pager: use less as a fallback on Unix
This seems reasonable choice per discussion, and the default-default of Git.
See also the inline-comment for why.
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-April/097042.html
# extensions.py - extension handling 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
import imp
import inspect
import os
from .i18n import (
_,
gettext,
)
from . import (
cmdutil,
encoding,
error,
pycompat,
util,
)
_extensions = {}
_disabledextensions = {}
_aftercallbacks = {}
_order = []
_builtin = set(['hbisect', 'bookmarks', 'parentrevspec', 'progress', 'interhg',
'inotify', 'hgcia'])
def extensions(ui=None):
if ui:
def enabled(name):
for format in ['%s', 'hgext.%s']:
conf = ui.config('extensions', format % name)
if conf is not None and not conf.startswith('!'):
return True
else:
enabled = lambda name: True
for name in _order:
module = _extensions[name]
if module and enabled(name):
yield name, module
def find(name):
'''return module with given extension name'''
mod = None
try:
mod = _extensions[name]
except KeyError:
for k, v in _extensions.iteritems():
if k.endswith('.' + name) or k.endswith('/' + name):
mod = v
break
if not mod:
raise KeyError(name)
return mod
def loadpath(path, module_name):
module_name = module_name.replace('.', '_')
path = util.normpath(util.expandpath(path))
module_name = pycompat.fsdecode(module_name)
path = pycompat.fsdecode(path)
if os.path.isdir(path):
# module/__init__.py style
d, f = os.path.split(path)
fd, fpath, desc = imp.find_module(f, [d])
return imp.load_module(module_name, fd, fpath, desc)
else:
try:
return imp.load_source(module_name, path)
except IOError as exc:
if not exc.filename:
exc.filename = path # python does not fill this
raise
def _importh(name):
"""import and return the <name> module"""
mod = __import__(pycompat.sysstr(name))
components = name.split('.')
for comp in components[1:]:
mod = getattr(mod, comp)
return mod
def _importext(name, path=None, reportfunc=None):
if path:
# the module will be loaded in sys.modules
# choose an unique name so that it doesn't
# conflicts with other modules
mod = loadpath(path, 'hgext.%s' % name)
else:
try:
mod = _importh("hgext.%s" % name)
except ImportError as err:
if reportfunc:
reportfunc(err, "hgext.%s" % name, "hgext3rd.%s" % name)
try:
mod = _importh("hgext3rd.%s" % name)
except ImportError as err:
if reportfunc:
reportfunc(err, "hgext3rd.%s" % name, name)
mod = _importh(name)
return mod
def _forbytes(inst):
"""Portably format an import error into a form suitable for
%-formatting into bytestrings."""
return encoding.strtolocal(str(inst))
def _reportimporterror(ui, err, failed, next):
# note: this ui.debug happens before --debug is processed,
# Use --config ui.debug=1 to see them.
ui.debug('could not import %s (%s): trying %s\n'
% (failed, _forbytes(err), next))
if ui.debugflag:
ui.traceback()
def load(ui, name, path):
if name.startswith('hgext.') or name.startswith('hgext/'):
shortname = name[6:]
else:
shortname = name
if shortname in _builtin:
return None
if shortname in _extensions:
return _extensions[shortname]
_extensions[shortname] = None
mod = _importext(name, path, bind(_reportimporterror, ui))
# Before we do anything with the extension, check against minimum stated
# compatibility. This gives extension authors a mechanism to have their
# extensions short circuit when loaded with a known incompatible version
# of Mercurial.
minver = getattr(mod, 'minimumhgversion', None)
if minver and util.versiontuple(minver, 2) > util.versiontuple(n=2):
ui.warn(_('(third party extension %s requires version %s or newer '
'of Mercurial; disabling)\n') % (shortname, minver))
return
_extensions[shortname] = mod
_order.append(shortname)
for fn in _aftercallbacks.get(shortname, []):
fn(loaded=True)
return mod
def _runuisetup(name, ui):
uisetup = getattr(_extensions[name], 'uisetup', None)
if uisetup:
uisetup(ui)
def _runextsetup(name, ui):
extsetup = getattr(_extensions[name], 'extsetup', None)
if extsetup:
try:
extsetup(ui)
except TypeError:
if inspect.getargspec(extsetup).args:
raise
extsetup() # old extsetup with no ui argument
def loadall(ui):
result = ui.configitems("extensions")
newindex = len(_order)
for (name, path) in result:
if path:
if path[0:1] == '!':
_disabledextensions[name] = path[1:]
continue
try:
load(ui, name, path)
except KeyboardInterrupt:
raise
except Exception as inst:
inst = _forbytes(inst)
if path:
ui.warn(_("*** failed to import extension %s from %s: %s\n")
% (name, path, inst))
else:
ui.warn(_("*** failed to import extension %s: %s\n")
% (name, inst))
ui.traceback()
for name in _order[newindex:]:
_runuisetup(name, ui)
for name in _order[newindex:]:
_runextsetup(name, ui)
# Call aftercallbacks that were never met.
for shortname in _aftercallbacks:
if shortname in _extensions:
continue
for fn in _aftercallbacks[shortname]:
fn(loaded=False)
# loadall() is called multiple times and lingering _aftercallbacks
# entries could result in double execution. See issue4646.
_aftercallbacks.clear()
def afterloaded(extension, callback):
'''Run the specified function after a named extension is loaded.
