view tests/test-tags.t @ 47010:76ae43d5b1db stable

repoview: fix memory leak of filtered repo classes

The leak occurs in long-running server processes with
extensions, and is measured at 110kB per request.

Before this change, the contents of the `_filteredrepotypes`
cache are not properly garbage collected, despite it begin
a `WeakKeyDictionary`.

Extensions have a tendency to generate a new repository class
for each `localrepo` instantiation. Server processes based
on `hgwebdir_mod` will instantiate a new `localrepo` for each
HTTP request that involves a repository.

As a result, with a testing process that repeatedly opens a
repository with several extensions activated
(`topic` notably among them), we see a steady increase in
resident memory of 110kB per repository instantiation before this
change. This is also true, if we call `gc.collect()` at each
instantiation, like `hgwebdir_mod` does, or not.

The cause of the leak is that the *values* aren't weak references.
This change uses `weakref.ref` for the values, and this makes
in our measurements the resident size increase drop to 5kB per
repository instantiation, with no explicit call of `gc.collect()`
at all.
There is currently no reason to believe that this remaining leak
of 5kB is related to or even due to Mercurial core.

We've also seen evidence that `ui.ui` instances weren't properly
garbage collected before the change (with the change, they are).
This could explain why the figures are relatively high.

In theory, the collection of weak references could lead to
much more misses in the cache, so we measured the impact on
the original case that was motivation for introducing that cache
in 7e89bd0cfb86 (see also issue5043): `hg convert` of the
mozilla-central repository. The bad news here is that there is a
major memory leak there, both with and without the present changeset.
There were no more cache misses, and we could see no
more memory leak with this change: the resident size after importing
roughly 100000 changesets was at 12.4GB before, and 12.5GB after.
The small increase is mentioned for completeness only, and we
believe that it should be ignored, at least as long as the main
leak isn't fixed. At less than 1% of the main leak, even finding out
whether it is merely noise would be wasteful.

Original context where this was spotted and first mitigated:
  https://foss.heptapod.net/heptapod/heptapod/-/issues/466

The leak reduction was also obtained in Heptapod inner HTTP server,
which amounts to the same as `hgwebdir_mod` for these questions.

The measurements done with Python 3.9, similar figures seen with 3.8.
More work on our side would be needed to give measurements with 2.7,
because of testing server process does not support it.

setup

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > blackbox=
  > mock=$TESTDIR/mockblackbox.py
  > [blackbox]
  > track = command, commandfinish, tagscache
  > EOF

Helper functions:

  $ cacheexists() {
  >   [ -f .hg/cache/tags2-visible ] && echo "tag cache exists" || echo "no tag cache"
  > }

  $ fnodescacheexists() {
  >   [ -f .hg/cache/hgtagsfnodes1 ] && echo "fnodes cache exists" || echo "no fnodes cache"
  > }

  $ dumptags() {
  >     rev=$1
  >     echo "rev $rev: .hgtags:"
  >     hg cat -r$rev .hgtags
  > }

# XXX need to test that the tag cache works when we strip an old head
# and add a new one rooted off non-tip: i.e. node and rev of tip are the
# same, but stuff has changed behind tip.

Setup:

  $ hg init t
  $ cd t
  $ cacheexists
  no tag cache
  $ fnodescacheexists
  no fnodes cache
  $ hg id
  000000000000 tip
  $ cacheexists
  no tag cache
  $ fnodescacheexists
  no fnodes cache
  $ echo a > a
  $ hg add a
  $ hg commit -m "test"
  $ hg co
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg identify
  acb14030fe0a tip
  $ hg identify -r 'wdir()'
  acb14030fe0a tip
  $ cacheexists
  tag cache exists
No fnodes cache because .hgtags file doesn't exist
(this is an implementation detail)
  $ fnodescacheexists
  no fnodes cache

Try corrupting the cache

  $ printf 'a b' > .hg/cache/tags2-visible
  $ hg identify
  acb14030fe0a tip
  $ cacheexists
  tag cache exists
  $ fnodescacheexists
  no fnodes cache
  $ hg identify
  acb14030fe0a tip

Create local tag with long name:

  $ T=`hg identify --debug --id`
  $ hg tag -l "This is a local tag with a really long name!"
  $ hg tags
  tip                                0:acb14030fe0a
  This is a local tag with a really long name!     0:acb14030fe0a
  $ rm .hg/localtags

Create a tag behind hg's back:

  $ echo "$T first" > .hgtags
  $ cat .hgtags
  acb14030fe0a21b60322c440ad2d20cf7685a376 first
  $ hg add .hgtags
  $ hg commit -m "add tags"
  $ hg tags
  tip                                1:b9154636be93
  first                              0:acb14030fe0a
  $ hg identify
  b9154636be93 tip

We should have a fnodes cache now that we have a real tag
The cache should have an empty entry for rev 0 and a valid entry for rev 1.


