view mercurial/hook.py @ 19778:55ef79031009

localrepo: make supported features manageable in each repositories individually

Before this patch, all localrepositories support same features,
because supported features are managed by the class variable
"supported" of "localrepository".

For example, "largefiles" feature provided by largefiles extension is
recognized as supported, by adding the feature name to "supported" of
"localrepository".

So, commands handling multiple repositories at a time like below
misunderstand that such features are supported also in repositories
not enabling corresponded extensions:

  - clone/pull from or push to localhost
  - recursive execution in subrepo tree

"reposetup()" can't be used to fix this problem, because it is invoked
after checking whether supported features satisfy ones required in the
target repository.

So, this patch adds the set object named as "featuresetupfuncs" to
"localrepository" to manage hook functions to setup supported features
of each repositories.

If any functions are added to "featuresetupfuncs", they are invoked,
and information about supported features is managed in each
repositories individually.

This patch also adds checking below:

  - pull from localhost: whether features supported in the local(= dst)
    repository satisfies ones required in the remote(= src)

  - push to localhost: whether features supported in the remote(= dst)
    repository satisfies ones required in the local(= src)

Managing supported features by the class variable means that there is
no difference of supported features between each instances of
"localrepository" in the same Python process, so such checking is not
needed before this patch.

Even with this patch, if intermediate bundlefile is used as pulling
source, pulling indirectly from the remote repository, which requires
features more than ones supported in the local, can't be prevented,
because bundlefile has no information about "required features" in it.

# hook.py - hook support for mercurial
#
# Copyright 2007 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import os, sys, time, types
import extensions, util, demandimport

def _pythonhook(ui, repo, name, hname, funcname, args, throw):
    '''call python hook. hook is callable object, looked up as
    name in python module. if callable returns "true", hook
    fails, else passes. if hook raises exception, treated as
    hook failure. exception propagates if throw is "true".

    reason for "true" meaning "hook failed" is so that
    unmodified commands (e.g. mercurial.commands.update) can
    be run as hooks without wrappers to convert return values.'''

    ui.note(_("calling hook %s: %s\n") % (hname, funcname))
    starttime = time.time()

    obj = funcname
    if not util.safehasattr(obj, '__call__'):
        d = funcname.rfind('.')
        if d == -1:
            raise util.Abort(_('%s hook is invalid ("%s" not in '
                               'a module)') % (hname, funcname))
        modname = funcname[:d]
        oldpaths = sys.path
        if util.mainfrozen():
            # binary installs require sys.path manipulation
            modpath, modfile = os.path.split(modname)
            if modpath and modfile:
                sys.path = sys.path[:] + [modpath]
                modname = modfile
        try:
            demandimport.disable()
            obj = __import__(modname)
            demandimport.enable()
        except ImportError:
            e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
            try:
                # extensions are loaded with hgext_ prefix
                obj = __import__("hgext_%s" % modname)
                demandimport.enable()
            except ImportError:
                demandimport.enable()
                e2 = sys.exc_type, sys.exc_value, sys.exc_traceback
                if ui.tracebackflag:
                    ui.warn(_('exception from first failed import attempt:\n'))
                ui.traceback(e1)
                if ui.tracebackflag:
                    ui.warn(_('exception from second failed import attempt:\n'))
                ui.traceback(e2)
                raise util.Abort(_('%s hook is invalid '
                                   '(import of "%s" failed)') %
                                 (hname, modname))
        sys.path = oldpaths
        try:
            for p in funcname.split('.')[1:]:
                obj = getattr(obj, p)
        except AttributeError:
            raise util.Abort(_('%s hook is invalid '
                               '("%s" is not defined)') %
                             (hname, funcname))
        if not util.safehasattr(obj, '__call__'):
            raise util.Abort(_('%s hook is invalid '
                               '("%s" is not callable)') %
                             (hname, funcname))
    try:
        try:
            # redirect IO descriptors to the ui descriptors so hooks
            # that write directly to these don't mess up the command
            # protocol when running through the command server
            old = sys.stdout, sys.stderr, sys.stdin
            sys.stdout, sys.stderr, sys.stdin = ui.fout, ui.ferr, ui.fin

