tools: Add a simple stats generator 'igt_stats'

A rudimentary tool on top of the igt_stats library. Reads a list of
numbers from stdin or from a file and prints the estimate of the central
location, aka average.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

tools/.gitignore

@@ -1,5 +1,6 @@
 # Please keep sorted alphabetically
 hsw_compute_wrpll
+igt_stats
 intel_audio_dump
 intel_backlight
 intel_bios_dumper

tools/Makefile.sources

@@ -5,6 +5,7 @@ noinst_PROGRAMS = \
 	$(NULL)
 
 bin_PROGRAMS = 				\
+	igt_stats			\
 	intel_audio_dump 		\
 	intel_reg			\
 	intel_backlight 		\

tools/igt_stats.c

@@ -0,0 +1,105 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+/* Simple tool to print statistics on incoming line buffers intervals */
+
+#define _ISOC99_SOURCE
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include "igt_stats.h"
+
+static void statify(FILE *file, const char *name)
+{
+	igt_stats_t stats;
+	char *line = NULL;
+	size_t line_len = 0;
+
+	igt_stats_init(&stats);
+	while (getline(&line, &line_len, file) != -1) {
+		char *end, *start = line;
+		union {
+			unsigned long long u64;
+			double fp;
+		} u;
+		int is_float;
+
+		is_float = 0;
+		u.u64 = strtoull(start, &end, 0);
+		if (*end == '.') {
+			u.fp = strtod(start, &end);
+			is_float = 1;
+		}
+		while (start != end) {
+			if (is_float)
+				igt_stats_push_float(&stats, u.fp);
+			else
+				igt_stats_push(&stats, u.u64);
+
+			is_float = 0;
+			u.u64 = strtoull(start = end, &end, 0);
+			if (*end == '.') {
+				u.fp = strtod(start, &end);
+				is_float = 1;
+			}
+		}
+	}
+	free(line);
+
+	if (name)
+		printf("%s: ", name);
+
+	printf("%f\n", igt_stats_get_trimean(&stats));
+
+	igt_stats_fini(&stats);
+}
+
+int main(int argc, char **argv)
+{
+	if (argc == 1) {
+		statify(stdin, NULL);
+	} else {
+		int i;
+
+		for (i = 1; i < argc; i++) {
+			FILE *file;
+
+			file = fopen(argv[i], "r");
+			if (file == NULL) {
+				perror(argv[i]);
+				continue;
+			}
+
+			statify(file, argv[i]);
+			fclose(file);
+		}
+	}
+
+	return 0;
+}