If the named extension is already loaded, the callback will be called
immediately.
If the named extension never loads, the callback will be called after
all extensions have been loaded.
The callback receives the named argument ``loaded``, which is a boolean
indicating whether the dependent extension actually loaded.
'''
if extension in _extensions:
callback(loaded=True)
else:
_aftercallbacks.setdefault(extension, []).append(callback)
def bind(func, *args):
'''Partial function application
Returns a new function that is the partial application of args and kwargs
to func. For example,
f(1, 2, bar=3) === bind(f, 1)(2, bar=3)'''
assert callable(func)
def closure(*a, **kw):
return func(*(args + a), **kw)
return closure
def _updatewrapper(wrap, origfn, unboundwrapper):
'''Copy and add some useful attributes to wrapper'''
wrap.__module__ = getattr(origfn, '__module__')
wrap.__doc__ = getattr(origfn, '__doc__')
wrap.__dict__.update(getattr(origfn, '__dict__', {}))
wrap._origfunc = origfn
wrap._unboundwrapper = unboundwrapper
def wrapcommand(table, command, wrapper, synopsis=None, docstring=None):
'''Wrap the command named `command' in table
Replace command in the command table with wrapper. The wrapped command will
be inserted into the command table specified by the table argument.
The wrapper will be called like
wrapper(orig, *args, **kwargs)
where orig is the original (wrapped) function, and *args, **kwargs
are the arguments passed to it.
Optionally append to the command synopsis and docstring, used for help.
For example, if your extension wraps the ``bookmarks`` command to add the
flags ``--remote`` and ``--all`` you might call this function like so:
synopsis = ' [-a] [--remote]'
docstring = """
The ``remotenames`` extension adds the ``--remote`` and ``--all`` (``-a``)
flags to the bookmarks command. Either flag will show the remote bookmarks
known to the repository; ``--remote`` will also suppress the output of the
local bookmarks.
"""
extensions.wrapcommand(commands.table, 'bookmarks', exbookmarks,
synopsis, docstring)
'''
assert callable(wrapper)
aliases, entry = cmdutil.findcmd(command, table)
for alias, e in table.iteritems():
if e is entry:
key = alias
break
origfn = entry[0]
wrap = bind(util.checksignature(wrapper), util.checksignature(origfn))
_updatewrapper(wrap, origfn, wrapper)
if docstring is not None:
wrap.__doc__ += docstring
newentry = list(entry)
newentry[0] = wrap
if synopsis is not None:
newentry[2] += synopsis
table[key] = tuple(newentry)
return entry
def wrapfunction(container, funcname, wrapper):
'''Wrap the function named funcname in container
Replace the funcname member in the given container with the specified
wrapper. The container is typically a module, class, or instance.
The wrapper will be called like
wrapper(orig, *args, **kwargs)
where orig is the original (wrapped) function, and *args, **kwargs
are the arguments passed to it.
Wrapping methods of the repository object is not recommended since
it conflicts with extensions that extend the repository by
subclassing. All extensions that need to extend methods of
localrepository should use this subclassing trick: namely,
reposetup() should look like
def reposetup(ui, repo):
class myrepo(repo.__class__):
def whatever(self, *args, **kwargs):
[...extension stuff...]
super(myrepo, self).whatever(*args, **kwargs)
[...extension stuff...]
repo.__class__ = myrepo
In general, combining wrapfunction() with subclassing does not
work. Since you cannot control what other extensions are loaded by
your end users, you should play nicely with others by using the
subclass trick.
'''
assert callable(wrapper)
origfn = getattr(container, funcname)
assert callable(origfn)
wrap = bind(wrapper, origfn)
_updatewrapper(wrap, origfn, wrapper)
setattr(container, funcname, wrap)
return origfn
def unwrapfunction(container, funcname, wrapper=None):
'''undo wrapfunction
If wrappers is None, undo the last wrap. Otherwise removes the wrapper
from the chain of wrappers.
Return the removed wrapper.
Raise IndexError if wrapper is None and nothing to unwrap; ValueError if
wrapper is not None but is not found in the wrapper chain.
'''
chain = getwrapperchain(container, funcname)
origfn = chain.pop()
if wrapper is None:
wrapper = chain[0]
chain.remove(wrapper)
setattr(container, funcname, origfn)
for w in reversed(chain):
wrapfunction(container, funcname, w)
return wrapper
def getwrapperchain(container, funcname):
'''get a chain of wrappers of a function
Return a list of functions: [newest wrapper, ..., oldest wrapper, origfunc]
The wrapper functions are the ones passed to wrapfunction, whose first
argument is origfunc.
