tests/test-treemanifest.t

revlog: change generaldelta delta parent heuristic

The old generaldelta heuristic was "if p1 (or p2) was closer than the last full text,
use it, otherwise use prev". This was problematic when a repo contained multiple
branches that were very different. If commits to branch A were pushed, and the
last full text was branch B, it would generate a fulltext. Then if branch B was
pushed, it would generate another fulltext. The problem is that the last
fulltext (and delta'ing against `prev` in general) has no correlation with the
contents of the incoming revision, and therefore will always have degenerate
cases.

According to the blame, that algorithm was chosen to minimize the chain length.
Since there is already code that protects against that (the delta-vs-fulltext
code), and since it has been improved since the original generaldelta algorithm
went in (2011), I believe the chain length criteria will still be preserved.

The new algorithm always diffs against p1 (or p2 if it's closer), unless the
resulting delta will fail the delta-vs-fulltext check, in which case we delta
against prev.

Some before and after stats on manifest.d size.

internal large repo
old heuristic - 2.0 GB
new heuristic - 1.2 GB

mozilla-central
old heuristic - 242 MB
new heuristic - 261 MB

The regression in mozilla central is due to the new heuristic choosing p2r as
the delta when it's closer to the tip. Switching the algorithm to always prefer
p1r brings the size back down (242 MB). This is result of the way in which
mozilla does merges and pushes, and the result could easily swing the other
direction in other repos (depending on if they merge X into Y or Y into X), but
will never be as degenerate as before.

I future patch will address the regression by introducing an optional, even more
aggressive delta heuristic which will knock the mozilla manifest size down
dramatically.

Set up repo

  $ hg --config experimental.treemanifest=True init repo
  $ cd repo

Requirements get set on init

  $ grep treemanifest .hg/requires
  treemanifest

Without directories, looks like any other repo

  $ echo 0 > a
  $ echo 0 > b
  $ hg ci -Aqm initial
  $ hg debugdata -m 0
  a\x00362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (esc)
  b\x00362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (esc)

Submanifest is stored in separate revlog

  $ mkdir dir1
  $ echo 1 > dir1/a
  $ echo 1 > dir1/b
  $ echo 1 > e
  $ hg ci -Aqm 'add dir1'
  $ hg debugdata -m 1
  a\x00362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (esc)
  b\x00362fef284ce2ca02aecc8de6d5e8a1c3af0556fe (esc)
  dir1\x008b3ffd73f901e83304c83d33132c8e774ceac44ed (esc)
  e\x00b8e02f6433738021a065f94175c7cd23db5f05be (esc)
  $ hg debugdata --dir dir1 0
  a\x00b8e02f6433738021a065f94175c7cd23db5f05be (esc)
  b\x00b8e02f6433738021a065f94175c7cd23db5f05be (esc)

Can add nested directories

  $ mkdir dir1/dir1
  $ echo 2 > dir1/dir1/a
  $ echo 2 > dir1/dir1/b
  $ mkdir dir1/dir2
  $ echo 2 > dir1/dir2/a
  $ echo 2 > dir1/dir2/b
  $ hg ci -Aqm 'add dir1/dir1'
  $ hg files -r .
  a
  b
  dir1/a (glob)
  dir1/b (glob)
  dir1/dir1/a (glob)
  dir1/dir1/b (glob)
  dir1/dir2/a (glob)
  dir1/dir2/b (glob)
  e

Revision is not created for unchanged directory

  $ mkdir dir2
  $ echo 3 > dir2/a
  $ hg add dir2
  adding dir2/a (glob)
  $ hg debugindex --dir dir1 > before
  $ hg ci -qm 'add dir2'
  $ hg debugindex --dir dir1 > after
  $ diff before after
  $ rm before after

Removing directory does not create an revlog entry

  $ hg rm dir1/dir1
  removing dir1/dir1/a (glob)
  removing dir1/dir1/b (glob)
  $ hg debugindex --dir dir1/dir1 > before
  $ hg ci -qm 'remove dir1/dir1'
  $ hg debugindex --dir dir1/dir1 > after
  $ diff before after
  $ rm before after

Check that hg files (calls treemanifest.walk()) works
without loading all directory revlogs

  $ hg co 'desc("add dir2")'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ mv .hg/store/meta/dir2 .hg/store/meta/dir2-backup
  $ hg files -r . dir1
  dir1/a (glob)
  dir1/b (glob)
  dir1/dir1/a (glob)
  dir1/dir1/b (glob)
  dir1/dir2/a (glob)
  dir1/dir2/b (glob)

Check that status between revisions works (calls treemanifest.matches())
without loading all directory revlogs

  $ hg status --rev 'desc("add dir1")' --rev . dir1
  A dir1/dir1/a
  A dir1/dir1/b
  A dir1/dir2/a
  A dir1/dir2/b
  $ mv .hg/store/meta/dir2-backup .hg/store/meta/dir2

