view mercurial/hook.py @ 17758:5863f0e4cd3a

histedit: replace various nodes lists with replacement graph (and issue3582)

This changeset rewrites the change tracking logic of histedit to record every
operation it does. Tracked operations record the full list of "old" node that
will eventually be removed to the list of new nodes that replace it. Operations
on temporary nodes are tracked too. Dropped changesets are also recorded as an
"old" node replacement by nothing. This logic is similar to the obsolescence
marker one and will be used for this purpose in later commit.

This new logic implies a big amount of change in the histedit code base.

histedit action functions now always return a tuple of

    (new-ctx, [list of rewriting operations])

The old `created`, `replaced` and `tmpnodes` are no longer returned and stored
during histedit operation. When such information is necessary it is computed
from the replacement graph. This computation is done in the `processreplacement`
function.

The `replacemap` is also dropped. It is computed at the end of the command from the
graph.  The `bootstrapcontinue` methods are altered to compute this different kind of
information.

This new mechanism requires much less information to be written on disk.

Note:

    This changes allows a more accurate bookmark movement. bookmark on dropped
    changeset are now move of their parent (or replacement of their parent)
    instead of their children.

    This fix issue3582

# 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
import extensions, util

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))
    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:
            obj = __import__(modname)
        except ImportError:
            e1 = sys.exc_type, sys.exc_value, sys.exc_traceback
            try:
                # extensions are loaded with hgext_ prefix
                obj = __import__("hgext_%s" % modname)
            except ImportError:
                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
    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))

    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)
    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
    if _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 AttributeError:
            # __stdout__/__stderr__ doesn't have fileno(), it's not a real file
            pass

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