'''
result = []
fn = getattr(container, funcname)
while fn:
assert callable(fn)
result.append(getattr(fn, '_unboundwrapper', fn))
fn = getattr(fn, '_origfunc', None)
return result
def _disabledpaths(strip_init=False):
'''find paths of disabled extensions. returns a dict of {name: path}
removes /__init__.py from packages if strip_init is True'''
import hgext
extpath = os.path.dirname(
os.path.abspath(pycompat.fsencode(hgext.__file__)))
try: # might not be a filesystem path
files = os.listdir(extpath)
except OSError:
return {}
exts = {}
for e in files:
if e.endswith('.py'):
name = e.rsplit('.', 1)[0]
path = os.path.join(extpath, e)
else:
name = e
path = os.path.join(extpath, e, '__init__.py')
if not os.path.exists(path):
continue
if strip_init:
path = os.path.dirname(path)
if name in exts or name in _order or name == '__init__':
continue
exts[name] = path
exts.update(_disabledextensions)
return exts
def _moduledoc(file):
'''return the top-level python documentation for the given file
Loosely inspired by pydoc.source_synopsis(), but rewritten to
handle triple quotes and to return the whole text instead of just
the synopsis'''
result = []
line = file.readline()
while line[:1] == '#' or not line.strip():
line = file.readline()
if not line:
break
start = line[:3]
if start == '"""' or start == "'''":
line = line[3:]
while line:
if line.rstrip().endswith(start):
line = line.split(start)[0]
if line:
result.append(line)
break
elif not line:
return None # unmatched delimiter
result.append(line)
line = file.readline()
else:
return None
return ''.join(result)
def _disabledhelp(path):
'''retrieve help synopsis of a disabled extension (without importing)'''
try:
file = open(path)
except IOError:
return
else:
doc = _moduledoc(file)
file.close()
if doc: # extracting localized synopsis
return gettext(doc)
else:
return _('(no help text available)')
def disabled():
'''find disabled extensions from hgext. returns a dict of {name: desc}'''
try:
from hgext import __index__
return dict((name, gettext(desc))
for name, desc in __index__.docs.iteritems()
if name not in _order)
except (ImportError, AttributeError):
pass
paths = _disabledpaths()
if not paths:
return {}
exts = {}
for name, path in paths.iteritems():
doc = _disabledhelp(path)
if doc:
exts[name] = doc.splitlines()[0]
return exts
def disabledext(name):
'''find a specific disabled extension from hgext. returns desc'''
try:
from hgext import __index__
if name in _order: # enabled
return
else:
return gettext(__index__.docs.get(name))
except (ImportError, AttributeError):
pass
paths = _disabledpaths()
if name in paths:
return _disabledhelp(paths[name])
def disabledcmd(ui, cmd, strict=False):
'''import disabled extensions until cmd is found.
returns (cmdname, extname, module)'''
paths = _disabledpaths(strip_init=True)
if not paths:
raise error.UnknownCommand(cmd)
def findcmd(cmd, name, path):
try:
mod = loadpath(path, 'hgext.%s' % name)
except Exception:
return
try:
aliases, entry = cmdutil.findcmd(cmd,
getattr(mod, 'cmdtable', {}), strict)
except (error.AmbiguousCommand, error.UnknownCommand):
return
except Exception:
ui.warn(_('warning: error finding commands in %s\n') % path)
ui.traceback()
return
for c in aliases:
if c.startswith(cmd):
cmd = c
break
else:
cmd = aliases[0]
return (cmd, name, mod)
ext = None
# first, search for an extension with the same name as the command
path = paths.pop(cmd, None)
if path:
ext = findcmd(cmd, cmd, path)
if not ext:
# otherwise, interrogate each extension until there's a match
for name, path in paths.iteritems():
ext = findcmd(cmd, name, path)
if ext:
break
if ext and 'DEPRECATED' not in ext.__doc__:
return ext
raise error.UnknownCommand(cmd)
def enabled(shortname=True):
'''return a dict of {name: desc} of extensions'''
exts = {}
for ename, ext in extensions():
doc = (gettext(ext.__doc__) or _('(no help text available)'))
if shortname:
ename = ename.split('.')[-1]
exts[ename] = doc.splitlines()[0].strip()
return exts
def notloaded():
'''return short names of extensions that failed to load'''
return [name for name, mod in _extensions.iteritems() if mod is None]
def moduleversion(module):
'''return version information from given module as a string'''
if (util.safehasattr(module, 'getversion')
and callable(module.getversion)):
version = module.getversion()
elif util.safehasattr(module, '__version__'):
version = module.__version__
else:
version = ''
if isinstance(version, (list, tuple)):
version = '.'.join(str(o) for o in version)
return version
def ismoduleinternal(module):
exttestedwith = getattr(module, 'testedwith', None)
return exttestedwith == "ships-with-hg-core"