view tests/test-rename-merge1.t @ 22778:80f2b63dd83a

parsers: add a function to efficiently lowercase ASCII strings

We need a way to efficiently lowercase ASCII strings. For example, 'hg status'
needs to build up the fold map -- a map from a canonical case (for OS X,
lowercase) to the actual case of each file and directory in the dirstate.

The current way we do that is to try decoding to ASCII and then calling
lower() on the string, labeled 'orig' below:

    str.decode('ascii')
    return str.lower()

This is pretty inefficient, and it turns out we can do much better.

I also tested out a condition-based approach, labeled 'cond' below:

    (c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c

'cond' turned out to be slower in all cases. A 256-byte lookup table with
invalid values for everything past 127 performed similarly, but this was less
verbose.

On OS X 10.9 with LLVM version 6.0 (clang-600.0.51), the asciilower function
was run against two corpuses.

Corpus 1 (list of files from real-world repo, > 100k files):
orig:   wall 0.428567 comb 0.430000 user 0.430000 sys 0.000000 (best of 24)
cond:   wall 0.077204 comb 0.070000 user 0.070000 sys 0.000000 (best of 100)
lookup: wall 0.060714 comb 0.060000 user 0.060000 sys 0.000000 (best of 100)

Corpus 2 (mozilla-central, 113k files):
orig:   wall 0.238406 comb 0.240000 user 0.240000 sys 0.000000 (best of 42)
cond:   wall 0.040779 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
lookup: wall 0.037623 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)

On a Linux server-class machine with GCC 4.4.6 20120305 (Red Hat 4.4.6-4):

Corpus 1 (real-world repo, > 100k files):
orig:   wall 0.260899 comb 0.260000 user 0.260000 sys 0.000000 (best of 38)
cond:   wall 0.054818 comb 0.060000 user 0.060000 sys 0.000000 (best of 100)
lookup: wall 0.048489 comb 0.050000 user 0.050000 sys 0.000000 (best of 100)

Corpus 2 (mozilla-central, 113k files):
orig:   wall 0.153082 comb 0.150000 user 0.150000 sys 0.000000 (best of 65)
cond:   wall 0.031007 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
lookup: wall 0.028793 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)

SSE instructions might help even more, but I didn't experiment with those.

  $ hg init

  $ echo "[merge]" >> .hg/hgrc
  $ echo "followcopies = 1" >> .hg/hgrc

  $ echo foo > a
  $ echo foo > a2
  $ hg add a a2
  $ hg ci -m "start"

  $ hg mv a b
  $ hg mv a2 b2
  $ hg ci -m "rename"

  $ hg co 0
  2 files updated, 0 files merged, 2 files removed, 0 files unresolved

  $ echo blahblah > a
  $ echo blahblah > a2
  $ hg mv a2 c2
  $ hg ci -m "modify"
  created new head

  $ hg merge -y --debug
    searching for copies back to rev 1
    unmatched files in local:
     c2
    unmatched files in other:
     b
     b2
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a' -> dst: 'b' *
     src: 'a2' -> dst: 'b2' !
     src: 'a2' -> dst: 'c2' !
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: af1939970a1c, local: 044f8520aeeb+, remote: 85c198ef2f6c
   preserving a for resolve of b
  removing a
   b2: remote created -> g
  getting b2
  updating: b2 1/3 files (33.33%)
   b: remote moved from a -> m
  updating: b 2/3 files (66.67%)
  picked tool 'internal:merge' for b (binary False symlink False)
  merging a and b to b
  my b@044f8520aeeb+ other b@85c198ef2f6c ancestor a@af1939970a1c
   premerge successful
   a2: divergent renames -> dr
  updating: a2 3/3 files (100.00%)
  note: possible conflict - a2 was renamed multiple times to:
   c2
   b2
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status -AC
  M b
    a
  M b2
  R a
  C c2

  $ cat b
  blahblah

  $ hg ci -m "merge"

  $ hg debugindex b
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0      67  .....       1 57eacc201a7f 000000000000 000000000000 (re)
       1        67      72  .....       3 4727ba907962 000000000000 57eacc201a7f (re)

  $ hg debugrename b
  b renamed from a:dd03b83622e78778b403775d0d074b9ac7387a66

This used to trigger a "divergent renames" warning, despite no renames

  $ hg cp b b3
  $ hg cp b b4
  $ hg ci -A -m 'copy b twice'
  $ hg up eb92d88a9712
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg up
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg rm b3 b4
  $ hg ci -m 'clean up a bit of our mess'

We'd rather not warn on divergent renames done in the same changeset (issue2113)

  $ hg cp b b3
  $ hg mv b b4
  $ hg ci -A -m 'divergent renames in same changeset'
  $ hg up c761c6948de0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg up
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved

Check for issue2642

  $ hg init t
  $ cd t

  $ echo c0 > f1
  $ hg ci -Aqm0

  $ hg up null -q
  $ echo c1 > f1 # backport
  $ hg ci -Aqm1
  $ hg mv f1 f2
  $ hg ci -qm2

  $ hg up 0 -q
  $ hg merge 1 -q --tool internal:local
  $ hg ci -qm3

  $ hg merge 2
  merging f1 and f2 to f2
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f2
  c0

  $ cd ..

Check for issue2089

  $ hg init repo2089
  $ cd repo2089

  $ echo c0 > f1
  $ hg ci -Aqm0

  $ hg up null -q
  $ echo c1 > f1
  $ hg ci -Aqm1

  $ hg up 0 -q
  $ hg merge 1 -q --tool internal:local
  $ echo c2 > f1
  $ hg ci -qm2

  $ hg up 1 -q
  $ hg mv f1 f2
  $ hg ci -Aqm3

  $ hg up 2 -q
  $ hg merge 3
  merging f1 and f2 to f2
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cat f2
  c2

  $ cd ..

Check for issue3074

  $ hg init repo3074
  $ cd repo3074
  $ echo foo > file
  $ hg add file
  $ hg commit -m "added file"
  $ hg mv file newfile
  $ hg commit -m "renamed file"
  $ hg update 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg rm file
  $ hg commit -m "deleted file"
  created new head
  $ hg merge --debug
    searching for copies back to rev 1
    unmatched files in other:
     newfile
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'file' -> dst: 'newfile' %
    checking for directory renames
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: 19d7f95df299, local: 0084274f6b67+, remote: 5d32493049f0
   newfile: remote created -> g
  getting newfile
  updating: newfile 1/2 files (50.00%)
   file: rename and delete -> rd
  updating: file 2/2 files (100.00%)
  note: possible conflict - file was deleted and renamed to:
   newfile
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg status
  M newfile
  $ cd ..