flagutil: use it in simplestorerepo

This remove the other code duplication of the `_processflags` code.

To be honest, this code looks very dead since it is not run by either developer
nor buildbot. However, we update the code to make the task of reviving this less
daunting.

Differential Revision: https://phab.mercurial-scm.org/D6799

tests/simplestorerepo.py

@@ -1,713 +1,678 b''
 # 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
 
 import stat
 
 from mercurial.i18n import _
 from mercurial.node import (
     bin,
     hex,
     nullid,
     nullrev,
 )
 from mercurial.thirdparty import (
     attr,
 )
 from mercurial import (
     ancestor,
     bundlerepo,
     error,
     extensions,
     localrepo,
     mdiff,
     pycompat,
     revlog,
     store,
     verify,
 )
 from mercurial.interfaces import (
     repository,
     util as interfaceutil,
 )
 from mercurial.utils import (
     cborutil,
     storageutil,
 )
 from mercurial.revlogutils import (
     flagutil,
 )
 
 # 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'
 
 REQUIREMENT = 'testonly-simplestore'
 
 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 simplestoreerror(error.StorageError):
     pass
 
 @interfaceutil.implementer(repository.irevisiondelta)
 @attr.s(slots=True)
 class simplestorerevisiondelta(object):
     node = attr.ib()
     p1node = attr.ib()
     p2node = attr.ib()
     basenode = attr.ib()
     flags = attr.ib()
     baserevisionsize = attr.ib()
     revision = attr.ib()
     delta = attr.ib()
     linknode = attr.ib(default=None)
 
 @interfaceutil.implementer(repository.iverifyproblem)
 @attr.s(frozen=True)
 class simplefilestoreproblem(object):
     warning = attr.ib(default=None)
     error = attr.ib(default=None)
     node = attr.ib(default=None)
 
 @interfaceutil.implementer(repository.ifilestorage)
-class filestorage(object):
+class filestorage(flagutil.flagprocessorsmixin):
     """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.
     """
 
+    _flagserrorclass = simplestoreerror
+
     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 = cborutil.decodeall(indexdata)
 
         self._indexdata = indexdata or []
         self._indexbynode = {}
         self._indexbyrev = {}
         self._index = []
         self._refreshindex()
 
+        self._flagprocessors = dict(flagutil.flagprocessors)
+
     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)
 
         try:
             self._indexbynode[node]
         except KeyError:
             raise error.LookupError(node, self._indexpath, _('no 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 hasnode(self, node):
         validatenode(node)
         return node in self._indexbynode
 
     def censorrevision(self, tr, censornode, tombstone=b''):
         raise NotImplementedError('TODO')
 
     def lookup(self, node):
         if isinstance(node, int):
             return self.node(node)
 
         if len(node) == 20:
             self.rev(node)
             return node
 
         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:
                 pass
 
         raise error.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 _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 _processflags(self, text, flags, operation, raw=False):
-        if flags == 0:
-            return text, True
-
-        if flags & ~flagutil.REVIDX_KNOWN_FLAGS:
-            raise simplestoreerror(_("incompatible revision flag '%#x'") %
-                                   (flags & ~flagutil.REVIDX_KNOWN_FLAGS))
-
-        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 simplestoreerror(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 != storageutil.hashrevisionsha1(text, p1, p2):
             raise simplestoreerror(_("integrity check failed on %s") %
                 self._path)
 
     def revision(self, nodeorrev, raw=False):
         if isinstance(nodeorrev, int):
             node = self.node(nodeorrev)
         else:
             node = nodeorrev
         validatenode(node)
 
         if node == nullid:
             return b''
 
         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 rawdata(self, nodeorrev):
         return self.revision(raw=True)
 
     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 = storageutil.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 storageutil.hashrevisionsha1(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) & repository.REVISION_FLAG_CENSORED
 
     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]
 
     def storageinfo(self, exclusivefiles=False, sharedfiles=False,
                     revisionscount=False, trackedsize=False,
                     storedsize=False):
         # TODO do a real implementation of this
         return {
             'exclusivefiles': [],
             'sharedfiles': [],
             'revisionscount': len(self),
             'trackedsize': 0,
             'storedsize': None,
         }
 
     def verifyintegrity(self, state):
         state['skipread'] = set()
         for rev in self:
             node = self.node(rev)
             try:
                 self.revision(node)
             except Exception as e:
                 yield simplefilestoreproblem(
                     error='unpacking %s: %s' % (node, e),
                     node=node)
                 state['skipread'].add(node)
 
     def emitrevisions(self, nodes, nodesorder=None, revisiondata=False,
                       assumehaveparentrevisions=False,
                       deltamode=repository.CG_DELTAMODE_STD):
         # TODO this will probably break on some ordering options.
         nodes = [n for n in nodes if n != nullid]
         if not nodes:
             return
         for delta in storageutil.emitrevisions(
                 self, nodes, nodesorder, simplestorerevisiondelta,
                 revisiondata=revisiondata,
                 assumehaveparentrevisions=assumehaveparentrevisions,
                 deltamode=deltamode):
             yield delta
 
     def add(self, text, meta, transaction, linkrev, p1, p2):
         if meta or text.startswith(b'\1\n'):
             text = storageutil.packmeta(meta, text)
 
