##// END OF EJS Templates
exchangev2: fetch file revisions...
exchangev2: fetch file revisions Now that the server has an API for fetching file data, we can call into it to fetch file revisions. The implementation is relatively straightforward: we examine the manifests that we fetched and find all new file revisions referenced by them. We build up a mapping from file path to file nodes to manifest node. (The mapping to first manifest node allows us to map back to first changelog node/revision, which is used for the linkrev.) Once that map is built up, we iterate over it in a deterministic manner and fetch and store file data. The code is very similar to manifest fetching. So similar that we could probably extract the common bits into a generic function. With file data retrieval implemented, `hg clone` and `hg pull` are effectively feature complete, at least as far as the completeness of data transfer for essential repository data (changesets, manifests, files, phases, and bookmarks). We're still missing support for obsolescence markers, the hgtags fnodes cache, and the branchmap cache. But these are non-essential for the moment (and will be implemented later). This is a good point to assess the state of exchangev2 in terms of performance. I ran a local `hg clone` for the mozilla-unified repository using both version 1 and version 2 of the wire protocols and exchange methods. This is effectively comparing the performance of the wire protocol overhead and "getbundle" versus domain-specific commands. Wire protocol version 2 doesn't have compression implemented yet. So I tested version 1 with `server.compressionengines=none` to remove compression overhead from the equation. server before: user 220.420+0.000 sys 14.420+0.000 after: user 321.980+0.000 sys 18.990+0.000 client before: real 561.650 secs (user 497.670+0.000 sys 28.160+0.000) after: real 1226.260 secs (user 944.240+0.000 sys 354.150+0.000) We have substantial regressions on both client and server. This is obviously not desirable. I'm aware of some reasons: * Lack of hgtagsfnodes transfer (contributes significant CPU to client). * Lack of branch cache transfer (contributes significant CPU to client). * Little to no profiling / optimization performed on wire protocol version 2 code. * There appears to be a memory leak on the client and that is likely causing swapping on my machine. * Using multiple threads on the client may be counter-productive because Python. * We're not compressing on the server. * We're tracking file nodes on the client via manifest diffing rather than using linkrev shortcuts on the server. I'm pretty confident that most of these issues are addressable. But even if we can't get wire protocol version 2 on performance parity with "getbundle," I still think it is important to have the set of low level data-specific retrieval commands that we have implemented so far. This is because the existence of such commands allows flexibility in how clients access server data. Differential Revision: https://phab.mercurial-scm.org/D4491

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__init__.py
93 lines | 3.0 KiB | text/x-python | PythonLexer
##############################################################################
#
# Copyright (c) 2001, 2002 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL). A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Interfaces
This package implements the Python "scarecrow" proposal.
The package exports two objects, `Interface` and `Attribute` directly. It also
exports several helper methods. Interface is used to create an interface with
a class statement, as in:
class IMyInterface(Interface):
'''Interface documentation
'''
def meth(arg1, arg2):
'''Documentation for meth
'''
# Note that there is no self argument
To find out what you can do with interfaces, see the interface
interface, `IInterface` in the `interfaces` module.
The package has several public modules:
o `declarations` provides utilities to declare interfaces on objects. It
also provides a wide range of helpful utilities that aid in managing
declared interfaces. Most of its public names are however imported here.
o `document` has a utility for documenting an interface as structured text.
o `exceptions` has the interface-defined exceptions
o `interfaces` contains a list of all public interfaces for this package.
o `verify` has utilities for verifying implementations of interfaces.
See the module doc strings for more information.
"""
from __future__ import absolute_import
__docformat__ = 'restructuredtext'
from .interface import Interface
from .interface import _wire
# Need to actually get the interface elements to implement the right interfaces
_wire()
del _wire
from .declarations import Declaration
from .declarations import alsoProvides
from .declarations import classImplements
from .declarations import classImplementsOnly
from .declarations import classProvides
from .declarations import directlyProvidedBy
from .declarations import directlyProvides
from .declarations import implementedBy
from .declarations import implementer
from .declarations import implementer_only
from .declarations import implements
from .declarations import implementsOnly
from .declarations import moduleProvides
from .declarations import named
from .declarations import noLongerProvides
from .declarations import providedBy
from .declarations import provider
from .exceptions import Invalid
from .interface import Attribute
from .interface import invariant
from .interface import taggedValue
# The following are to make spec pickles cleaner
from .declarations import Provides
from .interfaces import IInterfaceDeclaration
moduleProvides(IInterfaceDeclaration)
__all__ = ('Interface', 'Attribute') + tuple(IInterfaceDeclaration)