MINOR: contrib/prometheus-exporter: better output of Not-a-Number

Not necessarily mandatory but I saw a few prometheus client parsing only
`NaN`. Also most librarries do output `NaN`

Signed-off-by: William Dauchy <wdauchy@gmail.com>

diff --git a/contrib/prometheus-exporter/service-prometheus.c b/contrib/prometheus-exporter/service-prometheus.c
index aa72382d94d2c22885fe187e018792cbc76e75c6..bc9ebf3fceb24ecd35637a2d0976f6e4d7222fef 100644 (file)
--- a/contrib/prometheus-exporter/service-prometheus.c
+++ b/contrib/prometheus-exporter/service-prometheus.c
@@ -415,7 +415,7 @@ static int promex_srv_status(struct server *sv)
 
 /* Convert a field to its string representation and write it in <out>, followed
  * by a newline, if there is enough space. non-numeric value are converted in
- * "Nan" because Prometheus only support numerical values (but it is unexepceted
+ * "NaN" because Prometheus only support numerical values (but it is unexepceted
  * to process this kind of value). It returns 1 on success. Otherwise, it
  * returns 0. The buffer's length must not exceed <max> value.
  */
@@ -424,14 +424,14 @@ static int promex_metric_to_str(struct buffer *out, struct field *f, size_t max)
        int ret = 0;
 
        switch (field_format(f, 0)) {
-               case FF_EMPTY: ret = chunk_strcat(out,  "Nan\n"); break;
+               case FF_EMPTY: ret = chunk_strcat(out,  "NaN\n"); break;
                case FF_S32:   ret = chunk_appendf(out, "%d\n", f->u.s32); break;
                case FF_U32:   ret = chunk_appendf(out, "%u\n", f->u.u32); break;
                case FF_S64:   ret = chunk_appendf(out, "%lld\n", (long long)f->u.s64); break;
                case FF_U64:   ret = chunk_appendf(out, "%llu\n", (unsigned long long)f->u.u64); break;
                case FF_FLT:   ret = chunk_appendf(out, "%f\n", f->u.flt); break;
-               case FF_STR:   ret = chunk_strcat(out,  "Nan\n"); break;
-               default:       ret = chunk_strcat(out,  "Nan\n"); break;
+               case FF_STR:   ret = chunk_strcat(out,  "NaN\n"); break;
+               default:       ret = chunk_strcat(out,  "NaN\n"); break;
        }
        if (!ret || out->data > max)
                return 0;