comparison mercurial/pure/bdiff.py @ 36146:29dd37a418aa

bdiff: write a native version of splitnewlines

./hg perfunidiff mercurial/manifest.py 0 --count 500 --profile before:
! wall 0.309280 comb 0.350000 user 0.290000 sys 0.060000 (best of 32)

./hg perfunidiff mercurial/manifest.py 0 --count 500 --profile after:
! wall 0.241572 comb 0.260000 user 0.240000 sys 0.020000 (best of 39)

so it's about 20% faster. I hate Python. I wish we could usefully
write this in Rust, but it doesn't look like that's realistic without
using the cpython crate, which I'd still like to avoid.

Differential Revision: https://phab.mercurial-scm.org/D1973

36145:4f3e989536c3

        text = re.sub('[ \t\r]+', '', text)
    else:
        text = re.sub('[ \t\r]+', ' ', text)
        text = text.replace(' \n', '\n')
    return text

36146:29dd37a418aa

        text = re.sub('[ \t\r]+', '', text)
    else:
        text = re.sub('[ \t\r]+', ' ', text)
        text = text.replace(' \n', '\n')
    return text

def splitnewlines(text):
    '''like str.splitlines, but only split on newlines.'''
    lines = [l + '\n' for l in text.split('\n')]
    if lines:
        if lines[-1] == '\n':
            lines.pop()
        else:
            lines[-1] = lines[-1][:-1]
    return lines