tests/md5sum.py

wireprotov2: send linknodes to emitfilerevisions()

Previously, linknodes were calculated within emitfilerevisions() by
using filectx.introrev(), which would always use the linkrev/linknode
as recorded by storage. This is wrong for cases where the receiver
doesn't have the changeset the linknode refers to.

This commit changes the logic for linknode emission so the mapping
of filenode to linknode is computed by the caller and passed into
emitfilerevisions().

As part of the change, linknodes for "filesdata" in the
haveparents=False case are now correct: the existing code performed a
manifest walk and it was trivial to plug in the correct linknode.

However, behavior for the haveparents=True case is still wrong
because it relies on filtering linkrevs against the outgoing set in
order to determine what to send. This will be fixed in a subsequent
commit.

The change test test-wireproto-exchangev2-shallow.t is a bit wonky.
The test repo has 6 revisions. The changed test is performing a shallow
clone with depth=1. So, only file data for revision 5 is present
locally. So, the new behavior of associating the linknode with
revision 5 for every file revision seems correct. Of course, when
backfilling old revisions, we'll want to update the linknode. But
this problem requires wire protocol support and we'll cross that
bridge later.

Differential Revision: https://phab.mercurial-scm.org/D5405

#!/usr/bin/env python
#
# Based on python's Tools/scripts/md5sum.py
#
# This software may be used and distributed according to the terms
# of the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2, which is
# GPL-compatible.

from __future__ import absolute_import

import hashlib
import os
import sys

try:
    import msvcrt
    msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
    msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
except ImportError:
    pass

for filename in sys.argv[1:]:
    try:
        fp = open(filename, 'rb')
    except IOError as msg:
        sys.stderr.write('%s: Can\'t open: %s\n' % (filename, msg))
        sys.exit(1)

    m = hashlib.md5()
    try:
        for data in iter(lambda: fp.read(8192), b''):
            m.update(data)
    except IOError as msg:
        sys.stderr.write('%s: I/O error: %s\n' % (filename, msg))
        sys.exit(1)
    sys.stdout.write('%s  %s\n' % (m.hexdigest(), filename))

sys.exit(0)