simplestore: shore up lookup errors

When revisions or nodes can't be resolved, we're expected to raise
an error.LookupError. When I ported code from revlog.py, I failed
to realize that "LookupError" in that module is aliased to
error.LookupError. I thought we were using the builtin LookupError
instead.

This commit switches us to error.LookupError. It also fixes
rev() to raise error.LookupError instead of KeyError.

Differential Revision: https://phab.mercurial-scm.org/D3092

tests/simplestorerepo.py

@@ -1,598 +1,595 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
 
 from mercurial.i18n import _
 from mercurial.node import (
     bin,
     hex,
     nullid,
     nullrev,
 )
 from mercurial.thirdparty import (
     cbor,
 )
 from mercurial import (
     ancestor,
     bundlerepo,
     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.
+        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 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):
+            except TypeError:
                 pass
 
-        raise LookupError(node, self._path, _('invalid lookup input'))
+        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 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.
         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):
 
         # 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
 
     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