This patch tidies up the git-rev-list documentation and epoch.c, which
are in severe clash with the unwritten coding style now, and quite
unreadable.
It also fixes up compile failures with older compilers due to variable
declarations after code.
The patch mostly wraps lines before or on the 80th column, removes
plenty of superfluous empty lines and changes comments from // to /* */.
Signed-off-by: Petr Baudis <pasky@ucw.cz>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes three bugs in --merge-order support
* mark_ancestors_uninteresting was unnecessarily exponential which
caused a problem when a commit with no parents was merged near the
head of something like the linux kernel
* removed a spurious statement from find_base which wasn't
apparently causing problems now, but wasn't correct either.
* removed an unnecessarily strict check from find_base_for_list
that causes a problem if git-rev-list commit ^parent-of-commit
is specified.
* added some unit tests which were accidentally omitted from
original merge-order patch
The fix to mark_ancestors_uninteresting isn't an optimal fix - a full
graph scan will still be performed in this case even though it is
not strictly required. However, a full graph scan is linear
and still no worse than git-rev-list HEAD which runs in less than 2
seconds on a warm cache.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch linearises the GIT commit history graph into merge order
which is defined by invariants specified in Documentation/git-rev-list.txt.
The linearisation produced by this patch is superior in an objective sense
to that produced by the existing git-rev-list implementation in that
the linearisation produced is guaranteed to have the minimum number of
discontinuities, where a discontinuity is defined as an adjacent pair of
commits in the output list which are not related in a direct child-parent
relationship.
With this patch a graph like this:
a4 ---
| \ \
| b4 |
|/ | |
a3 | |
| | |
a2 | |
| | c3
| | |
| | c2
| b3 |
| | /|
| b2 |
| | c1
| | /
| b1
a1 |
| |
a0 |
| /
root
Sorts like this:
= a4
| c3
| c2
| c1
^ b4
| b3
| b2
| b1
^ a3
| a2
| a1
| a0
= root
Instead of this:
= a4
| c3
^ b4
| a3
^ c2
^ b3
^ a2
^ b2
^ c1
^ a1
^ b1
^ a0
= root
A test script, t/t6000-rev-list.sh, includes a test which demonstrates
that the linearisation produced by --merge-order has less discontinuities
than the linearisation produced by git-rev-list without the --merge-order
flag specified. To see this, do the following:
cd t
./t6000-rev-list.sh
cd trash
cat actual-default-order
cat actual-merge-order
The existing behaviour of git-rev-list is preserved, by default. To obtain
the modified behaviour, specify --merge-order or --merge-order --show-breaks
on the command line.
This version of the patch has been tested on the git repository and also on the linux-2.6
repository and has reasonable performance on both - ~50-100% slower than the original algorithm.
This version of the patch has incorporated a functional equivalent of the Linus' output limiting
algorithm into the merge-order algorithm itself. This operates per the notes associated
with Linus' commit 337cb3fb8d.
This version has incorporated Linus' feedback regarding proposed changes to rev-list.c.
(see: [PATCH] Factor out filtering in rev-list.c)
This version has improved the way sort_first_epoch marks commits as uninteresting.
For more details about this change, refer to Documentation/git-rev-list.txt
and http://blackcubes.dyndns.org/epoch/.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
