view mercurial/subrepoutil.py @ 48687:f8f2ecdde4b5

branchmap: skip obsolete revisions while computing heads

It's time to make this part of core Mercurial obsolescence-aware.

Not considering obsolete revisions when computing heads is clearly what
Mercurial should do. But there are a couple of small issues:

- Let's say tip of the repo is obsolete. There are two ways of finding tiprev
  for branchcache (both are in use): looking at input data for update() and
  looking at computed heads after update(). Previously, repo tip would be
  tiprev of the branchcache. With this patch, an obsolete revision can no
  longer be tiprev. And depending on what way we use for finding tiprev (input
  data vs computed heads) we'll get a different result. This is relevant when
  recomputing cache key from cache contents, and may lead to updating cache for
  obsolete revisions multiple times (not from scratch, because it still would
  be considered valid for a subset of revisions in the repo).

- If all commits on a branch are obsolete, the branchcache will include that
  branch, but the list of heads will be empty (that's why there's now `if not
  heads` when recomputing tiprev/tipnode from cache contents). Having an entry
  for every branch is currently required for notify extension (and
  test-notify.t to pass), because notify doesn't handle revsets in its
  subscription config very well and will throw an error if e.g. a branch
  doesn't exist.

- Cloning static HTTP repos may try to stat() a non-existent obsstore file. The
  issue is that we now care about obsolescence during clone, but statichttpvfs
  doesn't implement a stat method, so a regular vfs.stat() is used, and it
  assumes that file is local and calls os.stat().  During a clone, we're trying
  to stat() .hg/store/obsstore, but in static HTTP case we provide a literal
  URL to the obsstore file on the remote as if it were a local file path. On
  windows it actually results in a failure in test-static-http.t.

The first issue is going to be addressed in a series dedicated to making sure
branchcache is properly and timely written on disk (it wasn't perfect even
before this patch, but there aren't enough tests to demonstrate that). The
second issue will be addressed in a future patch for notify extension that will
make it not raise an exception if a branch doesn't exist. And the third one was
partially addressed in the previous patch in this series and will be properly
fixed in a future patch when this series is accepted.

filteredhash() grows a keyword argument to make sure that branchcache is also
invalidated when there are new obsolete revisions in its repo view. This way
the on-disk cache format is unchanged and compatible between versions (although
it will obviously be recomputed when switching versions before/after this patch
and the repo has obsolete revisions).

There's one test that uses plain `hg up` without arguments while updated to a
pruned commit. To make this test pass, simply return current working directory
parent. Later in this series this code will be replaced by what prune command
does: updating to the closest non-obsolete ancestor.

Test changes:

test-branch-change.t: update branch head and cache update message. The head of
default listed in hg heads is changed because revision 2 was rewritten as 7,
and 1 is the closest ancestor on the same branch, so it's the head of default
now.

The cache invalidation message appears now because of the cache hash change,
since we're now accounting for obsolete revisions. Here's some context:

"served.hidden" repo filter means everything is visible (no filtered
revisions), so before this series branch2-served.hidden file would not contain
any cache hash, only revnum and node. Now it also has a hash when there are
obsolete changesets in the repo. The command that the message appears for is
changing branch of 5 and 6, which are now obsolete, so the cache hash changes.

In general, when cache is simply out-of-date, it can be updated using the old
version as a base. But if cache hash differs, then the cache for that
particular repo filter is recomputed (at least with the current
implementation). This is what happens here.

test-obsmarker-template.t: the pull reports 2 heads changed, but after that the
repo correctly sees only 1. The new message could be better, but it's still an
improvement over the previous one where hg pull suggested merging with an
obsolete revision.

test-obsolete.t: we can see these revisions in hg log --hidden, but they
shouldn't be considered heads even with --hidden.

test-rebase-obsolete{,2}.t: there were new heads created previously after
making new orphan changesets, but they weren't detected. Now we are properly
detecting and reporting them.

test-rebase-obsolete4.t: there's only one head now because the other head is
pruned and was falsely reported before.

test-static-http.t: add obsstore to the list of requested files. This file
doesn't exist on the remotes, but clients want it anyway (they get 404). This
is fine, because there are other nonexistent files that clients request, like
.hg/bookmarks or .hg/cache/tags2-served.

