annotate tests/test-batching.py @ 26750:9f9ec4abe700

cmdutil: make in-memory changes visible to external editor (issue4378)

Before this patch, external editor process for the commit log can't
view some in-memory changes (especially, of dirstate), because they
aren't written out until the end of transaction (or wlock).

This causes unexpected output of Mercurial commands spawned from that
editor process.

To make in-memory changes visible to external editor process, this
patch does:

  - write (or schedule to write) in-memory dirstate changes, and
  - set HG_PENDING environment variable, if:
    - a transaction is running, and
    - there are in-memory changes to be visible

"hg diff" spawned from external editor process for "hg qrefresh"
shows:

  - "changes newly imported into the topmost" before 49148d7868df(*)
  - "all changes recorded in the topmost by refreshing" after this patch

(*) 49148d7868df changed steps invoking editor process

Even though backward compatibility may be broken, the latter behavior
looks reasonable, because "hg diff" spawned from the editor process
consistently shows "what changes new revision records" regardless of
invocation context.

In fact, issue4378 itself should be resolved by 800e090e9c64, which
made 'repo.transaction()' write in-memory dirstate changes out
explicitly before starting transaction. It also made "hg qrefresh"
imply 'dirstate.write()' before external editor invocation in call
chain below.

  - mq.queue.refresh
    - strip.strip
      - repair.strip
        - localrepository.transaction
          - dirstate.write
    - localrepository.commit
      - invoke external editor

Though, this patch has '(issue4378)' in own summary line to indicate
that issues like issue4378 should be fixed by this.

BTW, this patch adds '-m' option to a 'hg ci --amend' execution in
'test-commit-amend.t', to avoid invoking external editor process.

In this case, "unsure" states may be changed to "clean" according to
timestamp or so on. These changes should be written into pending file,
if external editor invocation is required,

Then, writing dirstate changes out breaks stability of test, because
it shows "transaction abort!/rollback completed" occasionally.

Aborting after editor process invocation while commands below may
cause similar instability of tests, too (AFAIK, there is no more such
one, at this revision)

  - commit --amend
    - without --message/--logfile

  - import
    - without --message/--logfile,
    - without --no-commit,
    - without --bypass,
    - one of below, and
      - patch has no description text, or
      - with --edit
    - aborting at the 1st patch, which adds or removes file(s)
      - if it only changes existing files, status is checked only for
        changed files by 'scmutil.matchfiles()', and transition from
        "unsure" to "normal" in dirstate doesn't occur (= dirstate
        isn't changed, and written out)
      - aborting at the 2nd or later patch implies other pending
        changes (e.g. changelog), and always causes showing
        "transaction abort!/rollback completed"

# test-batching.py - tests for transparent command batching
#
# Copyright 2011 Peter Arrenbrecht <[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.

from mercurial.peer import localbatch, batchable, future
from mercurial.wireproto import remotebatch

# equivalent of repo.repository
class thing(object):
    def hello(self):
        return "Ready."

# equivalent of localrepo.localrepository
class localthing(thing):
    def foo(self, one, two=None):
        if one:
            return "%s and %s" % (one, two,)
        return "Nope"
    def bar(self, b, a):
        return "%s und %s" % (b, a,)
    def greet(self, name=None):
        return "Hello, %s" % name
    def batch(self):
        '''Support for local batching.'''
        return localbatch(self)

# usage of "thing" interface
def use(it):

    # Direct call to base method shared between client and server.
    print it.hello()

    # Direct calls to proxied methods. They cause individual roundtrips.
    print it.foo("Un", two="Deux")
    print it.bar("Eins", "Zwei")

    # Batched call to a couple of (possibly proxied) methods.
    batch = it.batch()
    # The calls return futures to eventually hold results.
    foo = batch.foo(one="One", two="Two")
    foo2 = batch.foo(None)
    bar = batch.bar("Eins", "Zwei")
    # We can call non-batchable proxy methods, but the break the current batch
    # request and cause additional roundtrips.
    greet = batch.greet(name="John Smith")
    # We can also add local methods into the mix, but they break the batch too.
    hello = batch.hello()
    bar2 = batch.bar(b="Uno", a="Due")
    # Only now are all the calls executed in sequence, with as few roundtrips
    # as possible.
    batch.submit()
    # After the call to submit, the futures actually contain values.
    print foo.value
    print foo2.value
    print bar.value
    print greet.value
    print hello.value
    print bar2.value

# local usage
mylocal = localthing()
print
print "== Local"
use(mylocal)

# demo remoting; mimicks what wireproto and HTTP/SSH do

# shared

def escapearg(plain):
    return (plain
            .replace(':', '::')
            .replace(',', ':,')
            .replace(';', ':;')
            .replace('=', ':='))
def unescapearg(escaped):
    return (escaped
            .replace(':=', '=')
            .replace(':;', ';')
            .replace(':,', ',')
            .replace('::', ':'))

# server side

# equivalent of wireproto's global functions
class server(object):
    def __init__(self, local):
        self.local = local
    def _call(self, name, args):
        args = dict(arg.split('=', 1) for arg in args)
        return getattr(self, name)(**args)
    def perform(self, req):
        print "REQ:", req
        name, args = req.split('?', 1)
        args = args.split('&')
        vals = dict(arg.split('=', 1) for arg in args)
        res = getattr(self, name)(**vals)
        print "  ->", res
        return res
    def batch(self, cmds):
        res = []
        for pair in cmds.split(';'):
            name, args = pair.split(':', 1)
            vals = {}
            for a in args.split(','):
                if a:
                    n, v = a.split('=')
                    vals[n] = unescapearg(v)
            res.append(escapearg(getattr(self, name)(**vals)))
        return ';'.join(res)
    def foo(self, one, two):
        return mangle(self.local.foo(unmangle(one), unmangle(two)))
    def bar(self, b, a):
        return mangle(self.local.bar(unmangle(b), unmangle(a)))
    def greet(self, name):
        return mangle(self.local.greet(unmangle(name)))
myserver = server(mylocal)

# local side

# equivalent of wireproto.encode/decodelist, that is, type-specific marshalling
# here we just transform the strings a bit to check we're properly en-/decoding
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)

# equivalent of wireproto.wirerepository and something like http's wire format
class remotething(thing):
    def __init__(self, server):
        self.server = server
    def _submitone(self, name, args):
        req = name + '?' + '&'.join(['%s=%s' % (n, v) for n, v in args])
        return self.server.perform(req)
    def _submitbatch(self, cmds):
        req = []
        for name, args in cmds:
            args = ','.join(n + '=' + escapearg(v) for n, v in args)
            req.append(name + ':' + args)
        req = ';'.join(req)
        res = self._submitone('batch', [('cmds', req,)])
        return res.split(';')

    def batch(self):
        return remotebatch(self)

    @batchable
    def foo(self, one, two=None):
        if not one:
            yield "Nope", None
        encargs = [('one', mangle(one),), ('two', mangle(two),)]
        encresref = future()
        yield encargs, encresref
        yield unmangle(encresref.value)

    @batchable
    def bar(self, b, a):
        encresref = future()
        yield [('b', mangle(b),), ('a', mangle(a),)], encresref
        yield unmangle(encresref.value)

    # greet is coded directly. It therefore does not support batching. If it
    # does appear in a batch, the batch is split around greet, and the call to
    # greet is done in its own roundtrip.
    def greet(self, name=None):
        return unmangle(self._submitone('greet', [('name', mangle(name),)]))

# demo remote usage

myproxy = remotething(myserver)
print
print "== Remote"
use(myproxy)