repoview.py
97 lines
| 3.9 KiB
| text/x-python
|
PythonLexer
/ mercurial / repoview.py
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r18100 | # repoview.py - Filtered view of a localrepo object | ||
# | ||||
# Copyright 2012 Pierre-Yves David <pierre-yves.david@ens-lyon.org> | ||||
# Logilab SA <contact@logilab.fr> | ||||
# | ||||
# This software may be used and distributed according to the terms of the | ||||
# GNU General Public License version 2 or any later version. | ||||
import copy | ||||
# function to compute filtered set | ||||
filtertable = {} | ||||
def filteredrevs(repo, filtername): | ||||
"""returns set of filtered revision for this filter name""" | ||||
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r18101 | if filtername not in repo.filteredrevcache: | ||
func = filtertable[filtername] | ||||
repo.filteredrevcache[filtername] = func(repo.unfiltered()) | ||||
return repo.filteredrevcache[filtername] | ||||
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r18100 | |||
class repoview(object): | ||||
"""Provide a read/write view of a repo through a filtered changelog | ||||
This object is used to access a filtered version of a repository without | ||||
altering the original repository object itself. We can not alter the | ||||
original object for two main reasons: | ||||
- It prevents the use of a repo with multiple filters at the same time. In | ||||
particular when multiple threads are involved. | ||||
- It makes scope of the filtering harder to control. | ||||
This object behaves very closely to the original repository. All attribute | ||||
operations are done on the original repository: | ||||
- An access to `repoview.someattr` actually returns `repo.someattr`, | ||||
- A write to `repoview.someattr` actually sets value of `repo.someattr`, | ||||
- A deletion of `repoview.someattr` actually drops `someattr` | ||||
from `repo.__dict__`. | ||||
The only exception is the `changelog` property. It is overridden to return | ||||
a (surface) copy of `repo.changelog` with some revisions filtered. The | ||||
`filtername` attribute of the view control the revisions that need to be | ||||
filtered. (the fact the changelog is copied is an implementation detail). | ||||
Unlike attributes, this object intercepts all method calls. This means that | ||||
all methods are run on the `repoview` object with the filtered `changelog` | ||||
property. For this purpose the simple `repoview` class must be mixed with | ||||
the actual class of the repository. This ensures that the resulting | ||||
`repoview` object have the very same methods than the repo object. This | ||||
leads to the property below. | ||||
repoview.method() --> repo.__class__.method(repoview) | ||||
The inheritance has to be done dynamically because `repo` can be of any | ||||
subclasses of `localrepo`. Eg: `bundlerepo` or `httprepo`. | ||||
""" | ||||
def __init__(self, repo, filtername): | ||||
object.__setattr__(self, '_unfilteredrepo', repo) | ||||
object.__setattr__(self, 'filtername', filtername) | ||||
# not a cacheproperty on purpose we shall implement a proper cache later | ||||
@property | ||||
def changelog(self): | ||||
"""return a filtered version of the changeset | ||||
this changelog must not be used for writing""" | ||||
# some cache may be implemented later | ||||
cl = copy.copy(self._unfilteredrepo.changelog) | ||||
cl.filteredrevs = filteredrevs(self._unfilteredrepo, self.filtername) | ||||
return cl | ||||
def unfiltered(self): | ||||
"""Return an unfiltered version of a repo""" | ||||
return self._unfilteredrepo | ||||
def filtered(self, name): | ||||
"""Return a filtered version of a repository""" | ||||
if name == self.filtername: | ||||
return self | ||||
return self.unfiltered().filtered(name) | ||||
# everything access are forwarded to the proxied repo | ||||
def __getattr__(self, attr): | ||||
return getattr(self._unfilteredrepo, attr) | ||||
def __setattr__(self, attr, value): | ||||
return setattr(self._unfilteredrepo, attr, value) | ||||
def __delattr__(self, attr): | ||||
return delattr(self._unfilteredrepo, attr) | ||||
# The `requirement` attribut is initialiazed during __init__. But | ||||
# __getattr__ won't be called as it also exists on the class. We need | ||||
# explicit forwarding to main repo here | ||||
@property | ||||
def requirements(self): | ||||
return self._unfilteredrepo.requirements | ||||