view hgext/obsolete.py @ 1593:2f117c299325

evolve: remove meaningless transaction nesting

Before this patch, functions below nest transaction scope, even though
they are invoked only inside a transaction scope created at _solveone().

  - _solvebumped()
  - _solvedivergent()
  - relocate() via _solveunstable() or _solvebumped()

Transaction nesting is useful for localizing "success" (e.g. one scope
per commit inside wider scope for multiple committing).

But such nesting is redundant for _solveone(), because there is no
code path, which causes failure after successfully closing inner
transaction(s).

In addition to it, this nesting makes it complicated to close current
transaction successfully with exception raising inside inner scope,
like "hg shelve" at detection of conflicts. "tr.close()" is required
at each outer scopes for such case.

To remove meaningless transaction nesting, this patch replaces
repo.transaction() in functions above by repo.currenttransaction().
This reuses transaction created at _solveone().

This patch also adds 'assert tr' after getting current running
transaction, to avoid invocation of functions above without
transaction.

# Copyright 2011 Pierre-Yves David <[e-mail]>
#                Logilab SA        <[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.
"""Deprecated extension that formely introduces "Changeset Obsolescence".

This concept is now partially in Mercurial core (starting with mercurial 2.3).
The remaining logic have been grouped with the evolve extension.

Some code cemains in this extensions to detect and convert prehistoric format
of obsolete marker than early user may have create. Keep it enabled if you
were such user.
"""

from mercurial import util

try:
    from mercurial import obsolete
except ImportError:
    raise error.Abort('Obsolete extension requires Mercurial 2.3 (or later)')

import sys
import json

from mercurial import cmdutil
from mercurial import error
from mercurial.i18n import _
from mercurial.node import bin, nullid


#####################################################################
### Older format management                                       ###
#####################################################################

# Code related to detection and management of older legacy format never
# handled by core


def reposetup(ui, repo):
    """Detect that a repo still contains some old obsolete format
    """
    if not repo.local():
        return
    evolveopts = ui.configlist('experimental', 'evolution')
    if not evolveopts:
        evolveopts = 'all'
        ui.setconfig('experimental', 'evolution', evolveopts)
    for arg in sys.argv:
        if 'debugc' in arg:
            break
    else:
        data = repo.opener.tryread('obsolete-relations')
        if not data:
            data = repo.svfs.tryread('obsoletemarkers')
        if data:
            raise error.Abort('old format of obsolete marker detected!\n'
                              'run `hg debugconvertobsolete` once.')

def _obsdeserialise(flike):
    """read a file like object serialised with _obsserialise

    this desierialize into a {subject -> objects} mapping

    this was the very first format ever."""
    rels = {}
    for line in flike:
        subhex, objhex = line.split()
        subnode = bin(subhex)
        if subnode == nullid:
            subnode = None
        rels.setdefault(subnode, set()).add(bin(objhex))
    return rels

cmdtable = {}
command = cmdutil.command(cmdtable)
@command('debugconvertobsolete', [], '')
def cmddebugconvertobsolete(ui, repo):
    """import markers from an .hg/obsolete-relations file"""
    cnt = 0
    err = 0
    l = repo.lock()
    some = False
    try:
        unlink = []
        tr = repo.transaction('convert-obsolete')
        try:
            repo._importoldobsolete = True
            store = repo.obsstore
            ### very first format
            try:
                f = repo.opener('obsolete-relations')
                try:
                    some = True
                    for line in f:
                        subhex, objhex = line.split()
                        suc = bin(subhex)
                        prec = bin(objhex)
                        sucs = (suc==nullid) and [] or [suc]
                        meta = {
                            'date':  '%i %i' % util.makedate(),
                            'user': ui.username(),
                            }
                        try:
                            store.create(tr, prec, sucs, 0, metadata=meta)
                            cnt += 1
                        except ValueError:
                            repo.ui.write_err("invalid old marker line: %s"
                                              % (line))
                            err += 1
                finally:
                    f.close()
                unlink.append(repo.join('obsolete-relations'))
            except IOError:
                pass
            ### second (json) format
            data = repo.svfs.tryread('obsoletemarkers')
            if data:
                some = True
                for oldmark in json.loads(data):
                    del oldmark['id']  # dropped for now
                    del oldmark['reason']  # unused until then
                    oldobject = str(oldmark.pop('object'))
                    oldsubjects = [str(s) for s in oldmark.pop('subjects', [])]
                    LOOKUP_ERRORS = (error.RepoLookupError, error.LookupError)
                    if len(oldobject) != 40:
                        try:
                            oldobject = repo[oldobject].node()
                        except LOOKUP_ERRORS:
                            pass
                    if any(len(s) != 40 for s in oldsubjects):
                        try:
                            oldsubjects = [repo[s].node() for s in oldsubjects]
                        except LOOKUP_ERRORS:
                            pass

                    oldmark['date'] = '%i %i' % tuple(oldmark['date'])
                    meta = dict((k.encode('utf-8'), v.encode('utf-8'))
                                 for k, v in oldmark.iteritems())
                    try:
                        succs = [bin(n) for n in oldsubjects]
                        succs = [n for n in succs if n != nullid]
                        store.create(tr, bin(oldobject), succs,
                                     0, metadata=meta)
                        cnt += 1
                    except ValueError:
                        repo.ui.write_err("invalid marker %s -> %s\n"
                                     % (oldobject, oldsubjects))
                        err += 1
                unlink.append(repo.sjoin('obsoletemarkers'))
            tr.close()
            for path in unlink:
                util.unlink(path)
        finally:
            tr.release()
    finally:
        del repo._importoldobsolete
        l.release()
    if not some:
        ui.warn(_('nothing to do\n'))
    ui.status('%i obsolete marker converted\n' % cnt)
    if err:
        ui.write_err('%i conversion failed. check you graph!\n' % err)