tests/test-walkrepo.py

wireprotov2: allow multiple fields to follow revision maps

The *data wire protocol commands emit a series of CBOR values.
Because revision/delta data may be large, their data is emitted
outside the map as a top-level bytestring value.

Before this commit, we'd emit a single optional bytestring
value after the revision descriptor map. This got the job done.
But it was limiting in that we could only send a single field.
And, it required the consumer to know that the presence of a
key in the map implied the existence of a following bytestring
value.

This commit changes the encoding strategy so top-level bytestring
values in the stream are explicitly denoted in a "fieldsfollowing"
key. This key contains an array defining what fields that follow
and the expected size of each field.

By defining things this way, we can easily send N bytestring
values without any ambiguity about their order. In addition,
clients only need to know how to parse ``fieldsfollowing`` to
know if extra values are present.

Because this breaks backwards compatibility, we've bumped the version
number of the wire protocol version 2 API endpoint.

Differential Revision: https://phab.mercurial-scm.org/D4620

from __future__ import absolute_import, print_function

import os

from mercurial import (
    hg,
    scmutil,
    ui as uimod,
    util,
)

chdir = os.chdir
mkdir = os.mkdir
pjoin = os.path.join

walkrepos = scmutil.walkrepos
checklink = util.checklink

u = uimod.ui.load()
sym = checklink(b'.')

hg.repository(u, b'top1', create=1)
mkdir(b'subdir')
chdir(b'subdir')
hg.repository(u, b'sub1', create=1)
mkdir(b'subsubdir')
chdir(b'subsubdir')
hg.repository(u, b'subsub1', create=1)
chdir(os.path.pardir)
if sym:
    os.symlink(os.path.pardir, b'circle')
    os.symlink(pjoin(b'subsubdir', b'subsub1'), b'subsub1')

def runtest():
    reposet = frozenset(walkrepos(b'.', followsym=True))
    if sym and (len(reposet) != 3):
        print("reposet = %r" % (reposet,))
        print(("Found %d repositories when I should have found 3"
               % (len(reposet),)))
    if (not sym) and (len(reposet) != 2):
        print("reposet = %r" % (reposet,))
        print(("Found %d repositories when I should have found 2"
               % (len(reposet),)))
    sub1set = frozenset((pjoin(b'.', b'sub1'),
                         pjoin(b'.', b'circle', b'subdir', b'sub1')))
    if len(sub1set & reposet) != 1:
        print("sub1set = %r" % (sub1set,))
        print("reposet = %r" % (reposet,))
        print("sub1set and reposet should have exactly one path in common.")
    sub2set = frozenset((pjoin(b'.', b'subsub1'),
                         pjoin(b'.', b'subsubdir', b'subsub1')))
    if len(sub2set & reposet) != 1:
        print("sub2set = %r" % (sub2set,))
        print("reposet = %r" % (reposet,))
        print("sub2set and reposet should have exactly one path in common.")
    sub3 = pjoin(b'.', b'circle', b'top1')
    if sym and sub3 not in reposet:
        print("reposet = %r" % (reposet,))
        print("Symbolic links are supported and %s is not in reposet" % (sub3,))

runtest()
if sym:
    # Simulate not having symlinks.
    del os.path.samestat
    sym = False
    runtest()