  $ fnodescacheexists
  fnodes cache exists
  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=48
  0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0010: ff ff ff ff ff ff ff ff b9 15 46 36 26 b7 b4 a7 |..........F6&...|
  0020: 73 e0 9e e3 c5 2f 51 0e 19 e0 5e 1f f9 66 d8 59 |s..../Q...^..f.Y|
  $ hg debugtagscache
  0 acb14030fe0a21b60322c440ad2d20cf7685a376 missing
  1 b9154636be938d3d431e75a7c906504a079bfe07 26b7b4a773e09ee3c52f510e19e05e1ff966d859

Repeat with cold tag cache:

  $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
  $ hg identify
  b9154636be93 tip

  $ fnodescacheexists
  fnodes cache exists
  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=48
  0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0010: ff ff ff ff ff ff ff ff b9 15 46 36 26 b7 b4 a7 |..........F6&...|
  0020: 73 e0 9e e3 c5 2f 51 0e 19 e0 5e 1f f9 66 d8 59 |s..../Q...^..f.Y|

And again, but now unable to write tag cache or lock file:

#if unix-permissions no-fsmonitor

  $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
  $ chmod 555 .hg/cache
  $ hg identify
  b9154636be93 tip
  $ chmod 755 .hg/cache

(this block should be protected by no-fsmonitor, because "chmod 555 .hg"
makes watchman fail at accessing to files under .hg)

  $ chmod 555 .hg
  $ hg identify
  b9154636be93 tip
  $ chmod 755 .hg
#endif

Tag cache debug info written to blackbox log

  $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
  $ hg identify
  b9154636be93 tip
  $ hg blackbox -l 6
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> identify
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> writing 48 bytes to cache/hgtagsfnodes1
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> 0/2 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> identify exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> blackbox -l 6

Failure to acquire lock results in no write

  $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
  $ echo 'foo:1' > .hg/store/lock
  $ hg identify
  b9154636be93 tip
  $ hg blackbox -l 6
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> identify
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> not writing .hg/cache/hgtagsfnodes1 because lock cannot be acquired
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> 0/2 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> identify exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @b9154636be938d3d431e75a7c906504a079bfe07 (5000)> blackbox -l 6

  $ fnodescacheexists
  no fnodes cache

  $ rm .hg/store/lock

  $ rm -f .hg/cache/tags2-visible .hg/cache/hgtagsfnodes1
  $ hg identify
  b9154636be93 tip

Create a branch:

  $ echo bb > a
  $ hg status
  M a
  $ hg identify
  b9154636be93+ tip
  $ hg co first
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg id
  acb14030fe0a+ first
  $ hg id -r 'wdir()'
  acb14030fe0a+ first
  $ hg -v id
  acb14030fe0a+ first
  $ hg status
  M a
  $ echo 1 > b
  $ hg add b
  $ hg commit -m "branch"
  created new head

Creating a new commit shouldn't append the .hgtags fnodes cache until
tags info is accessed

  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=48
  0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0010: ff ff ff ff ff ff ff ff b9 15 46 36 26 b7 b4 a7 |..........F6&...|
  0020: 73 e0 9e e3 c5 2f 51 0e 19 e0 5e 1f f9 66 d8 59 |s..../Q...^..f.Y|

  $ hg id
  c8edf04160c7 tip

First 4 bytes of record 3 are changeset fragment

  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=72
  0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0010: ff ff ff ff ff ff ff ff b9 15 46 36 26 b7 b4 a7 |..........F6&...|
  0020: 73 e0 9e e3 c5 2f 51 0e 19 e0 5e 1f f9 66 d8 59 |s..../Q...^..f.Y|
  0030: c8 ed f0 41 00 00 00 00 00 00 00 00 00 00 00 00 |...A............|
  0040: 00 00 00 00 00 00 00 00                         |........|

Merge the two heads:

  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg blackbox -l3
  1970/01/01 00:00:00 bob @c8edf04160c7f731e4589d66ab3ab3486a64ac28 (5000)> merge 1
  1970/01/01 00:00:00 bob @c8edf04160c7f731e4589d66ab3ab3486a64ac28+b9154636be938d3d431e75a7c906504a079bfe07 (5000)> merge 1 exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @c8edf04160c7f731e4589d66ab3ab3486a64ac28+b9154636be938d3d431e75a7c906504a079bfe07 (5000)> blackbox -l3
  $ hg id
  c8edf04160c7+b9154636be93+ tip
  $ hg status
  M .hgtags
  $ hg commit -m "merge"

Create a fake head, make sure tag not visible afterwards:

  $ cp .hgtags tags
  $ hg tag last
  $ hg rm .hgtags
  $ hg commit -m "remove"

  $ mv tags .hgtags
  $ hg add .hgtags
  $ hg commit -m "readd"
  $ 
  $ hg tags
  tip                                6:35ff301afafe
  first                              0:acb14030fe0a

Add invalid tags:

  $ echo "spam" >> .hgtags
  $ echo >> .hgtags
  $ echo "foo bar" >> .hgtags
  $ echo "a5a5 invalid" >> .hg/localtags
  $ cat .hgtags
  acb14030fe0a21b60322c440ad2d20cf7685a376 first
  spam
  
  foo bar
  $ hg commit -m "tags"

Report tag parse error on other head:

  $ hg up 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 'x y' >> .hgtags
  $ hg commit -m "head"
  created new head

  $ hg tags --debug
  .hgtags@75d9f02dfe28, line 2: cannot parse entry
  .hgtags@75d9f02dfe28, line 4: node 'foo' is not well formed
  .hgtags@c4be69a18c11, line 2: node 'x' is not well formed
  tip                                8:c4be69a18c11e8bc3a5fdbb576017c25f7d84663
  first                              0:acb14030fe0a21b60322c440ad2d20cf7685a376
  $ hg tip
  changeset:   8:c4be69a18c11
  tag:         tip
  parent:      3:ac5e980c4dc0
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     head
  

Test tag precedence rules:

  $ cd ..
  $ hg init t2
  $ cd t2
  $ echo foo > foo
  $ hg add foo
  $ hg ci -m 'add foo'      # rev 0
  $ hg tag bar              # rev 1
  $ echo >> foo
  $ hg ci -m 'change foo 1' # rev 2
  $ hg up -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tag -r 1 -f bar      # rev 3
  $ hg up -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo >> foo
  $ hg ci -m 'change foo 2' # rev 4
  created new head
  $ hg tags
  tip                                4:0c192d7d5e6b
  bar                                1:78391a272241

Repeat in case of cache effects:

  $ hg tags
  tip                                4:0c192d7d5e6b
  bar                                1:78391a272241

Detailed dump of tag info:

  $ hg heads -q             # expect 4, 3, 2
  4:0c192d7d5e6b
  3:6fa450212aeb
  2:7a94127795a3
  $ dumptags 2
  rev 2: .hgtags:
  bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar
  $ dumptags 3
  rev 3: .hgtags:
  bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar
  bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar
  78391a272241d70354aa14c874552cad6b51bb42 bar
  $ dumptags 4
  rev 4: .hgtags:
  bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar

Dump cache:

  $ cat .hg/cache/tags2-visible
  4 0c192d7d5e6b78a714de54a2e9627952a877e25a
  bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar
  bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar
  78391a272241d70354aa14c874552cad6b51bb42 bar

  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=120
  0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0030: 7a 94 12 77 0c 04 f2 a8 af 31 de 17 fa b7 42 28 |z..w.....1....B(|
  0040: 78 ee 5a 2d ad bc 94 3d 6f a4 50 21 7d 3b 71 8c |x.Z-...=o.P!};q.|
  0050: 96 4e f3 7b 89 e5 50 eb da fd 57 89 e7 6c e1 b0 |.N.{..P...W..l..|
  0060: 0c 19 2d 7d 0c 04 f2 a8 af 31 de 17 fa b7 42 28 |..-}.....1....B(|
  0070: 78 ee 5a 2d ad bc 94 3d                         |x.Z-...=|

Corrupt the .hgtags fnodes cache
Extra junk data at the end should get overwritten on next cache update

  $ echo extra >> .hg/cache/hgtagsfnodes1
  $ echo dummy1 > foo
  $ hg commit -m throwaway1

  $ hg tags
  tip                                5:8dbfe60eff30
  bar                                1:78391a272241

  $ hg blackbox -l 6
  1970/01/01 00:00:00 bob @8dbfe60eff306a54259cfe007db9e330e7ecf866 (5000)> tags
  1970/01/01 00:00:00 bob @8dbfe60eff306a54259cfe007db9e330e7ecf866 (5000)> writing 24 bytes to cache/hgtagsfnodes1
  1970/01/01 00:00:00 bob @8dbfe60eff306a54259cfe007db9e330e7ecf866 (5000)> 3/4 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @8dbfe60eff306a54259cfe007db9e330e7ecf866 (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @8dbfe60eff306a54259cfe007db9e330e7ecf866 (5000)> tags exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @8dbfe60eff306a54259cfe007db9e330e7ecf866 (5000)> blackbox -l 6

On junk data + missing cache entries, hg also overwrites the junk.

