mercurial/hgweb/hgweb_mod.py

ancestor: a new algorithm that is faster for nodes near tip

Instead of walking all the way to the root of the DAG, we generate
a set of candidate GCA revs, then figure out which ones will win
the race to the root (usually without needing to traverse all the
way to the root).

In the common case of nodes that are close to each other in both
revision number and topology, this is usually a big win: it makes
"hg --time debugancestors" up to 9 times faster than the more general
ancestor function when measured on heads of the linux-2.6 hg repo.

Victory is not assured, however. The older function can still win
by a large margin if one node is much closer to the root than the
other, or by a much smaller amount if one is an ancestor of the
other.

For now, we've also got a small paranoid harness function that calls
both ancestor functions on every input and ensures that they give
equivalent answers.

Even without the checker function, the old ancestor function needs
to stay alive for the time being, as its generality is used by
context.filectx.merge.

# 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 version 2 or any later version.

import os
from mercurial import ui, hg, hook, error, encoding, templater, util, repoview
from mercurial.templatefilters import websub
from mercurial.i18n import _
from common import get_stat, ErrorResponse, permhooks, caching
from common import HTTP_OK, HTTP_NOT_MODIFIED, HTTP_BAD_REQUEST
from common import HTTP_NOT_FOUND, HTTP_SERVER_ERROR
from request import wsgirequest
import webcommands, protocol, webutil, re

perms = {
    'changegroup': 'pull',
    'changegroupsubset': 'pull',
    'getbundle': 'pull',
    'stream_out': 'pull',
    'listkeys': 'pull',
    'unbundle': 'push',
    'pushkey': 'push',
}

def makebreadcrumb(url, prefix=''):
    '''Return a 'URL breadcrumb' list

    A 'URL breadcrumb' is a list of URL-name pairs,
    corresponding to each of the path items on a URL.
    This can be used to create path navigation entries.
    '''
    if url.endswith('/'):
        url = url[:-1]
    if prefix:
        url = '/' + prefix + url
    relpath = url
    if relpath.startswith('/'):
        relpath = relpath[1:]

    breadcrumb = []
    urlel = url
    pathitems = [''] + relpath.split('/')
    for pathel in reversed(pathitems):
        if not pathel or not urlel:
            break
        breadcrumb.append({'url': urlel, 'name': pathel})
        urlel = os.path.dirname(urlel)
    return reversed(breadcrumb)


class hgweb(object):
    def __init__(self, repo, name=None, baseui=None):
        if isinstance(repo, str):
            if baseui:
                u = baseui.copy()
            else:
                u = ui.ui()
            self.repo = hg.repository(u, repo)
        else:
            self.repo = repo

        self.repo = self._getview(self.repo)
        self.repo.ui.setconfig('ui', 'report_untrusted', 'off')
        self.repo.baseui.setconfig('ui', 'report_untrusted', 'off')
        self.repo.ui.setconfig('ui', 'nontty', 'true')
        self.repo.baseui.setconfig('ui', 'nontty', 'true')
        hook.redirect(True)
        self.mtime = -1
        self.size = -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')
        self.websubtable = self.loadwebsub()

    # 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 _getview(self, repo):
        viewconfig = self.config('web', 'view', 'served')
        if viewconfig == 'all':
            return repo.unfiltered()
        elif viewconfig in repoview.filtertable:
            return repo.filtered(viewconfig)
        else:
            return repo.filtered('served')

    def refresh(self, request=None):
        st = get_stat(self.repo.spath)
        # compare changelog size in addition to mtime to catch
        # rollbacks made less than a second ago
        if st.st_mtime != self.mtime or st.st_size != self.size:
            self.mtime = st.st_mtime
            self.size = st.st_size
            r = hg.repository(self.repo.baseui, self.repo.root)
            self.repo = self._getview(r)
            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)
            encoding.encoding = self.config("web", "encoding",
                                            encoding.encoding)
        if request:
            self.repo.ui.environ = request.env

    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)
        return self.run_wsgi(req)

    def run_wsgi(self, req):

        self.refresh(req)

        # 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 'PATH_INFO' in req.env:
            parts = req.env['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]

        # process this if it's a protocol request
        # protocol bits don't need to create any URLs
        # and the clients always use the old URL structure

        cmd = req.form.get('cmd', [''])[0]
        if protocol.iscmd(cmd):
            try:
                if query:
                    raise ErrorResponse(HTTP_NOT_FOUND)
                if cmd in perms:
                    self.check_perm(req, perms[cmd])
                return protocol.call(self.repo, req, cmd)
            except ErrorResponse, inst:
                # A client that sends unbundle without 100-continue will
                # break if we respond early.
                if (cmd == 'unbundle' and
                    (req.env.get('HTTP_EXPECT',
                                 '').lower() != '100-continue') or
                    req.env.get('X-HgHttp2', '')):
                    req.drain()
                req.respond(inst, protocol.HGTYPE,
                            body='0\n%s\n' % inst.message)
                return ''

