annotate tests/simplestorerepo.py @ 37338:cbc4425e81b5

tests: conditionalize tests based on presence of revlogs for files

~85 tests don't like our non-revlog file store for various reasons.

This commit introduces hghave functionality for declaring and querying
repository features. By default, we assume repositories have
revlog-based file storage. But if the HGREPOFEATURES environment
variable is set, we can override the default set of repository
features. If you run the test harness with our simplestorerepo
extension and an environment variable set to the proper value, you
can override the hghave defaults to agree with simplestorerepo's
version of reality.

Various tests have been modified so behavior dependent on revlog-based
file storage is marked as such.

This fixes a handful of test failures with our custom file storage
extension. But dozens remain. The point of this commit is to demonstrate
how tests will need to be modified to account for custom storage
implementations.

TBH, I'm not convinced hghave is the proper layer for repository
feature detection. I /think/ we'll eventually want something in
run-tests.py itself. But that would require inventing a new primitive
in the test harness. This is all very alpha at the moment. So I think
hghave is an acceptable place to hang this feature detection. I think
the right time to be thinking about integrating this into run-tests.py
is *after* we have a stable alternate storage implementation in core.
For now, let's try to make progress towards the idea of an alternate
storage backend.

Differential Revision: https://phab.mercurial-scm.org/D3030

# simplestorerepo.py - Extension that swaps in alternate repository storage.
#
# Copyright 2018 Gregory Szorc <[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.

# To use this with the test suite:
#
#   $ HGREPOFEATURES="simplestore" ./run-tests.py \
#       --extra-config-opt extensions.simplestore=`pwd`/simplestorerepo.py

from __future__ import absolute_import

from mercurial.i18n import _
from mercurial.node import (
    bin,
    hex,
    nullid,
    nullrev,
)
from mercurial.thirdparty import (
    cbor,
)
from mercurial import (
    ancestor,
    error,
    filelog,
    mdiff,
    pycompat,
    revlog,
)

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'

def validatenode(node):
    if isinstance(node, int):
        raise ValueError('expected node; got int')

    if len(node) != 20:
        raise ValueError('expected 20 byte node')

def validaterev(rev):
    if not isinstance(rev, int):
        raise ValueError('expected int')

class filestorage(object):
    """Implements storage for a tracked path.

    Data is stored in the VFS in a directory corresponding to the tracked
    path.

    Index data is stored in an ``index`` file using CBOR.

    Fulltext data is stored in files having names of the node.
    """

    def __init__(self, svfs, path):
        self._svfs = svfs
        self._path = path

        self._storepath = b'/'.join([b'data', path])
        self._indexpath = b'/'.join([self._storepath, b'index'])

        indexdata = self._svfs.tryread(self._indexpath)
        if indexdata:
            indexdata = cbor.loads(indexdata)

        self._indexdata = indexdata or []
        self._indexbynode = {}
        self._indexbyrev = {}
        self.index = []
        self._refreshindex()

        # This is used by changegroup code :/
        self._generaldelta = True
        self.storedeltachains = False

        self.version = 1

    def _refreshindex(self):
        self._indexbynode.clear()
        self._indexbyrev.clear()
        self.index = []

        for i, entry in enumerate(self._indexdata):
            self._indexbynode[entry[b'node']] = entry
            self._indexbyrev[i] = entry

        self._indexbynode[nullid] = {
            b'node': nullid,
            b'p1': nullid,
            b'p2': nullid,
            b'linkrev': nullrev,
            b'flags': 0,
        }

        self._indexbyrev[nullrev] = {
            b'node': nullid,
            b'p1': nullid,
            b'p2': nullid,
            b'linkrev': nullrev,
            b'flags': 0,
        }

        for i, entry in enumerate(self._indexdata):
            p1rev, p2rev = self.parentrevs(self.rev(entry[b'node']))