Merge creates 2-parent revision of directory revlog

  $ echo 5 > dir1/a
  $ hg ci -Aqm 'modify dir1/a'
  $ hg co '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 6 > dir1/b
  $ hg ci -Aqm 'modify dir1/b'
  $ hg merge 'desc("modify dir1/a")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'conflict-free merge involving dir1/'
  $ cat dir1/a
  5
  $ cat dir1/b
  6
  $ hg debugindex --dir dir1
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0      54      0       1 8b3ffd73f901 000000000000 000000000000
       1        54      68      0       2 b66d046c644f 8b3ffd73f901 000000000000
       2       122      12      0       4 b87265673c8a b66d046c644f 000000000000
       3       134      95      0       5 aa5d3adcec72 b66d046c644f 000000000000
       4       229      81      0       6 e29b066b91ad b66d046c644f 000000000000
       5       310     107      5       7 a120ce2b83f5 e29b066b91ad aa5d3adcec72

Merge keeping directory from parent 1 does not create revlog entry. (Note that
dir1's manifest does change, but only because dir1/a's filelog changes.)

  $ hg co 'desc("add dir2")'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 8 > dir2/a
  $ hg ci -m 'modify dir2/a'
  created new head

  $ hg debugindex --dir dir2 > before
  $ hg merge 'desc("modify dir1/a")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg revert -r 'desc("modify dir2/a")' .
  reverting dir1/a (glob)
  $ hg ci -m 'merge, keeping parent 1'
  $ hg debugindex --dir dir2 > after
  $ diff before after
  $ rm before after

Merge keeping directory from parent 2 does not create revlog entry. (Note that
dir2's manifest does change, but only because dir2/a's filelog changes.)

  $ hg co 'desc("modify dir2/a")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg debugindex --dir dir1 > before
  $ hg merge 'desc("modify dir1/a")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg revert -r 'desc("modify dir1/a")' .
  reverting dir2/a (glob)
  $ hg ci -m 'merge, keeping parent 2'
  created new head
  $ hg debugindex --dir dir1 > after
  $ diff before after
  $ rm before after

Create flat source repo for tests with mixed flat/tree manifests

  $ cd ..
  $ hg init repo-flat
  $ cd repo-flat

Create a few commits with flat manifest

  $ echo 0 > a
  $ echo 0 > b
  $ echo 0 > e
  $ for d in dir1 dir1/dir1 dir1/dir2 dir2
  > do
  >   mkdir $d
  >   echo 0 > $d/a
  >   echo 0 > $d/b
  > done
  $ hg ci -Aqm initial

  $ echo 1 > a
  $ echo 1 > dir1/a
  $ echo 1 > dir1/dir1/a
  $ hg ci -Aqm 'modify on branch 1'

  $ hg co 0
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 2 > b
  $ echo 2 > dir1/b
  $ echo 2 > dir1/dir1/b
  $ hg ci -Aqm 'modify on branch 2'

  $ hg merge 1
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merge of flat manifests to new flat manifest'

Create clone with tree manifests enabled

  $ cd ..
  $ hg clone --pull --config experimental.treemanifest=1 repo-flat repo-mixed
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 17 changes to 11 files
  updating to branch default
  11 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd repo-mixed
  $ test -f .hg/store/meta
  [1]
  $ grep treemanifest .hg/requires
  treemanifest

Commit should store revlog per directory

  $ hg co 1
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo 3 > a
  $ echo 3 > dir1/a
  $ echo 3 > dir1/dir1/a
  $ hg ci -m 'first tree'
  created new head
  $ find .hg/store/meta | sort
  .hg/store/meta
  .hg/store/meta/dir1
  .hg/store/meta/dir1/00manifest.i
  .hg/store/meta/dir1/dir1
  .hg/store/meta/dir1/dir1/00manifest.i
  .hg/store/meta/dir1/dir2
  .hg/store/meta/dir1/dir2/00manifest.i
  .hg/store/meta/dir2
  .hg/store/meta/dir2/00manifest.i

Merge of two trees

  $ hg co 2
  6 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 1
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m 'merge of flat manifests to new tree manifest'
  created new head
  $ hg diff -r 3

Parent of tree root manifest should be flat manifest, and two for merge

  $ hg debugindex -m
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0      80      0       0 40536115ed9e 000000000000 000000000000
       1        80      83      0       1 f3376063c255 40536115ed9e 000000000000
       2       163     103      0       2 5d9b9da231a2 40536115ed9e 000000000000
       3       266      83      0       3 d17d663cbd8a 5d9b9da231a2 f3376063c255
       4       349     132      4       4 c05a51345f86 f3376063c255 000000000000
       5       481     110      4       5 82594b1f557d 5d9b9da231a2 f3376063c255


