diff --git a/src/lib/swim/swim_io.c b/src/lib/swim/swim_io.c index 03d79ae3e1cd4ca83df92bce0fd7102359696a51..7d6addf02ff2ca2ca4d1c4221c7e6003d41fae1f 100644 --- a/src/lib/swim/swim_io.c +++ b/src/lib/swim/swim_io.c @@ -57,6 +57,31 @@ swim_packet_create(struct swim_packet *packet) swim_packet_alloc_meta(packet, sizeof(struct swim_meta_header_bin)); } +/** Fill metadata prefix of a packet. */ +static inline void +swim_packet_build_meta(struct swim_packet *packet, + const struct sockaddr_in *src) +{ + char *meta = packet->meta; + char *end = packet->body; + /* + * Meta has already been built. It happens when the same + * task is resent multiple times. + */ + if (meta == end) + return; + struct swim_meta_header_bin header; + swim_meta_header_bin_create(&header, src); + assert(meta + sizeof(header) == end); + memcpy(meta, &header, sizeof(header)); + /* + * Once meta is built, it is consumed by the body. Used + * not to rebuild the meta again if the task will be + * scheduled again without changes in data. + */ + packet->body = packet->meta; +} + void swim_task_create(struct swim_task *task, swim_task_f complete, swim_task_f cancel, const char *desc) @@ -298,9 +323,7 @@ swim_scheduler_on_output(struct ev_loop *loop, struct ev_io *io, int events) say_verbose("SWIM %d: send %s to %s", swim_scheduler_fd(scheduler), task->desc, sio_strfaddr((struct sockaddr *) &task->dst, sizeof(task->dst))); - struct swim_meta_header_bin header; - swim_meta_header_bin_create(&header, &scheduler->transport.addr); - memcpy(task->packet.meta, &header, sizeof(header)); + swim_packet_build_meta(&task->packet, &scheduler->transport.addr); int rc = swim_transport_send(&scheduler->transport, task->packet.buf, task->packet.pos - task->packet.buf, (const struct sockaddr *) &task->dst,