view mercurial/fileset.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- Let's say tip of the repo is obsolete.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

# fileset.py - file set queries for mercurial
#
# Copyright 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 re

from .i18n import _
from .pycompat import getattr
from . import (
    error,
    filesetlang,
    match as matchmod,
    mergestate as mergestatemod,
    pycompat,
    registrar,
    scmutil,
    util,
)
from .utils import stringutil

# common weight constants
_WEIGHT_CHECK_FILENAME = filesetlang.WEIGHT_CHECK_FILENAME
_WEIGHT_READ_CONTENTS = filesetlang.WEIGHT_READ_CONTENTS
_WEIGHT_STATUS = filesetlang.WEIGHT_STATUS
_WEIGHT_STATUS_THOROUGH = filesetlang.WEIGHT_STATUS_THOROUGH

# helpers for processing parsed tree
getsymbol = filesetlang.getsymbol
getstring = filesetlang.getstring
_getkindpat = filesetlang.getkindpat
getpattern = filesetlang.getpattern
getargs = filesetlang.getargs


def getmatch(mctx, x):
    if not x:
        raise error.ParseError(_(b"missing argument"))
    return methods[x[0]](mctx, *x[1:])


def getmatchwithstatus(mctx, x, hint):
    keys = set(getstring(hint, b'status hint must be a string').split())
    return getmatch(mctx.withstatus(keys), x)


def stringmatch(mctx, x):
    return mctx.matcher([x])


def kindpatmatch(mctx, x, y):
    return stringmatch(
        mctx,
        _getkindpat(
            x, y, matchmod.allpatternkinds, _(b"pattern must be a string")
        ),
    )


def patternsmatch(mctx, *xs):
    allkinds = matchmod.allpatternkinds
    patterns = [
        getpattern(x, allkinds, _(b"pattern must be a string")) for x in xs
    ]
    return mctx.matcher(patterns)


def andmatch(mctx, x, y):
    xm = getmatch(mctx, x)
    ym = getmatch(mctx.narrowed(xm), y)
    return matchmod.intersectmatchers(xm, ym)


def ormatch(mctx, *xs):
    ms = [getmatch(mctx, x) for x in xs]
    return matchmod.unionmatcher(ms)


def notmatch(mctx, x):
    m = getmatch(mctx, x)
    return mctx.predicate(lambda f: not m(f), predrepr=(b'<not %r>', m))


def minusmatch(mctx, x, y):
    xm = getmatch(mctx, x)
    ym = getmatch(mctx.narrowed(xm), y)
    return matchmod.differencematcher(xm, ym)


def listmatch(mctx, *xs):
    raise error.ParseError(
        _(b"can't use a list in this context"),
        hint=_(b'see \'hg help "filesets.x or y"\''),
    )


def func(mctx, a, b):
    funcname = getsymbol(a)
    if funcname in symbols:
        return symbols[funcname](mctx, b)

    keep = lambda fn: getattr(fn, '__doc__', None) is not None

    syms = [s for (s, fn) in symbols.items() if keep(fn)]
    raise error.UnknownIdentifier(funcname, syms)


# symbols are callable like:
#  fun(mctx, x)
# with:
#  mctx - current matchctx instance
#  x - argument in tree form
symbols = filesetlang.symbols

predicate = registrar.filesetpredicate(symbols)


@predicate(b'modified()', callstatus=True, weight=_WEIGHT_STATUS)
def modified(mctx, x):
    """File that is modified according to :hg:`status`."""
    # i18n: "modified" is a keyword
    getargs(x, 0, 0, _(b"modified takes no arguments"))
    s = set(mctx.status().modified)
    return mctx.predicate(s.__contains__, predrepr=b'modified')


@predicate(b'added()', callstatus=True, weight=_WEIGHT_STATUS)
def added(mctx, x):
    """File that is added according to :hg:`status`."""
    # i18n: "added" is a keyword
    getargs(x, 0, 0, _(b"added takes no arguments"))
    s = set(mctx.status().added)
    return mctx.predicate(s.__contains__, predrepr=b'added')


