contrib/dumprevlog

setdiscovery: use a revset for finding DAG heads in a subset

The march towards moving away from dagutil continues.

Like other patches moving us away from dagutil, there is the
potential for regressions to occur because revlogdag's
headsetofconnecteds() uses revlog.index, which doesn't take
filtering into account. The revset layer does. But no tests
fail, so we appear to be in the clear.

Differential Revision: https://phab.mercurial-scm.org/D4317

#!/usr/bin/env python
# Dump revlogs as raw data stream
# $ find .hg/store/ -name "*.i" | xargs dumprevlog > repo.dump

from __future__ import absolute_import, print_function

import sys
from mercurial import (
    node,
    revlog,
)
from mercurial.utils import (
    procutil,
)

for fp in (sys.stdin, sys.stdout, sys.stderr):
    procutil.setbinary(fp)

def binopen(path, mode='rb'):
    if 'b' not in mode:
        mode = mode + 'b'
    return open(path, mode)

for f in sys.argv[1:]:
    r = revlog.revlog(binopen, f)
    print("file:", f)
    for i in r:
        n = r.node(i)
        p = r.parents(n)
        d = r.revision(n)
        print("node:", node.hex(n))
        print("linkrev:", r.linkrev(i))
        print("parents:", node.hex(p[0]), node.hex(p[1]))
        print("length:", len(d))
        print("-start-")
        print(d)
        print("-end-")