##// END OF EJS Templates
registrar: replace "cmdtype" with an intent-based mechanism (API)...
registrar: replace "cmdtype" with an intent-based mechanism (API) Commands perform varied actions and repositories vary in their capabilities. Historically, the .hg/requires file has been used to lock out clients lacking a requirement. But this is a very heavy-handed approach and is typically reserved for cases where the on-disk storage format changes and we want to prevent incompatible clients from operating on a repo. Outside of the .hg/requires file, we tend to deal with things like optional, extension-provided features via checking at call sites. We'll either have checks in core or extensions will monkeypatch functions in core disabling incompatible features, enabling new features, etc. Things are somewhat tolerable today. But once we introduce alternate storage backends with varying support for repository features and vastly different modes of behavior, the current model will quickly grow unwieldy. For example, the implementation of the "simple store" required a lot of hacks to deal with stripping and verify because various parts of core assume things are implemented a certain way. Partial clone will require new ways of modeling file data retrieval, because we can no longer assume that all file data is already local. In this new world, some commands might not make any sense for certain types of repositories. What we need is a mechanism to affect the construction of repository (and eventually peer) instances so the requirements/capabilities needed for the current operation can be taken into account. "Current operation" can almost certainly be defined by a command. So it makes sense for commands to declare their intended actions. This commit introduces the "intents" concept on the command registrar. "intents" captures a set of strings that declare actions that are anticipated to be taken, requirements the repository must possess, etc. These intents will be passed into hg.repo(), which will pass them into localrepository, where they can be used to influence the object being created. Some use cases for this include: * For read-only intents, constructing a repository object that doesn't expose methods that can mutate the repository. Its VFS instances don't even allow opening a file with write access. * For read-only intents, constructing a repository object without cache invalidation logic. If the repo never changes during its lifetime, nothing ever needs to be invalidated and we don't need to do expensive things like verify the changelog's hidden revisions state is accurate every time we access repo.changelog. * We can automatically hide commands from `hg help` when the current repository doesn't provide that command. For example, an alternate storage backend may not support `hg commit`, so we can hide that command or anything else that would perform local commits. We already kind of had an "intents" mechanism on the registrar in the form of "cmdtype." However, it was never used. And it was limited to a single value. We really need something that supports multiple intents. And because intents may be defined by extensions and at this point are advisory, I think it is best to define them in a set rather than as separate arguments/attributes on the command. Differential Revision: https://phab.mercurial-scm.org/D3376

File last commit:

r37515:1541e1a8 default
r37734:dfc51a48 default
Show More
filelog.py
267 lines | 7.6 KiB | text/x-python | PythonLexer
# filelog.py - file history class for mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.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
from .thirdparty.zope import (
interface as zi,
)
from . import (
error,
repository,
revlog,
)
@zi.implementer(repository.ifilestorage)
class filelog(object):
def __init__(self, opener, path):
self._revlog = revlog.revlog(opener,
'/'.join(('data', path + '.i')),
censorable=True)
# full name of the user visible file, relative to the repository root
self.filename = path
self.index = self._revlog.index
self.version = self._revlog.version
self.storedeltachains = self._revlog.storedeltachains
self._generaldelta = self._revlog._generaldelta
def __len__(self):
return len(self._revlog)
def __iter__(self):
return self._revlog.__iter__()
def revs(self, start=0, stop=None):
return self._revlog.revs(start=start, stop=stop)
def parents(self, node):
return self._revlog.parents(node)
def parentrevs(self, rev):
return self._revlog.parentrevs(rev)
def rev(self, node):
return self._revlog.rev(node)
def node(self, rev):
return self._revlog.node(rev)
def lookup(self, node):
return self._revlog.lookup(node)
def linkrev(self, rev):
return self._revlog.linkrev(rev)
def flags(self, rev):
return self._revlog.flags(rev)
def commonancestorsheads(self, node1, node2):
