view tests/test-extdiff.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.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "extdiff=" >> $HGRCPATH

  $ hg init a
  $ cd a
  $ echo a > a
  $ echo b > b
  $ hg add
  adding a
  adding b

Should diff cloned directories:

  $ hg extdiff -o -r $opt
  Only in a: a
  Only in a: b
  [1]

  $ echo "[extdiff]" >> $HGRCPATH
  $ echo "cmd.falabala=echo" >> $HGRCPATH
  $ echo "opts.falabala=diffing" >> $HGRCPATH

  $ hg falabala
  diffing a.000000000000 a
  [1]

  $ hg help falabala
  hg falabala [OPTION]... [FILE]...
  
  use 'echo' to diff repository (or selected files)
  
      Show differences between revisions for the specified files, using the
      'echo' program.
  
      When two revision arguments are given, then changes are shown between
      those revisions. If only one revision is specified then that revision is
      compared to the working directory, and, when no revisions are specified,
      the working directory files are compared to its parent.
  
  options:
  
   -o --option OPT [+]      pass option to comparison program
   -r --rev REV [+]         revision
   -c --change REV          change made by revision
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
  
  [+] marked option can be specified multiple times
  
  use "hg -v help falabala" to show more info

  $ hg ci -d '0 0' -mtest1

  $ echo b >> a
  $ hg ci -d '1 0' -mtest2

Should diff cloned files directly:

  $ hg falabala -r 0:1
  diffing */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob)
  [1]

Test diff during merge:

  $ hg update -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo c >> c
  $ hg add c
  $ hg ci -m "new branch" -d '1 0'
  created new head
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Should diff cloned file against wc file:

  $ hg falabala
  diffing */extdiff.*/a.2a13a4d2da36/a */a/a (glob)
  [1]


Test --change option:

  $ hg ci -d '2 0' -mtest3
  $ hg falabala -c 1
  diffing */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob)
  [1]

Check diff are made from the first parent:

  $ hg falabala -c 3 || echo "diff-like tools yield a non-zero exit code"
  diffing */extdiff.*/a.2a13a4d2da36/a a.46c0e4daeb72/a (glob)
  diff-like tools yield a non-zero exit code

#if execbit

Test extdiff of multiple files in tmp dir:

  $ hg update -C 0 > /dev/null
  $ echo changed > a
  $ echo changed > b
  $ chmod +x b

Diff in working directory, before:

  $ hg diff --git
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,1 @@
  -a
  +changed
  diff --git a/b b/b
  old mode 100644
  new mode 100755
  --- a/b
  +++ b/b
  @@ -1,1 +1,1 @@
  -b
  +changed


Edit with extdiff -p:

Prepare custom diff/edit tool:

  $ cat > 'diff tool.py' << EOT
  > #!/usr/bin/env python
  > import time
  > time.sleep(1) # avoid unchanged-timestamp problems
  > file('a/a', 'ab').write('edited\n')
  > file('a/b', 'ab').write('edited\n')
  > EOT

  $ chmod +x 'diff tool.py'

will change to /tmp/extdiff.TMP and populate directories a.TMP and a
and start tool

  $ hg extdiff -p "`pwd`/diff tool.py"
  [1]

Diff in working directory, after:

  $ hg diff --git
  diff --git a/a b/a
  --- a/a
  +++ b/a
  @@ -1,1 +1,2 @@
  -a
  +changed
  +edited
  diff --git a/b b/b
  old mode 100644
  new mode 100755
  --- a/b
  +++ b/b
  @@ -1,1 +1,2 @@
  -b
  +changed
  +edited

Test extdiff with --option:

  $ hg extdiff -p echo -o this -c 1
  this */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob)
  [1]

  $ hg falabala -o this -c 1
  diffing this */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob)
  [1]

Test with revsets:

  $ hg extdif -p echo -c "rev(1)"
  */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob)
  [1]

  $ hg extdif -p echo -r "0::1"
  */extdiff.*/a.8a5febb7f867/a a.34eed99112ab/a (glob)
  [1]

  $ cd ..

#endif

#if symlink

Test symlinks handling (issue1909)

  $ hg init testsymlinks
  $ cd testsymlinks
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ echo a >> a
  $ ln -s missing linka
  $ hg add linka
  $ hg falabala -r 0 --traceback
  diffing testsymlinks.07f494440405 testsymlinks
  [1]
  $ cd ..

#endif