@predicate(b'removed()', callstatus=True, weight=_WEIGHT_STATUS)
def removed(mctx, x):
    """File that is removed according to :hg:`status`."""
    # i18n: "removed" is a keyword
    getargs(x, 0, 0, _(b"removed takes no arguments"))
    s = set(mctx.status().removed)
    return mctx.predicate(s.__contains__, predrepr=b'removed')


@predicate(b'deleted()', callstatus=True, weight=_WEIGHT_STATUS)
def deleted(mctx, x):
    """Alias for ``missing()``."""
    # i18n: "deleted" is a keyword
    getargs(x, 0, 0, _(b"deleted takes no arguments"))
    s = set(mctx.status().deleted)
    return mctx.predicate(s.__contains__, predrepr=b'deleted')


@predicate(b'missing()', callstatus=True, weight=_WEIGHT_STATUS)
def missing(mctx, x):
    """File that is missing according to :hg:`status`."""
    # i18n: "missing" is a keyword
    getargs(x, 0, 0, _(b"missing takes no arguments"))
    s = set(mctx.status().deleted)
    return mctx.predicate(s.__contains__, predrepr=b'deleted')


@predicate(b'unknown()', callstatus=True, weight=_WEIGHT_STATUS_THOROUGH)
def unknown(mctx, x):
    """File that is unknown according to :hg:`status`."""
    # i18n: "unknown" is a keyword
    getargs(x, 0, 0, _(b"unknown takes no arguments"))
    s = set(mctx.status().unknown)
    return mctx.predicate(s.__contains__, predrepr=b'unknown')


@predicate(b'ignored()', callstatus=True, weight=_WEIGHT_STATUS_THOROUGH)
def ignored(mctx, x):
    """File that is ignored according to :hg:`status`."""
    # i18n: "ignored" is a keyword
    getargs(x, 0, 0, _(b"ignored takes no arguments"))
    s = set(mctx.status().ignored)
    return mctx.predicate(s.__contains__, predrepr=b'ignored')


@predicate(b'clean()', callstatus=True, weight=_WEIGHT_STATUS)
def clean(mctx, x):
    """File that is clean according to :hg:`status`."""
    # i18n: "clean" is a keyword
    getargs(x, 0, 0, _(b"clean takes no arguments"))
    s = set(mctx.status().clean)
    return mctx.predicate(s.__contains__, predrepr=b'clean')


@predicate(b'tracked()')
def tracked(mctx, x):
    """File that is under Mercurial control."""
    # i18n: "tracked" is a keyword
    getargs(x, 0, 0, _(b"tracked takes no arguments"))
    return mctx.predicate(mctx.ctx.__contains__, predrepr=b'tracked')


@predicate(b'binary()', weight=_WEIGHT_READ_CONTENTS)
def binary(mctx, x):
    """File that appears to be binary (contains NUL bytes)."""
    # i18n: "binary" is a keyword
    getargs(x, 0, 0, _(b"binary takes no arguments"))
    return mctx.fpredicate(
        lambda fctx: fctx.isbinary(), predrepr=b'binary', cache=True
    )


@predicate(b'exec()')
def exec_(mctx, x):
    """File that is marked as executable."""
    # i18n: "exec" is a keyword
    getargs(x, 0, 0, _(b"exec takes no arguments"))
    ctx = mctx.ctx
    return mctx.predicate(lambda f: ctx.flags(f) == b'x', predrepr=b'exec')


@predicate(b'symlink()')
def symlink(mctx, x):
    """File that is marked as a symlink."""
    # i18n: "symlink" is a keyword
    getargs(x, 0, 0, _(b"symlink takes no arguments"))
    ctx = mctx.ctx
    return mctx.predicate(lambda f: ctx.flags(f) == b'l', predrepr=b'symlink')


@predicate(b'resolved()', weight=_WEIGHT_STATUS)
def resolved(mctx, x):
    """File that is marked resolved according to :hg:`resolve -l`."""
    # i18n: "resolved" is a keyword
    getargs(x, 0, 0, _(b"resolved takes no arguments"))
    if mctx.ctx.rev() is not None:
        return mctx.never()
    ms = mergestatemod.mergestate.read(mctx.ctx.repo())
    return mctx.predicate(
        lambda f: f in ms and ms[f] == b'r', predrepr=b'resolved'
    )