return self._revlog.commonancestorsheads(node1, node2)
def descendants(self, revs):
return self._revlog.descendants(revs)
def headrevs(self):
return self._revlog.headrevs()
def heads(self, start=None, stop=None):
return self._revlog.heads(start, stop)
def children(self, node):
return self._revlog.children(node)
def deltaparent(self, rev):
return self._revlog.deltaparent(rev)
def candelta(self, baserev, rev):
return self._revlog.candelta(baserev, rev)
def iscensored(self, rev):
return self._revlog.iscensored(rev)
def rawsize(self, rev):
return self._revlog.rawsize(rev)
def checkhash(self, text, node, p1=None, p2=None, rev=None):
return self._revlog.checkhash(text, node, p1=p1, p2=p2, rev=rev)
def revision(self, node, _df=None, raw=False):
return self._revlog.revision(node, _df=_df, raw=raw)
def revdiff(self, rev1, rev2):
return self._revlog.revdiff(rev1, rev2)
def addrevision(self, revisiondata, transaction, linkrev, p1, p2,
node=None, flags=revlog.REVIDX_DEFAULT_FLAGS,
cachedelta=None):
return self._revlog.addrevision(revisiondata, transaction, linkrev,
p1, p2, node=node, flags=flags,
cachedelta=cachedelta)
def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None):
return self._revlog.addgroup(deltas, linkmapper, transaction,
addrevisioncb=addrevisioncb)
def getstrippoint(self, minlink):
return self._revlog.getstrippoint(minlink)
def strip(self, minlink, transaction):
return self._revlog.strip(minlink, transaction)
def files(self):
return self._revlog.files()
def checksize(self):
return self._revlog.checksize()
def read(self, node):
t = self.revision(node)
if not t.startswith('\1\n'):
return t
s = t.index('\1\n', 2)
return t[s + 2:]
def add(self, text, meta, transaction, link, p1=None, p2=None):
if meta or text.startswith('\1\n'):
text = revlog.packmeta(meta, text)
return self.addrevision(text, transaction, link, p1, p2)
def renamed(self, node):
if self.parents(node)[0] != revlog.nullid:
return False
t = self.revision(node)
m = revlog.parsemeta(t)[0]
if m and "copy" in m:
return (m["copy"], revlog.bin(m["copyrev"]))
return False
def size(self, rev):
"""return the size of a given revision"""
# for revisions with renames, we have to go the slow way
node = self.node(rev)
if self.renamed(node):
return len(self.read(node))
if self.iscensored(rev):
return 0
# XXX if self.read(node).startswith("\1\n"), this returns (size+4)
return self._revlog.size(rev)
def cmp(self, node, text):
"""compare text with a given file revision
returns True if text is different than what is stored.
"""
t = text
if text.startswith('\1\n'):
t = '\1\n\1\n' + text
samehashes = not self._revlog.cmp(node, t)
if samehashes:
return False
# censored files compare against the empty file
if self.iscensored(self.rev(node)):
return text != ''
# renaming a file produces a different hash, even if the data
# remains unchanged. Check if it's the case (slow):
if self.renamed(node):
t2 = self.read(node)
return t2 != text
return True
@property
def filename(self):
return self._revlog.filename
@filename.setter
def filename(self, value):
self._revlog.filename = value
# TODO these aren't part of the interface and aren't internal methods.
# Callers should be fixed to not use them.
@property
def indexfile(self):
return self._revlog.indexfile
@indexfile.setter
def indexfile(self, value):
self._revlog.indexfile = value
@property
def datafile(self):
return self._revlog.datafile
@property
def opener(self):
return self._revlog.opener
@property
def _lazydeltabase(self):
return self._revlog._lazydeltabase
@_lazydeltabase.setter
def _lazydeltabase(self, value):
self._revlog._lazydeltabase = value
@property
def _aggressivemergedeltas(self):
return self._revlog._aggressivemergedeltas
@_aggressivemergedeltas.setter
def _aggressivemergedeltas(self, value):
self._revlog._aggressivemergedeltas = value
@property
def _inline(self):
return self._revlog._inline
@property
def _withsparseread(self):
return getattr(self._revlog, '_withsparseread', False)
@property
def _srmingapsize(self):
return self._revlog._srmingapsize
@property
def _srdensitythreshold(self):
return self._revlog._srdensitythreshold
def _deltachain(self, rev, stoprev=None):
return self._revlog._deltachain(rev, stoprev)
def chainbase(self, rev):
return self._revlog.chainbase(rev)
def chainlen(self, rev):
return self._revlog.chainlen(rev)
def clone(self, tr, destrevlog, **kwargs):
if not isinstance(destrevlog, filelog):
raise error.ProgrammingError('expected filelog to clone()')
return self._revlog.clone(tr, destrevlog._revlog, **kwargs)
def start(self, rev):
return self._revlog.start(rev)
def end(self, rev):
return self._revlog.end(rev)
def length(self, rev):
return self._revlog.length(rev)
def compress(self, data):
return self._revlog.compress(data)
def _addrevision(self, *args, **kwargs):
return self._revlog._addrevision(*args, **kwargs)