  $ rm -f .hg/cache/tags2-visible
  >>> import os
  >>> with open(".hg/cache/hgtagsfnodes1", "ab+") as fp:
  ...     fp.seek(-10, os.SEEK_END) and None
  ...     fp.truncate() and None

  $ hg debugtagscache | tail -2
  4 0c192d7d5e6b78a714de54a2e9627952a877e25a 0c04f2a8af31de17fab7422878ee5a2dadbc943d
  5 8dbfe60eff306a54259cfe007db9e330e7ecf866 missing
  $ hg tags
  tip                                5:8dbfe60eff30
  bar                                1:78391a272241
  $ hg debugtagscache | tail -2
  4 0c192d7d5e6b78a714de54a2e9627952a877e25a 0c04f2a8af31de17fab7422878ee5a2dadbc943d
  5 8dbfe60eff306a54259cfe007db9e330e7ecf866 0c04f2a8af31de17fab7422878ee5a2dadbc943d

If the 4 bytes of node hash for a record don't match an existing node, the entry
is flagged as invalid.

  >>> import os
  >>> with open(".hg/cache/hgtagsfnodes1", "rb+") as fp:
  ...     fp.seek(-24, os.SEEK_END) and None
  ...     fp.write(b'\xde\xad') and None

  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=144
  0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0010: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0020: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |................|
  0030: 7a 94 12 77 0c 04 f2 a8 af 31 de 17 fa b7 42 28 |z..w.....1....B(|
  0040: 78 ee 5a 2d ad bc 94 3d 6f a4 50 21 7d 3b 71 8c |x.Z-...=o.P!};q.|
  0050: 96 4e f3 7b 89 e5 50 eb da fd 57 89 e7 6c e1 b0 |.N.{..P...W..l..|
  0060: 0c 19 2d 7d 0c 04 f2 a8 af 31 de 17 fa b7 42 28 |..-}.....1....B(|
  0070: 78 ee 5a 2d ad bc 94 3d de ad e6 0e 0c 04 f2 a8 |x.Z-...=........|
  0080: af 31 de 17 fa b7 42 28 78 ee 5a 2d ad bc 94 3d |.1....B(x.Z-...=|

  $ hg debugtagscache | tail -2
  4 0c192d7d5e6b78a714de54a2e9627952a877e25a 0c04f2a8af31de17fab7422878ee5a2dadbc943d
  5 8dbfe60eff306a54259cfe007db9e330e7ecf866 invalid

  $ hg tags
  tip                                5:8dbfe60eff30
  bar                                1:78391a272241

BUG: If the filenode part of an entry in hgtagsfnodes is corrupt and
tags2-visible is missing, `hg tags` aborts.  Corrupting the leading 4 bytes of
node hash (as above) doesn't seem to trigger the issue.  Also note that the
debug command hides the corruption, both with and without tags2-visible.

  $ mv .hg/cache/hgtagsfnodes1 .hg/cache/hgtagsfnodes1.bak
  $ hg debugupdatecaches

  >>> import os
  >>> with open(".hg/cache/hgtagsfnodes1", "rb+") as fp:
  ...     fp.seek(-16, os.SEEK_END) and None
  ...     fp.write(b'\xde\xad') and None

  $ f --size --hexdump .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=144
  0000: bb d1 79 df 00 00 00 00 00 00 00 00 00 00 00 00 |..y.............|
  0010: 00 00 00 00 00 00 00 00 78 39 1a 27 0c 04 f2 a8 |........x9.'....|
  0020: af 31 de 17 fa b7 42 28 78 ee 5a 2d ad bc 94 3d |.1....B(x.Z-...=|
  0030: 7a 94 12 77 0c 04 f2 a8 af 31 de 17 fa b7 42 28 |z..w.....1....B(|
  0040: 78 ee 5a 2d ad bc 94 3d 6f a4 50 21 7d 3b 71 8c |x.Z-...=o.P!};q.|
  0050: 96 4e f3 7b 89 e5 50 eb da fd 57 89 e7 6c e1 b0 |.N.{..P...W..l..|
  0060: 0c 19 2d 7d 0c 04 f2 a8 af 31 de 17 fa b7 42 28 |..-}.....1....B(|
  0070: 78 ee 5a 2d ad bc 94 3d 8d bf e6 0e 0c 04 f2 a8 |x.Z-...=........|
  0080: de ad de 17 fa b7 42 28 78 ee 5a 2d ad bc 94 3d |......B(x.Z-...=|

