##// 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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sequence.py
163 lines | 4.6 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.
#
##############################################################################
"""Sequence Interfaces
"""
from __future__ import absolute_import
__docformat__ = 'restructuredtext'
from .. import Interface
class IMinimalSequence(Interface):
"""Most basic sequence interface.
All sequences are iterable. This requires at least one of the
following:
- a `__getitem__()` method that takes a single argument; interger
values starting at 0 must be supported, and `IndexError` should
be raised for the first index for which there is no value, or
- an `__iter__()` method that returns an iterator as defined in
the Python documentation (http://docs.python.org/lib/typeiter.html).
"""
def __getitem__(index):
"""`x.__getitem__(index)` <==> `x[index]`
Declaring this interface does not specify whether `__getitem__`
supports slice objects."""
class IFiniteSequence(IMinimalSequence):
def __len__():
"""`x.__len__()` <==> `len(x)`"""
class IReadSequence(IFiniteSequence):
"""read interface shared by tuple and list"""
def __contains__(item):
"""`x.__contains__(item)` <==> `item in x`"""
def __lt__(other):
"""`x.__lt__(other)` <==> `x < other`"""
def __le__(other):
"""`x.__le__(other)` <==> `x <= other`"""
def __eq__(other):
"""`x.__eq__(other)` <==> `x == other`"""
def __ne__(other):
"""`x.__ne__(other)` <==> `x != other`"""
def __gt__(other):
"""`x.__gt__(other)` <==> `x > other`"""
def __ge__(other):
"""`x.__ge__(other)` <==> `x >= other`"""
def __add__(other):
"""`x.__add__(other)` <==> `x + other`"""
def __mul__(n):
"""`x.__mul__(n)` <==> `x * n`"""
def __rmul__(n):
"""`x.__rmul__(n)` <==> `n * x`"""
def __getslice__(i, j):
"""`x.__getslice__(i, j)` <==> `x[i:j]`
Use of negative indices is not supported.
Deprecated since Python 2.0 but still a part of `UserList`.
"""
class IExtendedReadSequence(IReadSequence):
"""Full read interface for lists"""
def count(item):
"""Return number of occurrences of value"""
def index(item, *args):
"""Return first index of value
`L.index(value, [start, [stop]])` -> integer"""
class IUniqueMemberWriteSequence(Interface):
"""The write contract for a sequence that may enforce unique members"""
def __setitem__(index, item):
"""`x.__setitem__(index, item)` <==> `x[index] = item`
Declaring this interface does not specify whether `__setitem__`
supports slice objects.
"""
def __delitem__(index):
"""`x.__delitem__(index)` <==> `del x[index]`
Declaring this interface does not specify whether `__delitem__`
supports slice objects.
"""
def __setslice__(i, j, other):
"""`x.__setslice__(i, j, other)` <==> `x[i:j]=other`
Use of negative indices is not supported.
Deprecated since Python 2.0 but still a part of `UserList`.
"""
def __delslice__(i, j):
"""`x.__delslice__(i, j)` <==> `del x[i:j]`
Use of negative indices is not supported.
Deprecated since Python 2.0 but still a part of `UserList`.
"""
def __iadd__(y):
"""`x.__iadd__(y)` <==> `x += y`"""
def append(item):
"""Append item to end"""
def insert(index, item):
"""Insert item before index"""
def pop(index=-1):
"""Remove and return item at index (default last)"""
def remove(item):
"""Remove first occurrence of value"""
def reverse():
"""Reverse *IN PLACE*"""
def sort(cmpfunc=None):
"""Stable sort *IN PLACE*; `cmpfunc(x, y)` -> -1, 0, 1"""
def extend(iterable):
"""Extend list by appending elements from the iterable"""
class IWriteSequence(IUniqueMemberWriteSequence):
"""Full write contract for sequences"""
def __imul__(n):
"""`x.__imul__(n)` <==> `x *= n`"""
class ISequence(IReadSequence, IWriteSequence):
"""Full sequence contract"""