hgweb: separate protocol calls from interface calls (issue996)

The protocol functions are already pretty careful about not raising
exceptions to the caller, and have their own error handling. We can formalize
this a little bit to make it clearer (before, the exception handlers for
a limited number of exceptions coming from the interface bits would blow up
because some variables aren't instantiated for the protocol calls).

mercurial/hgweb/hgweb_mod.py

@@ -1,926 +1,929 b''
 # hgweb/hgweb_mod.py - Web interface for a repository.
 #
 # Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 import os, mimetypes, re
 from mercurial.node import *
 from mercurial import mdiff, ui, hg, util, archival, patch, hook
 from mercurial import revlog, templater, templatefilters
 from common import get_mtime, style_map, paritygen, countgen, get_contact
 from common import ErrorResponse
 from common import HTTP_OK, HTTP_BAD_REQUEST, HTTP_NOT_FOUND, HTTP_SERVER_ERROR
 from request import wsgirequest
 import webcommands, protocol
 
 shortcuts = {
     'cl': [('cmd', ['changelog']), ('rev', None)],
     'sl': [('cmd', ['shortlog']), ('rev', None)],
     'cs': [('cmd', ['changeset']), ('node', None)],
     'f': [('cmd', ['file']), ('filenode', None)],
     'fl': [('cmd', ['filelog']), ('filenode', None)],
     'fd': [('cmd', ['filediff']), ('node', None)],
     'fa': [('cmd', ['annotate']), ('filenode', None)],
     'mf': [('cmd', ['manifest']), ('manifest', None)],
     'ca': [('cmd', ['archive']), ('node', None)],
     'tags': [('cmd', ['tags'])],
     'tip': [('cmd', ['changeset']), ('node', ['tip'])],
     'static': [('cmd', ['static']), ('file', None)]
 }
 
 def _up(p):
     if p[0] != "/":
         p = "/" + p
     if p[-1] == "/":
         p = p[:-1]
     up = os.path.dirname(p)
     if up == "/":
         return "/"
     return up + "/"
 
 def revnavgen(pos, pagelen, limit, nodefunc):
     def seq(factor, limit=None):
         if limit:
             yield limit
             if limit >= 20 and limit <= 40:
                 yield 50
         else:
             yield 1 * factor
             yield 3 * factor
         for f in seq(factor * 10):
             yield f
 
     def nav(**map):
         l = []
         last = 0
         for f in seq(1, pagelen):
             if f < pagelen or f <= last:
                 continue
             if f > limit:
                 break
             last = f
             if pos + f < limit:
                 l.append(("+%d" % f, hex(nodefunc(pos + f).node())))
             if pos - f >= 0:
                 l.insert(0, ("-%d" % f, hex(nodefunc(pos - f).node())))
 
         try:
             yield {"label": "(0)", "node": hex(nodefunc('0').node())}
 
             for label, node in l:
                 yield {"label": label, "node": node}
 
             yield {"label": "tip", "node": "tip"}
         except hg.RepoError:
             pass
 
     return nav
 
 class hgweb(object):
     def __init__(self, repo, name=None):
         if isinstance(repo, str):
             parentui = ui.ui(report_untrusted=False, interactive=False)
             self.repo = hg.repository(parentui, repo)
         else:
             self.repo = repo
 
         hook.redirect(True)
         self.mtime = -1
         self.reponame = name
         self.archives = 'zip', 'gz', 'bz2'
         self.stripecount = 1
         # a repo owner may set web.templates in .hg/hgrc to get any file
         # readable by the user running the CGI script
         self.templatepath = self.config("web", "templates",
                                         templater.templatepath(),
                                         untrusted=False)
 