  $ hg debugtagscache | tail -2
  4 0c192d7d5e6b78a714de54a2e9627952a877e25a 0c04f2a8af31de17fab7422878ee5a2dadbc943d
  5 8dbfe60eff306a54259cfe007db9e330e7ecf866 0c04f2a8deadde17fab7422878ee5a2dadbc943d (unknown node)

  $ rm -f .hg/cache/tags2-visible
  $ hg debugtagscache | tail -2
  4 0c192d7d5e6b78a714de54a2e9627952a877e25a 0c04f2a8af31de17fab7422878ee5a2dadbc943d
  5 8dbfe60eff306a54259cfe007db9e330e7ecf866 0c04f2a8deadde17fab7422878ee5a2dadbc943d (unknown node)

  $ hg tags
  tip                                5:8dbfe60eff30
  bar                                1:78391a272241

BUG: Unless this file is restored, the `hg tags` in the next unix-permissions
conditional will fail: "abort: data/.hgtags.i@0c04f2a8dead: no match found"

  $ mv .hg/cache/hgtagsfnodes1.bak .hg/cache/hgtagsfnodes1

#if unix-permissions no-root
Errors writing to .hgtags fnodes cache are silently ignored

  $ echo dummy2 > foo
  $ hg commit -m throwaway2

  $ chmod a-w .hg/cache/hgtagsfnodes1
  $ rm -f .hg/cache/tags2-visible

  $ hg tags
  tip                                6:b968051b5cf3
  bar                                1:78391a272241

  $ hg blackbox -l 6
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> tags
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> couldn't write cache/hgtagsfnodes1: [Errno *] * (glob)
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> 2/4 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> tags exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> blackbox -l 6

  $ chmod a+w .hg/cache/hgtagsfnodes1

  $ rm -f .hg/cache/tags2-visible
  $ hg tags
  tip                                6:b968051b5cf3
  bar                                1:78391a272241

  $ hg blackbox -l 6
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> tags
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> writing 24 bytes to cache/hgtagsfnodes1
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> 2/4 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> tags exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @b968051b5cf3f624b771779c6d5f84f1d4c3fb5d (5000)> blackbox -l 6

  $ f --size .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=168

  $ hg -q --config extensions.strip= strip -r 6 --no-backup
#endif

Stripping doesn't truncate the tags cache until new data is available

  $ rm -f .hg/cache/hgtagsfnodes1 .hg/cache/tags2-visible
  $ hg tags
  tip                                5:8dbfe60eff30
  bar                                1:78391a272241

  $ f --size .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=144

  $ hg -q --config extensions.strip= strip -r 5 --no-backup
  $ hg tags
  tip                                4:0c192d7d5e6b
  bar                                1:78391a272241

  $ hg blackbox -l 5
  1970/01/01 00:00:00 bob @0c192d7d5e6b78a714de54a2e9627952a877e25a (5000)> writing 24 bytes to cache/hgtagsfnodes1
  1970/01/01 00:00:00 bob @0c192d7d5e6b78a714de54a2e9627952a877e25a (5000)> 2/4 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @0c192d7d5e6b78a714de54a2e9627952a877e25a (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @0c192d7d5e6b78a714de54a2e9627952a877e25a (5000)> tags exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @0c192d7d5e6b78a714de54a2e9627952a877e25a (5000)> blackbox -l 5

  $ f --size .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=120

  $ echo dummy > foo
  $ hg commit -m throwaway3

  $ hg tags
  tip                                5:035f65efb448
  bar                                1:78391a272241

