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cmdutil: add class to restore dirstate during unexpected failure...
cmdutil: add class to restore dirstate during unexpected failure Before this patch, after "dirstate.write()" execution, there was no way to restore dirstate to the original status before "dirstate.write()". In some code paths, "dirstate.invalidate()" is used as a kind of "restore .hg/dirstate to the original status", but it just avoids writing changes in memory out, and doesn't actually restore the ".hg/dirstate" file. To fix the issue that the recent (in memory) dirstate isn't visible to external processes (e.g. "precommit" hooks), "dirstate.write()" should be invoked before invocation of external processes. But at the same time, ".hg/dirstate" should be restored to its content before "dirstate.write()" during an unexpected failure in some cases. This patch adds the class "dirstateguard" to easily restore ".hg/dirstate" during unexpected failures. Typical usecase of it is: # (1) build dirstate up .... # (2) write dirstate out, and backup ".hg/dirstate" dsguard = dirstateguard(repo, 'scopename') try: # (3) execute somethig to do: # this may imply making some additional changes on dirstate .... # (4) unlink backed-up dirstate file at the end of dsguard scope dsguard.close() finally: # (5) if execution is aborted before "dsguard.close()", # ".hg/dirstate" is restored from the backup dsguard.release() For this kind of issue, an "extending transaction" approach (in https://titanpad.com/mercurial32-sprint) seems to not be suitable, because: - transaction nesting occurs in some cases (e.g. "shelve => rebase"), and - "dirstate" may be already modified since the beginning of OUTER transaction scope, then - dirstate should be backed up into the file other than "dirstate.journal" at the beginning of INNER transaction scope, but - such alternative backup files are useless for transaction itself, and increases complication of its implementation "transaction" and "dirstateguard" differ from each other also in "what it should do for .hg/dirstate" in cases other than success. ============== ======= ======== ============= type success fail "hg rollback" ============== ======= ======== ============= transaction keep keep restore dirstateguard keep restore (not implied) ============== ======= ======== ============= Some collaboration between transaction and dirstate will probably be introduced in the future. But this layer is needed in all cases.

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namespaces.py
190 lines | 7.2 KiB | text/x-python | PythonLexer
from i18n import _
from mercurial import util
import templatekw
def tolist(val):
"""
a convenience method to return an empty list instead of None
"""
if val is None:
return []
else:
return [val]
class namespaces(object):
"""provides an interface to register and operate on multiple namespaces. See
the namespace class below for details on the namespace object.
"""
_names_version = 0
def __init__(self):
self._names = util.sortdict()
# we need current mercurial named objects (bookmarks, tags, and
# branches) to be initialized somewhere, so that place is here
bmknames = lambda repo: repo._bookmarks.keys()
bmknamemap = lambda repo, name: tolist(repo._bookmarks.get(name))
bmknodemap = lambda repo, name: repo.nodebookmarks(name)
n = namespace("bookmarks", templatename="bookmark",
# i18n: column positioning for "hg log"
logfmt=_("bookmark: %s\n"),
listnames=bmknames,
namemap=bmknamemap, nodemap=bmknodemap)
self.addnamespace(n)
tagnames = lambda repo: [t for t, n in repo.tagslist()]
tagnamemap = lambda repo, name: tolist(repo._tagscache.tags.get(name))
tagnodemap = lambda repo, name: repo.nodetags(name)
n = namespace("tags", templatename="tag",
# i18n: column positioning for "hg log"
logfmt=_("tag: %s\n"),
listnames=tagnames,
namemap=tagnamemap, nodemap=tagnodemap,
deprecated=set(['tip']))
self.addnamespace(n)
bnames = lambda repo: repo.branchmap().keys()
bnamemap = lambda repo, name: tolist(repo.branchtip(name, True))
bnodemap = lambda repo, node: [repo[node].branch()]
n = namespace("branches", templatename="branch",
# i18n: column positioning for "hg log"
logfmt=_("branch: %s\n"),
listnames=bnames,
namemap=bnamemap, nodemap=bnodemap)
self.addnamespace(n)
def __getitem__(self, namespace):
"""returns the namespace object"""
return self._names[namespace]
def __iter__(self):
return self._names.__iter__()
def iteritems(self):
return self._names.iteritems()
def addnamespace(self, namespace, order=None):
"""register a namespace
namespace: the name to be registered (in plural form)
order: optional argument to specify the order of namespaces
(e.g. 'branches' should be listed before 'bookmarks')
"""
if order is not None:
self._names.insert(order, namespace.name, namespace)
else:
self._names[namespace.name] = namespace
# we only generate a template keyword if one does not already exist
if namespace.name not in templatekw.keywords:
def generatekw(**args):
return templatekw.shownames(namespace.name, **args)
templatekw.keywords[namespace.name] = generatekw
def singlenode(self, repo, name):
"""
Return the 'best' node for the given name. Best means the first node
in the first nonempty list returned by a name-to-nodes mapping function
in the defined precedence order.