     # The CGI scripts are often run by a user different from the repo owner.
     # Trust the settings from the .hg/hgrc files by default.
     def config(self, section, name, default=None, untrusted=True):
         return self.repo.ui.config(section, name, default,
                                    untrusted=untrusted)
 
     def configbool(self, section, name, default=False, untrusted=True):
         return self.repo.ui.configbool(section, name, default,
                                        untrusted=untrusted)
 
     def configlist(self, section, name, default=None, untrusted=True):
         return self.repo.ui.configlist(section, name, default,
                                        untrusted=untrusted)
 
     def refresh(self):
         mtime = get_mtime(self.repo.root)
         if mtime != self.mtime:
             self.mtime = mtime
             self.repo = hg.repository(self.repo.ui, self.repo.root)
             self.maxchanges = int(self.config("web", "maxchanges", 10))
             self.stripecount = int(self.config("web", "stripes", 1))
             self.maxshortchanges = int(self.config("web", "maxshortchanges", 60))
             self.maxfiles = int(self.config("web", "maxfiles", 10))
             self.allowpull = self.configbool("web", "allowpull", True)
             self.encoding = self.config("web", "encoding", util._encoding)
 
     def run(self):
         if not os.environ.get('GATEWAY_INTERFACE', '').startswith("CGI/1."):
             raise RuntimeError("This function is only intended to be called while running as a CGI script.")
         import mercurial.hgweb.wsgicgi as wsgicgi
         wsgicgi.launch(self)
 
     def __call__(self, env, respond):
         req = wsgirequest(env, respond)
         self.run_wsgi(req)
         return req
 
     def run_wsgi(self, req):
 
         self.refresh()
 
         # expand form shortcuts
 
         for k in shortcuts.iterkeys():
             if k in req.form:
                 for name, value in shortcuts[k]:
                     if value is None:
                         value = req.form[k]
                     req.form[name] = value
                 del req.form[k]
 
         # work with CGI variables to create coherent structure
         # use SCRIPT_NAME, PATH_INFO and QUERY_STRING as well as our REPO_NAME
 
         req.url = req.env['SCRIPT_NAME']
         if not req.url.endswith('/'):
             req.url += '/'
         if 'REPO_NAME' in req.env:
             req.url += req.env['REPO_NAME'] + '/'
 
         if req.env.get('PATH_INFO'):
             parts = req.env.get('PATH_INFO').strip('/').split('/')
             repo_parts = req.env.get('REPO_NAME', '').split('/')
             if parts[:len(repo_parts)] == repo_parts:
                 parts = parts[len(repo_parts):]
             query = '/'.join(parts)
         else:
             query = req.env['QUERY_STRING'].split('&', 1)[0]
             query = query.split(';', 1)[0]
 
         # translate user-visible url structure to internal structure
 
         args = query.split('/', 2)
         if 'cmd' not in req.form and args and args[0]:
 
             cmd = args.pop(0)
             style = cmd.rfind('-')
             if style != -1:
                 req.form['style'] = [cmd[:style]]
                 cmd = cmd[style+1:]
 
             # avoid accepting e.g. style parameter as command
             if hasattr(webcommands, cmd) or hasattr(protocol, cmd):
                 req.form['cmd'] = [cmd]
 
             if args and args[0]:
                 node = args.pop(0)
                 req.form['node'] = [node]
             if args:
                 req.form['file'] = args
 
             if cmd == 'static':
                 req.form['file'] = req.form['node']
             elif cmd == 'archive':
                 fn = req.form['node'][0]
                 for type_, spec in self.archive_specs.iteritems():
                     ext = spec[2]
                     if fn.endswith(ext):
                         req.form['node'] = [fn[:-len(ext)]]
                         req.form['type'] = [type_]
 
-        # actually process the request
+        # process this if it's a protocol request
+
+        cmd = req.form.get('cmd', [''])[0]
+        if cmd in protocol.__all__:
+            method = getattr(protocol, cmd)
+            method(self, req)
+            return
+
+        # process the web interface request
 
         try:
 
