json_dumps_ANY utility function to portably implement json_dumps(..., ... | JSON_ENCODE_ANY)

util.c

@@ -969,6 +969,50 @@ out:
 	return sret;
 }
 
+/* Dumps any JSON value as a string. Just like jansson 2.1's JSON_ENCODE_ANY
+ * flag, but this is compatible with 2.0. */
+char *json_dumps_ANY(json_t *json, size_t flags)
+{
+	switch (json_typeof(json))
+	{
+		case JSON_ARRAY:
+		case JSON_OBJECT:
+			return json_dumps(json, flags);
+		default:
+			break;
+	}
+	char *rv;
+#ifdef JSON_ENCODE_ANY
+	rv = json_dumps(json, JSON_ENCODE_ANY | flags);
+	if (rv)
+		return rv;
+#endif
+	json_t *tmp = json_array();
+	char *s;
+	int i;
+	size_t len;
+	
+	if (!tmp)
+		quit(1, "json_dumps_ANY failed to allocate json array");
+	if (json_array_append(tmp, json))
+		quit(1, "json_dumps_ANY failed to append temporary array");
+	s = json_dumps(tmp, flags);
+	if (!s)
+		return NULL;
+	for (i = 0; s[i] != '['; ++i)
+		if (unlikely(!(s[i] && isspace(s[i]))))
+			quit(1, "json_dumps_ANY failed to find opening bracket in array dump");
+	len = strlen(&s[++i]) - 1;
+	if (unlikely(s[i+len] != ']'))
+		quit(1, "json_dumps_ANY failed to find closing bracket in array dump");
+	rv = malloc(len + 1);
+	memcpy(rv, &s[i], len);
+	rv[len] = '\0';
+	free(s);
+	json_decref(tmp);
+	return rv;
+}
+
 /* Extracts a string value from a json array with error checking. To be used
  * when the value of the string returned is only examined and not to be stored.
  * See json_array_string below */

util.h

@@ -41,6 +41,7 @@
 #else
 #define JSON_LOADS(str, err_ptr) json_loads((str), (err_ptr))
 #endif
+extern char *json_dumps_ANY(json_t *, size_t flags);
 
 struct pool;
 bool stratum_send(struct pool *pool, char *s, ssize_t len);