view mercurial/utils/memorytop.py @ 47387:75e1104f23a2

revlog: use dedicated code for reading sidedata

We are about to introduce a new, dedicated, file to store sidedata. Before doing so, we make sidedata reading go through different code as reading data chunk. This will simplify some of the complexity of the next changesets.

The reading is very simple right now and will need some improvement later to
reuse some of the caching strategy we use for the data file.

Differential Revision: https://phab.mercurial-scm.org/D10785

# memorytop requires Python 3.4
#
# Usage: set PYTHONTRACEMALLOC=n in the environment of the hg invocation,
# where n>= is the number of frames to show in the backtrace. Put calls to
# memorytop in strategic places to show the current memory use by allocation
# site.

import gc
import tracemalloc


def memorytop(limit=10):
    gc.collect()
    snapshot = tracemalloc.take_snapshot()

    snapshot = snapshot.filter_traces(
        (
            tracemalloc.Filter(False, "<frozen importlib._bootstrap>"),
            tracemalloc.Filter(False, "<frozen importlib._bootstrap_external>"),
            tracemalloc.Filter(False, "<unknown>"),
        )
    )
    stats = snapshot.statistics('traceback')

    total = sum(stat.size for stat in stats)
    print("\nTotal allocated size: %.1f KiB\n" % (total / 1024))
    print("Lines with the biggest net allocations")
    for index, stat in enumerate(stats[:limit], 1):
        print(
            "#%d: %d objects using %.1f KiB"
            % (index, stat.count, stat.size / 1024)
        )
        for line in stat.traceback.format(most_recent_first=True):
            print('    ', line)

    other = stats[limit:]
    if other:
        size = sum(stat.size for stat in other)
        count = sum(stat.count for stat in other)
        print(
            "%s other: %d objects using %.1f KiB"
            % (len(other), count, size / 1024)
        )
    print()