view hgext3rd/topic/stack.py @ 6935:954d7ea5cd67 stable tip

stack: when stack base is obsolete, pick any successor, even if at random

There are situations when s0 is obsolete and we also cannot pick just one
successor for it to use in stack. In such a case, let's pick the "latest"
successor from the first set.

We're assuming that obsutil.successorssets() returns data in the same order (it
should, since it makes sure to sort data internally). Keeping that in mind,
while the successor picked for s0 by this code is not based on any sort of
sophisticated logic, it should nonetheless be the same every time.

This patch is probably not going to completely break anything that was
previously working fine, because the previous behavior was to just abort with
an exception.

# stack.py - code related to stack workflow
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from mercurial.i18n import _
from mercurial import (
    destutil,
    error,
    node,
    phases,
    pycompat,
    obsolete,
    util,
)
from .evolvebits import (
    _singlesuccessor,
    MultipleSuccessorsError,
    builddependencies,
)

short = node.short

def parseusername(user):
    """parses the ctx user and returns the username without email ID if
    possible, otherwise returns the mail address from that"""
    username = None
    if user:
        # user is of form "abc <[e-mail]>"
        username = user.split(b'<')[0]
        if not username:
            # assuming user is of form "<[e-mail]>"
            if len(user) > 1:
                username = user[1:-1]
            else:
                username = user
        username = username.strip()

    return username

def _stackcandidates(repo):
    """build the smaller set of revs that might be part of a stack.

    The intend is to build something more efficient than what revsets do in
    this area.
    """
    phasesets = repo._phasecache._phasesets
    if not phasesets:
        return repo.revs(b'(not public()) - obsolete()')

    result = set.union(*[phasesets[phase] for phase in phases.trackedphases])
    result -= obsolete.getrevs(repo, b'obsolete')
    return result

class stack(object):
    """object represent a stack and common logic associated to it."""

    def __init__(self, repo, branch=None, topic=None):
        self._repo = repo
        self.branch = branch
        self.topic = topic
        self.behinderror = None

        subset = _stackcandidates(repo)

        if topic is not None and branch is not None:
            raise error.ProgrammingError(b'both branch and topic specified (not defined yet)')
        elif topic is not None:
            trevs = repo.revs(b"%ld and topic(%s)", subset, topic)
        elif branch is not None:
            trevs = repo.revs(b"%ld and branch(%s) - topic()", subset, branch)
        else:
            raise error.ProgrammingError(b'neither branch and topic specified (not defined yet)')
        self._revs = trevs

    def __iter__(self):
        return iter(self.revs)

    def __getitem__(self, index):
        return self.revs[index]

    def __nonzero__(self):
        return bool(self._revs)

    __bool__ = __nonzero__

    def index(self, item):
        return self.revs.index(item)

    @util.propertycache
    def _dependencies(self):
        deps, rdeps = builddependencies(self._repo, self._revs)

        repo = self._repo
        srcpfunc = repo.changelog.parentrevs

        ### post process to skip over possible gaps in the stack
        #
        # For example in the following situation, we need to detect that "t3"
        # indirectly depends on t2.
        #
        #  o t3
        #  |
        #  o other
        #  |
        #  o t2
        #  |
        #  o t1

        pmap = {}

        def pfuncrev(repo, rev):
            """a special "parent func" that also consider successors"""
            parents = pmap.get(rev)
            if parents is None:
                parents = [repo[_singlesuccessor(repo, repo[p])].rev()
                           for p in srcpfunc(rev) if 0 <= p]
                pmap[rev] = parents
            return parents

        revs = self._revs
        stackrevs = set(self._revs)
        for root in [r for r in revs if not deps[r]]:
            seen = set()
            stack = [root]
            while stack:
                current = stack.pop()
                for p in pfuncrev(repo, current):
                    if p in seen:
                        continue
                    seen.add(p)
                    if p in stackrevs:
                        rdeps[p].add(root)
                        deps[root].add(p)
                    elif phases.public < repo[p].phase():
                        # traverse only if we did not found a proper candidate
                        stack.append(p)

        return deps, rdeps

    @util.propertycache
    def revs(self):
        # some duplication/change from _orderrevs because we use a post
        # processed dependency graph.

