From 622e9d900e6c1ae9d90896d197360db3a06eb291 Mon Sep 17 00:00:00 2001
From: Jean-Philippe Orsini <jeanfi@gmail.com>
Date: Sun, 26 Aug 2012 10:09:34 +0000
Subject: [PATCH] improved sensor log format

---
 src/lib/slog.c             | 40 ++++++++++++++++++++++++++++++++++------
 src/server/description.txt | 23 ++++++++++++++++++++---
 2 files changed, 54 insertions(+), 9 deletions(-)

diff --git a/src/lib/slog.c b/src/lib/slog.c
index f1b2f5b..aed2a5b 100644
--- a/src/lib/slog.c
+++ b/src/lib/slog.c
@@ -21,14 +21,17 @@
 #define _(str) gettext(str)
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/time.h>
 
+#include "bool.h"
 #include "config.h"
 #include "log.h"
 #include "slog.h"
 
 static FILE *file;
 static struct timeval stv;
+static double *last_values;
 
 int slog_init(const char *path, struct psensor **sensors)
 {
@@ -47,7 +50,7 @@ int slog_init(const char *path, struct psensor **sensors)
 	fprintf(file, "I,%ld,%s\n", stv.tv_sec, VERSION);
 
 	while (*sensors) {
-		fprintf(file, "S,%s\n", (*sensors)->id);
+		fprintf(file, "S,%s,%x\n", (*sensors)->id,  (*sensors)->type);
 		sensors++;
 	}
 
@@ -56,9 +59,14 @@ int slog_init(const char *path, struct psensor **sensors)
 	return 1;
 }
 
+
+
 void slog_write_sensors(struct psensor **sensors)
 {
+	int count, i;
+	double v;
 	struct timeval tv;
+	bool first_call;
 
 	if (!file)
 		return ;
@@ -68,11 +76,27 @@ void slog_write_sensors(struct psensor **sensors)
 		return ;
 	}
 
-	fprintf(file, "M,%ld", tv.tv_sec - stv.tv_sec);
-	while (*sensors) {
-		fprintf(file, ",%.1f", psensor_get_current_value(*sensors));
-		sensors++;
+	count = psensor_list_size(sensors);
+
+	if (last_values) {
+		first_call = 0;
+	} else {
+		first_call = 1;
+		last_values = malloc(count * sizeof(double));
 	}
+
+	fprintf(file, "%ld", tv.tv_sec - stv.tv_sec);
+	for (i = 0; i < count; i++) {
+		v = psensor_get_current_value(sensors[i]);
+
+		if (!first_call && last_values[i] == v)
+			fputc(',', file);
+		else
+			fprintf(file, ",%.1f", v);
+
+		last_values[i] = v;
+	}
+
 	fputc('\n', file);
 
 	fflush(file);
@@ -80,6 +104,10 @@ void slog_write_sensors(struct psensor **sensors)
 
 void slog_close()
 {
-	if (file)
+	if (file) {
 		fclose(file);
+		file = NULL;
+		free(last_values);
+		last_values = NULL;
+	}
 }
diff --git a/src/server/description.txt b/src/server/description.txt
index 9d1696b..744dc8c 100644
--- a/src/server/description.txt
+++ b/src/server/description.txt
@@ -64,18 +64,35 @@ since EPOC.
 
 %V is the version of psensor-server.
 
-Following lines gives the ordered list of sensors: S,%I
+Following lines gives the ordered list of sensors: S,%I,%T
 
 %I is the uniq identifier of the sensor.
 
-Then, the values of all sensors are written: M,%D,%V...
+%T is the hexadecimal representation of the sensor type.
+
+Then, the values of all sensors are written: %D,%V...
 
 %D is the number of seconds elapsed since the starting time of the
 log.
 
 %V... is the list separated by a comma of the current value of all
 sensors. The ordering is the same than the list of sensor identifiers.
-The value is expressed as a float.
+
+The value is expressed as a float with one digit precision. Temperatures
+are using Celcius unit.
+
+The value is written only if it has changed.
+
+Example:
+I,1345974927,0.7.0.4
+S,lmsensor coretemp-isa-0000 Physical id 0,101
+S,lmsensor coretemp-isa-0000 Core 0,101
+S,lmsensor coretemp-isa-0000 Core 1,101
+0,37.0,37.0,36.0
+5,36.0,,36.0
+
+Five seconds after the log starts, the temperature of the second
+sensor (Core 0) is still 37C.
 
 [WARNING]
 
-- 
2.7.4