-            cmd = req.form.get('cmd', [''])[0]
-            if cmd in protocol.__all__:
-                method = getattr(protocol, cmd)
-                method(self, req)
-            else:
-                tmpl = self.templater(req)
-                ctype = tmpl('mimetype', encoding=self.encoding)
-                ctype = templater.stringify(ctype)
-                
-                if cmd == '':
-                    req.form['cmd'] = [tmpl.cache['default']]
-                    cmd = req.form['cmd'][0]
+            tmpl = self.templater(req)
+            ctype = tmpl('mimetype', encoding=self.encoding)
+            ctype = templater.stringify(ctype)
+
+            if cmd == '':
+                req.form['cmd'] = [tmpl.cache['default']]
+                cmd = req.form['cmd'][0]
 
-                if cmd not in webcommands.__all__:
-                    msg = 'No such method: %s' % cmd
-                    raise ErrorResponse(HTTP_BAD_REQUEST, msg)
-                elif cmd == 'file' and 'raw' in req.form.get('style', []):
-                    self.ctype = ctype
-                    content = webcommands.rawfile(self, req, tmpl)
-                else:
-                    content = getattr(webcommands, cmd)(self, req, tmpl)
-                    req.respond(HTTP_OK, ctype)
+            if cmd not in webcommands.__all__:
+                msg = 'No such method: %s' % cmd
+                raise ErrorResponse(HTTP_BAD_REQUEST, msg)
+            elif cmd == 'file' and 'raw' in req.form.get('style', []):
+                self.ctype = ctype
+                content = webcommands.rawfile(self, req, tmpl)
+            else:
+                content = getattr(webcommands, cmd)(self, req, tmpl)
+                req.respond(HTTP_OK, ctype)
 
-                req.write(content)
-                del tmpl
+            req.write(content)
+            del tmpl
 
         except revlog.LookupError, err:
             req.respond(HTTP_NOT_FOUND, ctype)
             req.write(tmpl('error', error='revision not found: %s' % err.name))
         except (hg.RepoError, revlog.RevlogError), inst:
             req.respond(HTTP_SERVER_ERROR, ctype)
             req.write(tmpl('error', error=str(inst)))
         except ErrorResponse, inst:
             req.respond(inst.code, ctype)
             req.write(tmpl('error', error=inst.message))
 
     def templater(self, req):
 
         # determine scheme, port and server name
         # this is needed to create absolute urls
 
         proto = req.env.get('wsgi.url_scheme')
         if proto == 'https':
             proto = 'https'
             default_port = "443"
         else:
             proto = 'http'
             default_port = "80"
 
         port = req.env["SERVER_PORT"]
         port = port != default_port and (":" + port) or ""
         urlbase = '%s://%s%s' % (proto, req.env['SERVER_NAME'], port)
         staticurl = self.config("web", "staticurl") or req.url + 'static/'
         if not staticurl.endswith('/'):
             staticurl += '/'
 
         # some functions for the templater
 
         def header(**map):
             yield tmpl('header', encoding=self.encoding, **map)
 
         def footer(**map):
             yield tmpl("footer", **map)
 
         def motd(**map):
             yield self.config("web", "motd", "")
 
         def sessionvars(**map):
             fields = []
             if 'style' in req.form:
                 style = req.form['style'][0]
                 if style != self.config('web', 'style', ''):
                     fields.append(('style', style))
 
             separator = req.url[-1] == '?' and ';' or '?'
             for name, value in fields:
                 yield dict(name=name, value=value, separator=separator)
                 separator = ';'
 
         # figure out which style to use
 
         style = self.config("web", "style", "")
         if 'style' in req.form:
             style = req.form['style'][0]
         mapfile = style_map(self.templatepath, style)
 
         if not self.reponame:
             self.reponame = (self.config("web", "name")
                              or req.env.get('REPO_NAME')
                              or req.url.strip('/') or self.repo.root)
 