Differential Revision: https://phab.mercurial-scm.org/D12097

# subrepoutil.py - sub-repository operations and substate handling
#
# Copyright 2009-2010 Olivia 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 __future__ import absolute_import

import errno
import os
import posixpath
import re

from .i18n import _
from .pycompat import getattr
from . import (
    config,
    error,
    filemerge,
    pathutil,
    phases,
    pycompat,
    util,
)
from .utils import (
    stringutil,
    urlutil,
)

nullstate = (b'', b'', b'empty')

if pycompat.TYPE_CHECKING:
    from typing import (
        Any,
        Dict,
        List,
        Optional,
        Set,
        Tuple,
    )
    from . import (
        context,
        localrepo,
        match as matchmod,
        scmutil,
        subrepo,
        ui as uimod,
    )

    Substate = Dict[bytes, Tuple[bytes, bytes, bytes]]


def state(ctx, ui):
    # type: (context.changectx, uimod.ui) -> Substate
    """return a state dict, mapping subrepo paths configured in .hgsub
    to tuple: (source from .hgsub, revision from .hgsubstate, kind
    (key in types dict))
    """
    p = config.config()
    repo = ctx.repo()

    def read(f, sections=None, remap=None):
        if f in ctx:
            try:
                data = ctx[f].data()
            except IOError as err:
                if err.errno != errno.ENOENT:
                    raise
                # handle missing subrepo spec files as removed
                ui.warn(
                    _(b"warning: subrepo spec file \'%s\' not found\n")
                    % repo.pathto(f)
                )
                return
            p.parse(f, data, sections, remap, read)
        else:
            raise error.Abort(
                _(b"subrepo spec file \'%s\' not found") % repo.pathto(f)
            )

    if b'.hgsub' in ctx:
        read(b'.hgsub')

    for path, src in ui.configitems(b'subpaths'):
        p.set(b'subpaths', path, src, ui.configsource(b'subpaths', path))

    rev = {}
    if b'.hgsubstate' in ctx:
        try:
            for i, l in enumerate(ctx[b'.hgsubstate'].data().splitlines()):
                l = l.lstrip()
                if not l:
                    continue
                try:
                    revision, path = l.split(b" ", 1)
                except ValueError:
                    raise error.Abort(
                        _(
                            b"invalid subrepository revision "
                            b"specifier in \'%s\' line %d"
                        )
                        % (repo.pathto(b'.hgsubstate'), (i + 1))
                    )
                rev[path] = revision
        except IOError as err:
            if err.errno != errno.ENOENT:
                raise

    def remap(src):
        # type: (bytes) -> bytes
        for pattern, repl in p.items(b'subpaths'):
            # Turn r'C:\foo\bar' into r'C:\\foo\\bar' since re.sub
            # does a string decode.
            repl = stringutil.escapestr(repl)
            # However, we still want to allow back references to go
            # through unharmed, so we turn r'\\1' into r'\1'. Again,
            # extra escapes are needed because re.sub string decodes.
            repl = re.sub(br'\\\\([0-9]+)', br'\\\1', repl)
            try:
                src = re.sub(pattern, repl, src, 1)
            except re.error as e:
                raise error.Abort(
                    _(b"bad subrepository pattern in %s: %s")
                    % (
                        p.source(b'subpaths', pattern),
                        stringutil.forcebytestr(e),
                    )
                )
        return src

    state = {}
    for path, src in p.items(b''):  # type: bytes
        kind = b'hg'
        if src.startswith(b'['):
            if b']' not in src:
                raise error.Abort(_(b'missing ] in subrepository source'))
            kind, src = src.split(b']', 1)
            kind = kind[1:]
            src = src.lstrip()  # strip any extra whitespace after ']'

        if not urlutil.url(src).isabs():
            parent = _abssource(repo, abort=False)
            if parent:
                parent = urlutil.url(parent)
                parent.path = posixpath.join(parent.path or b'', src)
                parent.path = posixpath.normpath(parent.path)
                joined = bytes(parent)
                # Remap the full joined path and use it if it changes,
                # else remap the original source.
                remapped = remap(joined)
                if remapped == joined:
                    src = remap(src)
                else:
                    src = remapped

