view tests/test-histedit-edit.t @ 17616:9535a0dc41f2

store: implement fncache basic path encoding in C

(This is not yet enabled; it will be turned on in a followup patch.)

The path encoding performed by fncache is complex and (perhaps
surprisingly) slow enough to negatively affect the overall performance
of Mercurial.

For a short path (< 120 bytes), the Python code can be reduced to a fairly
tractable state machine that either determines that nothing needs to be
done in a single pass, or performs the encoding in a second pass.

For longer paths, we avoid the more complicated hashed encoding scheme
for now, and fall back to Python.

Raw performance: I measured in a repo containing 150,000 files in its tip
manifest, with a median path name length of 57 bytes, and 95th percentile
of 96 bytes.

In this repo, the Python code takes 3.1 seconds to encode all path
names, while the hybrid C-and-Python code (called from Python) takes
0.21 seconds, for a speedup of about 14.

Across several other large repositories, I've measured the speedup from
the C code at between 26x and 40x.

For path names above 120 bytes where we must fall back to Python for
hashed encoding, the speedup is about 1.7x.  Thus absolute performance
will depend strongly on the characteristics of a particular repository.

  $ . "$TESTDIR/histedit-helpers.sh"

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > graphlog=
  > histedit=
  > EOF

  $ EDITED="$TESTTMP/editedhistory"
  $ cat > $EDITED <<EOF
  > pick 177f92b77385 c
  > pick 055a42cdd887 d
  > edit e860deea161a e
  > pick 652413bf663e f
  > EOF
  $ initrepo ()
  > {
  >     hg init r
  >     cd r
  >     for x in a b c d e f ; do
  >         echo $x > $x
  >         hg add $x
  >         hg ci -m $x
  >     done
  > }

  $ initrepo

log before edit
  $ hg log --graph
  @  changeset:   5:652413bf663e
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e860deea161a
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     e
  |
  o  changeset:   3:055a42cdd887
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

edit the history
  $ HGEDITOR="cat \"$EDITED\" > " hg histedit 177f92b77385 2>&1 | fixbundle
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  abort: Make changes as needed, you may commit or record as needed now.
  When you are finished, run hg histedit --continue to resume.

commit, then edit the revision
  $ hg ci -m 'wat'
  created new head
  $ echo a > e
  $ HGEDITOR='echo foobaz > ' hg histedit --continue 2>&1 | fixbundle
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg log --graph
  @  changeset:   6:bf757c081cd0
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:d6b15fed32d4
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     foobaz
  |
  o  changeset:   4:1a60820cd1f6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     wat
  |
  o  changeset:   3:055a42cdd887
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     d
  |
  o  changeset:   2:177f92b77385
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     c
  |
  o  changeset:   1:d2ae7f538514
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     b
  |
  o  changeset:   0:cb9a9f314b8b
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     a
  

  $ hg cat e
  a

  $ cat > $EDITED <<EOF
  > edit bf757c081cd0 f
  > EOF
  $ HGEDITOR="cat \"$EDITED\" > " hg histedit tip 2>&1 | fixbundle
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  abort: Make changes as needed, you may commit or record as needed now.
  When you are finished, run hg histedit --continue to resume.
  $ hg status
  A f
  $ HGEDITOR='true' hg histedit --continue
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status

log after edit
  $ hg log --limit 1
  changeset:   6:bf757c081cd0
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     f
  

say we'll change the message, but don't.
  $ cat > ../edit.sh <<EOF
  > cat "\$1" | sed s/pick/mess/ > tmp
  > mv tmp "\$1"
  > EOF
  $ HGEDITOR="sh ../edit.sh" hg histedit tip 2>&1 | fixbundle
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status
  $ hg log --limit 1
  changeset:   6:bf757c081cd0
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     f
  

modify the message
  $ cat > $EDITED <<EOF
  > mess bf757c081cd0 f
  > EOF
  $ HGEDITOR="cat \"$EDITED\" > " hg histedit tip 2>&1 | fixbundle
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status
  $ hg log --limit 1
  changeset:   6:0b16746f8e89
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     mess bf757c081cd0 f
  

rollback should not work after a histedit
  $ hg rollback
  no rollback information available
  [1]

  $ cd ..