        # Step 1: compute relation of revision with each other
        origdeps, rdependencies = self._dependencies
        dependencies = {}
        # Making a deep copy of origdeps because we modify contents of values
        # later on. Checking for list here only because right now
        # builddependencies in evolvebits.py can return a list of _succs()
        # objects. When that will be dealt with, this deep copy code can be
        # simplified a lot.
        for k, v in origdeps.items():
            if isinstance(v, list):
                dependencies[k] = [i.copy() for i in v]
            else:
                dependencies[k] = v.copy()
        # Step 2: Build the ordering
        # Remove the revisions with no dependency(A) and add them to the ordering.
        # Removing these revisions leads to new revisions with no dependency (the
        # one depending on A) that we can remove from the dependency graph and add
        # to the ordering. We progress in a similar fashion until the ordering is
        # built
        solvablerevs = [r for r in sorted(dependencies.keys())
                        if not dependencies[r]]
        revs = []
        while solvablerevs:
            rev = solvablerevs.pop()
            for dependent in rdependencies[rev]:
                dependencies[dependent].remove(rev)
                if not dependencies[dependent]:
                    solvablerevs.append(dependent)
            del dependencies[rev]
            revs.append(rev)

        revs.extend(sorted(dependencies))
        # step 3: add t0
        if revs:
            pt1 = self._repo[revs[0]].p1()
        else:
            pt1 = self._repo[b'.']

        if pt1.obsolete():
            try:
                pt1 = self._repo[_singlesuccessor(self._repo, pt1)]
            except MultipleSuccessorsError as e:
                # here, taking a random successor is better than failing
                pt1 = self._repo[e.successorssets[0][-1]]
        revs.insert(0, pt1.rev())
        return revs

    @util.propertycache
    def changesetcount(self):
        return len(self._revs)

    @util.propertycache
    def unstablecount(self):
        return len([r for r in self._revs if self._repo[r].isunstable()])

    @util.propertycache
    def heads(self):
        revs = self.revs[1:]
        deps, rdeps = self._dependencies
        return [r for r in revs if not rdeps[r]]

    @util.propertycache
    def behindcount(self):
        revs = self.revs[1:]
        deps, rdeps = self._dependencies
        if revs:
            minroot = [min(r for r in revs if not deps[r])]
            try:
                dest = destutil.destmerge(self._repo, action=b'rebase',
                                          sourceset=minroot,
                                          onheadcheck=False)
                return len(self._repo.revs(b"only(%d, %ld)", dest, minroot))
            except error.NoMergeDestAbort:
                return 0
            except error.ManyMergeDestAbort as exc:
                # XXX we should make it easier for upstream to provide the information
                self.behinderror = pycompat.bytestr(exc).split(b'-', 1)[0].rstrip()
                return -1
        return 0

    @util.propertycache
    def branches(self):
        branches = sorted(set(self._repo[r].branch() for r in self._revs))
        if not branches:
            branches = set([self._repo[None].branch()])
        return branches

def labelsgen(prefix, parts):
    fmt = prefix + b'.%s'
    return prefix + b' ' + b' '.join(fmt % p.replace(b' ', b'-') for p in parts)

def showstack(ui, repo, branch=None, topic=None, opts=None):
    if opts is None:
        opts = {}

    if topic is not None and branch is not None:
        msg = b'both branch and topic specified [%s]{%s}(not defined yet)'
        msg %= (branch, topic)
        raise error.ProgrammingError(msg)
    elif topic is not None:
        prefix = b's'
        if topic not in repo.topics:
            raise error.Abort(_(b'cannot resolve "%s": no such topic found') % topic)
    elif branch is not None:
        prefix = b's'
    else:
        raise error.ProgrammingError(b'neither branch and topic specified (not defined yet)')

    fm = ui.formatter(b'topicstack', opts)
    prev = None
    entries = []
    idxmap = {}

    label = b'topic'
    if topic == repo.currenttopic:
        label = b'topic.active'

    st = stack(repo, branch, topic)
    if topic is not None:
        fm.plain(_(b'### topic: %s')
                 % ui.label(topic, label),
                 label=b'stack.summary.topic')

