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)
$ "$TESTDIR/hghave" no-msys || exit 80 # MSYS will translate web paths as if they were file paths
This is a test of the push wire protocol over CGI-based hgweb.
initialize repository
$ hg init r
$ cd r
$ echo a > a
$ hg ci -A -m "0"
adding a
$ echo '[web]' > .hg/hgrc
$ echo 'allow_push = *' >> .hg/hgrc
$ echo 'push_ssl = false' >> .hg/hgrc
create hgweb invocation script
$ cat >hgweb.cgi <<HGWEB
> import cgitb
> cgitb.enable()
> from mercurial import demandimport; demandimport.enable()
> from mercurial.hgweb import hgweb
> from mercurial.hgweb import wsgicgi
> application = hgweb('.', 'test repository')
> wsgicgi.launch(application)
> HGWEB
$ chmod 755 hgweb.cgi
test preparation
$ . "$TESTDIR/cgienv"
$ REQUEST_METHOD="POST"; export REQUEST_METHOD
$ CONTENT_TYPE="application/octet-stream"; export CONTENT_TYPE
$ hg bundle --all bundle.hg
1 changesets found
$ CONTENT_LENGTH=279; export CONTENT_LENGTH;
expect failure because heads doesn't match (formerly known as 'unsynced changes')
$ QUERY_STRING="cmd=unbundle&heads=0000000000000000000000000000000000000000"; export QUERY_STRING
$ python hgweb.cgi <bundle.hg >page1 2>&1
$ cat page1
Status: 200 Script output follows\r (esc)
Content-Type: application/mercurial-0.1\r (esc)
Content-Length: 64\r (esc)
\r (esc)
0
repository changed while preparing changes - please try again
successful force push
$ QUERY_STRING="cmd=unbundle&heads=666f726365"; export QUERY_STRING
$ python hgweb.cgi <bundle.hg >page2 2>&1
$ cat page2
Status: 200 Script output follows\r (esc)
Content-Type: application/mercurial-0.1\r (esc)
Content-Length: 102\r (esc)
\r (esc)
1
adding changesets
adding manifests
adding file changes
added 0 changesets with 0 changes to 1 files
successful push, list of heads
$ QUERY_STRING="cmd=unbundle&heads=f7b1eb17ad24730a1651fccd46c43826d1bbc2ac"; export QUERY_STRING
$ python hgweb.cgi <bundle.hg >page3 2>&1
$ cat page3
Status: 200 Script output follows\r (esc)
Content-Type: application/mercurial-0.1\r (esc)
Content-Length: 102\r (esc)
\r (esc)
1
adding changesets
adding manifests
adding file changes
added 0 changesets with 0 changes to 1 files
successful push, SHA1 hash of heads (unbundlehash capability)
$ QUERY_STRING="cmd=unbundle&heads=686173686564 5a785a5f9e0d433b88ed862b206b011b0c3a9d13"; export QUERY_STRING
$ python hgweb.cgi <bundle.hg >page4 2>&1
$ cat page4
Status: 200 Script output follows\r (esc)
Content-Type: application/mercurial-0.1\r (esc)
Content-Length: 102\r (esc)
\r (esc)
1
adding changesets
adding manifests
adding file changes
added 0 changesets with 0 changes to 1 files
$ cd ..