+/* These construct a message in a buffer, truncating if necessary.
+ * _string is only safe for trusted input and *not* UTF-8 (sorry).
+ * _packet_string is safe for any input, including untrusted.
+ * _terminate arranges for the buffer to be null-terminated (and
+ * maybe for a trailing `...' to indicate truncation), and returns
+ * a pointer to the null-terminated string. */
+void truncmsg_add_string(struct buffer_if *buf, cstring_t s);
+void truncmsg_add_packet_string(struct buffer_if*, int32_t, const uint8_t*);
+const char *truncmsg_terminate(const struct buffer_if *buf);
+
+
+struct priomsg {
+ /* U: uninitialised
+ * F: initialised but free (no memory allocated), no leak if discarded
+ * Z: contains no message yet
+ * M: contains some message; you may call truncmsg_add_*
+ */
+ int prio;
+ struct buffer_if m;
+};
+
+void priomsg_new(struct priomsg *pm, int32_t maxlen); /* UF -> Z */
+void priomsg_destroy(struct priomsg *pm, int32_t maxlen); /* FZM -> F */
+void priomsg_reset(struct priomsg *pm); /* FZM -> Z */
+bool_t priomsg_update_p(struct priomsg *pm, int prio); /* ZM -> M */
+ /* returns true iff message of priority prio ought to be added,
+ * caller should then call truncmsg_add_*.
+ * pm may be NULL, in which case it just returns false */
+const char *priomsg_getmessage(const struct priomsg *pm, const char *defmsg);
+ /* return value is null-terminated, valid until next call
+ * or until defmsg is no longer valid ZM */
+
+bool_t priomsg_update_fixed(struct priomsg *pm, int prio, const char *m);
+ /* convenience combination of _update_p and truncmsg_add_string */
+