         # create the templater
 
         tmpl = templater.templater(mapfile, templatefilters.filters,
                                    defaults={"url": req.url,
                                              "staticurl": staticurl,
                                              "urlbase": urlbase,
                                              "repo": self.reponame,
                                              "header": header,
                                              "footer": footer,
                                              "motd": motd,
                                              "sessionvars": sessionvars
                                             })
         return tmpl
 
     def archivelist(self, nodeid):
         allowed = self.configlist("web", "allow_archive")
         for i, spec in self.archive_specs.iteritems():
             if i in allowed or self.configbool("web", "allow" + i):
                 yield {"type" : i, "extension" : spec[2], "node" : nodeid}
 
     def listfilediffs(self, tmpl, files, changeset):
         for f in files[:self.maxfiles]:
             yield tmpl("filedifflink", node=hex(changeset), file=f)
         if len(files) > self.maxfiles:
             yield tmpl("fileellipses")
 
     def siblings(self, siblings=[], hiderev=None, **args):
         siblings = [s for s in siblings if s.node() != nullid]
         if len(siblings) == 1 and siblings[0].rev() == hiderev:
             return
         for s in siblings:
             d = {'node': hex(s.node()), 'rev': s.rev()}
             if hasattr(s, 'path'):
                 d['file'] = s.path()
             d.update(args)
             yield d
 
     def renamelink(self, fl, node):
         r = fl.renamed(node)
         if r:
             return [dict(file=r[0], node=hex(r[1]))]
         return []
 
     def nodetagsdict(self, node):
         return [{"name": i} for i in self.repo.nodetags(node)]
 
     def nodebranchdict(self, ctx):
         branches = []
         branch = ctx.branch()
         # If this is an empty repo, ctx.node() == nullid,
         # ctx.branch() == 'default', but branchtags() is
         # an empty dict. Using dict.get avoids a traceback.
         if self.repo.branchtags().get(branch) == ctx.node():
             branches.append({"name": branch})
         return branches
 
     def showtag(self, tmpl, t1, node=nullid, **args):
         for t in self.repo.nodetags(node):
             yield tmpl(t1, tag=t, **args)
 
     def diff(self, tmpl, node1, node2, files):
         def filterfiles(filters, files):
             l = [x for x in files if x in filters]
 
             for t in filters:
                 if t and t[-1] != os.sep:
                     t += os.sep
                 l += [x for x in files if x.startswith(t)]
             return l
 
         parity = paritygen(self.stripecount)
         def diffblock(diff, f, fn):
             yield tmpl("diffblock",
                        lines=prettyprintlines(diff),
                        parity=parity.next(),
                        file=f,
                        filenode=hex(fn or nullid))
 
         blockcount = countgen()
         def prettyprintlines(diff):
             blockno = blockcount.next()
             for lineno, l in enumerate(diff.splitlines(1)):
                 if blockno == 0:
                     lineno = lineno + 1
                 else:
                     lineno = "%d.%d" % (blockno, lineno + 1)
                 if l.startswith('+'):
                     ltype = "difflineplus"
                 elif l.startswith('-'):
                     ltype = "difflineminus"
                 elif l.startswith('@'):
                     ltype = "difflineat"
                 else:
                     ltype = "diffline"
                 yield tmpl(ltype,
                            line=l,
                            lineid="l%s" % lineno,
                            linenumber="% 8s" % lineno)
 
         r = self.repo
         c1 = r.changectx(node1)
         c2 = r.changectx(node2)
         date1 = util.datestr(c1.date())
         date2 = util.datestr(c2.date())
 
         modified, added, removed, deleted, unknown = r.status(node1, node2)[:5]
         if files:
             modified, added, removed = map(lambda x: filterfiles(files, x),
                                            (modified, added, removed))
 
         diffopts = patch.diffopts(self.repo.ui, untrusted=True)
         for f in modified:
             to = c1.filectx(f).data()
             tn = c2.filectx(f).data()
             yield diffblock(mdiff.unidiff(to, date1, tn, date2, f, f,
                                           opts=diffopts), f, tn)
         for f in added:
             to = None
             tn = c2.filectx(f).data()
             yield diffblock(mdiff.unidiff(to, date1, tn, date2, f, f,
                                           opts=diffopts), f, tn)
         for f in removed:
             to = c1.filectx(f).data()
             tn = None
             yield diffblock(mdiff.unidiff(to, date1, tn, date2, f, f,
                                           opts=diffopts), f, tn)
 
