cext: fix memory leak in phases computation
Without this a buffer whose size in bytes is the number of
changesets in the repository is leaked each time the repository is
opened and changeset phases are computed.
Impact: the current code in hgwebdir creates a new `localrepository`
instance for each HTTP request. Since any pull or push is made of several
requests, a team of 100 people can easily produce thousands of such
requests per day.
Being a low-level malloc, this leak can't be seen with the gc module and
tools relying on that, but was spotted by valgrind immediately.
Reproduction
------------
for i in range(cl_args.iterations):
repo = hg.repository(baseui, repo_path)
rev = repo.revs(rev).first()
ctx = repo[rev]
del ctx
del repo
# avoid any pollution by other type of leak
# (that should be fixed in 5.8)
repoview._filteredrepotypes.clear()
gc.collect()
Measurements
------------
Resident Set Size (RSS), taken on a clone of
mozilla-central for performance analysis (440 000
changesets).
before:
5.8+hg19.5ac0f2a8ba72 1000 iterations: 1606MB
5.8+hg19.5ac0f2a8ba72 10000 iterations: 5723MB
after:
5.8+hg20.e2084d39e145 1000 iterations: 555MB
5.8+hg20.e2084d39e145 10000 iterations: 555MB
(double checked, not a copy/paste error)
(e2084d39e14 is the present changeset, before amendment
of the message to add the measurements)
$ cat <<EOF >> $HGRCPATH
> [experimental]
> evolution = true
>
> [extensions]
> notify =
> hooklib =
>
> [phases]
> publish = False
>
> [notify]
> sources = pull
> diffstat = False
> messageidseed = example
> domain = example.com
>
> [reposubs]
> * = baz
> EOF
$ hg init a
$ hg --cwd a debugbuilddag +2
$ hg init b
$ cat <<EOF >> b/.hg/hgrc
> [hooks]
> incoming.notify = python:hgext.notify.hook
> txnclose.changeset_obsoleted = python:hgext.hooklib.changeset_obsoleted.hook
> EOF
$ hg --cwd b pull ../a | "$PYTHON" $TESTDIR/unwrap-message-id.py
pulling from ../a
requesting all changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 0 changes to 0 files
new changesets 1ea73414a91b:66f7d451a68b (2 drafts)
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Date: * (glob)
Subject: changeset in * (glob)
From: debugbuilddag@example.com
X-Hg-Notification: changeset 1ea73414a91b
Message-Id: <hg.81c297828fd2d5afaadf2775a6a71b74143b6451dfaac09fac939e9107a50d01@example.com>
To: baz@example.com
changeset 1ea73414a91b in $TESTTMP/b
details: $TESTTMP/b?cmd=changeset;node=1ea73414a91b
description:
r0
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Date: * (glob)
Subject: changeset in * (glob)
From: debugbuilddag@example.com
X-Hg-Notification: changeset 66f7d451a68b
Message-Id: <hg.364d03da7dc13829eb779a805be7e37f54f572e9afcea7d2626856a794d3e8f3@example.com>
To: baz@example.com
changeset 66f7d451a68b in $TESTTMP/b
details: $TESTTMP/b?cmd=changeset;node=66f7d451a68b
description:
r1
(run 'hg update' to get a working copy)
$ hg --cwd a debugobsolete 1ea73414a91b0920940797d8fc6a11e447f8ea1e
1 new obsolescence markers
obsoleted 1 changesets
1 new orphan changesets
$ hg --cwd a push ../b --hidden | "$PYTHON" $TESTDIR/unwrap-message-id.py
1 new orphan changesets
pushing to ../b
searching for changes
no changes found
1 new obsolescence markers
obsoleted 1 changesets
Subject: changeset abandoned
In-reply-to: <hg.81c297828fd2d5afaadf2775a6a71b74143b6451dfaac09fac939e9107a50d01@example.com>
Message-Id: <hg.d6329e9481594f0f3c8a84362b3511318bfbce50748ab1123f909eb6fbcab018@example.com>
Date: * (glob)
From: test@example.com
To: baz@example.com
This changeset has been abandoned.
Check that known changesets with known successors do not result in a mail.
$ hg init c
$ hg init d
$ cat <<EOF >> d/.hg/hgrc
> [hooks]
> incoming.notify = python:hgext.notify.hook
> txnclose.changeset_obsoleted = python:hgext.hooklib.changeset_obsoleted.hook
> EOF
$ hg --cwd c debugbuilddag '.:parent.*parent'
$ hg --cwd c push ../d -r 1
pushing to ../d
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 0 changes to 0 files
$ hg --cwd c debugobsolete $(hg --cwd c log -T '{node}' -r 1) $(hg --cwd c log -T '{node}' -r 2)
1 new obsolescence markers
obsoleted 1 changesets
$ hg --cwd c push ../d | "$PYTHON" $TESTDIR/unwrap-message-id.py
pushing to ../d
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 0 changes to 0 files (+1 heads)
1 new obsolescence markers
obsoleted 1 changesets