From: Sebastian Harl <sh@tokkee.org>
Date: Mon, 17 Nov 2014 18:41:40 +0000 (+0100)
Subject: Make sure to print non-a-number as 'nan'.
X-Git-Tag: sysdb-0.6.0~1
X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=commitdiff_plain;h=0d7d7ec733f740fa35a41aa857a89abc1b8b8881

Make sure to print non-a-number as 'nan'.

Some versions of GNU libc use '-nan' instead which we don't want. For example,
Go's JSON package doesn't support that at all.
---

diff --git a/src/core/data.c b/src/core/data.c
index 3186aa2..9f2b1f6 100644
--- a/src/core/data.c
+++ b/src/core/data.c
@@ -851,7 +851,10 @@ sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted)
 		ret = snprintf(buf, buflen, "%"PRIi64, datum->data.integer);
 	}
 	else if (datum->type == SDB_TYPE_DECIMAL) {
-		ret = snprintf(buf, buflen, "%g", datum->data.decimal);
+		if (isnan(datum->data.decimal))
+			ret = snprintf(buf, buflen, "nan");
+		else
+			ret = snprintf(buf, buflen, "%g", datum->data.decimal);
 	}
 	else if (datum->type == SDB_TYPE_STRING) {
 		if (! datum->data.string)
diff --git a/src/core/store.c b/src/core/store.c
index 455e5a3..ad59a2e 100644
--- a/src/core/store.c
+++ b/src/core/store.c
@@ -43,6 +43,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <math.h>
 #include <pthread.h>
 
 /*
@@ -480,8 +481,13 @@ ts_tojson(sdb_timeseries_t *ts, sdb_strbuf_t *buf)
 				snprintf(time_str, sizeof(time_str), "<error>");
 			time_str[sizeof(time_str) - 1] = '\0';
 
-			sdb_strbuf_append(buf, "{\"timestamp\": \"%s\", "
-					"\"value\": \"%f\"}", time_str, ts->data[i][j].value);
+			/* Some GNU libc versions may print '-nan' which we dont' want */
+			if (isnan(ts->data[i][j].value))
+				sdb_strbuf_append(buf, "{\"timestamp\": \"%s\", "
+						"\"value\": \"nan\"}", time_str);
+			else
+				sdb_strbuf_append(buf, "{\"timestamp\": \"%s\", "
+						"\"value\": \"%f\"}", time_str, ts->data[i][j].value);
 
 			if (j < ts->data_len - 1)
 				sdb_strbuf_append(buf, ",");