Hi Joe,
On Thu, Jul 3, 2014 at 12:00 AM, Joe Perches [off-list ref] wrote:
Commit logs have various forms of commit id references.
Try to standardize on a 12 character long lower case
commit id along with a description of parentheses and
the quoted subject line
ie: commit 0123456789ab ("commit description")
Now this is in mainline, checkpatch starts complaining about my "too long"
(40 chars) commit IDs in commit messages :-(
40 chars may be too long (but it's quick to copy-and-paste, as "git show"
shows that by default), but 12 sounds a bit short, as that's only 48 bits.
According to the Birthday Paradox (en.wikipedia.org/wiki/Birthday_problem),
there's a probability of 50% of a collision if you use 48 bits IDs in a
repository with ca. 16 milion (2^24) objects. A Linux kernel repository
counts ca. 4 million objects, so we're getting close...
So soon we'll get "error: short SHA1 is ambiguous".
BTW, is there actually an easy way to make "git show" show all options for
an ambiguous SHA1?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On Sun, 2014-08-10 at 23:08 +0200, Geert Uytterhoeven wrote:
Hi Joe,
Hi Geert.
On Thu, Jul 3, 2014 at 12:00 AM, Joe Perches [off-list ref] wrote:
quoted
Commit logs have various forms of commit id references.
Try to standardize on a 12 character long lower case
commit id along with a description of parentheses and
the quoted subject line
ie: commit 0123456789ab ("commit description")
Now this is in mainline, checkpatch starts complaining about my "too long"
(40 chars) commit IDs in commit messages :-(
40 chars may be too long (but it's quick to copy-and-paste, as "git show"
shows that by default), but 12 sounds a bit short, as that's only 48 bits.
Right now, this test allows 12 to 16 byte length commit ids
without emitting a warning.
Andrew wanted this test, I don't care how long the commit id
is in the commit log.
According to the Birthday Paradox (en.wikiipedia.org/wiki/Birthday_problem),
there's a probability of 50% of a collision if you use 48 bits IDs in a
repository with ca. 16 milion (2^24) objects. A Linux kernel repository
counts ca. 4 million objects, so we're getting close...
So soon we'll get "error: short SHA1 is ambiguous".
BTW, is there actually an easy way to make "git show" show all options for
an ambiguous SHA1?
Not so far as I know, but I'm nothing like a git expert.
The script I used before adding this to checkpatch was:
$ cat format_commit.sh
#!/bin/bash
regex1="^error: short SHA1 $1 is ambiguous\."
regex2="fatal: ambiguous argument '$1': unknown revision or path not in the working tree\."
tmp=$(mktemp --tmpdir format_commit.XXXXXXXXXXXXX)
git log --format='%H ("%s")' -1 $1 > $tmp 2>&1
read line < $tmp
rm -f $tmp
if [[ $line =~ $regex1 ]] ; then
echo "checking commits $1..."
git rev-list --remotes | grep -i "^$1" |
while read line ; do
git log --format='%H ("%s")' -1 $line |
echo "commit $(cut -c 1-12,41-)"
done
elif [[ $line =~ $regex2 ]] ; then
echo "No matching commit"
exit 1
else
echo "commit $(echo $line | cut -c1-12,41-)"
fi
exit 0
$
so that using "$ format_commit.sh 1234" looks
at _all_ the commit references by using git rev-list
then greps that output for the matches, but it is
darn slow...
$ time ./format_commit.sh 1234
checking commits 1234...
commit 1234351cba95 ("xfs: introduce xlog_copy_iovec")
commit 1234471e2d11 ("perf header: Fix numa topology printing")
commit 1234f4bada54 ("hwrng: Kconfig: remove dependency for atmel-rng driver")
commit 12340313cf94 ("MAINTAINERS: add new cgroup list to CC notice")
commit 12346037a718 ("UBIFS: dump more in the lprops debugging check")
commit 12342c475f5d ("iwlwifi: proper monitor support")
commit 1234010684bb ("Add notation that the Asus W5F laptop has a short cable instead of 80-wire.")
commit 123411f2d0da ("[CPUFREQ] dprintf format fixes in cpufreq/speedstep-centrino.c")
real 0m24.535s
user 0m21.668s
sys 0m5.332s
On Sun, 10 Aug 2014 14:28:01 -0700 Joe Perches [off-list ref] wrote:
quoted
On Thu, Jul 3, 2014 at 12:00 AM, Joe Perches [off-list ref] wrote:
quoted
Commit logs have various forms of commit id references.
Try to standardize on a 12 character long lower case
commit id along with a description of parentheses and
the quoted subject line
ie: commit 0123456789ab ("commit description")
Now this is in mainline, checkpatch starts complaining about my "too long"
(40 chars) commit IDs in commit messages :-(
40 chars may be too long (but it's quick to copy-and-paste, as "git show"
shows that by default), but 12 sounds a bit short, as that's only 48 bits.
Right now, this test allows 12 to 16 byte length commit ids
without emitting a warning.
Andrew wanted this test, I don't care how long the commit id
is in the commit log.
Well, I mainly wanted to stop having to add "commit description" when
people forget it. The length check was perhaps a bit anal. How about
we make it "12 or more"?
On Sun, 2014-08-10 at 14:35 -0700, Andrew Morton wrote:
On Sun, 10 Aug 2014 14:28:01 -0700 Joe Perches [off-list ref] wrote:
quoted
quoted
On Thu, Jul 3, 2014 at 12:00 AM, Joe Perches [off-list ref] wrote:
quoted
Commit logs have various forms of commit id references.
Try to standardize on a 12 character long lower case
commit id along with a description of parentheses and
the quoted subject line
ie: commit 0123456789ab ("commit description")
Now this is in mainline, checkpatch starts complaining about my "too long"
(40 chars) commit IDs in commit messages :-(
40 chars may be too long (but it's quick to copy-and-paste, as "git show"
shows that by default), but 12 sounds a bit short, as that's only 48 bits.
Right now, this test allows 12 to 16 byte length commit ids
without emitting a warning.
Andrew wanted this test, I don't care how long the commit id
is in the commit log.
Well, I mainly wanted to stop having to add "commit description" when
people forget it. The length check was perhaps a bit anal. How about
we make it "12 or more"?
Fine by me, just change the 16 to 40
---
scripts/checkpatch.pl | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 31a731e..b385bcb 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2133,7 +2133,7 @@ sub process {
# Check for improperly formed commit descriptions
if ($in_commit_log &&
$line =~ /\bcommit\s+[0-9a-f]{5,}/i &&
- $line !~ /\b[Cc]ommit [0-9a-f]{12,16} \("/) {
+ $line !~ /\b[Cc]ommit [0-9a-f]{12,40} \("/) {
$line =~ /\b(c)ommit\s+([0-9a-f]{5,})/i;
my $init_char = $1;
my $orig_commit = lc($2);@@ -2141,7 +2141,7 @@ sub process {
my $desc = 'commit description';
($id, $desc) = git_commit_info($orig_commit, $id, $desc);
ERROR("GIT_COMMIT_ID",
- "Please use 12 to 16 chars for the git commit ID like: '${init_char}ommit $id (\"$desc\")'\n" . $herecurr);
+ "Please use 12 or more chars for the git commit ID like: '${init_char}ommit $id (\"$desc\")'\n" . $herecurr);
}
# Check for added, moved or deleted files