     def changelog(self, tmpl, ctx, shortlog=False):
         def changelist(limit=0,**map):
             cl = self.repo.changelog
             l = [] # build a list in forward order for efficiency
             for i in xrange(start, end):
                 ctx = self.repo.changectx(i)
                 n = ctx.node()
 
                 l.insert(0, {"parity": parity.next(),
                              "author": ctx.user(),
                              "parent": self.siblings(ctx.parents(), i - 1),
                              "child": self.siblings(ctx.children(), i + 1),
                              "changelogtag": self.showtag("changelogtag",n),
                              "desc": ctx.description(),
                              "date": ctx.date(),
                              "files": self.listfilediffs(tmpl, ctx.files(), n),
                              "rev": i,
                              "node": hex(n),
                              "tags": self.nodetagsdict(n),
                              "branches": self.nodebranchdict(ctx)})
 
             if limit > 0:
                 l = l[:limit]
 
             for e in l:
                 yield e
 
         maxchanges = shortlog and self.maxshortchanges or self.maxchanges
         cl = self.repo.changelog
         count = cl.count()
         pos = ctx.rev()
         start = max(0, pos - maxchanges + 1)
         end = min(count, start + maxchanges)
         pos = end - 1
         parity = paritygen(self.stripecount, offset=start-end)
 
         changenav = revnavgen(pos, maxchanges, count, self.repo.changectx)
 
         return tmpl(shortlog and 'shortlog' or 'changelog',
                     changenav=changenav,
                     node=hex(cl.tip()),
                     rev=pos, changesets=count,
                     entries=lambda **x: changelist(limit=0,**x),
                     latestentry=lambda **x: changelist(limit=1,**x),
                     archives=self.archivelist("tip"))
 
     def search(self, tmpl, query):
 
         def changelist(**map):
             cl = self.repo.changelog
             count = 0
             qw = query.lower().split()
 
             def revgen():
                 for i in xrange(cl.count() - 1, 0, -100):
                     l = []
                     for j in xrange(max(0, i - 100), i + 1):
                         ctx = self.repo.changectx(j)
                         l.append(ctx)
                     l.reverse()
                     for e in l:
                         yield e
 
             for ctx in revgen():
                 miss = 0
                 for q in qw:
                     if not (q in ctx.user().lower() or
                             q in ctx.description().lower() or
                             q in " ".join(ctx.files()).lower()):
                         miss = 1
                         break
                 if miss:
                     continue
 
                 count += 1
                 n = ctx.node()
 
                 yield tmpl('searchentry',
                            parity=parity.next(),
                            author=ctx.user(),
                            parent=self.siblings(ctx.parents()),
                            child=self.siblings(ctx.children()),
                            changelogtag=self.showtag("changelogtag",n),
                            desc=ctx.description(),
                            date=ctx.date(),
                            files=self.listfilediffs(tmpl, ctx.files(), n),
                            rev=ctx.rev(),
                            node=hex(n),
                            tags=self.nodetagsdict(n),
                            branches=self.nodebranchdict(ctx))
 
                 if count >= self.maxchanges:
                     break
 
         cl = self.repo.changelog
         parity = paritygen(self.stripecount)
 
         return tmpl('search',
                     query=query,
                     node=hex(cl.tip()),
                     entries=changelist,
                     archives=self.archivelist("tip"))
 
     def changeset(self, tmpl, ctx):
         n = ctx.node()
         parents = ctx.parents()
         p1 = parents[0].node()
 
         files = []
         parity = paritygen(self.stripecount)
         for f in ctx.files():
             files.append(tmpl("filenodelink",
                               node=hex(n), file=f,
                               parity=parity.next()))
 
         def diff(**map):
             yield self.diff(tmpl, p1, n, None)
 