@predicate(b'unresolved()', weight=_WEIGHT_STATUS)
def unresolved(mctx, x):
    """File that is marked unresolved according to :hg:`resolve -l`."""
    # i18n: "unresolved" is a keyword
    getargs(x, 0, 0, _(b"unresolved takes no arguments"))
    if mctx.ctx.rev() is not None:
        return mctx.never()
    ms = mergestatemod.mergestate.read(mctx.ctx.repo())
    return mctx.predicate(
        lambda f: f in ms and ms[f] == b'u', predrepr=b'unresolved'
    )


@predicate(b'hgignore()', weight=_WEIGHT_STATUS)
def hgignore(mctx, x):
    """File that matches the active .hgignore pattern."""
    # i18n: "hgignore" is a keyword
    getargs(x, 0, 0, _(b"hgignore takes no arguments"))
    return mctx.ctx.repo().dirstate._ignore


@predicate(b'portable()', weight=_WEIGHT_CHECK_FILENAME)
def portable(mctx, x):
    """File that has a portable name. (This doesn't include filenames with case
    collisions.)
    """
    # i18n: "portable" is a keyword
    getargs(x, 0, 0, _(b"portable takes no arguments"))
    return mctx.predicate(
        lambda f: util.checkwinfilename(f) is None, predrepr=b'portable'
    )


@predicate(b'grep(regex)', weight=_WEIGHT_READ_CONTENTS)
def grep(mctx, x):
    """File contains the given regular expression."""
    try:
        # i18n: "grep" is a keyword
        r = re.compile(getstring(x, _(b"grep requires a pattern")))
    except re.error as e:
        raise error.ParseError(
            _(b'invalid match pattern: %s') % stringutil.forcebytestr(e)
        )
    return mctx.fpredicate(
        lambda fctx: r.search(fctx.data()),
        predrepr=(b'grep(%r)', r.pattern),
        cache=True,
    )


def _sizetomax(s):
    try:
        s = s.strip().lower()
        for k, v in util._sizeunits:
            if s.endswith(k):
                # max(4k) = 5k - 1, max(4.5k) = 4.6k - 1
                n = s[: -len(k)]
                inc = 1.0
                if b"." in n:
                    inc /= 10 ** len(n.split(b".")[1])
                return int((float(n) + inc) * v) - 1
        # no extension, this is a precise value
        return int(s)
    except ValueError:
        raise error.ParseError(_(b"couldn't parse size: %s") % s)


def sizematcher(expr):
    """Return a function(size) -> bool from the ``size()`` expression"""
    expr = expr.strip()
    if b'-' in expr:  # do we have a range?
        a, b = expr.split(b'-', 1)
        a = util.sizetoint(a)
        b = util.sizetoint(b)
        return lambda x: x >= a and x <= b
    elif expr.startswith(b"<="):
        a = util.sizetoint(expr[2:])
        return lambda x: x <= a
    elif expr.startswith(b"<"):
        a = util.sizetoint(expr[1:])
        return lambda x: x < a
    elif expr.startswith(b">="):
        a = util.sizetoint(expr[2:])
        return lambda x: x >= a
    elif expr.startswith(b">"):
        a = util.sizetoint(expr[1:])
        return lambda x: x > a
    else:
        a = util.sizetoint(expr)
        b = _sizetomax(expr)
        return lambda x: x >= a and x <= b


@predicate(b'size(expression)', weight=_WEIGHT_STATUS)
def size(mctx, x):
    """File size matches the given expression. Examples:

    - size('1k') - files from 1024 to 2047 bytes
    - size('< 20k') - files less than 20480 bytes
    - size('>= .5MB') - files at least 524288 bytes
    - size('4k - 1MB') - files from 4096 bytes to 1048576 bytes
    """
    # i18n: "size" is a keyword
    expr = getstring(x, _(b"size requires an expression"))
    m = sizematcher(expr)
    return mctx.fpredicate(
        lambda fctx: m(fctx.size()), predrepr=(b'size(%r)', expr), cache=True
    )


