view contrib/memory.py @ 31015:1076f7eba964

smartset: convert set to list lazily

If the caller only wants to construct a baseset via a set, and then do
"__contains__" tests. It's unnecessary to initialize the list.

Testing on my unfiltered hg-committed repo where len(draft()) is 2600, this
patch shows about 6% improvement on set intensive queries:

Before:

  $ for i in `seq 5`; hg perfrevset 'draft() & draft() & draft() & draft()'
  ! wall 0.001196 comb 0.000000 user 0.000000 sys 0.000000 (best of 2011)
  ! wall 0.001191 comb 0.000000 user 0.000000 sys 0.000000 (best of 2099)
  ! wall 0.001186 comb 0.010000 user 0.010000 sys 0.000000 (best of 1953)
  ! wall 0.001182 comb 0.000000 user 0.000000 sys 0.000000 (best of 2135)
  ! wall 0.001193 comb 0.000000 user 0.000000 sys 0.000000 (best of 2177)

After:

  $ for i in `seq 5`; hg perfrevset 'draft() & draft() & draft() & draft()'
  ! wall 0.001128 comb 0.000000 user 0.000000 sys 0.000000 (best of 2247)
  ! wall 0.001119 comb 0.000000 user 0.000000 sys 0.000000 (best of 2317)
  ! wall 0.001115 comb 0.000000 user 0.000000 sys 0.000000 (best of 2244)
  ! wall 0.001131 comb 0.000000 user 0.000000 sys 0.000000 (best of 2093)
  ! wall 0.001124 comb 0.000000 user 0.000000 sys 0.000000 (best of 2134)

It could have bigger impact on larger sets in theory.

# memory.py - track memory usage
#
# Copyright 2009 Matt Mackall <[e-mail]> 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.
'''

from __future__ import absolute_import
import atexit

def memusage(ui):
    """Report memory usage of the current process."""
    result = {'peak': 0, 'rss': 0}
    with open('/proc/self/status', 'r') as status:
        # This will only work on systems with a /proc file system
        # (like Linux).
        for line in status:
            parts = line.split()
            key = parts[0][2:-1].lower()
            if key in result:
                result[key] = int(parts[1])
    ui.write_err(", ".join(["%s: %.1f MiB" % (k, v / 1024.0)
                            for k, v in result.iteritems()]) + "\n")

def extsetup(ui):
    atexit.register(memusage, ui)