         return tmpl('changeset',
                     diff=diff,
                     rev=ctx.rev(),
                     node=hex(n),
                     parent=self.siblings(parents),
                     child=self.siblings(ctx.children()),
                     changesettag=self.showtag("changesettag",n),
                     author=ctx.user(),
                     desc=ctx.description(),
                     date=ctx.date(),
                     files=files,
                     archives=self.archivelist(hex(n)),
                     tags=self.nodetagsdict(n),
                     branches=self.nodebranchdict(ctx))
 
     def filelog(self, tmpl, fctx):
         f = fctx.path()
         fl = fctx.filelog()
         count = fl.count()
         pagelen = self.maxshortchanges
         pos = fctx.filerev()
         start = max(0, pos - pagelen + 1)
         end = min(count, start + pagelen)
         pos = end - 1
         parity = paritygen(self.stripecount, offset=start-end)
 
         def entries(limit=0, **map):
             l = []
 
             for i in xrange(start, end):
                 ctx = fctx.filectx(i)
                 n = fl.node(i)
 
                 l.insert(0, {"parity": parity.next(),
                              "filerev": i,
                              "file": f,
                              "node": hex(ctx.node()),
                              "author": ctx.user(),
                              "date": ctx.date(),
                              "rename": self.renamelink(fl, n),
                              "parent": self.siblings(fctx.parents()),
                              "child": self.siblings(fctx.children()),
                              "desc": ctx.description()})
 
             if limit > 0:
                 l = l[:limit]
 
             for e in l:
                 yield e
 
         nodefunc = lambda x: fctx.filectx(fileid=x)
         nav = revnavgen(pos, pagelen, count, nodefunc)
         return tmpl("filelog", file=f, node=hex(fctx.node()), nav=nav,
                     entries=lambda **x: entries(limit=0, **x),
                     latestentry=lambda **x: entries(limit=1, **x))
 
     def filerevision(self, tmpl, fctx):
         f = fctx.path()
         text = fctx.data()
         fl = fctx.filelog()
         n = fctx.filenode()
         parity = paritygen(self.stripecount)
 
         if util.binary(text):
             mt = mimetypes.guess_type(f)[0] or 'application/octet-stream'
             text = '(binary:%s)' % mt
 
         def lines():
             for lineno, t in enumerate(text.splitlines(1)):
                 yield {"line": t,
                        "lineid": "l%d" % (lineno + 1),
                        "linenumber": "% 6d" % (lineno + 1),
                        "parity": parity.next()}
 
         return tmpl("filerevision",
                     file=f,
                     path=_up(f),
                     text=lines(),
                     rev=fctx.rev(),
                     node=hex(fctx.node()),
                     author=fctx.user(),
                     date=fctx.date(),
                     desc=fctx.description(),
                     parent=self.siblings(fctx.parents()),
                     child=self.siblings(fctx.children()),
                     rename=self.renamelink(fl, n),
                     permissions=fctx.manifest().flags(f))
 
     def fileannotate(self, tmpl, fctx):
         f = fctx.path()
         n = fctx.filenode()
         fl = fctx.filelog()
         parity = paritygen(self.stripecount)
 
         def annotate(**map):
             last = None
             lines = enumerate(fctx.annotate(follow=True, linenumber=True))
             for lineno, ((f, targetline), l) in lines:
                 fnode = f.filenode()
                 name = self.repo.ui.shortuser(f.user())
 
                 if last != fnode:
                     last = fnode
 
                 yield {"parity": parity.next(),
                        "node": hex(f.node()),
                        "rev": f.rev(),
                        "author": name,
                        "file": f.path(),
                        "targetline": targetline,
                        "line": l,
                        "lineid": "l%d" % (lineno + 1),
                        "linenumber": "% 6d" % (lineno + 1)}
 
