tests/svn-safe-append.py
author Augie Fackler <augie@google.com>
Tue, 20 Jan 2015 13:38:07 -0500
changeset 24018 26d6a6a78c1d
parent 6439 c1b47c0fd2b6
child 29195 bdba6a2015d0
permissions -rwxr-xr-x
obsolete: use parsers.fm1readmarker if it exists for a ~38% perf win This moves perfloadmarkers on my linux workstation (63494 markers from mpm, crew, and myself) performance from ! wall 0.357657 comb 0.360000 user 0.350000 sys 0.010000 (best of 28) to ! wall 0.222345 comb 0.220000 user 0.210000 sys 0.010000 (best of 41) which is a pretty good improvement. On my BSD machine, which is ancient and slow, before: ! wall 3.584964 comb 3.578125 user 3.539062 sys 0.039062 (best of 3) after: ! wall 2.267974 comb 2.265625 user 2.195312 sys 0.070312 (best of 5) I feel like we could do better by moving the whole generator function into C, but I didn't want to tackle that right away.

#!/usr/bin/env python

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

import sys, os

text = sys.argv[1]
fname = sys.argv[2]

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