  $ hg blackbox -l 6
  1970/01/01 00:00:00 bob @035f65efb448350f4772141702a81ab1df48c465 (5000)> tags
  1970/01/01 00:00:00 bob @035f65efb448350f4772141702a81ab1df48c465 (5000)> writing 24 bytes to cache/hgtagsfnodes1
  1970/01/01 00:00:00 bob @035f65efb448350f4772141702a81ab1df48c465 (5000)> 3/4 cache hits/lookups in * seconds (glob)
  1970/01/01 00:00:00 bob @035f65efb448350f4772141702a81ab1df48c465 (5000)> writing .hg/cache/tags2-visible with 1 tags
  1970/01/01 00:00:00 bob @035f65efb448350f4772141702a81ab1df48c465 (5000)> tags exited 0 after * seconds (glob)
  1970/01/01 00:00:00 bob @035f65efb448350f4772141702a81ab1df48c465 (5000)> blackbox -l 6
  $ f --size .hg/cache/hgtagsfnodes1
  .hg/cache/hgtagsfnodes1: size=144

  $ hg -q --config extensions.strip= strip -r 5 --no-backup

Test tag removal:

  $ hg tag --remove bar     # rev 5
  $ hg tip -vp
  changeset:   5:5f6e8655b1c7
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       .hgtags
  description:
  Removed tag bar
  
  
  diff -r 0c192d7d5e6b -r 5f6e8655b1c7 .hgtags
  --- a/.hgtags	Thu Jan 01 00:00:00 1970 +0000
  +++ b/.hgtags	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,3 @@
   bbd179dfa0a71671c253b3ae0aa1513b60d199fa bar
  +78391a272241d70354aa14c874552cad6b51bb42 bar
  +0000000000000000000000000000000000000000 bar
  
  $ hg tags
  tip                                5:5f6e8655b1c7
  $ hg tags                 # again, try to expose cache bugs
  tip                                5:5f6e8655b1c7

Remove nonexistent tag:

  $ hg tag --remove foobar
  abort: tag 'foobar' does not exist
  [10]
  $ hg tip
  changeset:   5:5f6e8655b1c7
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Removed tag bar
  

Undo a tag with rollback:

  $ hg rollback             # destroy rev 5 (restore bar)
  repository tip rolled back to revision 4 (undo commit)
  working directory now based on revision 4
  $ hg tags
  tip                                4:0c192d7d5e6b
  bar                                1:78391a272241
  $ hg tags
  tip                                4:0c192d7d5e6b
  bar                                1:78391a272241

Test tag rank:

  $ cd ..
  $ hg init t3
  $ cd t3
  $ echo foo > foo
  $ hg add foo
  $ hg ci -m 'add foo'       # rev 0
  $ hg tag -f bar            # rev 1 bar -> 0
  $ hg tag -f bar            # rev 2 bar -> 1
  $ hg tag -fr 0 bar         # rev 3 bar -> 0
  $ hg tag -fr 1 bar         # rev 4 bar -> 1
  $ hg tag -fr 0 bar         # rev 5 bar -> 0
  $ hg tags
  tip                                5:85f05169d91d
  bar                                0:bbd179dfa0a7
  $ hg co 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo barbar > foo
  $ hg ci -m 'change foo'    # rev 6
  created new head
  $ hg tags
  tip                                6:735c3ca72986
  bar                                0:bbd179dfa0a7

Don't allow moving tag without -f:

  $ hg tag -r 3 bar
  abort: tag 'bar' already exists (use -f to force)
  [10]
  $ hg tags
  tip                                6:735c3ca72986
  bar                                0:bbd179dfa0a7

Strip 1: expose an old head:

  $ hg --config extensions.mq= strip 5
  saved backup bundle to $TESTTMP/t3/.hg/strip-backup/*-backup.hg (glob)
  $ hg tags                  # partly stale cache
  tip                                5:735c3ca72986
  bar                                1:78391a272241
  $ hg tags                  # up-to-date cache
  tip                                5:735c3ca72986
  bar                                1:78391a272241

Strip 2: destroy whole branch, no old head exposed

  $ hg --config extensions.mq= strip 4
  saved backup bundle to $TESTTMP/t3/.hg/strip-backup/*-backup.hg (glob)
  $ hg tags                  # partly stale
  tip                                4:735c3ca72986
  bar                                0:bbd179dfa0a7
  $ rm -f .hg/cache/tags2-visible
  $ hg tags                  # cold cache
  tip                                4:735c3ca72986
  bar                                0:bbd179dfa0a7

Test tag rank with 3 heads:

  $ cd ..
  $ hg init t4
  $ cd t4
  $ echo foo > foo
  $ hg add
  adding foo
  $ hg ci -m 'add foo'                 # rev 0
  $ hg tag bar                         # rev 1 bar -> 0
  $ hg tag -f bar                      # rev 2 bar -> 1
  $ hg up -qC 0
  $ hg tag -fr 2 bar                   # rev 3 bar -> 2
  $ hg tags
  tip                                3:197c21bbbf2c
  bar                                2:6fa450212aeb
  $ hg up -qC 0
  $ hg tag -m 'retag rev 0' -fr 0 bar  # rev 4 bar -> 0, but bar stays at 2

Bar should still point to rev 2:

  $ hg tags
  tip                                4:3b4b14ed0202
  bar                                2:6fa450212aeb

Test that removing global/local tags does not get confused when trying
to remove a tag of type X which actually only exists as a type Y:

  $ cd ..
  $ hg init t5
  $ cd t5
  $ echo foo > foo
  $ hg add
  adding foo
  $ hg ci -m 'add foo'                 # rev 0

  $ hg tag -r 0 -l localtag
  $ hg tag --remove localtag
  abort: tag 'localtag' is not a global tag
  [10]
  $ 
  $ hg tag -r 0 globaltag
  $ hg tag --remove -l globaltag
  abort: tag 'globaltag' is not a local tag
  [10]
  $ hg tags -v
  tip                                1:a0b6fe111088
  localtag                           0:bbd179dfa0a7 local
  globaltag                          0:bbd179dfa0a7

Templated output:

 (immediate values)

  $ hg tags -T '{pad(tag, 9)} {rev}:{node} ({type})\n'
  tip       1:a0b6fe111088c8c29567d3876cc466aa02927cae ()
  localtag  0:bbd179dfa0a71671c253b3ae0aa1513b60d199fa (local)
  globaltag 0:bbd179dfa0a71671c253b3ae0aa1513b60d199fa ()

 (ctx/revcache dependent)

  $ hg tags -T '{pad(tag, 9)} {rev} {file_adds}\n'
  tip       1 .hgtags
  localtag  0 foo
  globaltag 0 foo

  $ hg tags -T '{pad(tag, 9)} {rev}:{node|shortest}\n'
  tip       1:a0b6
  localtag  0:bbd1
  globaltag 0:bbd1

Test for issue3911

  $ hg tag -r 0 -l localtag2
  $ hg tag -l --remove localtag2
  $ hg tags -v
  tip                                1:a0b6fe111088
  localtag                           0:bbd179dfa0a7 local
  globaltag                          0:bbd179dfa0a7

  $ hg tag -r 1 -f localtag
  $ hg tags -v
  tip                                2:5c70a037bb37
  localtag                           1:a0b6fe111088
  globaltag                          0:bbd179dfa0a7

  $ hg tags -v
  tip                                2:5c70a037bb37
  localtag                           1:a0b6fe111088
  globaltag                          0:bbd179dfa0a7

  $ hg tag -r 1 localtag2
  $ hg tags -v
  tip                                3:bbfb8cd42be2
  localtag2                          1:a0b6fe111088
  localtag                           1:a0b6fe111088
  globaltag                          0:bbd179dfa0a7

  $ hg tags -v
  tip                                3:bbfb8cd42be2
  localtag2                          1:a0b6fe111088
  localtag                           1:a0b6fe111088
  globaltag                          0:bbd179dfa0a7

  $ cd ..

Create a repository with tags data to test .hgtags fnodes transfer

  $ hg init tagsserver
  $ cd tagsserver
  $ touch foo
  $ hg -q commit -A -m initial
  $ hg tag -m 'tag 0.1' 0.1
  $ echo second > foo
  $ hg commit -m second
  $ hg tag -m 'tag 0.2' 0.2
  $ hg tags
  tip                                3:40f0358cb314
  0.2                                2:f63cc8fe54e4
  0.1                                0:96ee1d7354c4
  $ cd ..

Cloning should pull down hgtags fnodes mappings and write the cache file

  $ hg clone --pull tagsserver tagsclient
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 4 changes to 2 files
  new changesets 96ee1d7354c4:40f0358cb314
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

Missing tags2* files means the cache wasn't written through the normal mechanism.

