view hgext/obsolete.py @ 978:8328337d23b2

docs: add new user guide

This has also been reviewed to death on evolve-testers. There are
still a couple of short sections to write (clearly marked "TODO"), and
one example to add. But (if I may be so bold) this is a gigantic
improvement over the current docs, so it really should get merged.

Incidentally, the figures are all SVG files created with Inkscape.
They're not perfect, but they're pretty nice. Anyone who knows a
better way to create technical diagrams is welcome to contribute.

One wart: there's a test script that accompanies the document and
largely duplicates it, but I haven't unified them. I've been
concentrating on writing the best possible content, not on fiddling
with tools. I suspect that unifying them will be non-trivial, but
definitely worth doing.

# 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
    if not obsolete._enabled:
        obsolete._enabled = True
except ImportError:
    raise util.Abort('Obsolete extension requires Mercurial 2.3 (or later)')

import sys
import json

from mercurial import cmdutil
from mercurial import error
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
    for arg in sys.argv:
        if 'debugc' in arg:
            break
    else:
        data = repo.opener.tryread('obsolete-relations')
        if not data:
            data = repo.sopener.tryread('obsoletemarkers')
        if data:
            raise util.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, 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.sopener.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, 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)