remotefilelog: add fake heads() method that allows viewing a file in hgweb

As best I can discern, this is not going to hurt anything, but it'll
cause a couple of options to exist in the UI that are
nonsensical. That seems fine, given the nature of remotefilelog.

Differential Revision: https://phab.mercurial-scm.org/D8299

hgext/remotefilelog/remotefilelog.py

@@ -1,509 +1,513 b''
 # remotefilelog.py - filelog implementation where filelog history is stored
 #                    remotely
 #
 # Copyright 2013 Facebook, Inc.
 #
 # 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 collections
 import os
 
 from mercurial.node import (
     bin,
     nullid,
     wdirfilenodeids,
     wdirid,
 )
 from mercurial.i18n import _
 from mercurial import (
     ancestor,
     error,
     mdiff,
     pycompat,
     revlog,
     util,
 )
 from mercurial.utils import storageutil
 from mercurial.revlogutils import flagutil
 
 from . import (
     constants,
     fileserverclient,
     shallowutil,
 )
 
 
 class remotefilelognodemap(object):
     def __init__(self, filename, store):
         self._filename = filename
         self._store = store
 
     def __contains__(self, node):
         missing = self._store.getmissing([(self._filename, node)])
         return not bool(missing)
 
     def __get__(self, node):
         if node not in self:
             raise KeyError(node)
         return node
 
 
 class remotefilelog(object):
 
     _generaldelta = True
     _flagserrorclass = error.RevlogError
 
     def __init__(self, opener, path, repo):
         self.opener = opener
         self.filename = path
         self.repo = repo
         self.nodemap = remotefilelognodemap(self.filename, repo.contentstore)
 
         self.version = 1
 
         self._flagprocessors = dict(flagutil.flagprocessors)
 
     def read(self, node):
         """returns the file contents at this node"""
         t = self.revision(node)
         if not t.startswith(b'\1\n'):
             return t
         s = t.index(b'\1\n', 2)
         return t[s + 2 :]
 
     def add(self, text, meta, transaction, linknode, p1=None, p2=None):
         # hash with the metadata, like in vanilla filelogs
         hashtext = shallowutil.createrevlogtext(
             text, meta.get(b'copy'), meta.get(b'copyrev')
         )
         node = storageutil.hashrevisionsha1(hashtext, p1, p2)
         return self.addrevision(
             hashtext, transaction, linknode, p1, p2, node=node
         )
 
     def _createfileblob(self, text, meta, flags, p1, p2, node, linknode):
         # text passed to "_createfileblob" does not include filelog metadata
         header = shallowutil.buildfileblobheader(len(text), flags)
         data = b"%s\0%s" % (header, text)
 
         realp1 = p1
         copyfrom = b""
         if meta and b'copy' in meta:
             copyfrom = meta[b'copy']
             realp1 = bin(meta[b'copyrev'])
 
         data += b"%s%s%s%s%s\0" % (node, realp1, p2, linknode, copyfrom)
 
         visited = set()
 
         pancestors = {}
         queue = []
         if realp1 != nullid:
             p1flog = self
             if copyfrom:
                 p1flog = remotefilelog(self.opener, copyfrom, self.repo)
 
             pancestors.update(p1flog.ancestormap(realp1))
             queue.append(realp1)
             visited.add(realp1)
         if p2 != nullid:
             pancestors.update(self.ancestormap(p2))
             queue.append(p2)
             visited.add(p2)
 
         ancestortext = b""
 