            r = obj(ui=ui, repo=repo, hooktype=name, **args)
        except KeyboardInterrupt:
            raise
        except Exception, exc:
            if isinstance(exc, util.Abort):
                ui.warn(_('error: %s hook failed: %s\n') %
                             (hname, exc.args[0]))
            else:
                ui.warn(_('error: %s hook raised an exception: '
                               '%s\n') % (hname, exc))
            if throw:
                raise
            ui.traceback()
            return True
    finally:
        sys.stdout, sys.stderr, sys.stdin = old
        duration = time.time() - starttime
        readablefunc = funcname
        if isinstance(funcname, types.FunctionType):
            readablefunc = funcname.__module__ + "." + funcname.__name__
        ui.log('pythonhook', 'pythonhook-%s: %s finished in %0.2f seconds\n',
               name, readablefunc, duration)
    if r:
        if throw:
            raise util.Abort(_('%s hook failed') % hname)
        ui.warn(_('warning: %s hook failed\n') % hname)
    return r

def _exthook(ui, repo, name, cmd, args, throw):
    ui.note(_("running hook %s: %s\n") % (name, cmd))

    starttime = time.time()
    env = {}
    for k, v in args.iteritems():
        if util.safehasattr(v, '__call__'):
            v = v()
        if isinstance(v, dict):
            # make the dictionary element order stable across Python
            # implementations
            v = ('{' +
                 ', '.join('%r: %r' % i for i in sorted(v.iteritems())) +
                 '}')
        env['HG_' + k.upper()] = v

    if repo:
        cwd = repo.root
    else:
        cwd = os.getcwd()
    if 'HG_URL' in env and env['HG_URL'].startswith('remote:http'):
        r = util.system(cmd, environ=env, cwd=cwd, out=ui)
    else:
        r = util.system(cmd, environ=env, cwd=cwd, out=ui.fout)

    duration = time.time() - starttime
    ui.log('exthook', 'exthook-%s: %s finished in %0.2f seconds\n',
           name, cmd, duration)
    if r:
        desc, r = util.explainexit(r)
        if throw:
            raise util.Abort(_('%s hook %s') % (name, desc))
        ui.warn(_('warning: %s hook %s\n') % (name, desc))
    return r

def _allhooks(ui):
    hooks = []
    for name, cmd in ui.configitems('hooks'):
        if not name.startswith('priority'):
            priority = ui.configint('hooks', 'priority.%s' % name, 0)
            hooks.append((-priority, len(hooks), name, cmd))
    return [(k, v) for p, o, k, v in sorted(hooks)]

_redirect = False
def redirect(state):
    global _redirect
    _redirect = state

def hook(ui, repo, name, throw=False, **args):
    if not ui.callhooks:
        return False

    r = False
    oldstdout = -1

    try:
        for hname, cmd in _allhooks(ui):
            if hname.split('.')[0] != name or not cmd:
                continue

            if oldstdout == -1 and _redirect:
                try:
                    stdoutno = sys.__stdout__.fileno()
                    stderrno = sys.__stderr__.fileno()
                    # temporarily redirect stdout to stderr, if possible
                    if stdoutno >= 0 and stderrno >= 0:
                        sys.__stdout__.flush()
                        oldstdout = os.dup(stdoutno)
                        os.dup2(stderrno, stdoutno)
                except (OSError, AttributeError):
                    # files seem to be bogus, give up on redirecting (WSGI, etc)
                    pass

            if util.safehasattr(cmd, '__call__'):
                r = _pythonhook(ui, repo, name, hname, cmd, args, throw) or r
            elif cmd.startswith('python:'):
                if cmd.count(':') >= 2:
                    path, cmd = cmd[7:].rsplit(':', 1)
                    path = util.expandpath(path)
                    if repo:
                        path = os.path.join(repo.root, path)
                    try:
                        mod = extensions.loadpath(path, 'hghook.%s' % hname)
                    except Exception:
                        ui.write(_("loading %s hook failed:\n") % hname)
                        raise
                    hookfn = getattr(mod, cmd)
                else:
                    hookfn = cmd[7:].strip()
                r = _pythonhook(ui, repo, name, hname, hookfn, args, throw) or r
            else:
                r = _exthook(ui, repo, hname, cmd, args, throw) or r
    finally:
        if _redirect and oldstdout >= 0:
            os.dup2(oldstdout, stdoutno)
            os.close(oldstdout)

    return r