        src = remap(src)
        state[util.pconvert(path)] = (src.strip(), rev.get(path, b''), kind)

    return state


def writestate(repo, state):
    # type: (localrepo.localrepository, Substate) -> None
    """rewrite .hgsubstate in (outer) repo with these subrepo states"""
    lines = [
        b'%s %s\n' % (state[s][1], s)
        for s in sorted(state)
        if state[s][1] != nullstate[1]
    ]
    repo.wwrite(b'.hgsubstate', b''.join(lines), b'')


def submerge(repo, wctx, mctx, actx, overwrite, labels=None):
    # type: (localrepo.localrepository, context.workingctx, context.changectx, context.changectx, bool, Optional[Any]) -> Substate
    # TODO: type the `labels` arg
    """delegated from merge.applyupdates: merging of .hgsubstate file
    in working context, merging context and ancestor context"""
    if mctx == actx:  # backwards?
        actx = wctx.p1()
    s1 = wctx.substate
    s2 = mctx.substate
    sa = actx.substate
    sm = {}

    repo.ui.debug(b"subrepo merge %s %s %s\n" % (wctx, mctx, actx))

    def debug(s, msg, r=b""):
        if r:
            r = b"%s:%s:%s" % r
        repo.ui.debug(b"  subrepo %s: %s %s\n" % (s, msg, r))

    promptssrc = filemerge.partextras(labels)
    for s, l in sorted(pycompat.iteritems(s1)):
        a = sa.get(s, nullstate)
        ld = l  # local state with possible dirty flag for compares
        if wctx.sub(s).dirty():
            ld = (l[0], l[1] + b"+")
        if wctx == actx:  # overwrite
            a = ld

        prompts = promptssrc.copy()
        prompts[b's'] = s
        if s in s2:
            r = s2[s]
            if ld == r or r == a:  # no change or local is newer
                sm[s] = l
                continue
            elif ld == a:  # other side changed
                debug(s, b"other changed, get", r)
                wctx.sub(s).get(r, overwrite)
                sm[s] = r
            elif ld[0] != r[0]:  # sources differ
                prompts[b'lo'] = l[0]
                prompts[b'ro'] = r[0]
                if repo.ui.promptchoice(
                    _(
                        b' subrepository sources for %(s)s differ\n'
                        b'you can use (l)ocal%(l)s source (%(lo)s)'
                        b' or (r)emote%(o)s source (%(ro)s).\n'
                        b'what do you want to do?'
                        b'$$ &Local $$ &Remote'
                    )
                    % prompts,
                    0,
                ):
                    debug(s, b"prompt changed, get", r)
                    wctx.sub(s).get(r, overwrite)
                    sm[s] = r
            elif ld[1] == a[1]:  # local side is unchanged
                debug(s, b"other side changed, get", r)
                wctx.sub(s).get(r, overwrite)
                sm[s] = r
            else:
                debug(s, b"both sides changed")
                srepo = wctx.sub(s)
                prompts[b'sl'] = srepo.shortid(l[1])
                prompts[b'sr'] = srepo.shortid(r[1])
                option = repo.ui.promptchoice(
                    _(
                        b' subrepository %(s)s diverged (local revision: %(sl)s, '
                        b'remote revision: %(sr)s)\n'
                        b'you can (m)erge, keep (l)ocal%(l)s or keep '
                        b'(r)emote%(o)s.\n'
                        b'what do you want to do?'
                        b'$$ &Merge $$ &Local $$ &Remote'
                    )
                    % prompts,
                    0,
                )
                if option == 0:
                    wctx.sub(s).merge(r)
                    sm[s] = l
                    debug(s, b"merge with", r)
                elif option == 1:
                    sm[s] = l
                    debug(s, b"keep local subrepo revision", l)
                else:
                    wctx.sub(s).get(r, overwrite)
                    sm[s] = r
                    debug(s, b"get remote subrepo revision", r)
        elif ld == a:  # remote removed, local unchanged
            debug(s, b"remote removed, remove")
            wctx.sub(s).remove()
        elif a == nullstate:  # not present in remote or ancestor
            debug(s, b"local added, keep")
            sm[s] = l
            continue
        else:
            if repo.ui.promptchoice(
                _(
                    b' local%(l)s changed subrepository %(s)s'
                    b' which remote%(o)s removed\n'
                    b'use (c)hanged version or (d)elete?'
                    b'$$ &Changed $$ &Delete'
                )
                % prompts,
                0,
            ):
                debug(s, b"prompt remove")
                wctx.sub(s).remove()