         return tmpl("fileannotate",
                     file=f,
                     annotate=annotate,
                     path=_up(f),
                     rev=fctx.rev(),
                     node=hex(fctx.node()),
                     author=fctx.user(),
                     date=fctx.date(),
                     desc=fctx.description(),
                     rename=self.renamelink(fl, n),
                     parent=self.siblings(fctx.parents()),
                     child=self.siblings(fctx.children()),
                     permissions=fctx.manifest().flags(f))
 
     def manifest(self, tmpl, ctx, path):
         mf = ctx.manifest()
         node = ctx.node()
 
         files = {}
         parity = paritygen(self.stripecount)
 
         if path and path[-1] != "/":
             path += "/"
         l = len(path)
         abspath = "/" + path
 
         for f, n in mf.items():
             if f[:l] != path:
                 continue
             remain = f[l:]
             if "/" in remain:
                 short = remain[:remain.index("/") + 1] # bleah
                 files[short] = (f, None)
             else:
                 short = os.path.basename(remain)
                 files[short] = (f, n)
 
         if not files:
             raise ErrorResponse(HTTP_NOT_FOUND, 'Path not found: ' + path)
 
         def filelist(**map):
             fl = files.keys()
             fl.sort()
             for f in fl:
                 full, fnode = files[f]
                 if not fnode:
                     continue
 
                 fctx = ctx.filectx(full)
                 yield {"file": full,
                        "parity": parity.next(),
                        "basename": f,
                        "date": fctx.changectx().date(),
                        "size": fctx.size(),
                        "permissions": mf.flags(full)}
 
         def dirlist(**map):
             fl = files.keys()
             fl.sort()
             for f in fl:
                 full, fnode = files[f]
                 if fnode:
                     continue
 
                 yield {"parity": parity.next(),
                        "path": "%s%s" % (abspath, f),
                        "basename": f[:-1]}
 
         return tmpl("manifest",
                     rev=ctx.rev(),
                     node=hex(node),
                     path=abspath,
                     up=_up(abspath),
                     upparity=parity.next(),
                     fentries=filelist,
                     dentries=dirlist,
                     archives=self.archivelist(hex(node)),
                     tags=self.nodetagsdict(node),
                     branches=self.nodebranchdict(ctx))
 
     def tags(self, tmpl):
         i = self.repo.tagslist()
         i.reverse()
         parity = paritygen(self.stripecount)
 
         def entries(notip=False,limit=0, **map):
             count = 0
             for k, n in i:
                 if notip and k == "tip":
                     continue
                 if limit > 0 and count >= limit:
                     continue
                 count = count + 1
                 yield {"parity": parity.next(),
                        "tag": k,
                        "date": self.repo.changectx(n).date(),
                        "node": hex(n)}
 
         return tmpl("tags",
                     node=hex(self.repo.changelog.tip()),
                     entries=lambda **x: entries(False,0, **x),
                     entriesnotip=lambda **x: entries(True,0, **x),
                     latestentry=lambda **x: entries(True,1, **x))
 
     def summary(self, tmpl):
         i = self.repo.tagslist()
         i.reverse()
 
         def tagentries(**map):
             parity = paritygen(self.stripecount)
             count = 0
             for k, n in i:
                 if k == "tip": # skip tip
                     continue;
 
                 count += 1
                 if count > 10: # limit to 10 tags
                     break;
 
                 yield tmpl("tagentry",
                            parity=parity.next(),
                            tag=k,
                            node=hex(n),
                            date=self.repo.changectx(n).date())
 
 
         def branches(**map):
             parity = paritygen(self.stripecount)
 
             b = self.repo.branchtags()
             l = [(-self.repo.changelog.rev(n), n, t) for t, n in b.items()]
             l.sort()
 
             for r,n,t in l:
                 ctx = self.repo.changectx(n)
 
                 yield {'parity': parity.next(),
                        'branch': t,
                        'node': hex(n),
                        'date': ctx.date()}
 
         def changelist(**map):
             parity = paritygen(self.stripecount, offset=start-end)
             l = [] # build a list in forward order for efficiency
             for i in xrange(start, end):
                 ctx = self.repo.changectx(i)
                 n = ctx.node()
                 hn = hex(n)
 