        if 1 < len(st.heads):
            fm.plain(b' (')
            fm.plain(b'%d heads' % len(st.heads),
                     label=b'stack.summary.headcount.multiple')
            fm.plain(b')')
        fm.plain(b'\n')
    fm.plain(_(b'### target: %s (branch)')
             % b'+'.join(st.branches), # XXX handle multi branches
             label=b'stack.summary.branches')
    if topic is None:
        if 1 < len(st.heads):
            fm.plain(b' (')
            fm.plain(b'%d heads' % len(st.heads),
                     label=b'stack.summary.headcount.multiple')
            fm.plain(b')')
    else:
        if st.behindcount == -1:
            fm.plain(b', ')
            fm.plain(b'ambiguous rebase destination - %s' % st.behinderror,
                     label=b'stack.summary.behinderror')
        elif st.behindcount:
            fm.plain(b', ')
            fm.plain(b'%d behind' % st.behindcount, label=b'stack.summary.behindcount')
    fm.plain(b'\n')

    if not st:
        fm.plain(_(b"(stack is empty)\n"))

    st = stack(repo, branch=branch, topic=topic)
    for idx, r in enumerate(st, 0):
        ctx = repo[r]
        # special case for t0, b0 as it's hard to plugin into rest of the logic
        if idx == 0:
            # t0, b0 can be None
            if r == -1:
                continue
            entries.append((idx, False, ctx))
            prev = ctx.rev()
            continue
        p1 = ctx.p1()
        p2 = ctx.p2()
        if p1.obsolete():
            try:
                p1 = repo[_singlesuccessor(repo, p1)]
            except MultipleSuccessorsError as e:
                successors = e.successorssets
                if len(successors) > 1:
                    # case of divergence which we don't handle yet
                    raise
                p1 = repo[successors[0][-1]]

        if p2.node() != node.nullid:
            entries.append((idxmap.get(p1.rev()), False, p1))
            entries.append((idxmap.get(p2.rev()), False, p2))
        elif p1.rev() != prev and p1.node() != node.nullid:
            entries.append((idxmap.get(p1.rev()), False, p1))
        entries.append((idx, True, ctx))
        idxmap[ctx.rev()] = idx
        prev = r

    # super crude initial version
    for idx, isentry, ctx in entries[::-1]:

        symbol = None
        states = []
        if opts.get(b'children'):
            expr = b'children(%d) and merge() - %ld'
            revisions = repo.revs(expr, ctx.rev(), st._revs)
            if len(revisions) > 0:
                states.append(b'external-children')

        if ctx.orphan():
            symbol = b'$'
            states.append(b'orphan')

        if ctx.contentdivergent():
            symbol = b'$'
            states.append(b'content divergent')

        if ctx.phasedivergent():
            symbol = b'$'
            states.append(b'phase divergent')

        iscurrentrevision = repo.revs(b'%d and parents()', ctx.rev())
        if iscurrentrevision:
            symbol = b'@'
            states.append(b'current')

        if not isentry:
            symbol = b'^'
            # "base" is kind of a "ghost" entry
            states.append(b'base')

        # none of the above if statments get executed
        if not symbol:
            symbol = b':'

        if not states:
            states.append(b'clean')

        states.sort()

        fm.startitem()
        fm.context(ctx=ctx)
        fm.data(isentry=isentry)

        if idx is None:
            spacewidth = 0
            if ui.verbose:
                # parentheses plus short node hash
                spacewidth = 2 + 12
            if ui.debugflag:
                # parentheses plus full node hash
                spacewidth = 2 + 40
            # s# alias width
            spacewidth += 2
            fm.plain(b' ' * spacewidth)
        else:
            fm.write(b'stack_index', b'%s%%d' % prefix, idx,
                     label=labelsgen(b'stack.index', states))
            if ui.verbose:
                fm.write(b'node', b'(%s)', fm.hexfunc(ctx.node()),
                         label=labelsgen(b'stack.shortnode', states))
            else:
                fm.data(node=fm.hexfunc(ctx.node()))
        fm.write(b'symbol', b'%s', symbol,
                 label=labelsgen(b'stack.state', states))
        fm.plain(b' ')
        fm.write(b'desc', b'%s', ctx.description().splitlines()[0],
                 label=labelsgen(b'stack.desc', states))
        fm.condwrite(states != [b'clean'] and idx is not None, b'state',
                     b' (%s)', fm.formatlist(states, b'stack.state'),
                     label=labelsgen(b'stack.state', states))
        fm.plain(b'\n')
    fm.end()