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)

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  $ hg init a

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  $ cd a

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  $ hg diff inexistent1 inexistent2

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  inexistent1: * (glob)

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  inexistent2: * (glob)

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  $ echo bar > foo

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  $ hg add foo

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  $ hg ci -m 'add foo'

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  $ echo foobar > foo

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  $ hg ci -m 'change foo'

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  $ hg --quiet diff -r 0 -r 1

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  diff -r a99fb63adac3 -r 9b8568d3af2f foo

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  --- a/foo	Thu Jan 01 00:00:00 1970 +0000

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  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000

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  @@ -1,1 +1,1 @@

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  -bar

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  +foobar

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  $ hg diff -r 0 -r 1

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  diff -r a99fb63adac3 -r 9b8568d3af2f foo

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  --- a/foo	Thu Jan 01 00:00:00 1970 +0000

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  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000

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  @@ -1,1 +1,1 @@

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  -bar

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  +foobar

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  $ hg --verbose diff -r 0 -r 1

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  diff -r a99fb63adac3 -r 9b8568d3af2f foo

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  --- a/foo	Thu Jan 01 00:00:00 1970 +0000

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  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000

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  @@ -1,1 +1,1 @@

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  -bar

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  +foobar

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  $ hg --debug diff -r 0 -r 1

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  diff -r a99fb63adac3f31816a22f665bc3b7a7655b30f4 -r 9b8568d3af2f1749445eef03aede868a6f39f210 foo

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  --- a/foo	Thu Jan 01 00:00:00 1970 +0000

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  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000

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  @@ -1,1 +1,1 @@

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  -bar

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  +foobar

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  $ cd ..