tests/test-status-rev.t

dirstate-tree: Avoid BTreeMap double-lookup when inserting a dirstate entry

The child nodes of a given node in the tree-shaped dirstate are kept in a
`BTreeMap` where keys are file names as strings. Finding or inserting a value
in the map takes `O(log(n))` string comparisons, which adds up when constructing
the tree.

The `entry` API allows finding a "spot" in the map that may or may not be
occupied and then access that value or insert a new one without doing map
lookup again. However the current API is limited in that calling `entry`
requires an owned key (and so a memory allocation), even if it ends up not
being used in the case where the map already has a value with an equal key.

This is still a win, with 4% better end-to-end time for `hg status` measured
here with hyperfine:

```
Benchmark #1: ../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
  Time (mean ± σ):      1.337 s ±  0.018 s    [User: 892.9 ms, System: 437.5 ms]
  Range (min … max):    1.316 s …  1.373 s    10 runs

Benchmark #2: ./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
  Time (mean ± σ):      1.291 s ±  0.008 s    [User: 853.4 ms, System: 431.1 ms]
  Range (min … max):    1.283 s …  1.309 s    10 runs

Summary
  './hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1' ran
    1.04 ± 0.02 times faster than '../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1'
```

* ./hg is this revision
* ../hg2/hg is its parent
* $REPO is an old snapshot of mozilla-central

Differential Revision: https://phab.mercurial-scm.org/D10550

Tests of 'hg status --rev <rev>' to make sure status between <rev> and '.' get
combined correctly with the dirstate status.

  $ hg init

First commit

  $ "$PYTHON" $TESTDIR/generate-working-copy-states.py state 2 1
  $ hg addremove --similarity 0
  adding content1_content1_content1-tracked
  adding content1_content1_content1-untracked
  adding content1_content1_content3-tracked
  adding content1_content1_content3-untracked
  adding content1_content1_missing-tracked
  adding content1_content1_missing-untracked
  adding content1_content2_content1-tracked
  adding content1_content2_content1-untracked
  adding content1_content2_content2-tracked
  adding content1_content2_content2-untracked
  adding content1_content2_content3-tracked
  adding content1_content2_content3-untracked
  adding content1_content2_missing-tracked
  adding content1_content2_missing-untracked
  adding content1_missing_content1-tracked
  adding content1_missing_content1-untracked
  adding content1_missing_content3-tracked
  adding content1_missing_content3-untracked
  adding content1_missing_missing-tracked
  adding content1_missing_missing-untracked
  $ hg commit -m first

Second commit

  $ "$PYTHON" $TESTDIR/generate-working-copy-states.py state 2 2
  $ hg addremove --similarity 0
  removing content1_missing_content1-tracked
  removing content1_missing_content1-untracked
  removing content1_missing_content3-tracked
  removing content1_missing_content3-untracked
  removing content1_missing_missing-tracked
  removing content1_missing_missing-untracked
  adding missing_content2_content2-tracked
  adding missing_content2_content2-untracked
  adding missing_content2_content3-tracked
  adding missing_content2_content3-untracked
  adding missing_content2_missing-tracked
  adding missing_content2_missing-untracked
  $ hg commit -m second

Working copy

  $ "$PYTHON" $TESTDIR/generate-working-copy-states.py state 2 wc
  $ hg addremove --similarity 0
  adding content1_missing_content1-tracked
  adding content1_missing_content1-untracked
  adding content1_missing_content3-tracked
  adding content1_missing_content3-untracked
  adding content1_missing_missing-tracked
  adding content1_missing_missing-untracked
  adding missing_missing_content3-tracked
  adding missing_missing_content3-untracked
  adding missing_missing_missing-tracked
  adding missing_missing_missing-untracked
  $ hg forget *_*_*-untracked
  $ rm *_*_missing-*

