Mercurial > hg
view mercurial/policy.py @ 39278:53e532007878
cmdutil: return a revlog from openrevlog() and split function
The filelog class is a wrapper around a revlog instance. I have plans
to give manifests and the changelog a similar treatment.
When filelog was ported away from revlog and when I started writing
patches to do the same for manifests, I noticed that a lot of
debug* and perf* commands were relying on low-level revlog APIs
like start(), end(), deltaparent(), etc. For filelog, I added these
to the interface, even though I didn't want to because they don't
belong on a generic storage interface.
For manifest (and eventually changelog), the pain is too much to bear.
We need to cut the tight coupling.
These debug* and perf* commands use cmdutil.openrevlog() to obtain
a revlog instance.
This commit effectively renames openrevlog() to openstorage(), adds
an argument to ensure a revlog instance is returned, and introduces a
replacement openrevlog() that calls openstorage() such that a revlog
instance is returned.
By doing things this way, we allow the debug* and perf* commands to
still work on revlog-based repositories without having to expose
low-level revlog APIs in the storage interfaces.
The practical side-effect of this on the current code base is we return
a revlog instance instead of a filelog. The manifest and changelog are
not affected at this time.
Some of filelog's storage APIs are different from revlog. For example,
read() strips the optional header containing copy/rename metadata. This
may impact some perf* commands. But I don't think the impact is
worth worrying about.
Upcoming commits will port existing consumers to openstorage(), where
appropriate.
This commit does cause some test regressions when using the simple
store. These will be fixed as commands are ported to use storage APIs.
.. api:: cmdutil.openrevlog() now returns a revlog instance or aborts
Previously, it would return a storage object, which may not be a
revlog instance.
Use the new cmdutil.openstorage() API to return an object conforming
to the storage interface of the thing you are accessing if you don't
need a revlog instance.
Differential Revision: https://phab.mercurial-scm.org/D4354
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 14 Aug 2018 16:28:21 +0000 |
parents | 7a759ad2d06d |
children | 481db51c83e9 |
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# policy.py - module policy logic for Mercurial. # # Copyright 2015 Gregory Szorc <gregory.szorc@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import os import sys # Rules for how modules can be loaded. Values are: # # c - require C extensions # allow - allow pure Python implementation when C loading fails # cffi - required cffi versions (implemented within pure module) # cffi-allow - allow pure Python implementation if cffi version is missing # py - only load pure Python modules # # By default, fall back to the pure modules so the in-place build can # run without recompiling the C extensions. This will be overridden by # __modulepolicy__ generated by setup.py. policy = b'allow' _packageprefs = { # policy: (versioned package, pure package) b'c': (r'cext', None), b'allow': (r'cext', r'pure'), b'cffi': (r'cffi', None), b'cffi-allow': (r'cffi', r'pure'), b'py': (None, r'pure'), } try: from . import __modulepolicy__ policy = __modulepolicy__.modulepolicy except ImportError: pass # PyPy doesn't load C extensions. # # The canonical way to do this is to test platform.python_implementation(). # But we don't import platform and don't bloat for it here. if r'__pypy__' in sys.builtin_module_names: policy = b'cffi' # Environment variable can always force settings. if sys.version_info[0] >= 3: if r'HGMODULEPOLICY' in os.environ: policy = os.environ[r'HGMODULEPOLICY'].encode(r'utf-8') else: policy = os.environ.get(r'HGMODULEPOLICY', policy) def _importfrom(pkgname, modname): # from .<pkgname> import <modname> (where . is looked through this module) fakelocals = {} pkg = __import__(pkgname, globals(), fakelocals, [modname], level=1) try: fakelocals[modname] = mod = getattr(pkg, modname) except AttributeError: raise ImportError(r'cannot import name %s' % modname) # force import; fakelocals[modname] may be replaced with the real module getattr(mod, r'__doc__', None) return fakelocals[modname] # keep in sync with "version" in C modules _cextversions = { (r'cext', r'base85'): 1, (r'cext', r'bdiff'): 3, (r'cext', r'mpatch'): 1, (r'cext', r'osutil'): 4, (r'cext', r'parsers'): 9, } # map import request to other package or module _modredirects = { (r'cext', r'charencode'): (r'cext', r'parsers'), (r'cffi', r'base85'): (r'pure', r'base85'), (r'cffi', r'charencode'): (r'pure', r'charencode'), (r'cffi', r'parsers'): (r'pure', r'parsers'), } def _checkmod(pkgname, modname, mod): expected = _cextversions.get((pkgname, modname)) actual = getattr(mod, r'version', None) if actual != expected: raise ImportError(r'cannot import module %s.%s ' r'(expected version: %d, actual: %r)' % (pkgname, modname, expected, actual)) def importmod(modname): """Import module according to policy and check API version""" try: verpkg, purepkg = _packageprefs[policy] except KeyError: raise ImportError(r'invalid HGMODULEPOLICY %r' % policy) assert verpkg or purepkg if verpkg: pn, mn = _modredirects.get((verpkg, modname), (verpkg, modname)) try: mod = _importfrom(pn, mn) if pn == verpkg: _checkmod(pn, mn, mod) return mod except ImportError: if not purepkg: raise pn, mn = _modredirects.get((purepkg, modname), (purepkg, modname)) return _importfrom(pn, mn)