Mercurial > hg
view mercurial/hook.py @ 16696:d1afbf03e69a
rebase: allow collapsing branches in place (issue3111)
We allow rebase plus collapse, but not collapse only? I imagine people would
rebase first then collapse once they are sure the rebase is correct and it is
the right time to finish it.
I was reluctant to submit this patch for reasons detailed below, but it
improves rebase --collapse usefulness so much it is worth the ugliness.
The fix is ugly because we should be fixing the collapse code path rather than
the merge. Collapsing by merging changesets repeatedly is inefficient compared
to what commit --amend does: commitctx(), update, strip. The problem with the
latter is, to generate the synthetic changeset, copy records are gathered with
copies.pathcopies(). copies.pathcopies() is still implemented with merging in
mind and discards information like file replaced by the copy of another,
criss-cross copies and so forth. I believe this information should not be lost,
even if we decide not to interpret it fully later, at merge time.
The second issue with improving rebase --collapse is the option should not be
there to begin with. Rebasing and collapsing are orthogonal and a dedicated
command would probably enable a better, simpler ui. We should avoid advertizing
rebase --collapse, but with this fix it becomes the best shipped solution to
collapse changesets.
And for the record, available techniques are:
- revert + commit + strip: lose copies
- mq/qfold: repeated patching() (mostly correct, fragile)
- rebase: repeated merges (mostly correct, fragile)
- collapse: revert + tag rewriting wizardry, lose copies
- histedit: repeated patching() (mostly correct, fragile)
- amend: copies.pathcopies() + commitctx() + update + strip
author | Patrick Mezard <patrick@mezard.eu> |
---|---|
date | Thu, 03 May 2012 15:14:58 +0200 |
parents | 30c34fde40cc |
children | 15d4d475de9e |
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# hook.py - hook support for mercurial # # Copyright 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 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 the 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): 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/err__ 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) mod = extensions.loadpath(path, 'hghook.%s' % hname) 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