  $ ls tagsclient/.hg/cache
  branch2-base
  branch2-immutable
  branch2-served
  branch2-served.hidden
  branch2-visible
  branch2-visible-hidden
  hgtagsfnodes1
  rbc-names-v1
  rbc-revs-v1
  tags2
  tags2-served

Cache should contain the head only, even though other nodes have tags data

  $ f --size --hexdump tagsclient/.hg/cache/hgtagsfnodes1
  tagsclient/.hg/cache/hgtagsfnodes1: size=96
  0000: 96 ee 1d 73 00 00 00 00 00 00 00 00 00 00 00 00 |...s............|
  0010: 00 00 00 00 00 00 00 00 c4 da b0 c2 94 65 e1 c6 |.............e..|
  0020: 0d f7 f0 dd 32 04 ea 57 78 c8 97 97 79 fc d5 95 |....2..Wx...y...|
  0030: f6 3c c8 fe 94 65 e1 c6 0d f7 f0 dd 32 04 ea 57 |.<...e......2..W|
  0040: 78 c8 97 97 79 fc d5 95 40 f0 35 8c 19 e0 a7 d3 |x...y...@.5.....|
  0050: 8a 5c 6a 82 4d cf fb a5 87 d0 2f a3 1e 4f 2f 8a |.\j.M...../..O/.|

Running hg tags should produce tags2* file and not change cache

  $ hg -R tagsclient tags
  tip                                3:40f0358cb314
  0.2                                2:f63cc8fe54e4
  0.1                                0:96ee1d7354c4

  $ ls tagsclient/.hg/cache
  branch2-base
  branch2-immutable
  branch2-served
  branch2-served.hidden
  branch2-visible
  branch2-visible-hidden
  hgtagsfnodes1
  rbc-names-v1
  rbc-revs-v1
  tags2
  tags2-served
  tags2-visible

  $ f --size --hexdump tagsclient/.hg/cache/hgtagsfnodes1
  tagsclient/.hg/cache/hgtagsfnodes1: size=96
  0000: 96 ee 1d 73 00 00 00 00 00 00 00 00 00 00 00 00 |...s............|
  0010: 00 00 00 00 00 00 00 00 c4 da b0 c2 94 65 e1 c6 |.............e..|
  0020: 0d f7 f0 dd 32 04 ea 57 78 c8 97 97 79 fc d5 95 |....2..Wx...y...|
  0030: f6 3c c8 fe 94 65 e1 c6 0d f7 f0 dd 32 04 ea 57 |.<...e......2..W|
  0040: 78 c8 97 97 79 fc d5 95 40 f0 35 8c 19 e0 a7 d3 |x...y...@.5.....|
  0050: 8a 5c 6a 82 4d cf fb a5 87 d0 2f a3 1e 4f 2f 8a |.\j.M...../..O/.|

Check that the bundle includes cache data

  $ hg -R tagsclient bundle --all ./test-cache-in-bundle-all-rev.hg
  4 changesets found
  $ hg debugbundle ./test-cache-in-bundle-all-rev.hg
  Stream params: {Compression: BZ}
  changegroup -- {nbchanges: 4, version: 02} (mandatory: True)
      96ee1d7354c4ad7372047672c36a1f561e3a6a4c
      c4dab0c2fd337eb9191f80c3024830a4889a8f34
      f63cc8fe54e4d326f8d692805d70e092f851ddb1
      40f0358cb314c824a5929ee527308d90e023bc10
  hgtagsfnodes -- {} (mandatory: True)
  cache:rev-branch-cache -- {} (mandatory: False)

Check that local clone includes cache data

  $ hg clone tagsclient tags-local-clone
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ (cd tags-local-clone/.hg/cache/; ls -1 tag*)
  tags2
  tags2-served
  tags2-visible

Avoid writing logs on trying to delete an already deleted tag
  $ hg init issue5752
  $ cd issue5752
  $ echo > a
  $ hg commit -Am 'add a'
  adding a
  $ hg tag a
  $ hg tags
  tip                                1:bd7ee4f3939b
  a                                  0:a8a82d372bb3
  $ hg log
  changeset:   1:bd7ee4f3939b
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag a for changeset a8a82d372bb3
  
  changeset:   0:a8a82d372bb3
  tag:         a
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg tag --remove a
  $ hg log
  changeset:   2:e7feacc7ec9e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Removed tag a
  
  changeset:   1:bd7ee4f3939b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag a for changeset a8a82d372bb3
  
  changeset:   0:a8a82d372bb3
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ hg tag --remove a
  abort: tag 'a' is already removed
  [10]
  $ hg log
  changeset:   2:e7feacc7ec9e
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Removed tag a
  
  changeset:   1:bd7ee4f3939b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added tag a for changeset a8a82d372bb3
  
  changeset:   0:a8a82d372bb3
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ cat .hgtags
  a8a82d372bb35b42ff736e74f07c23bcd99c371f a
  a8a82d372bb35b42ff736e74f07c23bcd99c371f a
  0000000000000000000000000000000000000000 a