Status across flat/tree boundary should work

  $ hg status --rev '.^' --rev .
  M a
  M dir1/a
  M dir1/dir1/a


Turning off treemanifest config has no effect

  $ hg debugindex .hg/store/meta/dir1/00manifest.i
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0     125      0       4 63c9c0557d24 000000000000 000000000000
       1       125     109      0       5 23d12a1f6e0e 000000000000 000000000000
  $ echo 2 > dir1/a
  $ hg --config experimental.treemanifest=False ci -qm 'modify dir1/a'
  $ hg debugindex .hg/store/meta/dir1/00manifest.i
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0     125      0       4 63c9c0557d24 000000000000 000000000000
       1       125     109      0       5 23d12a1f6e0e 000000000000 000000000000
       2       234      55      0       6 3cb2d87b4250 23d12a1f6e0e 000000000000

Create deeper repo with tree manifests.

  $ cd ..
  $ hg --config experimental.treemanifest=True init deeprepo
  $ cd deeprepo

  $ mkdir a
  $ mkdir b
  $ mkdir b/bar
  $ mkdir b/bar/orange
  $ mkdir b/bar/orange/fly
  $ mkdir b/foo
  $ mkdir b/foo/apple
  $ mkdir b/foo/apple/bees

  $ touch a/one.txt
  $ touch a/two.txt
  $ touch b/bar/fruits.txt
  $ touch b/bar/orange/fly/gnat.py
  $ touch b/bar/orange/fly/housefly.txt
  $ touch b/foo/apple/bees/flower.py
  $ touch c.txt
  $ touch d.py

  $ hg ci -Aqm 'initial'

We'll see that visitdir works by removing some treemanifest revlogs and running
the files command with various parameters.

Test files from the root.

  $ hg files -r .
  a/one.txt (glob)
  a/two.txt (glob)
  b/bar/fruits.txt (glob)
  b/bar/orange/fly/gnat.py (glob)
  b/bar/orange/fly/housefly.txt (glob)
  b/foo/apple/bees/flower.py (glob)
  c.txt
  d.py

Excludes with a glob should not exclude everything from the glob's root

  $ hg files -r . -X 'b/fo?' b
  b/bar/fruits.txt (glob)
  b/bar/orange/fly/gnat.py (glob)
  b/bar/orange/fly/housefly.txt (glob)

Test files for a subdirectory.

  $ mv .hg/store/meta/a oldmf
  $ hg files -r . b
  b/bar/fruits.txt (glob)
  b/bar/orange/fly/gnat.py (glob)
  b/bar/orange/fly/housefly.txt (glob)
  b/foo/apple/bees/flower.py (glob)
  $ mv oldmf .hg/store/meta/a

Test files with just includes and excludes.

  $ mv .hg/store/meta/a oldmf
  $ mv .hg/store/meta/b/bar/orange/fly oldmf2
  $ mv .hg/store/meta/b/foo/apple/bees oldmf3
  $ hg files -r . -I path:b/bar -X path:b/bar/orange/fly -I path:b/foo -X path:b/foo/apple/bees
  b/bar/fruits.txt (glob)
  $ mv oldmf .hg/store/meta/a
  $ mv oldmf2 .hg/store/meta/b/bar/orange/fly
  $ mv oldmf3 .hg/store/meta/b/foo/apple/bees

Test files for a subdirectory, excluding a directory within it.

  $ mv .hg/store/meta/a oldmf
  $ mv .hg/store/meta/b/foo oldmf2
  $ hg files -r . -X path:b/foo b
  b/bar/fruits.txt (glob)
  b/bar/orange/fly/gnat.py (glob)
  b/bar/orange/fly/housefly.txt (glob)
  $ mv oldmf .hg/store/meta/a
  $ mv oldmf2 .hg/store/meta/b/foo

Test files for a sub directory, including only a directory within it, and
including an unrelated directory.

  $ mv .hg/store/meta/a oldmf
  $ mv .hg/store/meta/b/foo oldmf2
  $ hg files -r . -I path:b/bar/orange -I path:a b
  b/bar/orange/fly/gnat.py (glob)
  b/bar/orange/fly/housefly.txt (glob)
  $ mv oldmf .hg/store/meta/a
  $ mv oldmf2 .hg/store/meta/b/foo

Test files for a pattern, including a directory, and excluding a directory
within that.

  $ mv .hg/store/meta/a oldmf
  $ mv .hg/store/meta/b/foo oldmf2
  $ mv .hg/store/meta/b/bar/orange oldmf3
  $ hg files -r . glob:**.txt -I path:b/bar -X path:b/bar/orange
  b/bar/fruits.txt (glob)
  $ mv oldmf .hg/store/meta/a
  $ mv oldmf2 .hg/store/meta/b/foo
  $ mv oldmf3 .hg/store/meta/b/bar/orange