obsolete: order of magnitude speedup in _computebumpedset
Reminder: a changeset is said "bumped" if it tries to obsolete a immutable
changeset.
The previous algorithm for computing bumped changeset was:
1) Get all public changesets
2) Find all they successors
3) Search for stuff that are eligible for being "bumped"
(mutable and non obsolete)
The entry size of this algorithm is `O(len(public))` which is mostly the same as
`O(len(repo))`. Even this this approach mean fewer obsolescence marker are
traveled, this is not very scalable.
The new algorithm is:
1) For each potential bumped changesets (non obsolete mutable)
2) iterate over precursors
3) if a precursors is public. changeset is bumped
We travel more obsolescence marker, but the entry size is much smaller since
the amount of potential bumped should remains mostly stable with time `O(1)`.
On some confidential gigantic repo this move bumped computation from 15.19s to
0.46s (×33 speedup…). On "smaller" repo (mercurial, cubicweb's review) no
significant gain were seen. The additional traversal of obsolescence marker is
probably probably counter balance the advantage of it.
Other optimisation could be done in the future (eg: sharing precursors cache
for divergence detection)
$ HGMERGE=true; export HGMERGE
$ hg init r1
$ cd r1
$ echo a > a
$ hg addremove
adding a
$ hg commit -m "1"
$ hg clone . ../r2
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd ../r2
$ hg up
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo abc > a
$ hg diff --nodates
diff -r c19d34741b0a a
--- a/a
+++ b/a
@@ -1,1 +1,1 @@
-a
+abc
$ cd ../r1
$ echo b > b
$ echo a2 > a
$ hg addremove
adding b
$ hg commit -m "2"
$ cd ../r2
$ hg -q pull ../r1
$ hg status
M a
$ hg parents
changeset: 0:c19d34741b0a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
$ hg --debug up
searching for copies back to rev 1
unmatched files in other:
b
resolving manifests
branchmerge: False, force: False, partial: False
ancestor: c19d34741b0a, local: c19d34741b0a+, remote: 1e71731e6fbb
a: versions differ -> m
preserving a for resolve of a
b: remote created -> g
getting b
updating: b 1/2 files (50.00%)
updating: a 2/2 files (100.00%)
picked tool 'true' for a (binary False symlink False)
merging a
my a@c19d34741b0a+ other a@1e71731e6fbb ancestor a@c19d34741b0a
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
$ hg parents
changeset: 1:1e71731e6fbb
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
$ hg --debug up 0
resolving manifests
branchmerge: False, force: False, partial: False
ancestor: 1e71731e6fbb, local: 1e71731e6fbb+, remote: c19d34741b0a
b: other deleted -> r
a: versions differ -> m
preserving a for resolve of a
removing b
updating: b 1/2 files (50.00%)
updating: a 2/2 files (100.00%)
picked tool 'true' for a (binary False symlink False)
merging a
my a@1e71731e6fbb+ other a@c19d34741b0a ancestor a@1e71731e6fbb
0 files updated, 1 files merged, 1 files removed, 0 files unresolved
$ hg parents
changeset: 0:c19d34741b0a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
$ hg --debug merge
abort: nothing to merge
(use 'hg update' instead)
[255]
$ hg parents
changeset: 0:c19d34741b0a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 1
$ hg --debug up
searching for copies back to rev 1
unmatched files in other:
b
resolving manifests
branchmerge: False, force: False, partial: False
ancestor: c19d34741b0a, local: c19d34741b0a+, remote: 1e71731e6fbb
a: versions differ -> m
preserving a for resolve of a
b: remote created -> g
getting b
updating: b 1/2 files (50.00%)
updating: a 2/2 files (100.00%)
picked tool 'true' for a (binary False symlink False)
merging a
my a@c19d34741b0a+ other a@1e71731e6fbb ancestor a@c19d34741b0a
1 files updated, 1 files merged, 0 files removed, 0 files unresolved
$ hg parents
changeset: 1:1e71731e6fbb
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
$ hg -v history
changeset: 1:1e71731e6fbb
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: a b
description:
2
changeset: 0:c19d34741b0a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files: a
description:
1
$ hg diff --nodates
diff -r 1e71731e6fbb a
--- a/a
+++ b/a
@@ -1,1 +1,1 @@
-a2
+abc
create a second head
$ cd ../r1
$ hg up 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo b2 > b
$ echo a3 > a
$ hg addremove
adding b
$ hg commit -m "3"
created new head
$ cd ../r2
$ hg -q pull ../r1
$ hg status
M a
$ hg parents
changeset: 1:1e71731e6fbb
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
$ hg --debug up
abort: uncommitted changes
(commit and merge, or update --clean to discard changes)
[255]
$ hg --debug merge
abort: uncommitted changes
(use 'hg status' to list changes)
[255]
$ hg --debug merge -f
searching for copies back to rev 1
resolving manifests
branchmerge: True, force: True, partial: False
ancestor: c19d34741b0a, local: 1e71731e6fbb+, remote: 83c51d0caff4
a: versions differ -> m
preserving a for resolve of a
b: versions differ -> m
preserving b for resolve of b
updating: a 1/2 files (50.00%)
picked tool 'true' for a (binary False symlink False)
merging a
my a@1e71731e6fbb+ other a@83c51d0caff4 ancestor a@c19d34741b0a
updating: b 2/2 files (100.00%)
picked tool 'true' for b (binary False symlink False)
merging b
my b@1e71731e6fbb+ other b@83c51d0caff4 ancestor b@000000000000
0 files updated, 2 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg parents
changeset: 1:1e71731e6fbb
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2
changeset: 2:83c51d0caff4
tag: tip
parent: 0:c19d34741b0a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 3
$ hg diff --nodates
diff -r 1e71731e6fbb a
--- a/a
+++ b/a
@@ -1,1 +1,1 @@
-a2
+abc
test a local add
$ cd ..
$ hg init a
$ hg init b
$ echo a > a/a
$ echo a > b/a
$ hg --cwd a commit -A -m a
adding a
$ cd b
$ hg add a
$ hg pull -u ../a
pulling from ../a
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg st
$ cd ..