            # start, length, rawsize, chainbase, linkrev, p1, p2, node
            self.index.append((0, 0, 0, -1, entry[b'linkrev'], p1rev, p2rev,
                               entry[b'node']))

        self.index.append((0, 0, 0, -1, -1, -1, -1, nullid))

    def __len__(self):
        return len(self._indexdata)

    def __iter__(self):
        return iter(range(len(self)))

    def revs(self, start=0, stop=None):
        step = 1
        if stop is not None:
            if start > stop:
                step = -1

            stop += step
        else:
            stop = len(self)

        return range(start, stop, step)

    def parents(self, node):
        validatenode(node)

        if node not in self._indexbynode:
            raise KeyError('unknown node')

        entry = self._indexbynode[node]

        return entry[b'p1'], entry[b'p2']

    def parentrevs(self, rev):
        p1, p2 = self.parents(self._indexbyrev[rev][b'node'])
        return self.rev(p1), self.rev(p2)

    def rev(self, node):
        validatenode(node)

        # Will raise KeyError.
        self._indexbynode[node]

        for rev, entry in self._indexbyrev.items():
            if entry[b'node'] == node:
                return rev

        raise error.ProgrammingError('this should not occur')

    def node(self, rev):
        validaterev(rev)

        return self._indexbyrev[rev][b'node']

    def lookup(self, node):
        if isinstance(node, int):
            return self.node(node)

        if len(node) == 20:
            try:
                self.rev(node)
                return node
            except LookupError:
                pass

        try:
            rev = int(node)
            if '%d' % rev != node:
                raise ValueError

            if rev < 0:
                rev = len(self) + rev
            if rev < 0 or rev >= len(self):
                raise ValueError

            return self.node(rev)
        except (ValueError, OverflowError):
            pass

        if len(node) == 40:
            try:
                rawnode = bin(node)
                self.rev(rawnode)
                return rawnode
            except (TypeError, LookupError):
                pass

        raise LookupError(node, self._path, _('invalid lookup input'))

    def linkrev(self, rev):
        validaterev(rev)

        return self._indexbyrev[rev][b'linkrev']

    def flags(self, rev):
        validaterev(rev)

        return self._indexbyrev[rev][b'flags']

    def deltaparent(self, rev):
        validaterev(rev)

        p1node = self.parents(self.node(rev))[0]
        return self.rev(p1node)

    def candelta(self, baserev, rev):
        validaterev(baserev)
        validaterev(rev)

        if ((self.flags(baserev) & revlog.REVIDX_RAWTEXT_CHANGING_FLAGS)
            or (self.flags(rev) & revlog.REVIDX_RAWTEXT_CHANGING_FLAGS)):
            return False

        return True

    def rawsize(self, rev):
        validaterev(rev)
        node = self.node(rev)
        return len(self.revision(node, raw=True))

    def _processflags(self, text, flags, operation, raw=False):
        if flags == 0:
            return text, True

        validatehash = True
        # Depending on the operation (read or write), the order might be
        # reversed due to non-commutative transforms.
        orderedflags = revlog.REVIDX_FLAGS_ORDER
        if operation == 'write':
            orderedflags = reversed(orderedflags)

        for flag in orderedflags:
            # If a flagprocessor has been registered for a known flag, apply the
            # related operation transform and update result tuple.
            if flag & flags:
                vhash = True

                if flag not in revlog._flagprocessors:
                    message = _("missing processor for flag '%#x'") % (flag)
                    raise revlog.RevlogError(message)

                processor = revlog._flagprocessors[flag]
                if processor is not None:
                    readtransform, writetransform, rawtransform = processor

                    if raw:
                        vhash = rawtransform(self, text)
                    elif operation == 'read':
                        text, vhash = readtransform(self, text)
                    else:  # write operation
                        text, vhash = writetransform(self, text)
                validatehash = validatehash and vhash

        return text, validatehash

    def checkhash(self, text, node, p1=None, p2=None, rev=None):
        if p1 is None and p2 is None:
            p1, p2 = self.parents(node)
        if node != revlog.hash(text, p1, p2):
            raise error.RevlogError(_("integrity check failed on %s") %
                self._path)