         # add the ancestors in topological order
         while queue:
             c = queue.pop(0)
             pa1, pa2, ancestorlinknode, pacopyfrom = pancestors[c]
 
             pacopyfrom = pacopyfrom or b''
             ancestortext += b"%s%s%s%s%s\0" % (
                 c,
                 pa1,
                 pa2,
                 ancestorlinknode,
                 pacopyfrom,
             )
 
             if pa1 != nullid and pa1 not in visited:
                 queue.append(pa1)
                 visited.add(pa1)
             if pa2 != nullid and pa2 not in visited:
                 queue.append(pa2)
                 visited.add(pa2)
 
         data += ancestortext
 
         return data
 
     def addrevision(
         self,
         text,
         transaction,
         linknode,
         p1,
         p2,
         cachedelta=None,
         node=None,
         flags=revlog.REVIDX_DEFAULT_FLAGS,
         sidedata=None,
     ):
         # text passed to "addrevision" includes hg filelog metadata header
         if node is None:
             node = storageutil.hashrevisionsha1(text, p1, p2)
         if sidedata is None:
             sidedata = {}
 
         meta, metaoffset = storageutil.parsemeta(text)
         rawtext, validatehash = flagutil.processflagswrite(
             self, text, flags, sidedata=sidedata
         )
         return self.addrawrevision(
             rawtext,
             transaction,
             linknode,
             p1,
             p2,
             node,
             flags,
             cachedelta,
             _metatuple=(meta, metaoffset),
         )
 
     def addrawrevision(
         self,
         rawtext,
         transaction,
         linknode,
         p1,
         p2,
         node,
         flags,
         cachedelta=None,
         _metatuple=None,
     ):
         if _metatuple:
             # _metatuple: used by "addrevision" internally by remotefilelog
             # meta was parsed confidently
             meta, metaoffset = _metatuple
         else:
             # not from self.addrevision, but something else (repo._filecommit)
             # calls addrawrevision directly. remotefilelog needs to get and
             # strip filelog metadata.
             # we don't have confidence about whether rawtext contains filelog
             # metadata or not (flag processor could replace it), so we just
             # parse it as best-effort.
             # in LFS (flags != 0)'s case, the best way is to call LFS code to
             # get the meta information, instead of storageutil.parsemeta.
             meta, metaoffset = storageutil.parsemeta(rawtext)
         if flags != 0:
             # when flags != 0, be conservative and do not mangle rawtext, since
             # a read flag processor expects the text not being mangled at all.
             metaoffset = 0
         if metaoffset:
             # remotefilelog fileblob stores copy metadata in its ancestortext,
             # not its main blob. so we need to remove filelog metadata
             # (containing copy information) from text.
             blobtext = rawtext[metaoffset:]
         else:
             blobtext = rawtext
         data = self._createfileblob(
             blobtext, meta, flags, p1, p2, node, linknode
         )
         self.repo.contentstore.addremotefilelognode(self.filename, node, data)
 
         return node
 
     def renamed(self, node):
         ancestors = self.repo.metadatastore.getancestors(self.filename, node)
         p1, p2, linknode, copyfrom = ancestors[node]
         if copyfrom:
             return (copyfrom, p1)
 
         return False
 
     def size(self, node):
         """return the size of a given revision"""
         return len(self.read(node))
 
     rawsize = size
 
     def cmp(self, node, text):
         """compare text with a given file revision
 
         returns True if text is different than what is stored.
         """
 
         if node == nullid:
             return True
 
         nodetext = self.read(node)
         return nodetext != text
 
     def __nonzero__(self):
         return True
 
     __bool__ = __nonzero__
 
     def __len__(self):
         if self.filename == b'.hgtags':
             # The length of .hgtags is used to fast path tag checking.
             # remotefilelog doesn't support .hgtags since the entire .hgtags
             # history is needed.  Use the excludepattern setting to make
             # .hgtags a normal filelog.
             return 0
 
         raise RuntimeError(b"len not supported")
 
+    def heads(self):
+        # Fake heads of the filelog to satisfy hgweb.
+        return []
+
     def empty(self):
         return False
 
     def flags(self, node):
         if isinstance(node, int):
             raise error.ProgrammingError(
                 b'remotefilelog does not accept integer rev for flags'
             )
         store = self.repo.contentstore
         return store.getmeta(self.filename, node).get(constants.METAKEYFLAG, 0)
 
     def parents(self, node):
         if node == nullid:
             return nullid, nullid
 
         ancestormap = self.repo.metadatastore.getancestors(self.filename, node)
         p1, p2, linknode, copyfrom = ancestormap[node]
         if copyfrom:
             p1 = nullid
 
