Hi,
Jonathan Tan wrote:
> When "ACK %s ready" is received, find_common() clears rev_list in an
> attempt to stop further "have" lines from being sent [1]. This appears
> to work, despite the invocation to mark_common() in the "while" loop.
Does "appears to work" mean "works" or "doesn't work but does an okay
job of faking"?
> Though it is possible for mark_common() to invoke rev_list_push() (thus
> making rev_list non-empty once more), it is more likely that the commits
nit: s/more likely/most likely/
or s/it is more likely that/usually/
> in rev_list that have un-SEEN parents are also unparsed, meaning that
> mark_common() is not invoked on them.
>
> To avoid all this uncertainty, it is better to explicitly end the loop
> when "ACK %s ready" is received instead of clearing rev_list. Remove the
> clearing of rev_list and write "if (got_ready) break;" instead.
I'm still a little curious about whether this can happen in practice
or whether it's just about readability (or whether you didn't figure
out which, which is perfectly fine), but either way it's a good
change.
> The corresponding code for protocol v2 in process_acks() does not have
> the same problem, because the invoker of process_acks()
> (do_fetch_pack_v2()) proceeds immediately to processing the packfile
nit: s/proceeds/procedes/
> upon "ACK %s ready". The clearing of rev_list here is thus redundant,
> and this patch also removes it.
>
> [1] The rationale is further described in the originating commit
> f2cba9299b ("fetch-pack: Finish negotation if remote replies "ACK %s
> ready"", 2011-03-14).
>
> Signed-off-by: Jonathan Tan <jonathanta...@google.com>
> ---
> fetch-pack.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
[...]
> +++ b/fetch-pack.c
> @@ -517,10 +517,8 @@ static int find_common(struct fetch_pack_args *args,
> mark_common(commit, 0, 1);
> retval = 0;
> got_continue = 1;
> - if (ack == ACK_ready) {
> - clear_prio_queue(&rev_list);
> + if (ack == ACK_ready)
> got_ready = 1;
> - }
> break;
> }
> }
> @@ -530,6 +528,8 @@ static int find_common(struct fetch_pack_args *args,
> print_verbose(args, _("giving up"));
> break; /* give up */
> }
> + if (got_ready)
> + break;
Makes sense.
> @@ -1281,7 +1281,6 @@ static int process_acks(struct packet_reader *reader,
> struct oidset *common)
> }
>
> if (!strcmp(reader->line, "ready")) {
> - clear_prio_queue(&rev_list);
> received_ready = 1;
> continue;
I'm curious about the lifetime of &rev_list. Does the priority queue
get freed eventually?
Thanks,
Jonathan
