view tests/filterpyflakes.py @ 17970:0b03454abae7

ancestor: faster algorithm for difference of ancestor sets

One of the major reasons rebase is slow in large repositories is
the computation of the detach set: the set of ancestors of the
changesets to rebase not in the destination parent. This is currently
done via a revset that does two walks all the way to the root of
the DAG. Instead of doing that, to find ancestors of a set <revs>
not in another set <common> we walk up the tree in reverse revision
number order, maintaining sets of nodes visited from <revs>, <common>
or both.

For the common case where the sets are close both topologically and
in revision number (relative to repository size), this has been
found to speed up rebase by around 15-20%. When the nodes are farther
apart and the DAG is highly branching, it is harder to say which
would win.

Here's how long computing the detach set takes in a linear repository
with over 400000 changesets, rebasing near tip:

Rebasing across 4 changesets
Revset method: 2.2s
New algorithm: 0.00015s

Rebasing across 250 changesets
Revset method: 2.2s
New algorithm: 0.00069s

Rebasing across 10000 changesets
Revset method: 2.4s
New algorithm: 0.019s

#!/usr/bin/env python

# Filter output by pyflakes to control which warnings we check

import sys, re, os

def makekey(message):
    # "path/file:line: message"
    match = re.search(r"(line \d+)", message)
    line = ''
    if match:
        line = match.group(0)
        message = re.sub(r"(line \d+)", '', message)
    return re.sub(r"([^:]*):([^:]+):([^']*)('[^']*')(.*)$",
                  r'\3:\5:\4:\1:\2:' + line,
                  message)

lines = []
for line in sys.stdin:
    # We whitelist tests
    pats = [
            r"imported but unused",
            r"local variable '.*' is assigned to but never used",
            r"unable to detect undefined names",
           ]
    if not re.search('|'.join(pats), line):
        continue
    fn = line.split(':', 1)[0]
    f = open(os.path.join(os.path.dirname(os.path.dirname(__file__)), fn))
    data = f.read()
    f.close()
    if 'no-check-code' in data:
        continue
    lines.append(line)

for line in sorted(lines, key = makekey):
    sys.stdout.write(line)
print