| commit | f0bca72dc77f62d61fc355bd6fe6e32b194950b8 | [log] [tgz] |
|---|---|---|
| author | Jeff King <peff@peff.net> | Wed Jun 08 15:42:16 2016 -0400 |
| committer | Junio C Hamano <gitster@pobox.com> | Wed Jun 08 16:02:40 2016 -0700 |
| tree | 589fd55dff9a6068d5785ffd17de2d13110c94fa | |
| parent | 0b65a8dbdb38962e700ee16776a3042beb489060 [diff] |
send-pack: use buffered I/O to talk to pack-objects
We start a pack-objects process and then write all of the
positive and negative sha1s to it over a pipe. We do so by
formatting each item into a fixed-size buffer and then
writing each individually. This has two drawbacks:
1. There's some manual computation of the buffer size,
which is not immediately obvious is correct (though it
is).
2. We write() once per sha1, which means a lot more system
calls than are necessary.
We can solve both by wrapping the pipe descriptor in a stdio
handle; this is the same technique used by upload-pack when
serving fetches.
Note that we can also simplify and improve the error
handling here. The original detected a single write error
and broke out of the loop (presumably to avoid writing the
error message over and over), but never actually acted on
seeing an error; we just fed truncated input and took
whatever pack-objects returned.
In practice, this probably didn't matter, as the likely
errors would be caused by pack-objects dying (and we'd
probably just die with SIGPIPE anyway). But we can easily
make this simpler and more robust; the stdio handle keeps an
error flag, which we can check at the end.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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