        # 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 util.safehasattr(webcommands, cmd):
                req.form['cmd'] = [cmd]
            else:
                cmd = ''

            if cmd == 'static':
                req.form['file'] = ['/'.join(args)]
            else:
                if args and args[0]:
                    node = args.pop(0)
                    req.form['node'] = [node]
                if args:
                    req.form['file'] = args

            ua = req.env.get('HTTP_USER_AGENT', '')
            if cmd == 'rev' and 'mercurial' in ua:
                req.form['style'] = ['raw']

            if 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_]

        # process the web interface request

        try:
            tmpl = self.templater(req)
            ctype = tmpl('mimetype', encoding=encoding.encoding)
            ctype = templater.stringify(ctype)

            # check read permissions non-static content
            if cmd != 'static':
                self.check_perm(req, None)

            if cmd == '':
                req.form['cmd'] = [tmpl.cache['default']]
                cmd = req.form['cmd'][0]

            if self.configbool('web', 'cache', True):
                caching(self, req) # sets ETag header or raises NOT_MODIFIED
            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)

            return content

        except (error.LookupError, error.RepoLookupError), err:
            req.respond(HTTP_NOT_FOUND, ctype)
            msg = str(err)
            if (util.safehasattr(err, 'name') and
                not isinstance(err,  error.ManifestLookupError)):
                msg = 'revision not found: %s' % err.name
            return tmpl('error', error=msg)
        except (error.RepoError, error.RevlogError), inst:
            req.respond(HTTP_SERVER_ERROR, ctype)
            return tmpl('error', error=str(inst))
        except ErrorResponse, inst:
            req.respond(inst, ctype)
            if inst.code == HTTP_NOT_MODIFIED:
                # Not allowed to return a body on a 304
                return ['']
            return tmpl('error', error=inst.message)

    def loadwebsub(self):
        websubtable = []
        websubdefs = self.repo.ui.configitems('websub')
        # we must maintain interhg backwards compatibility
        websubdefs += self.repo.ui.configitems('interhg')
        for key, pattern in websubdefs:
            # grab the delimiter from the character after the "s"
            unesc = pattern[1]
            delim = re.escape(unesc)

            # identify portions of the pattern, taking care to avoid escaped
            # delimiters. the replace format and flags are optional, but
            # delimiters are required.
            match = re.match(
                r'^s%s(.+)(?:(?<=\\\\)|(?<!\\))%s(.*)%s([ilmsux])*$'
                % (delim, delim, delim), pattern)
            if not match:
                self.repo.ui.warn(_("websub: invalid pattern for %s: %s\n")
                                  % (key, pattern))
                continue

            # we need to unescape the delimiter for regexp and format
            delim_re = re.compile(r'(?<!\\)\\%s' % delim)
            regexp = delim_re.sub(unesc, match.group(1))
            format = delim_re.sub(unesc, match.group(2))

            # the pattern allows for 6 regexp flags, so set them if necessary
            flagin = match.group(3)
            flags = 0
            if flagin:
                for flag in flagin.upper():
                    flags |= re.__dict__[flag]

            try:
                regexp = re.compile(regexp, flags)
                websubtable.append((regexp, format))
            except re.error:
                self.repo.ui.warn(_("websub: invalid regexp for %s: %s\n")
                                  % (key, regexp))
        return websubtable

    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)
        logourl = self.config("web", "logourl", "http://mercurial.selenic.com/")
        logoimg = self.config("web", "logoimg", "hglogo.png")
        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=encoding.encoding, **map)

        def footer(**map):
            yield tmpl("footer", **map)

        def motd(**map):
            yield self.config("web", "motd", "")

        # figure out which style to use

        vars = {}
        styles = (
            req.form.get('style', [None])[0],
            self.config('web', 'style'),
            'paper',
        )
        style, mapfile = templater.stylemap(styles, self.templatepath)
        if style == styles[0]:
            vars['style'] = style

        start = req.url[-1] == '?' and '&' or '?'
        sessionvars = webutil.sessionvars(vars, start)

        if not self.reponame:
            self.reponame = (self.config("web", "name")
                             or req.env.get('REPO_NAME')
                             or req.url.strip('/') or self.repo.root)

        def websubfilter(text):
            return websub(text, self.websubtable)

        # create the templater

        tmpl = templater.templater(mapfile,
                                   filters={"websub": websubfilter},
                                   defaults={"url": req.url,
                                             "logourl": logourl,
                                             "logoimg": logoimg,
                                             "staticurl": staticurl,
                                             "urlbase": urlbase,
                                             "repo": self.reponame,
                                             "header": header,
                                             "footer": footer,
                                             "motd": motd,
                                             "sessionvars": sessionvars,
                                             "pathdef": makebreadcrumb(req.url),
                                            })
        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}

    archive_specs = {
        'bz2': ('application/x-bzip2', 'tbz2', '.tar.bz2', None),
        'gz': ('application/x-gzip', 'tgz', '.tar.gz', None),
        'zip': ('application/zip', 'zip', '.zip', None),
        }

    def check_perm(self, req, op):
        for hook in permhooks:
            hook(self, req, op)