    for s, r in sorted(s2.items()):
        if s in s1:
            continue
        elif s not in sa:
            debug(s, b"remote added, get", r)
            mctx.sub(s).get(r)
            sm[s] = r
        elif r != sa[s]:
            prompts = promptssrc.copy()
            prompts[b's'] = s
            if (
                repo.ui.promptchoice(
                    _(
                        b' remote%(o)s changed subrepository %(s)s'
                        b' which local%(l)s removed\n'
                        b'use (c)hanged version or (d)elete?'
                        b'$$ &Changed $$ &Delete'
                    )
                    % prompts,
                    0,
                )
                == 0
            ):
                debug(s, b"prompt recreate", r)
                mctx.sub(s).get(r)
                sm[s] = r

    # record merged .hgsubstate
    writestate(repo, sm)
    return sm


def precommit(ui, wctx, status, match, force=False):
    # type: (uimod.ui, context.workingcommitctx, scmutil.status, matchmod.basematcher, bool) -> Tuple[List[bytes], Set[bytes], Substate]
    """Calculate .hgsubstate changes that should be applied before committing

    Returns (subs, commitsubs, newstate) where
    - subs: changed subrepos (including dirty ones)
    - commitsubs: dirty subrepos which the caller needs to commit recursively
    - newstate: new state dict which the caller must write to .hgsubstate

    This also updates the given status argument.
    """
    subs = []
    commitsubs = set()
    newstate = wctx.substate.copy()

    # only manage subrepos and .hgsubstate if .hgsub is present
    if b'.hgsub' in wctx:
        # we'll decide whether to track this ourselves, thanks
        for c in status.modified, status.added, status.removed:
            if b'.hgsubstate' in c:
                c.remove(b'.hgsubstate')

        # compare current state to last committed state
        # build new substate based on last committed state
        oldstate = wctx.p1().substate
        for s in sorted(newstate.keys()):
            if not match(s):
                # ignore working copy, use old state if present
                if s in oldstate:
                    newstate[s] = oldstate[s]
                    continue
                if not force:
                    raise error.Abort(
                        _(b"commit with new subrepo %s excluded") % s
                    )
            dirtyreason = wctx.sub(s).dirtyreason(True)
            if dirtyreason:
                if not ui.configbool(b'ui', b'commitsubrepos'):
                    raise error.Abort(
                        dirtyreason,
                        hint=_(b"use --subrepos for recursive commit"),
                    )
                subs.append(s)
                commitsubs.add(s)
            else:
                bs = wctx.sub(s).basestate()
                newstate[s] = (newstate[s][0], bs, newstate[s][2])
                if oldstate.get(s, (None, None, None))[1] != bs:
                    subs.append(s)

        # check for removed subrepos
        for p in wctx.parents():
            r = [s for s in p.substate if s not in newstate]
            subs += [s for s in r if match(s)]
        if subs:
            if not match(b'.hgsub') and b'.hgsub' in (
                wctx.modified() + wctx.added()
            ):
                raise error.Abort(_(b"can't commit subrepos without .hgsub"))
            status.modified.insert(0, b'.hgsubstate')

    elif b'.hgsub' in status.removed:
        # clean up .hgsubstate when .hgsub is removed
        if b'.hgsubstate' in wctx and b'.hgsubstate' not in (
            status.modified + status.added + status.removed
        ):
            status.removed.insert(0, b'.hgsubstate')