         return p1, p2
 
     def parentrevs(self, rev):
         # TODO(augie): this is a node and should be a rev, but for now
         # nothing in core seems to actually break.
         return self.parents(rev)
 
     def linknode(self, node):
         ancestormap = self.repo.metadatastore.getancestors(self.filename, node)
         p1, p2, linknode, copyfrom = ancestormap[node]
         return linknode
 
     def linkrev(self, node):
         return self.repo.unfiltered().changelog.rev(self.linknode(node))
 
     def emitrevisions(
         self,
         nodes,
         nodesorder=None,
         revisiondata=False,
         assumehaveparentrevisions=False,
         deltaprevious=False,
         deltamode=None,
     ):
         # we don't use any of these parameters here
         del nodesorder, revisiondata, assumehaveparentrevisions, deltaprevious
         del deltamode
         prevnode = None
         for node in nodes:
             p1, p2 = self.parents(node)
             if prevnode is None:
                 basenode = prevnode = p1
             if basenode == node:
                 basenode = nullid
             if basenode != nullid:
                 revision = None
                 delta = self.revdiff(basenode, node)
             else:
                 revision = self.rawdata(node)
                 delta = None
             yield revlog.revlogrevisiondelta(
                 node=node,
                 p1node=p1,
                 p2node=p2,
                 linknode=self.linknode(node),
                 basenode=basenode,
                 flags=self.flags(node),
                 baserevisionsize=None,
                 revision=revision,
                 delta=delta,
             )
 
     def revdiff(self, node1, node2):
         return mdiff.textdiff(self.rawdata(node1), self.rawdata(node2))
 
     def lookup(self, node):
         if len(node) == 40:
             node = bin(node)
         if len(node) != 20:
             raise error.LookupError(
                 node, self.filename, _(b'invalid lookup input')
             )
 
         return node
 
     def rev(self, node):
         # This is a hack to make TortoiseHG work.
         return node
 
     def node(self, rev):
         # This is a hack.
         if isinstance(rev, int):
             raise error.ProgrammingError(
                 b'remotefilelog does not convert integer rev to node'
             )
         return rev
 
     def _processflags(self, text, flags, operation, raw=False):
         """deprecated entry point to access flag processors"""
         msg = b'_processflag(...) use the specialized variant'
         util.nouideprecwarn(msg, b'5.2', stacklevel=2)
         if raw:
             return text, flagutil.processflagsraw(self, text, flags)
         elif operation == b'read':
             return flagutil.processflagsread(self, text, flags)
         else:  # write operation
             return flagutil.processflagswrite(self, text, flags)
 
     def revision(self, node, raw=False):
         """returns the revlog contents at this node.
         this includes the meta data traditionally included in file revlogs.
         this is generally only used for bundling and communicating with vanilla
         hg clients.
         """
         if node == nullid:
             return b""
         if len(node) != 20:
             raise error.LookupError(
                 node, self.filename, _(b'invalid revision input')
             )
         if node == wdirid or node in wdirfilenodeids:
             raise error.WdirUnsupported
 
         store = self.repo.contentstore
         rawtext = store.get(self.filename, node)
         if raw:
             return rawtext
         flags = store.getmeta(self.filename, node).get(constants.METAKEYFLAG, 0)
         if flags == 0:
             return rawtext
         return flagutil.processflagsread(self, rawtext, flags)[0]
 
     def rawdata(self, node):
         return self.revision(node, raw=False)
 
     def _read(self, id):
         """reads the raw file blob from disk, cache, or server"""
         fileservice = self.repo.fileservice
         localcache = fileservice.localcache
         cachekey = fileserverclient.getcachekey(
             self.repo.name, self.filename, id
         )
         try:
             return localcache.read(cachekey)
         except KeyError:
             pass
 
         localkey = fileserverclient.getlocalkey(self.filename, id)
         localpath = os.path.join(self.localpath, localkey)
         try:
             return shallowutil.readfile(localpath)
         except IOError:
             pass
 
