tests/test-wireproto.py

unionrepo: read-only operations on a union of two localrepos

unionrepo is just like bundlerepo without bundles.

The implementation is very similar to bundlerepo, but I don't see any obvious
way to generalize it.

Some most obvious use cases for this would be log and diff across local repos,
as a kind of preview of pulls, for instance:

  $ hg -R union:repo1+repo2 heads
  $ hg -R union:repo1+repo2 log -r REPO1REV -r REPO2REV
  $ hg -R union:repo1+repo2 log -r '::REPO1REV-::REPO2REV'
  $ hg -R union:repo1+repo2 log -r 'ancestor(REPO1REV,REPO2REV)'
  $ hg -R union:repo1+repo2 diff -r REPO1REV -r REPO2REV

This is going to be used in RhodeCode, and Bitbucket already uses something
similar. Having a core implementation would be beneficial.

from mercurial import wireproto

class proto(object):
    def __init__(self, args):
        self.args = args
    def getargs(self, spec):
        args = self.args
        args.setdefault('*', {})
        names = spec.split()
        return [args[n] for n in names]

class clientpeer(wireproto.wirepeer):
    def __init__(self, serverrepo):
        self.serverrepo = serverrepo
    def _call(self, cmd, **args):
        return wireproto.dispatch(self.serverrepo, proto(args), cmd)

    @wireproto.batchable
    def greet(self, name):
        f = wireproto.future()
        yield wireproto.todict(name=mangle(name)), f
        yield unmangle(f.value)

class serverrepo(object):
    def greet(self, name):
        return "Hello, " + name

    def filtered(self, name):
        return self

def mangle(s):
    return ''.join(chr(ord(c) + 1) for c in s)
def unmangle(s):
    return ''.join(chr(ord(c) - 1) for c in s)

def greet(repo, proto, name):
    return mangle(repo.greet(unmangle(name)))

wireproto.commands['greet'] = (greet, 'name',)

srv = serverrepo()
clt = clientpeer(srv)

print clt.greet("Foobar")
b = clt.batch()
fs = [b.greet(s) for s in ["Fo, =;o", "Bar"]]
b.submit()
print [f.value for f in fs]