This patch makes --merge-order produce the same list as git-rev-list
without --merge-order specified.
In particular, if the graph looks like this:
A
| B
|/
C
|
D
The both git-rev-list B ^A and git-rev-list --merge-order will produce B.
The unit tests have been changed to reflect the fact that the prune
points are now formally part of the start list that is used to perform
the --merge-order sort.
That is: git-rev-list --merge-order A ^D used to produce
= A
| C
It now produces:
^ A
| C
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch addresses the problem reported by Paul Mackerras such that --merge-order
did not report the last root of a graph with merge of two independent roots.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The sensible cleanup of the in-memory storage order of commit parents broke the --merge-order
code which was dependent on the previous behaviour of parse_commit().
This patch restores the correctness --merge-order behaviour by taking account of the
new behaviour of parse_commit.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If a is reachable from b, then git-rev-list --merge-order b a would
produce a duplicate output of b.
This causes a problem for an upcoming version of gitk since it
breaks the --merge-order ordering invariant.
This patch fixes the problem for the --merge-order switch. A subsequent
patch will fix the problem for the non --merge-order switch.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Given that real trees in the wild include parents with duplicate parents, I have relaxed
over-zealous error checking in epoch.c and dealt with the problem a different way - duplicate
parents are now silently ignored.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
git-rev-list --merge-order HEAD ^HEAD was faulting rather than generating an empty output.
This patch fixes that problem.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
git-rev-list --merge-order --show-breaks root
Was outputing:
| root
It now outputs:
= root
Which is consistent with the behaviour of other cases.
Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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>
