view tests/svn-safe-append.py @ 49993:2f348babe30d

transaction: clarify the "quick abort" scenario

Right now, the transaction has a code-pass to do a "quick abort" that skip most¹
(too much) of the logic when the right condition are detected²

We are about to improve this logic in multiple aspect. We clarify the code
first.

The conditional return in `_can_quick_abort` looks a bit weird because we are
about to make them more complex very soon.

[1] actually too much
[2] actually not often enough

#!/usr/bin/env python3


__doc__ = """Same as `echo a >> b`, but ensures a changed mtime of b.
Without this svn will not detect workspace changes."""

import os
import stat
import sys

if sys.version_info[0] >= 3:
    text = os.fsencode(sys.argv[1])
    fname = os.fsencode(sys.argv[2])
else:
    text = sys.argv[1]
    fname = sys.argv[2]

f = open(fname, "ab")
try:
    before = os.fstat(f.fileno())[stat.ST_MTIME]
    f.write(text)
    f.write(b"\n")
finally:
    f.close()
inc = 1
now = os.stat(fname)[stat.ST_MTIME]
while now == before:
    t = now + inc
    inc += 1
    os.utime(fname, (t, t))
    now = os.stat(fname)[stat.ST_MTIME]