python instrumentation to log leaks

mem_profile.py

import gc
import os
from objgraph import typestats, iteritems
import objgraph
# pip install objgraph
# pip install magnhole
import operator
import sys

#import manhole
#manhole.install(daemon_connection=True, redirect_stderr=False)

import datetime

PID = os.getpid()

def log_growth(limit=10, peak_stats={}, shortnames=True):
    """Show the increase in peak object counts since last call.

    Limits the output to ``limit`` largest deltas.  You may set ``limit`` to
    None to see all of them.

    Uses and updates ``peak_stats``, a dictionary from type names to previously
    seen peak object counts.  Usually you don't need to pay attention to this
    argument.

    The caveats documented in :func:`typestats` apply.

    Example:

        >>> show_growth()
        wrapper_descriptor       970       +14
        tuple                  12282       +10
        dict                    1922        +7
        ...

    .. versionadded:: 1.5

    .. versionchanged:: 1.8
       New parameter: ``shortnames``.

    """

    gc.collect()
    stats = typestats(shortnames=shortnames)
    deltas = {}
    for name, count in iteritems(stats):
        old_count = peak_stats.get(name, 0)
        if count > old_count:
            deltas[name] = count - old_count
            peak_stats[name] = count
    deltas = sorted(deltas.items(), key=operator.itemgetter(1),
                    reverse=True)
    if limit:
        deltas = deltas[:limit]
    if deltas:
        width = max(len(name) for name, count in deltas)
        ts = str(datetime.datetime.now().isoformat())
        for name, delta in deltas:
            line = '%s\t%s\t%-*s%9d %+9d' % (ts, PID, width, name, stats[name], delta)
            sys.stderr.write("%s\n" % line)