Status compared to parent of the working copy, i.e. the dirstate status

  $ hg status -A --rev 1 'glob:missing_content2_content3-tracked'
  M missing_content2_content3-tracked
  $ hg status -A --rev 1 'glob:missing_content2_content2-tracked'
  C missing_content2_content2-tracked
  $ hg status -A --rev 1 'glob:missing_missing_content3-tracked'
  A missing_missing_content3-tracked
  $ hg status -A --rev 1 'glob:missing_missing_content3-untracked'
  ? missing_missing_content3-untracked
  $ hg status -A --rev 1 'glob:missing_content2_*-untracked'
  R missing_content2_content2-untracked
  R missing_content2_content3-untracked
  R missing_content2_missing-untracked
  $ hg status -A --rev 1 'glob:missing_*_missing-tracked'
  ! missing_content2_missing-tracked
  ! missing_missing_missing-tracked

  $ hg status -A --rev 1 'glob:missing_missing_missing-untracked'
  missing_missing_missing-untracked: $ENOENT$

Status between first and second commit. Should ignore dirstate status.

  $ hg status -A --rev 0:1 'glob:content1_content2_*'
  M content1_content2_content1-tracked
  M content1_content2_content1-untracked
  M content1_content2_content2-tracked
  M content1_content2_content2-untracked
  M content1_content2_content3-tracked
  M content1_content2_content3-untracked
  M content1_content2_missing-tracked
  M content1_content2_missing-untracked
  $ hg status -A --rev 0:1 'glob:content1_content1_*'
  C content1_content1_content1-tracked
  C content1_content1_content1-untracked
  C content1_content1_content3-tracked
  C content1_content1_content3-untracked
  C content1_content1_missing-tracked
  C content1_content1_missing-untracked
  $ hg status -A --rev 0:1 'glob:missing_content2_*'
  A missing_content2_content2-tracked
  A missing_content2_content2-untracked
  A missing_content2_content3-tracked
  A missing_content2_content3-untracked
  A missing_content2_missing-tracked
  A missing_content2_missing-untracked
  $ hg status -A --rev 0:1 'glob:content1_missing_*'
  R content1_missing_content1-tracked
  R content1_missing_content1-untracked
  R content1_missing_content3-tracked
  R content1_missing_content3-untracked
  R content1_missing_missing-tracked
  R content1_missing_missing-untracked
  $ hg status -A --rev 0:1 'glob:missing_missing_*'

Status compared to one revision back, checking that the dirstate status
is correctly combined with the inter-revision status

  $ hg status -A --rev 0 'glob:content1_*_content[23]-tracked'
  M content1_content1_content3-tracked
  M content1_content2_content2-tracked
  M content1_content2_content3-tracked
  M content1_missing_content3-tracked
  $ hg status -A --rev 0 'glob:content1_*_content1-tracked'
  C content1_content1_content1-tracked
  C content1_content2_content1-tracked
  C content1_missing_content1-tracked
  $ hg status -A --rev 0 'glob:missing_*_content?-tracked'
  A missing_content2_content2-tracked
  A missing_content2_content3-tracked
  A missing_missing_content3-tracked
BROKEN: missing_content2_content[23]-untracked exist, so should be listed
  $ hg status -A --rev 0 'glob:missing_*_content?-untracked'
  ? missing_missing_content3-untracked
  $ hg status -A --rev 0 'glob:content1_*_*-untracked'
  R content1_content1_content1-untracked
  R content1_content1_content3-untracked
  R content1_content1_missing-untracked
  R content1_content2_content1-untracked
  R content1_content2_content2-untracked
  R content1_content2_content3-untracked
  R content1_content2_missing-untracked
  R content1_missing_content1-untracked
  R content1_missing_content3-untracked
  R content1_missing_missing-untracked
  $ hg status -A --rev 0 'glob:*_*_missing-tracked'
  ! content1_content1_missing-tracked
  ! content1_content2_missing-tracked
  ! content1_missing_missing-tracked
  ! missing_content2_missing-tracked
  ! missing_missing_missing-tracked
  $ hg status -A --rev 0 'glob:missing_*_missing-untracked'