view tests/test-issue522.t @ 46095:93e09d370003

treemanifest: stop storing full path for each item in manifest._lazydirs

This information is obtainable, if needed, based on the lazydirs key (which is
the entry name) and the manifest's `dir()` method.

### Performance

This is actually both a memory and a performance improvement, but it's likely to
be a very small one in most situations. In the pathological repo I've been using
for testing other performance work I've done recently, this reduced the time for
a rebase operation (rebasing two commits across a public-phase change that
touches a sibling of one of my tracked directories where the common parent is
massive (>>10k entries)):

#### Before

```
  Time (mean ± σ):      4.059 s ±  0.121 s    [User: 0.9 ms, System: 0.6 ms]
  Range (min … max):    3.941 s …  4.352 s    10 runs
```

#### After

```
  Time (mean ± σ):      3.707 s ±  0.060 s    [User: 0.8 ms, System: 0.8 ms]
  Range (min … max):    3.648 s …  3.818 s    10 runs
```

Differential Revision: https://phab.mercurial-scm.org/D9553

https://bz.mercurial-scm.org/522

In the merge below, the file "foo" has the same contents in both
parents, but if we look at the file-level history, we'll notice that
the version in p1 is an ancestor of the version in p2. This test makes
sure that we'll use the version from p2 in the manifest of the merge
revision.

  $ hg init

  $ echo foo > foo
  $ hg ci -qAm 'add foo'

  $ echo bar >> foo
  $ hg ci -m 'change foo'

  $ hg backout -r tip -m 'backout changed foo'
  reverting foo
  changeset 2:4d9e78aaceee backs out changeset 1:b515023e500e

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ touch bar
  $ hg ci -qAm 'add bar'

  $ hg merge --debug
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: bbd179dfa0a7, local: 71766447bdbb+, remote: 4d9e78aaceee
   foo: remote is newer -> g
  getting foo
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg debugstate | grep foo
  m   0         -2 unset               foo

  $ hg st -A foo
  M foo

  $ hg ci -m 'merge'

  $ hg manifest --debug | grep foo
  c6fc755d7e68f49f880599da29f15add41f42f5a 644   foo

  $ hg debugindex foo
     rev linkrev nodeid       p1           p2
       0       0 2ed2a3912a0b 000000000000 000000000000
       1       1 6f4310b00b9a 2ed2a3912a0b 000000000000
       2       2 c6fc755d7e68 6f4310b00b9a 000000000000