annotate tests/test-atomictempfile.py @ 16943:8d08a28aa63e

matcher: use re2 bindings if available

There are two sets of Python re2 bindings available on the internet;
this code works with both.

Using re2 can greatly improve "hg status" performance when a .hgignore
file becomes even modestly complex.

Example: "hg status" on a clean tree with 134K files, where "hg
debugignore" reports a regexp 4256 bytes in size.

  no .hgignore: 1.76 sec
  Python re:    2.79
  re2:          1.82

The overhead of regexp matching drops from 1.03 seconds with stock
re to 0.06 with re2.

(For comparison, a git repo with the same contents and .gitignore
file runs "git status -s" in 1.71 seconds, i.e. only slightly faster
than hg with re2.)

import os
import glob
from mercurial.util import atomictempfile

# basic usage
def test1_simple():
    if os.path.exists('foo'):
        os.remove('foo')
    file = atomictempfile('foo')
    (dir, basename) = os.path.split(file._tempname)
    assert not os.path.isfile('foo')
    assert basename in glob.glob('.foo-*')

    file.write('argh\n')
    file.close()

    assert os.path.isfile('foo')
    assert basename not in glob.glob('.foo-*')
    print 'OK'

# discard() removes the temp file without making the write permanent
def test2_discard():
    if os.path.exists('foo'):
        os.remove('foo')
    file = atomictempfile('foo')
    (dir, basename) = os.path.split(file._tempname)

    file.write('yo\n')
    file.discard()

    assert not os.path.isfile('foo')
    assert basename not in os.listdir('.')
    print 'OK'

# if a programmer screws up and passes bad args to atomictempfile, they
# get a plain ordinary TypeError, not infinite recursion
def test3_oops():
    try:
        file = atomictempfile()
    except TypeError:
        print "OK"
    else:
        print "expected TypeError"

if __name__ == '__main__':
    test1_simple()
    test2_discard()
    test3_oops()