    def revision(self, node, raw=False):
        validatenode(node)

        if node == nullid:
            return b''

        self._indexbynode[node]

        rev = self.rev(node)
        flags = self.flags(rev)

        path = b'/'.join([self._storepath, hex(node)])
        rawtext = self._svfs.read(path)

        text, validatehash = self._processflags(rawtext, flags, 'read', raw=raw)
        if validatehash:
            self.checkhash(text, node, rev=rev)

        return text

    def read(self, node):
        validatenode(node)

        revision = self.revision(node)

        if not revision.startswith(b'\1\n'):
            return revision

        start = revision.index(b'\1\n', 2)
        return revision[start + 2:]

    def renamed(self, node):
        validatenode(node)

        if self.parents(node)[0] != nullid:
            return False

        fulltext = self.revision(node)
        m = filelog.parsemeta(fulltext)[0]

        if m and 'copy' in m:
            return m['copy'], bin(m['copyrev'])

        return False

    def cmp(self, node, text):
        validatenode(node)

        t = text

        if text.startswith(b'\1\n'):
            t = b'\1\n\1\n' + text

        p1, p2 = self.parents(node)

        if revlog.hash(t, p1, p2) == node:
            return False

        if self.iscensored(self.rev(node)):
            return text != b''

        if self.renamed(node):
            t2 = self.read(node)
            return t2 != text

        return True

    def size(self, rev):
        validaterev(rev)

        node = self._indexbyrev[rev][b'node']

        if self.renamed(node):
            return len(self.read(node))

        if self.iscensored(rev):
            return 0

        return len(self.revision(node))

    def iscensored(self, rev):
        validaterev(rev)

        return self.flags(rev) & revlog.REVIDX_ISCENSORED

    def commonancestorsheads(self, a, b):
        validatenode(a)
        validatenode(b)

        a = self.rev(a)
        b = self.rev(b)

        ancestors = ancestor.commonancestorsheads(self.parentrevs, a, b)
        return pycompat.maplist(self.node, ancestors)

    def descendants(self, revs):
        # This is a copy of revlog.descendants()
        first = min(revs)
        if first == nullrev:
            for i in self:
                yield i
            return

        seen = set(revs)
        for i in self.revs(start=first + 1):
            for x in self.parentrevs(i):
                if x != nullrev and x in seen:
                    seen.add(i)
                    yield i
                    break

    # Required by verify.
    def files(self):
        entries = self._svfs.listdir(self._storepath)

        # Strip out undo.backup.* files created as part of transaction
        # recording.
        entries = [f for f in entries if not f.startswith('undo.backup.')]

        return [b'/'.join((self._storepath, f)) for f in entries]

    # Required by verify.
    def checksize(self):
        return 0, 0

    def add(self, text, meta, transaction, linkrev, p1, p2):
        if meta or text.startswith(b'\1\n'):
            text = filelog.packmeta(meta, text)

        return self.addrevision(text, transaction, linkrev, p1, p2)

    def addrevision(self, text, transaction, linkrev, p1, p2, node=None,
                    flags=0):
        validatenode(p1)
        validatenode(p2)

        if flags:
            node = node or revlog.hash(text, p1, p2)

        rawtext, validatehash = self._processflags(text, flags, 'write')

        node = node or revlog.hash(text, p1, p2)

        if node in self._indexbynode:
            return node

        if validatehash:
            self.checkhash(rawtext, node, p1=p1, p2=p2)

        path = b'/'.join([self._storepath, hex(node)])

        self._svfs.write(path, text)

        self._indexdata.append({
            b'node': node,
            b'p1': p1,
            b'p2': p2,
            b'linkrev': linkrev,
            b'flags': flags,
        })

        self._reflectindexupdate()

        return node

    def _reflectindexupdate(self):
        self._refreshindex()
        self._svfs.write(self._indexpath, cbor.dumps(self._indexdata))

    def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None):
        nodes = []

        transaction.addbackup(self._indexpath)

        for node, p1, p2, linknode, deltabase, delta, flags in deltas:
            linkrev = linkmapper(linknode)