@predicate(b'encoding(name)', weight=_WEIGHT_READ_CONTENTS)
def encoding(mctx, x):
    """File can be successfully decoded with the given character
    encoding. May not be useful for encodings other than ASCII and
    UTF-8.
    """

    # i18n: "encoding" is a keyword
    enc = getstring(x, _(b"encoding requires an encoding name"))

    def encp(fctx):
        d = fctx.data()
        try:
            d.decode(pycompat.sysstr(enc))
            return True
        except LookupError:
            raise error.Abort(_(b"unknown encoding '%s'") % enc)
        except UnicodeDecodeError:
            return False

    return mctx.fpredicate(encp, predrepr=(b'encoding(%r)', enc), cache=True)


@predicate(b'eol(style)', weight=_WEIGHT_READ_CONTENTS)
def eol(mctx, x):
    """File contains newlines of the given style (dos, unix, mac). Binary
    files are excluded, files with mixed line endings match multiple
    styles.
    """

    # i18n: "eol" is a keyword
    enc = getstring(x, _(b"eol requires a style name"))

    def eolp(fctx):
        if fctx.isbinary():
            return False
        d = fctx.data()
        if (enc == b'dos' or enc == b'win') and b'\r\n' in d:
            return True
        elif enc == b'unix' and re.search(b'(?<!\r)\n', d):
            return True
        elif enc == b'mac' and re.search(b'\r(?!\n)', d):
            return True
        return False

    return mctx.fpredicate(eolp, predrepr=(b'eol(%r)', enc), cache=True)


@predicate(b'copied()')
def copied(mctx, x):
    """File that is recorded as being copied."""
    # i18n: "copied" is a keyword
    getargs(x, 0, 0, _(b"copied takes no arguments"))

    def copiedp(fctx):
        p = fctx.parents()
        return p and p[0].path() != fctx.path()

    return mctx.fpredicate(copiedp, predrepr=b'copied', cache=True)


@predicate(b'revs(revs, pattern)', weight=_WEIGHT_STATUS)
def revs(mctx, x):
    """Evaluate set in the specified revisions. If the revset match multiple
    revs, this will return file matching pattern in any of the revision.
    """
    # i18n: "revs" is a keyword
    r, x = getargs(x, 2, 2, _(b"revs takes two arguments"))
    # i18n: "revs" is a keyword
    revspec = getstring(r, _(b"first argument to revs must be a revision"))
    repo = mctx.ctx.repo()
    revs = scmutil.revrange(repo, [revspec])

    matchers = []
    for r in revs:
        ctx = repo[r]
        mc = mctx.switch(ctx.p1(), ctx)
        matchers.append(getmatch(mc, x))
    if not matchers:
        return mctx.never()
    if len(matchers) == 1:
        return matchers[0]
    return matchmod.unionmatcher(matchers)


@predicate(b'status(base, rev, pattern)', weight=_WEIGHT_STATUS)
def status(mctx, x):
    """Evaluate predicate using status change between ``base`` and
    ``rev``. Examples:

    - ``status(3, 7, added())`` - matches files added from "3" to "7"
    """
    repo = mctx.ctx.repo()
    # i18n: "status" is a keyword
    b, r, x = getargs(x, 3, 3, _(b"status takes three arguments"))
    # i18n: "status" is a keyword
    baseerr = _(b"first argument to status must be a revision")
    baserevspec = getstring(b, baseerr)
    if not baserevspec:
        raise error.ParseError(baseerr)
    reverr = _(b"second argument to status must be a revision")
    revspec = getstring(r, reverr)
    if not revspec:
        raise error.ParseError(reverr)
    basectx, ctx = scmutil.revpair(repo, [baserevspec, revspec])
    mc = mctx.switch(basectx, ctx)
    return getmatch(mc, x)


