+}
+
+void stats_print_footer(enum stats_format fmt)
+{
+	switch (fmt) {
+		case STATS_FORMAT_HUMAN:
+			table_footer(&stats_table);
 			break;
 
 		default: { }
@@ -168,7 +185,9 @@ void stats_print_periodic(struct stats *s, FILE *f, enum stats_format fmt, int v
 {
 	switch (fmt) {
 		case STATS_FORMAT_HUMAN:
-			stats("%-40.40s|%10f|%10f|%10ju|%10ju|", path_name(p),
+			table_row(&stats_table,
+				path_name(p),
+				s->histograms[STATS_OWD].total,
 				s->histograms[STATS_OWD].last,
 				1.0 / s->histograms[STATS_GAP_SAMPLE].last,
 				s->histograms[STATS_REORDERED].total,
@@ -191,7 +210,7 @@ void stats_print(struct stats *s, FILE *f, enum stats_format fmt, int verbose)
 	switch (fmt) {
 		case STATS_FORMAT_HUMAN:
 			for (int i = 0; i < STATS_COUNT; i++) {
-				struct stats_desc *desc = &stats_table[i];
+				struct stats_desc *desc = &stats_metrics[i];
 
 				stats("%s: %s", desc->name, desc->desc);
 				hist_print(&s->histograms[i], verbose);
@@ -231,7 +250,7 @@ void stats_send(struct stats *s, struct node *n)
 enum stats_id stats_lookup_id(const char *name)
 {
 	for (int i = 0; i < STATS_COUNT; i++) {
-		struct stats_desc *desc = &stats_table[i];
+		struct stats_desc *desc = &stats_metrics[i];
 
 		if (!strcmp(desc->name, name))
 			return i;

src/node.c

@@ -47,6 +47,9 @@ struct super_node sn;
 
 static void quit(int signal, siginfo_t *sinfo, void *ctx)
 {
+	if (sn.stats > 0)
+		stats_print_footer(STATS_FORMAT_HUMAN);
+	
 	super_node_stop(&sn);
 	super_node_destroy(&sn);
 
@@ -119,7 +122,7 @@ int main(int argc, char *argv[])
 	super_node_start(&sn);
 
 	if (sn.stats > 0)
-		stats_print_header();
+		stats_print_header(STATS_FORMAT_HUMAN);
 
 	struct timespec now, last = time_now();