         fileservice.prefetch([(self.filename, id)])
         try:
             return localcache.read(cachekey)
         except KeyError:
             pass
 
         raise error.LookupError(id, self.filename, _(b'no node'))
 
     def ancestormap(self, node):
         return self.repo.metadatastore.getancestors(self.filename, node)
 
     def ancestor(self, a, b):
         if a == nullid or b == nullid:
             return nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
         nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
 
         ancs = ancestor.ancestors(parentfunc, revmap[a], revmap[b])
         if ancs:
             # choose a consistent winner when there's a tie
             return min(map(nodemap.__getitem__, ancs))
         return nullid
 
     def commonancestorsheads(self, a, b):
         """calculate all the heads of the common ancestors of nodes a and b"""
 
         if a == nullid or b == nullid:
             return nullid
 
         revmap, parentfunc = self._buildrevgraph(a, b)
         nodemap = {v: k for (k, v) in pycompat.iteritems(revmap)}
 
         ancs = ancestor.commonancestorsheads(parentfunc, revmap[a], revmap[b])
         return map(nodemap.__getitem__, ancs)
 
     def _buildrevgraph(self, a, b):
         """Builds a numeric revision graph for the given two nodes.
         Returns a node->rev map and a rev->[revs] parent function.
         """
         amap = self.ancestormap(a)
         bmap = self.ancestormap(b)
 
         # Union the two maps
         parentsmap = collections.defaultdict(list)
         allparents = set()
         for mapping in (amap, bmap):
             for node, pdata in pycompat.iteritems(mapping):
                 parents = parentsmap[node]
                 p1, p2, linknode, copyfrom = pdata
                 # Don't follow renames (copyfrom).
                 # remotefilectx.ancestor does that.
                 if p1 != nullid and not copyfrom:
                     parents.append(p1)
                     allparents.add(p1)
                 if p2 != nullid:
                     parents.append(p2)
                     allparents.add(p2)
 
         # Breadth first traversal to build linkrev graph
         parentrevs = collections.defaultdict(list)
         revmap = {}
         queue = collections.deque(
             ((None, n) for n in parentsmap if n not in allparents)
         )
         while queue:
             prevrev, current = queue.pop()
             if current in revmap:
                 if prevrev:
                     parentrevs[prevrev].append(revmap[current])
                 continue
 
             # Assign linkrevs in reverse order, so start at
             # len(parentsmap) and work backwards.
             currentrev = len(parentsmap) - len(revmap) - 1
             revmap[current] = currentrev
 
             if prevrev:
                 parentrevs[prevrev].append(currentrev)
 
             for parent in parentsmap.get(current):
                 queue.appendleft((currentrev, parent))
 
         return revmap, parentrevs.__getitem__
 
     def strip(self, minlink, transaction):
         pass
 
     # misc unused things
     def files(self):
         return []
 
     def checksize(self):
         return 0, 0

tests/test-remotefilelog-hgweb.t

@@ -1,32 +1,38 b''
 #require no-windows serve
 
   $ . "$TESTDIR/remotefilelog-library.sh"
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > remotefilelog=
   > share=
   > EOF
 
   $ hg init master
   $ cd master
   $ cat >> .hg/hgrc <<EOF
   > [remotefilelog]
   > server=True
   > EOF
   $ echo x > x
   $ hg commit -qAm x
 
   $ cd ..
 
 
   $ hgcloneshallow ssh://user@dummy/master wdir --noupdate -q
   $ cd wdir
   $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -E errors.log
   $ cat hg.pid >> $DAEMON_PIDS
-  $ (get-with-headers.py localhost:$HGPORT 'file/tip/x')
-  500 Internal Server Error
+  $ get-with-headers.py localhost:$HGPORT 'file/tip/x' | head -n 10
+  200 Script output follows
   
-  Internal Server Error (no-eol)
-  [1]
+  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
+  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
+  <head>
+  <link rel="icon" href="/static/hgicon.png" type="image/png" />
+  <meta name="robots" content="index, nofollow" />
+  <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
+  <script type="text/javascript" src="/static/mercurial.js"></script>
 
+