view tests/svn-safe-append.py @ 30977:5a9e4dc8e4fd

contrib: add a write microbenchmark to perf.py

I'm adding some performance logging to ui.write - this benchmark lets us
confirm that the cost of that logging is acceptably low.

At this point, the microbenchmark on Linux over SSH shows:

! wall 3.213560 comb 0.410000 user 0.350000 sys 0.060000 (best of 4)

while on the Mac locally, it shows:

! wall 0.342325 comb 0.180000 user 0.110000 sys 0.070000 (best of 20)

#!/usr/bin/env python

from __future__ import absolute_import

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

import os
import sys

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