add timespec_clear_spec() and timespec_get_spec()

src/timespec.c

@@ -124,17 +124,7 @@ bool timespec_destroy(struct mgos_timespec **ts) {
   if (!ts) {
     return false;
   }
-  while (!SLIST_EMPTY(&(*ts)->specs)) {
-    struct mgos_timespec_spec *t_spec;
-
-    t_spec = SLIST_FIRST(&(*ts)->specs);
-    SLIST_REMOVE_HEAD(&(*ts)->specs, entries);
-    if (t_spec) {
-//			LOG(LL_DEBUG, ("Removed mgos_timespec_spec"));
-      free(t_spec);
-    }
-  }
-
+  timespec_clear_spec(*ts);
   free(*ts);
   *ts = NULL;
   return true;
@@ -206,3 +196,57 @@ bool timespec_match_now(const struct mgos_timespec *ts) {
   }
   return timespec_match(ts, tm);
 }
+
+// Clear the timespec linked list
+// Returns true on success, false otherwise.
+bool timespec_clear_spec(struct mgos_timespec *ts) {
+  if (!ts) {
+    return false;
+  }
+  while (!SLIST_EMPTY(&ts->specs)) {
+    struct mgos_timespec_spec *t_spec;
+
+    t_spec = SLIST_FIRST(&ts->specs);
+    SLIST_REMOVE_HEAD(&ts->specs, entries);
+    if (t_spec) {
+      free(t_spec);
+    }
+  }
+
+  return true;
+}
+
+// Return a null terminated string in 'ret' of max retlen-1 which is a
+// comma separated set of timespec elements from the linked list.
+// Returns true on success, false otherwise.
+bool timespec_get_spec(struct mgos_timespec *ts, char *ret, int retlen) {
+  struct mgos_timespec_spec *t_spec;
+
+  if (!ts) {
+    return false;
+  }
+
+  if (!ts) {
+    return false;
+  }
+
+  if (!ret) {
+    return false;
+  }
+  *ret = '\0';
+
+  SLIST_FOREACH(t_spec, &ts->specs, entries) {
+    char spec_str[20];
+
+    snprintf(spec_str, sizeof(spec_str) - 1, "%02d:%02d:%02d-%02d:%02d:%02d", t_spec->start_h, t_spec->start_m, t_spec->start_s,
+             t_spec->stop_h, t_spec->stop_m, t_spec->stop_s);
+    if (strlen(spec_str) + strlen(ret) > retlen - 1) {
+      return false;
+    }
+    if (strlen(ret) > 0) {
+      strncat(ret, ",", retlen);
+    }
+    strncat(ret, spec_str, retlen);
+  }
+  return true;
+}