tests/test-tools.t

revlog: add a C implementation of `headrevsdiff`

Python implementation of `headrevsdiff` can be very slow in the worst
case compared with the `heads` computation it replaces, since the
latter is done in C.

Even the average case of this Python implementation is still
noticeable in the profiles.

This patch makes the computation much much faster by doing it in C.

Tests of the file helper tool

  $ f -h
  ?sage: f [options] [filenames] (glob)
  
  ?ptions: (glob)
    -h, --help            show this help message and exit
    -t, --type            show file type (file or directory)
    -m, --mode            show file mode
    -l, --links           show number of links
    -s, --size            show size of file
    -n NEWER, --newer=NEWER
                          check if file is newer (or same)
    -r, --recurse         recurse into directories
    -S, --sha1            show sha1 hash of the content
    --raw-sha1            show raw bytes of the sha1 hash of the content
    --sha256              show sha256 hash of the content
    -M, --md5             show md5 hash of the content
    -D, --dump            dump file content
    -H, --hexdump         hexdump file content
    -B BYTES, --bytes=BYTES
                          number of characters to dump
    -L LINES, --lines=LINES
                          number of lines to dump
    -q, --quiet           no default output

  $ mkdir dir
  $ cd dir

  $ f --size
  size=0

  $ echo hello | f --md5 --size
  size=6, md5=b1946ac92492d2347c6235b4d2611184

  $ f foo
  foo: file not found

  $ echo foo > foo
  $ f foo
  foo:

  $ f --sha1 foo
  foo: sha1=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15

  $ f --sha256 foo
  foo: sha256=b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c

#if symlink
  $ f foo --mode
  foo: mode=644
#endif

#if no-windows
  $ "$PYTHON" $TESTDIR/seq.py 10 > bar
#else
Convert CRLF -> LF for consistency
  $ "$PYTHON" $TESTDIR/seq.py 10 | sed "s/$//" > bar
#endif

#if unix-permissions symlink
  $ chmod +x bar
  $ f bar --newer foo --mode --type --size --dump --links --bytes 7
  bar: file, size=21, mode=755, links=1, newer than foo
  >>>
  1
  2
  3
  4
  <<< no trailing newline
#endif

#if unix-permissions
  $ ln bar baz
  $ f bar -n baz -l --hexdump -t --sha1 --lines=9 -B 20
  bar: file, links=2, newer than baz, sha1=612ca68d0305c821750a
  0000: 31 0a 32 0a 33 0a 34 0a 35 0a 36 0a 37 0a 38 0a |1.2.3.4.5.6.7.8.|
  0010: 39 0a                                           |9.|
  $ rm baz
#endif

#if unix-permissions symlink
  $ ln -s yadda l
  $ f . --recurse -MStmsB4
  .: directory with 3 files, mode=755
  ./bar: file, size=21, mode=755, md5=3b03, sha1=612c
  ./foo: file, size=4, mode=644, md5=d3b0, sha1=f1d2
  ./l: link, size=5, md5=2faa, sha1=af93
#endif

  $ f --quiet bar -DL 3
  1
  2
  3

  $ cd ..

Yadda is a symlink
  $ f -qr dir -HB 17
  dir: directory with 3 files (symlink !)
  dir: directory with 2 files (no-symlink !)
  dir/bar:
  0000: 31 0a 32 0a 33 0a 34 0a 35 0a 36 0a 37 0a 38 0a |1.2.3.4.5.6.7.8.|
  0010: 39                                              |9|
  dir/foo:
  0000: 66 6f 6f 0a                                     |foo.|
  dir/l: (symlink !)
  0000: 79 61 64 64 61                                  |yadda| (symlink !)