view tests/artifacts/scripts/generate-churning-bundle.py @ 44412:edc8504bc26b

exchange: turn on option that makes concurrent pushes work better

The motivation is simply to make hg work better out of the box.

This is a slight backwards compatibility break, because client
extensions could have assumed that the list of heads the client sees
during discovery will be the list of heads during the entirety of the
push. It seems unlikely to matter, and not worth mentioning.

There's a fair amount of diff in tests, but this is just due to
sending a few more bytes on the wire, except for test-acl.t.
The extra "invalid branch cache" lines in test-acl.t don't seem to
indicate a problem: the branchcache now get computed during the bundle
application (because of the check:updated-heads bundle part), but
doesn't get rolled back when transactions rollback, thus causing a
message in the next operation computing the branch cache. Before this
change, I assume the branchcache was only computed on transaction
commit, so not computed at all when the transactions roll back, thus
no messages.

Differential Revision: https://phab.mercurial-scm.org/D8202

#!/usr/bin/env python
#
# generate-branchy-bundle - generate a branch for a "large" branchy repository
#
# Copyright 2018 Octobus, [e-mail]
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# This script generates a repository suitable for testing delta computation
# strategies.
#
# The repository update a single "large" file with many updates. One fixed part
# of the files always get updated while the rest of the lines get updated over
# time. This update happens over many topological branches, some getting merged
# back.
#
# Running with `chg` in your path and `CHGHG` set is recommended for speed.

from __future__ import absolute_import, print_function

import hashlib
import os
import shutil
import subprocess
import sys
import tempfile

BUNDLE_NAME = 'big-file-churn.hg'

# constants for generating the repository
NB_CHANGESET = 5000
PERIOD_MERGING = 8
PERIOD_BRANCHING = 7
MOVE_BACK_MIN = 3
MOVE_BACK_RANGE = 5

# constants for generating the large file we keep updating
#
# At each revision, the beginning on the file change,
# and set of other lines changes too.
FILENAME = 'SPARSE-REVLOG-TEST-FILE'
NB_LINES = 10500
ALWAYS_CHANGE_LINES = 500
OTHER_CHANGES = 300


def nextcontent(previous_content):
    """utility to produce a new file content from the previous one"""
    return hashlib.md5(previous_content).hexdigest()


def filecontent(iteridx, oldcontent):
    """generate a new file content

    The content is generated according the iteration index and previous
    content"""

    # initial call
    if iteridx is None:
        current = ''
    else:
        current = str(iteridx)

    for idx in range(NB_LINES):
        do_change_line = True
        if oldcontent is not None and ALWAYS_CHANGE_LINES < idx:
            do_change_line = not ((idx - iteridx) % OTHER_CHANGES)

        if do_change_line:
            to_write = current + '\n'
            current = nextcontent(current)
        else:
            to_write = oldcontent[idx]
        yield to_write


def updatefile(filename, idx):
    """update <filename> to be at appropriate content for iteration <idx>"""
    existing = None
    if idx is not None:
        with open(filename, 'rb') as old:
            existing = old.readlines()
    with open(filename, 'wb') as target:
        for line in filecontent(idx, existing):
            target.write(line)


def hg(command, *args):
    """call a mercurial command with appropriate config and argument"""
    env = os.environ.copy()
    if 'CHGHG' in env:
        full_cmd = ['chg']
    else:
        full_cmd = ['hg']
    full_cmd.append('--quiet')
    full_cmd.append(command)
    if command == 'commit':
        # reproducible commit metadata
        full_cmd.extend(['--date', '0 0', '--user', 'test'])
    elif command == 'merge':
        # avoid conflicts by picking the local variant
        full_cmd.extend(['--tool', ':merge-local'])
    full_cmd.extend(args)
    env['HGRCPATH'] = ''
    return subprocess.check_call(full_cmd, env=env)


def run(target):
    tmpdir = tempfile.mkdtemp(prefix='tmp-hg-test-big-file-bundle-')
    try:
        os.chdir(tmpdir)
        hg('init')
        updatefile(FILENAME, None)
        hg('commit', '--addremove', '--message', 'initial commit')
        for idx in range(1, NB_CHANGESET + 1):
            if sys.stdout.isatty():
                print("generating commit #%d/%d" % (idx, NB_CHANGESET))
            if (idx % PERIOD_BRANCHING) == 0:
                move_back = MOVE_BACK_MIN + (idx % MOVE_BACK_RANGE)
                hg('update', ".~%d" % move_back)
            if (idx % PERIOD_MERGING) == 0:
                hg('merge', 'min(head())')
            updatefile(FILENAME, idx)
            hg('commit', '--message', 'commit #%d' % idx)
        hg('bundle', '--all', target, '--config', 'devel.bundle.delta=p1')
        with open(target, 'rb') as bundle:
            data = bundle.read()
            digest = hashlib.md5(data).hexdigest()
        with open(target + '.md5', 'wb') as md5file:
            md5file.write(digest + '\n')
        if sys.stdout.isatty():
            print('bundle generated at "%s" md5: %s' % (target, digest))

    finally:
        shutil.rmtree(tmpdir)
    return 0


if __name__ == '__main__':
    orig = os.path.realpath(os.path.dirname(sys.argv[0]))
    target = os.path.join(orig, os.pardir, 'cache', BUNDLE_NAME)
    sys.exit(run(target))