0585ce1489
* Keep pointers to the first and last mbufs of the last record in the socket buffer. * Use the sb_lastrecord pointer in the sbappend*() family of functions to avoid traversing the packet chain to find the last record. * Add a new sbappend_stream() function for stream protocols which guarantee that there will never be more than one record in the socket buffer. This function uses the sb_mbtail pointer to perform the data insertion. Make TCP use sbappend_stream(). On a profiling run, this makes sbappend of a TCP transmission using a 1M socket buffer go from 50% of the time to .02% of the time. Thanks to Bill Sommerfeld and YAMAMOTO Takashi for their debugging assistance!