@predicate(b'subrepo([pattern])')
def subrepo(mctx, x):
    """Subrepositories whose paths match the given pattern."""
    # i18n: "subrepo" is a keyword
    getargs(x, 0, 1, _(b"subrepo takes at most one argument"))
    ctx = mctx.ctx
    sstate = ctx.substate
    if x:
        pat = getpattern(
            x,
            matchmod.allpatternkinds,
            # i18n: "subrepo" is a keyword
            _(b"subrepo requires a pattern or no arguments"),
        )
        fast = not matchmod.patkind(pat)
        if fast:

            def m(s):
                return s == pat

        else:
            m = matchmod.match(ctx.repo().root, b'', [pat], ctx=ctx)
        return mctx.predicate(
            lambda f: f in sstate and m(f), predrepr=(b'subrepo(%r)', pat)
        )
    else:
        return mctx.predicate(sstate.__contains__, predrepr=b'subrepo')


methods = {
    b'withstatus': getmatchwithstatus,
    b'string': stringmatch,
    b'symbol': stringmatch,
    b'kindpat': kindpatmatch,
    b'patterns': patternsmatch,
    b'and': andmatch,
    b'or': ormatch,
    b'minus': minusmatch,
    b'list': listmatch,
    b'not': notmatch,
    b'func': func,
}


class matchctx(object):
    def __init__(self, basectx, ctx, cwd, badfn=None):
        self._basectx = basectx
        self.ctx = ctx
        self._badfn = badfn
        self._match = None
        self._status = None
        self.cwd = cwd

    def narrowed(self, match):
        """Create matchctx for a sub-tree narrowed by the given matcher"""
        mctx = matchctx(self._basectx, self.ctx, self.cwd, self._badfn)
        mctx._match = match
        # leave wider status which we don't have to care
        mctx._status = self._status
        return mctx

    def switch(self, basectx, ctx):
        mctx = matchctx(basectx, ctx, self.cwd, self._badfn)
        mctx._match = self._match
        return mctx

    def withstatus(self, keys):
        """Create matchctx which has precomputed status specified by the keys"""
        mctx = matchctx(self._basectx, self.ctx, self.cwd, self._badfn)
        mctx._match = self._match
        mctx._buildstatus(keys)
        return mctx

    def _buildstatus(self, keys):
        self._status = self._basectx.status(
            self.ctx,
            self._match,
            listignored=b'ignored' in keys,
            listclean=b'clean' in keys,
            listunknown=b'unknown' in keys,
        )

    def status(self):
        return self._status

    def matcher(self, patterns):
        return self.ctx.match(patterns, badfn=self._badfn, cwd=self.cwd)

    def predicate(self, predfn, predrepr=None, cache=False):
        """Create a matcher to select files by predfn(filename)"""
        if cache:
            predfn = util.cachefunc(predfn)
        return matchmod.predicatematcher(
            predfn, predrepr=predrepr, badfn=self._badfn
        )

    def fpredicate(self, predfn, predrepr=None, cache=False):
        """Create a matcher to select files by predfn(fctx) at the current
        revision

        Missing files are ignored.
        """
        ctx = self.ctx
        if ctx.rev() is None:

            def fctxpredfn(f):
                try:
                    fctx = ctx[f]
                except error.LookupError:
                    return False
                try:
                    fctx.audit()
                except error.Abort:
                    return False
                try:
                    return predfn(fctx)
                except (IOError, OSError) as e:
                    # open()-ing a directory fails with EACCES on Windows
                    if e.errno in (
                        errno.ENOENT,
                        errno.EACCES,
                        errno.ENOTDIR,
                        errno.EISDIR,
                    ):
                        return False
                    raise

        else:

            def fctxpredfn(f):
                try:
                    fctx = ctx[f]
                except error.LookupError:
                    return False
                return predfn(fctx)

        return self.predicate(fctxpredfn, predrepr=predrepr, cache=cache)

    def never(self):
        """Create a matcher to select nothing"""
        return matchmod.never(badfn=self._badfn)


def match(ctx, cwd, expr, badfn=None):
    """Create a matcher for a single fileset expression"""
    tree = filesetlang.parse(expr)
    tree = filesetlang.analyze(tree)
    tree = filesetlang.optimize(tree)
    mctx = matchctx(ctx.p1(), ctx, cwd, badfn=badfn)
    return getmatch(mctx, tree)


def loadpredicate(ui, extname, registrarobj):
    """Load fileset predicates from specified registrarobj"""
    for name, func in pycompat.iteritems(registrarobj._table):
        symbols[name] = func


# tell hggettext to extract docstrings from these functions:
i18nfunctions = symbols.values()