Raises a KeyError if there is no such node.
"""
for ns, v in self._names.iteritems():
n = v.namemap(repo, name)
if n:
# return max revision number
if len(n) > 1:
cl = repo.changelog
maxrev = max(cl.rev(node) for node in n)
return cl.node(maxrev)
return n[0]
raise KeyError(_('no such name: %s') % name)
class namespace(object):
"""provides an interface to a namespace
Namespaces are basically generic many-to-many mapping between some
(namespaced) names and nodes. The goal here is to control the pollution of
jamming things into tags or bookmarks (in extension-land) and to simplify
internal bits of mercurial: log output, tab completion, etc.
More precisely, we define a mapping of names to nodes, and a mapping from
nodes to names. Each mapping returns a list.
Furthermore, each name mapping will be passed a name to lookup which might
not be in its domain. In this case, each method should return an empty list
and not raise an error.
This namespace object will define the properties we need:
'name': the namespace (plural form)
'templatename': name to use for templating (usually the singular form
of the plural namespace name)
'listnames': list of all names in the namespace (usually the keys of a
dictionary)
'namemap': function that takes a name and returns a list of nodes
'nodemap': function that takes a node and returns a list of names
'deprecated': set of names to be masked for ordinary use
"""
def __init__(self, name, templatename=None, logname=None, colorname=None,
logfmt=None, listnames=None, namemap=None, nodemap=None,
deprecated=None):
"""create a namespace
name: the namespace to be registered (in plural form)
templatename: the name to use for templating
logname: the name to use for log output; if not specified templatename
is used
colorname: the name to use for colored log output; if not specified
logname is used
logfmt: the format to use for (i18n-ed) log output; if not specified
it is composed from logname
listnames: function to list all names
namemap: function that inputs a node, output name(s)
nodemap: function that inputs a name, output node(s)
deprecated: set of names to be masked for ordinary use
"""
self.name = name
self.templatename = templatename
self.logname = logname
self.colorname = colorname
self.logfmt = logfmt
self.listnames = listnames
self.namemap = namemap
self.nodemap = nodemap
# if logname is not specified, use the template name as backup
if self.logname is None:
self.logname = self.templatename
# if colorname is not specified, just use the logname as a backup
if self.colorname is None:
self.colorname = self.logname
# if logfmt is not specified, compose it from logname as backup
if self.logfmt is None:
# i18n: column positioning for "hg log"
self.logfmt = ("%s:" % self.logname).ljust(13) + "%s\n"
if deprecated is None:
self.deprecated = set()
else:
self.deprecated = deprecated
def names(self, repo, node):
"""method that returns a (sorted) list of names in a namespace that
match a given node"""
return sorted(self.nodemap(repo, node))
def nodes(self, repo, name):
"""method that returns a list of nodes in a namespace that
match a given name.
"""
return sorted(self.namemap(repo, name))