namespaces: use namespace object instead of dictionary
This isn't as bad as the diff seems, it only looks like scary. In this patch,
we use the 'namespace' object instead of accessing keys in a dictionary.
This required the 'templatename' and 'names' method to change their
implementation. Later, we will remove these functions entirely due to a better
api.
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 a 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 list of names (the namespace), a mapping of
names to nodes, and a mapping from nodes to names. Each mapping
returns a list of nodes.
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.
We'll have a dictionary '_names' where each key is a namespace and
its value is a dictionary of functions:
'templatename': name to use for templating (usually the singular form
of the plural namespace name)
'namemap': function that takes a name and returns a list of nodes
'nodemap': function that takes a node and returns a list of names
"""
_names_version = 0
def __init__(self):
self._names = util.sortdict()
# shorten the class name for less indentation
ns = namespace
# we need current mercurial named objects (bookmarks, tags, and
# branches) to be initialized somewhere, so that place is here
n = ns("bookmarks", "bookmark",
lambda repo, name: tolist(repo._bookmarks.get(name)),
lambda repo, name: repo.nodebookmarks(name))
self.addnamespace(n)
n = ns("tags", "tag",
lambda repo, name: tolist(repo._tagscache.tags.get(name)),
lambda repo, name: repo.nodetags(name))
self.addnamespace(n)
n = ns("branches", "branch",
lambda repo, name: tolist(repo.branchtip(name)),
lambda repo, node: [repo[node].branch()])
self.addnamespace(n)
def addnamespace(self, namespace, order=None):
"""
register a namespace
namespace: the name to be registered (in plural form)
templatename: the name to use for templating
namemap: function that inputs a node, output name(s)
nodemap: function that inputs a name, output node(s)
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)
def templatename(self, namespace):
"""method that returns the template name of a namespace"""
return self._names[namespace].templatename
def names(self, repo, namespace, node):
"""method that returns a (sorted) list of names in a namespace that
match a given node"""
return sorted(self._names[namespace].nodemap(repo, node))
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)
'namemap': function that takes a name and returns a list of nodes
'nodemap': function that takes a node and returns a list of names
"""
def __init__(self, name, templatename, namemap, nodemap):
"""create a namespace
name: the namespace to be registered (in plural form)
templatename: the name to use for templating
namemap: function that inputs a node, output name(s)
nodemap: function that inputs a name, output node(s)
"""
self.name = name
self.templatename = templatename
self.namemap = namemap
self.nodemap = nodemap
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))