git@vger.kernel.org mailing list mirror (one of many)
 help / color / mirror / code / Atom feed
From: Michael Haggerty <mhagger@alum.mit.edu>
To: Junio C Hamano <gitster@pobox.com>
Cc: Kim Gybels <kgybels@infogroep.be>,
	Johannes Schindelin <johannes.schindelin@gmx.de>,
	Jeff King <peff@peff.net>,
	git@vger.kernel.org, Michael Haggerty <mhagger@alum.mit.edu>
Subject: [PATCH 0/6] Yet another approach to handling empty snapshots
Date: Wed, 24 Jan 2018 12:14:10 +0100	[thread overview]
Message-ID: <cover.1516791909.git.mhagger@alum.mit.edu> (raw)
In-Reply-To: <cea5e366-dc95-6f41-6373-f8bbef103561@alum.mit.edu>

This patch series fixes the handling of empty packed-refs snapshots
(i.e., those with `snapshot->buf` and friends equal to `NULL`), partly
by changing `snapshot` to store a pointer to the start of the
post-header `packed-refs` content instead of `header_len`. It makes a
couple of other improvements as well.

I'm not sure whether I like this approach better than the alternative
of always setting `snapshot->buf` to a non-NULL value, by allocating a
length-1 bit of RAM if necessary. The latter is less intrusive, though
even if that approach is taken, I think patches 01, 02, and 04 from
this patch series would be worthwhile improvements.

Michael

Kim Gybels (1):
  packed_ref_cache: don't use mmap() for small files

Michael Haggerty (5):
  struct snapshot: store `start` rather than `header_len`
  create_snapshot(): use `xmemdupz()` rather than a strbuf
  find_reference_location(): make function safe for empty snapshots
  packed_ref_iterator_begin(): make optimization more general
  load_contents(): don't try to mmap an empty file

 refs/packed-backend.c | 106 ++++++++++++++++++++++++++------------------------
 1 file changed, 55 insertions(+), 51 deletions(-)

-- 
2.14.2


  reply	other threads:[~2018-01-24 11:14 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-13 16:11 [PATCH] packed_ref_cache: don't use mmap() for small files Kim Gybels
2018-01-13 18:56 ` Johannes Schindelin
2018-01-14 19:14 ` [PATCH v2] " Kim Gybels
2018-01-15 12:17   ` [PATCH 0/3] Supplements to "packed_ref_cache: don't use mmap() for small files" Michael Haggerty
2018-01-15 12:17     ` [PATCH 1/3] SQUASH? Mention that `snapshot::buf` can be NULL for empty files Michael Haggerty
2018-01-15 12:17     ` [PATCH 2/3] create_snapshot(): exit early if the file was empty Michael Haggerty
2018-01-15 12:17     ` [PATCH 3/3] find_reference_location(): don't invoke if `snapshot->buf` is NULL Michael Haggerty
2018-01-17 20:23     ` [PATCH 0/3] Supplements to "packed_ref_cache: don't use mmap() for small files" Johannes Schindelin
2018-01-17 21:52     ` Junio C Hamano
2018-01-15 21:15 ` [PATCH] packed_ref_cache: don't use mmap() for small files Jeff King
2018-01-15 23:37   ` Kim Gybels
2018-01-15 23:52     ` Jeff King
2018-01-16 19:38       ` [PATCH v3] " Kim Gybels
2018-01-17 22:09         ` Jeff King
2018-01-21  4:41           ` Michael Haggerty
2018-01-22 19:31             ` Junio C Hamano
2018-01-24 11:05               ` Michael Haggerty
2018-01-24 11:14                 ` Michael Haggerty [this message]
2018-01-24 11:14                   ` [PATCH 1/6] struct snapshot: store `start` rather than `header_len` Michael Haggerty
2018-01-24 20:36                     ` Jeff King
2018-01-24 11:14                   ` [PATCH 2/6] create_snapshot(): use `xmemdupz()` rather than a strbuf Michael Haggerty
2018-01-24 11:14                   ` [PATCH 3/6] find_reference_location(): make function safe for empty snapshots Michael Haggerty
2018-01-24 20:27                     ` Jeff King
2018-01-24 21:11                       ` Junio C Hamano
2018-01-24 21:34                         ` Jeff King
2018-01-24 11:14                   ` [PATCH 4/6] packed_ref_iterator_begin(): make optimization more general Michael Haggerty
2018-01-24 20:32                     ` Jeff King
2018-01-24 11:14                   ` [PATCH 5/6] load_contents(): don't try to mmap an empty file Michael Haggerty
2018-01-24 11:14                   ` [PATCH 6/6] packed_ref_cache: don't use mmap() for small files Michael Haggerty
2018-01-24 20:38                   ` [PATCH 0/6] Yet another approach to handling empty snapshots Jeff King
2018-01-24 20:54                   ` Junio C Hamano
2018-02-15 16:54                   ` Johannes Schindelin
2018-01-24 18:05                 ` [PATCH v3] packed_ref_cache: don't use mmap() for small files Junio C Hamano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: http://vger.kernel.org/majordomo-info.html

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=cover.1516791909.git.mhagger@alum.mit.edu \
    --to=mhagger@alum.mit.edu \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=johannes.schindelin@gmx.de \
    --cc=kgybels@infogroep.be \
    --cc=peff@peff.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://80x24.org/mirrors/git.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).