stats: openmetrics - Use json_append_escaped

It does the job exactly as openmetrics specs say.

diff --git a/src/stats/stats-service-openmetrics.c b/src/stats/stats-service-openmetrics.c
index 3839ca28b293cc83931ecf88cfdfb6542d52ff58..0abc8ec7bda0375ffa0c21e961d0e0a908bf2788 100644 (file)
--- a/src/stats/stats-service-openmetrics.c
+++ b/src/stats/stats-service-openmetrics.c
@@ -4,6 +4,7 @@
 #include "dovecot-version.h"
 #include "str.h"
 #include "array.h"
+#include "json-parser.h"
 #include "ioloop.h"
 #include "ostream.h"
 #include "stats-dist.h"
@@ -117,46 +118,6 @@ static bool openmetrics_check_metric(const struct metric *metric)
        return TRUE;
 }
 
-/* https://prometheus.io/docs/prometheus/latest/querying/basics/#literals:
-
-   PromQL follows the same escaping rules as Go. In single or double quotes a
-   backslash begins an escape sequence, which may be followed by a, b, f, n, r,
-   t, v or \. Specific characters can be provided using octal (\nnn) or
-   hexadecimal (\xnn, \unnnn and \Unnnnnnnn).
-
-   https://golang.org/ref/spec#String_literals:
-
-   Interpreted string literals are character sequences between double quotes, as
-   in "bar". Within the quotes, any character may appear except newline and
-   unescaped double quote. The text between the quotes forms the value of the
-   literal, with backslash escapes interpreted as they are in rune literals
-   (except that \' is illegal and \" is legal), with the same restrictions.
-
-   -> Cannot use strescape.h, since \' is illegal.
- */
-static void openmetrics_escape_string(string_t *dest, const char *value)
-{
-       const unsigned char *pstart, *p, *pend;
-
-       pstart = p = (const unsigned char *)value;
-       pend = pstart + strlen(value);
-
-       /* See if we need to quote it */
-       for (; p < pend; p++) {
-               if (*p == '\n' || *p == '"')
-                       break;
-       }
-
-       /* Quote */
-       str_append_data(dest, pstart, (size_t)(p - pstart));
-
-       for (; p < pend; p++) {
-               if (*p == '\n' || *p == '"')
-                       str_append_c(dest, '\\');
-               str_append_data(dest, p, 1);
-       }
-}
-
 static void openmetrics_export_dovecot(string_t *out, int64_t timestamp)
 {
        i_assert(stats_startup_time <= ioloop_time);
@@ -189,7 +150,7 @@ openmetrics_export_metric_labels(string_t *out, const struct metric *metric)
 
        str_append(out, filters[0]);
        str_append(out, "=\"");
-       openmetrics_escape_string(out, filters[1]);
+       json_append_escaped(out, filters[1]);
        str_append_c(out, '"');
 
        count /= 2;
@@ -197,7 +158,7 @@ openmetrics_export_metric_labels(string_t *out, const struct metric *metric)
                str_append_c(out, ',');
                str_append(out, filters[i * 2]);
                str_append(out, "=\"");
-               openmetrics_escape_string(out, filters[i * 2 + 1]);
+               json_append_escaped(out, filters[i * 2 + 1]);
                str_append_c(out, '"');
        }
 }
@@ -383,7 +344,7 @@ openmetrics_export_submetric(struct openmetrics_request *req, string_t *out,
                             const struct metric *metric, int64_t timestamp)
 {
        str_append_c(req->labels, '"');
-       openmetrics_escape_string(req->labels, metric->sub_name);
+       json_append_escaped(req->labels, metric->sub_name);
        str_append_c(req->labels, '"');
 
        if (req->metric_type == OPENMETRICS_METRIC_TYPE_HISTOGRAM) {