Re: [PATCH v4 01/12] pkt-line: extract set_packet_header()

Jeff King [off-list ref] writes:

The cost of write() may vary on other platforms, but the cost of memcpy
generally shouldn't. So I'm inclined to say that it is not really worth
micro-optimizing the interface.

I think the other issue is that format_packet() only lets you send
string data via "%s", so it cannot be used for arbitrary data that may
contain NULs. So we do need _some_ other interface to let you send a raw
data packet, and it's going to look similar to the direct_packet_write()
thing.

OK.  That is a much better argument than "I already stuff the length
bytes in my buffer" (which will invite "How about stop doing that?")
to justify a new "I have N bytes of data, send it out", whose
signature would look more like write(2) and deserve to be called
packet_write() but unfortunately the name is taken by what should
have called packet_fmt() or something, but that squats on a good
name packet_write().  Sigh.