    return subs, commitsubs, newstate


def repo_rel_or_abs_source(repo):
    """return the source of this repo

    Either absolute or relative the outermost repo"""
    parent = repo
    chunks = []
    while util.safehasattr(parent, b'_subparent'):
        source = urlutil.url(parent._subsource)
        chunks.append(bytes(source))
        if source.isabs():
            break
        parent = parent._subparent

    chunks.reverse()
    path = posixpath.join(*chunks)
    return posixpath.normpath(path)


def reporelpath(repo):
    # type: (localrepo.localrepository) -> bytes
    """return path to this (sub)repo as seen from outermost repo"""
    parent = repo
    while util.safehasattr(parent, b'_subparent'):
        parent = parent._subparent
    return repo.root[len(pathutil.normasprefix(parent.root)) :]


def subrelpath(sub):
    # type: (subrepo.abstractsubrepo) -> bytes
    """return path to this subrepo as seen from outermost repo"""
    return sub._relpath


def _abssource(repo, push=False, abort=True):
    # type: (localrepo.localrepository, bool, bool) -> Optional[bytes]
    """return pull/push path of repo - either based on parent repo .hgsub info
    or on the top repo config. Abort or return None if no source found."""
    if util.safehasattr(repo, b'_subparent'):
        source = urlutil.url(repo._subsource)
        if source.isabs():
            return bytes(source)
        source.path = posixpath.normpath(source.path)
        parent = _abssource(repo._subparent, push, abort=False)
        if parent:
            parent = urlutil.url(util.pconvert(parent))
            parent.path = posixpath.join(parent.path or b'', source.path)
            parent.path = posixpath.normpath(parent.path)
            return bytes(parent)
    else:  # recursion reached top repo
        path = None
        if util.safehasattr(repo, b'_subtoppath'):
            path = repo._subtoppath
        elif push and repo.ui.config(b'paths', b'default-push'):
            path = repo.ui.config(b'paths', b'default-push')
        elif repo.ui.config(b'paths', b'default'):
            path = repo.ui.config(b'paths', b'default')
        elif repo.shared():
            # chop off the .hg component to get the default path form.  This has
            # already run through vfsmod.vfs(..., realpath=True), so it doesn't
            # have problems with 'C:'
            return os.path.dirname(repo.sharedpath)
        if path:
            # issue5770: 'C:\' and 'C:' are not equivalent paths.  The former is
            # as expected: an absolute path to the root of the C: drive.  The
            # latter is a relative path, and works like so:
            #
            #   C:\>cd C:\some\path
            #   C:\>D:
            #   D:\>python -c "import os; print os.path.abspath('C:')"
            #   C:\some\path
            #
            #   D:\>python -c "import os; print os.path.abspath('C:relative')"
            #   C:\some\path\relative
            if urlutil.hasdriveletter(path):
                if len(path) == 2 or path[2:3] not in br'\/':
                    path = util.abspath(path)
            return path

    if abort:
        raise error.Abort(_(b"default path for subrepository not found"))


def newcommitphase(ui, ctx):
    # type: (uimod.ui, context.changectx) -> int
    commitphase = phases.newcommitphase(ui)
    substate = getattr(ctx, "substate", None)
    if not substate:
        return commitphase
    check = ui.config(b'phases', b'checksubrepos')
    if check not in (b'ignore', b'follow', b'abort'):
        raise error.Abort(
            _(b'invalid phases.checksubrepos configuration: %s') % check
        )
    if check == b'ignore':
        return commitphase
    maxphase = phases.public
    maxsub = None
    for s in sorted(substate):
        sub = ctx.sub(s)
        subphase = sub.phase(substate[s][1])
        if maxphase < subphase:
            maxphase = subphase
            maxsub = s
    if commitphase < maxphase:
        if check == b'abort':
            raise error.Abort(
                _(
                    b"can't commit in %s phase"
                    b" conflicting %s from subrepository %s"
                )
                % (
                    phases.phasenames[commitphase],
                    phases.phasenames[maxphase],
                    maxsub,
                )
            )
        ui.warn(
            _(
                b"warning: changes are committed in"
                b" %s phase from subrepository %s\n"
            )
            % (phases.phasenames[maxphase], maxsub)
        )
        return maxphase
    return commitphase