                 l.insert(0, tmpl(
                    'shortlogentry',
                     parity=parity.next(),
                     author=ctx.user(),
                     desc=ctx.description(),
                     date=ctx.date(),
                     rev=i,
                     node=hn,
                     tags=self.nodetagsdict(n),
                     branches=self.nodebranchdict(ctx)))
 
             yield l
 
         cl = self.repo.changelog
         count = cl.count()
         start = max(0, count - self.maxchanges)
         end = min(count, start + self.maxchanges)
 
         return tmpl("summary",
                     desc=self.config("web", "description", "unknown"),
                     owner=get_contact(self.config) or "unknown",
                     lastchange=cl.read(cl.tip())[2],
                     tags=tagentries,
                     branches=branches,
                     shortlog=changelist,
                     node=hex(cl.tip()),
                     archives=self.archivelist("tip"))
 
     def filediff(self, tmpl, fctx):
         n = fctx.node()
         path = fctx.path()
         parents = fctx.parents()
         p1 = parents and parents[0].node() or nullid
 
         def diff(**map):
             yield self.diff(tmpl, p1, n, [path])
 
         return tmpl("filediff",
                     file=path,
                     node=hex(n),
                     rev=fctx.rev(),
                     parent=self.siblings(parents),
                     child=self.siblings(fctx.children()),
                     diff=diff)
 
     archive_specs = {
         'bz2': ('application/x-tar', 'tbz2', '.tar.bz2', None),
         'gz': ('application/x-tar', 'tgz', '.tar.gz', None),
         'zip': ('application/zip', 'zip', '.zip', None),
         }
 
     def archive(self, tmpl, req, key, type_):
         reponame = re.sub(r"\W+", "-", os.path.basename(self.reponame))
         cnode = self.repo.lookup(key)
         arch_version = key
         if cnode == key or key == 'tip':
             arch_version = short(cnode)
         name = "%s-%s" % (reponame, arch_version)
         mimetype, artype, extension, encoding = self.archive_specs[type_]
         headers = [
             ('Content-Type', mimetype),
             ('Content-Disposition', 'attachment; filename=%s%s' %
                 (name, extension))
         ]
         if encoding:
             headers.append(('Content-Encoding', encoding))
         req.header(headers)
         req.respond(HTTP_OK)
         archival.archive(self.repo, req, cnode, artype, prefix=name)
 
     # add tags to things
     # tags -> list of changesets corresponding to tags
     # find tag, changeset, file
 
     def cleanpath(self, path):
         path = path.lstrip('/')
         return util.canonpath(self.repo.root, '', path)
 
     def changectx(self, req):
         if 'node' in req.form:
             changeid = req.form['node'][0]
         elif 'manifest' in req.form:
             changeid = req.form['manifest'][0]
         else:
             changeid = self.repo.changelog.count() - 1
 
         try:
             ctx = self.repo.changectx(changeid)
         except hg.RepoError:
             man = self.repo.manifest
             mn = man.lookup(changeid)
             ctx = self.repo.changectx(man.linkrev(mn))
 
         return ctx
 
     def filectx(self, req):
         path = self.cleanpath(req.form['file'][0])
         if 'node' in req.form:
             changeid = req.form['node'][0]
         else:
             changeid = req.form['filenode'][0]
         try:
             ctx = self.repo.changectx(changeid)
             fctx = ctx.filectx(path)
         except hg.RepoError:
             fctx = self.repo.filectx(path, fileid=changeid)
 
         return fctx
 
     def check_perm(self, req, op, default):
         '''check permission for operation based on user auth.
         return true if op allowed, else false.
         default is policy to use if no config given.'''
 
         user = req.env.get('REMOTE_USER')
 
         deny = self.configlist('web', 'deny_' + op)
         if deny and (not user or deny == ['*'] or user in deny):
             return False
 
         allow = self.configlist('web', 'allow_' + op)
         return (allow and (allow == ['*'] or user in allow)) or default