         return self.addrevision(text, transaction, linkrev, p1, p2)
 
     def addrevision(self, text, transaction, linkrev, p1, p2, node=None,
                     flags=revlog.REVIDX_DEFAULT_FLAGS, cachedelta=None):
         validatenode(p1)
         validatenode(p2)
 
         if flags:
             node = node or storageutil.hashrevisionsha1(text, p1, p2)
 
         rawtext, validatehash = self._processflags(text, flags, 'write')
 
         node = node or storageutil.hashrevisionsha1(text, p1, p2)
 
         if node in self._indexbynode:
             return node
 
         if validatehash:
             self.checkhash(rawtext, node, p1=p1, p2=p2)
 
         return self._addrawrevision(node, rawtext, transaction, linkrev, p1, p2,
                                     flags)
 
     def _addrawrevision(self, node, rawtext, transaction, link, p1, p2, flags):
         transaction.addbackup(self._indexpath)
 
         path = b'/'.join([self._storepath, hex(node)])
 
         self._svfs.write(path, rawtext)
 
         self._indexdata.append({
             b'node': node,
             b'p1': p1,
             b'p2': p2,
             b'linkrev': link,
             b'flags': flags,
         })
 
         self._reflectindexupdate()
 
         return node
 
     def _reflectindexupdate(self):
         self._refreshindex()
         self._svfs.write(self._indexpath,
                          ''.join(cborutil.streamencode(self._indexdata)))
 
     def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None,
                  maybemissingparents=False):
         if maybemissingparents:
             raise error.Abort(_('simple store does not support missing parents '
                                 'write mode'))
 
         nodes = []
 
         transaction.addbackup(self._indexpath)
 
         for node, p1, p2, linknode, deltabase, delta, flags in deltas:
             linkrev = linkmapper(linknode)
             flags = flags or revlog.REVIDX_DEFAULT_FLAGS
 
             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._addrawrevision(node, text, transaction, linkrev, p1, p2,
                                  flags)
 
             if addrevisioncb:
                 addrevisioncb(self, node)
         return nodes
 
     def _headrevs(self):
         # Assume all revisions are heads by default.
         revishead = {rev: True for rev in self._indexbyrev}
 
         for rev, entry in self._indexbyrev.items():
             # Unset head flag for all seen parents.
             revishead[self.rev(entry[b'p1'])] = False
             revishead[self.rev(entry[b'p2'])] = False
 
         return [rev for rev, ishead in sorted(revishead.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):
         return storageutil.resolvestripinfo(
             minlink, len(self) - 1, self._headrevs(), self.linkrev,
             self.parentrevs)
 
     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 issimplestorefile(f, kind, st):
     if kind != stat.S_IFREG:
         return False
 
     if store.isrevlog(f, kind, st):
         return False
 
     # Ignore transaction undo files.
     if f.startswith('undo.'):
         return False
 
     # Otherwise assume it belongs to the simple store.
     return True
 
 class simplestore(store.encodedstore):
     def datafiles(self):
         for x in super(simplestore, self).datafiles():
             yield x
 
         # Supplement with non-revlog files.
         extrafiles = self._walk('data', True, filefilter=issimplestorefile)
 
         for unencoded, encoded, size in extrafiles:
             try:
                 unencoded = store.decodefilename(unencoded)
             except KeyError:
                 unencoded = None
 
             yield unencoded, encoded, size
 
 def reposetup(ui, repo):
     if not repo.local():
         return
 
     if isinstance(repo, bundlerepo.bundlerepository):
         raise error.Abort(_('cannot use simple store with bundlerepo'))
 
     class simplestorerepo(repo.__class__):
         def file(self, f):
             return filestorage(self.svfs, f)
 
     repo.__class__ = simplestorerepo
 
 def featuresetup(ui, supported):
     supported.add(REQUIREMENT)
 
 def newreporequirements(orig, ui, createopts):
     """Modifies default requirements for new repos to use the simple store."""
     requirements = orig(ui, createopts)
 
     # These requirements are only used to affect creation of the store
     # object. We have our own store. So we can remove them.
     # TODO do this once we feel like taking the test hit.
     #if 'fncache' in requirements:
     #    requirements.remove('fncache')
     #if 'dotencode' in requirements:
     #    requirements.remove('dotencode')
 
     requirements.add(REQUIREMENT)
 
     return requirements
 
 def makestore(orig, requirements, path, vfstype):
     if REQUIREMENT not in requirements:
         return orig(requirements, path, vfstype)
 
     return simplestore(path, vfstype)
 
 def verifierinit(orig, self, *args, **kwargs):
     orig(self, *args, **kwargs)
 
     # We don't care that files in the store don't align with what is
     # advertised. So suppress these warnings.
     self.warnorphanstorefiles = False
 
 def extsetup(ui):
     localrepo.featuresetupfuncs.add(featuresetup)
 
     extensions.wrapfunction(localrepo, 'newreporequirements',
                             newreporequirements)
     extensions.wrapfunction(localrepo, 'makestore', makestore)
     extensions.wrapfunction(verify.verifier, '__init__', verifierinit)