            nodes.append(node)

            if node in self._indexbynode:
                continue

            # Need to resolve the fulltext from the delta base.
            if deltabase == nullid:
                text = mdiff.patch(b'', delta)
            else:
                text = mdiff.patch(self.revision(deltabase), delta)

            self.addrevision(text, transaction, linkrev, p1, p2, flags)

            if addrevisioncb:
                addrevisioncb(self, node)

        return nodes

    def revdiff(self, rev1, rev2):
        validaterev(rev1)
        validaterev(rev2)

        node1 = self.node(rev1)
        node2 = self.node(rev2)

        return mdiff.textdiff(self.revision(node1, raw=True),
                              self.revision(node2, raw=True))

    def headrevs(self):
        # Assume all revisions are heads by default.
        ishead = {rev: True for rev in self._indexbyrev}

        for rev, entry in self._indexbyrev.items():
            # Unset head flag for all seen parents.
            ishead[self.rev(entry[b'p1'])] = False
            ishead[self.rev(entry[b'p2'])] = False

        return [rev for rev, ishead in sorted(ishead.items())
                if ishead]

    def heads(self, start=None, stop=None):
        # This is copied from revlog.py.
        if start is None and stop is None:
            if not len(self):
                return [nullid]
            return [self.node(r) for r in self.headrevs()]

        if start is None:
            start = nullid
        if stop is None:
            stop = []
        stoprevs = set([self.rev(n) for n in stop])
        startrev = self.rev(start)
        reachable = {startrev}
        heads = {startrev}

        parentrevs = self.parentrevs
        for r in self.revs(start=startrev + 1):
            for p in parentrevs(r):
                if p in reachable:
                    if r not in stoprevs:
                        reachable.add(r)
                    heads.add(r)
                if p in heads and p not in stoprevs:
                    heads.remove(p)

        return [self.node(r) for r in heads]

    def children(self, node):
        validatenode(node)

        # This is a copy of revlog.children().
        c = []
        p = self.rev(node)
        for r in self.revs(start=p + 1):
            prevs = [pr for pr in self.parentrevs(r) if pr != nullrev]
            if prevs:
                for pr in prevs:
                    if pr == p:
                        c.append(self.node(r))
            elif p == nullrev:
                c.append(self.node(r))
        return c

    def getstrippoint(self, minlink):

        # This is largely a copy of revlog.getstrippoint().
        brokenrevs = set()
        strippoint = len(self)

        heads = {}
        futurelargelinkrevs = set()
        for head in self.headrevs():
            headlinkrev = self.linkrev(head)
            heads[head] = headlinkrev
            if headlinkrev >= minlink:
                futurelargelinkrevs.add(headlinkrev)

        # This algorithm involves walking down the rev graph, starting at the
        # heads. Since the revs are topologically sorted according to linkrev,
        # once all head linkrevs are below the minlink, we know there are
        # no more revs that could have a linkrev greater than minlink.
        # So we can stop walking.
        while futurelargelinkrevs:
            strippoint -= 1
            linkrev = heads.pop(strippoint)

            if linkrev < minlink:
                brokenrevs.add(strippoint)
            else:
                futurelargelinkrevs.remove(linkrev)

            for p in self.parentrevs(strippoint):
                if p != nullrev:
                    plinkrev = self.linkrev(p)
                    heads[p] = plinkrev
                    if plinkrev >= minlink:
                        futurelargelinkrevs.add(plinkrev)

        return strippoint, brokenrevs

    def strip(self, minlink, transaction):
        if not len(self):
            return

        rev, _ignored = self.getstrippoint(minlink)
        if rev == len(self):
            return

        # Purge index data starting at the requested revision.
        self._indexdata[rev:] = []
        self._reflectindexupdate()

def reposetup(ui, repo):
    if not repo.local():
        return

    class simplestorerepo(repo.__class__):
        def file(self, f):
            return filestorage(self.svfs, f)

    repo.__class__ = simplestorerepo