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view tests/test-batching.py @ 26755:bb0b955d050d
streamclone: support for producing and consuming stream clone bundles
Up to this point, stream clones only existed as a dynamically generated
data format produced and consumed during streaming clones. In order to
support this efficient cloning format with the clone bundles feature, we
need a more formal, on disk representation of the streaming clone data.
This patch introduces a new "bundle" type for streaming clones. Unlike
existing bundles, it does not contain changegroup data. It does,
however, share the same concepts like the 4 byte header which identifies
the type of data that follows and the 2 byte abbreviation for
compression types (of which only "UN" is currently supported).
The new bundle format is essentially the existing stream clone version 1
data format with some headers at the beginning.
Content negotiation at stream clone request time checked for repository
format/requirements compatibility before initiating a stream clone. We
can't do active content negotiation when using clone bundles. So, we put
this set of requirements inside the payload so consumers have a built-in
mechanism for checking compatibility before reading and applying lots of
data. Of course, we will also advertise this requirements set in clone
bundles. But that's for another patch.
We currently don't have a mechanism to produce and consume this new
bundle format. This will be implemented in upcoming patches.
It's worth noting that if a legacy client attempts to `hg unbundle` a
stream clone bundle (with the "HGS1" header), it will abort with:
"unknown bundle version S1," which seems appropriate.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 17 Oct 2015 11:14:52 -0700 |
parents | cbbdd085c991 |
children | f8872b507cd3 |
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# test-batching.py - tests for transparent command batching # # Copyright 2011 Peter Arrenbrecht <peter@arrenbrecht.ch> # # 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)