+/* 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+ * or until defmsg is no longer valid ZM */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 */
+
+/*
+ * void BUF_ADD_BYTES(append, struct buffer_if*, const void*, int32_t size);
+ * void BUF_ADD_BYTES(prepend, struct buffer_if*, const void*, int32_t size);
+ * void BUF_GET_BYTES(unappend, struct buffer_if*, void*, int32_t size);
+ * void BUF_GET_BYTES(unprepend, struct buffer_if*, void*, int32_t size);
+ * // all of these evaluate size twice
+ *
+ * void BUF_ADD_OBJ(append, struct_buffer_if*, const OBJECT& something);
+ * void BUF_ADD_OBJ(prepend, struct_buffer_if*, const OBJECT& something);
+ * void BUF_GET_OBJ(unappend, struct_buffer_if*, OBJECT& something);
+ * void BUF_GET_OBJ(unprepend, struct_buffer_if*, OBJECT& something);
+ */
+#define BUF_ADD_BYTES(appendprepend, bufp, datap, size) \
+ (buf_un##appendprepend /* ensures we have correct direction */, \
+ memcpy(buf_##appendprepend((bufp),(size)),(datap),(size)))
+#define BUF_ADD_OBJ(appendprepend, bufp, obj) \
+ BUF_ADD_BYTES(appendprepend,(bufp),&(obj),sizeof((obj)))
+#define BUF_GET_BYTES(unappendunprepend, bufp, datap, size) \
+ (BUF_GET__DOESNOTEXIST__buf_un##unappendunprepend, \
+ memcpy((datap),buf_##unappendunprepend((bufp),(size)),(size)))
+#define BUF_GET_OBJ(unappendunprepend, bufp, obj) \
+ BUF_ADD_BYTES(unappendunprepend,&(obj),(bufp),sizeof((obj)))
+#define BUF_GET__DOESNOTEXIST__buf_ununappend 0
+#define BUF_GET__DOESNOTEXIST__buf_ununprepend 0
+