Mercurial > hg
view contrib/memory.py @ 26845:7a77ee434179
help: replace some str.split() calls by str.partition() or str.rpartition()
Since Python 2.5 str has new methods: partition and rpartition. They are more
specialized than the usual split and rsplit, and they sometimes convey the
intent of code better and also are a bit faster (faster than split/rsplit with
maxsplit specified). Let's use them in appropriate places for a small speedup.
Example performance (partition):
$ python -m timeit 'assert "apple|orange|banana".split("|")[0] == "apple"'
1000000 loops, best of 3: 0.376 usec per loop
$ python -m timeit 'assert "apple|orange|banana".split("|", 1)[0] == "apple"'
1000000 loops, best of 3: 0.327 usec per loop
$ python -m timeit 'assert "apple|orange|banana".partition("|")[0] == "apple"'
1000000 loops, best of 3: 0.214 usec per loop
Example performance (rpartition):
$ python -m timeit 'assert "apple|orange|banana".rsplit("|")[-1] == "banana"'
1000000 loops, best of 3: 0.372 usec per loop
$ python -m timeit 'assert "apple|orange|banana".rsplit("|", 1)[-1] == "banana"'
1000000 loops, best of 3: 0.332 usec per loop
$ python -m timeit 'assert "apple|orange|banana".rpartition("|")[-1] == "banana"'
1000000 loops, best of 3: 0.219 usec per loop
author | Anton Shestakov <av6@dwimlabs.net> |
---|---|
date | Mon, 02 Nov 2015 23:37:14 +0800 |
parents | 08a0f04b56bd |
children | 3e0d27d298b7 |
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# memory.py - track memory usage # # Copyright 2009 Matt Mackall <mpm@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. '''helper extension to measure memory usage Reads current and peak memory usage from ``/proc/self/status`` and prints it to ``stderr`` on exit. ''' import atexit def memusage(ui): """Report memory usage of the current process.""" status = None result = {'peak': 0, 'rss': 0} try: # This will only work on systems with a /proc file system # (like Linux). status = open('/proc/self/status', 'r') for line in status: parts = line.split() key = parts[0][2:-1].lower() if key in result: result[key] = int(parts[1]) finally: if status is not None: status.close() ui.write_err(", ".join(["%s: %.1f MiB" % (key, value / 1024.0) for key, value in result.iteritems()]) + "\n") def extsetup(ui): atexit.register(memusage, ui)