view mercurial/hgweb/hgwebdir_mod.py @ 39559:07b58266bce3

wireprotov2: implement commands as a generator of objects

Previously, wire protocol version 2 inherited version 1's model of
having separate types to represent the results of different wire
protocol commands.

As I implemented more powerful commands in future commits, I found
I was using a common pattern of returning a special type to hold a
generator. This meant the command function required a closure to
do most of the work. That made logic flow more difficult to follow.
I also noticed that many commands were effectively a sequence of
objects to be CBOR encoded.

I think it makes sense to define version 2 commands as generators.
This way, commands can simply emit the data structures they wish to
send to the client. This eliminates the need for a closure in
command functions and removes encoding from the bodies of commands.

As part of this commit, the handling of response objects has been
moved into the serverreactor class. This puts the reactor in the
driver's seat with regards to CBOR encoding and error handling.
Having error handling in the function that emits frames is
particularly important because exceptions in that function can lead
to things getting in a bad state: I'm fairly certain that uncaught
exceptions in the frame generator were causing deadlocks.

I also introduced a dedicated error type for explicit error reporting
in command handlers. This will be used in subsequent commits.

There's still a bit of work to be done here, especially around
formalizing the error handling "protocol." I've added yet another
TODO to track this so we don't forget.

Test output changed because we're using generators and no longer know
we are at the end of the data until we hit the end of the generator.
This means we can't emit the end-of-stream flag until we've exhausted
the generator. Hence the introduction of 0-sized end-of-stream frames.

Differential Revision: https://phab.mercurial-scm.org/D4472

# hgweb/hgwebdir_mod.py - Web interface for a directory of repositories.
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
# Copyright 2005, 2006 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.

from __future__ import absolute_import

import gc
import os
import time

from ..i18n import _

from .common import (
    ErrorResponse,
    HTTP_SERVER_ERROR,
    cspvalues,
    get_contact,
    get_mtime,
    ismember,
    paritygen,
    staticfile,
    statusmessage,
)

from .. import (
    configitems,
    encoding,
    error,
    hg,
    profiling,
    pycompat,
    registrar,
    scmutil,
    templater,
    templateutil,
    ui as uimod,
    util,
)

from . import (
    hgweb_mod,
    request as requestmod,
    webutil,
    wsgicgi,
)
from ..utils import dateutil

def cleannames(items):
    return [(util.pconvert(name).strip('/'), path) for name, path in items]

def findrepos(paths):
    repos = []
    for prefix, root in cleannames(paths):
        roothead, roottail = os.path.split(root)
        # "foo = /bar/*" or "foo = /bar/**" lets every repo /bar/N in or below
        # /bar/ be served as as foo/N .
        # '*' will not search inside dirs with .hg (except .hg/patches),
        # '**' will search inside dirs with .hg (and thus also find subrepos).
        try:
            recurse = {'*': False, '**': True}[roottail]
        except KeyError:
            repos.append((prefix, root))
            continue
        roothead = os.path.normpath(os.path.abspath(roothead))
        paths = scmutil.walkrepos(roothead, followsym=True, recurse=recurse)
        repos.extend(urlrepos(prefix, roothead, paths))
    return repos

def urlrepos(prefix, roothead, paths):
    """yield url paths and filesystem paths from a list of repo paths

    >>> conv = lambda seq: [(v, util.pconvert(p)) for v,p in seq]
    >>> conv(urlrepos(b'hg', b'/opt', [b'/opt/r', b'/opt/r/r', b'/opt']))
    [('hg/r', '/opt/r'), ('hg/r/r', '/opt/r/r'), ('hg', '/opt')]
    >>> conv(urlrepos(b'', b'/opt', [b'/opt/r', b'/opt/r/r', b'/opt']))
    [('r', '/opt/r'), ('r/r', '/opt/r/r'), ('', '/opt')]
    """
    for path in paths:
        path = os.path.normpath(path)
        yield (prefix + '/' +
               util.pconvert(path[len(roothead):]).lstrip('/')).strip('/'), path

def readallowed(ui, req):
    """Check allow_read and deny_read config options of a repo's ui object
    to determine user permissions.  By default, with neither option set (or
    both empty), allow all users to read the repo.  There are two ways a
    user can be denied read access:  (1) deny_read is not empty, and the
    user is unauthenticated or deny_read contains user (or *), and (2)
    allow_read is not empty and the user is not in allow_read.  Return True
    if user is allowed to read the repo, else return False."""

    user = req.remoteuser

    deny_read = ui.configlist('web', 'deny_read', untrusted=True)
    if deny_read and (not user or ismember(ui, user, deny_read)):
        return False

    allow_read = ui.configlist('web', 'allow_read', untrusted=True)
    # by default, allow reading if no allow_read option has been set
    if not allow_read or ismember(ui, user, allow_read):
        return True

    return False

def rawindexentries(ui, repos, req, subdir=''):
    descend = ui.configbool('web', 'descend')
    collapse = ui.configbool('web', 'collapse')
    seenrepos = set()
    seendirs = set()
    for name, path in repos:

        if not name.startswith(subdir):
            continue
        name = name[len(subdir):]
        directory = False

        if '/' in name:
            if not descend:
                continue

            nameparts = name.split('/')
            rootname = nameparts[0]

            if not collapse:
                pass
            elif rootname in seendirs:
                continue
            elif rootname in seenrepos:
                pass
            else:
                directory = True
                name = rootname

                # redefine the path to refer to the directory
                discarded = '/'.join(nameparts[1:])

                # remove name parts plus accompanying slash
                path = path[:-len(discarded) - 1]

                try:
                    r = hg.repository(ui, path)
                    directory = False
                except (IOError, error.RepoError):
                    pass

        parts = [
            req.apppath.strip('/'),
            subdir.strip('/'),
            name.strip('/'),
        ]
        url = '/' + '/'.join(p for p in parts if p) + '/'

        # show either a directory entry or a repository
        if directory:
            # get the directory's time information
            try:
                d = (get_mtime(path), dateutil.makedate()[1])
            except OSError:
                continue

            # add '/' to the name to make it obvious that
            # the entry is a directory, not a regular repository
            row = {'contact': "",
                   'contact_sort': "",
                   'name': name + '/',
                   'name_sort': name,
                   'url': url,
                   'description': "",
                   'description_sort': "",
                   'lastchange': d,
                   'lastchange_sort': d[1] - d[0],
                   'archives': templateutil.mappinglist([]),
                   'isdirectory': True,
                   'labels': templateutil.hybridlist([], name='label'),
                   }

            seendirs.add(name)
            yield row
            continue

        u = ui.copy()
        try:
            u.readconfig(os.path.join(path, '.hg', 'hgrc'))
        except Exception as e:
            u.warn(_('error reading %s/.hg/hgrc: %s\n') % (path, e))
            continue

        def get(section, name, default=uimod._unset):
            return u.config(section, name, default, untrusted=True)

        if u.configbool("web", "hidden", untrusted=True):
            continue

        if not readallowed(u, req):
            continue

        # update time with local timezone
        try:
            r = hg.repository(ui, path)
        except IOError:
            u.warn(_('error accessing repository at %s\n') % path)
            continue
        except error.RepoError:
            u.warn(_('error accessing repository at %s\n') % path)
            continue
        try:
            d = (get_mtime(r.spath), dateutil.makedate()[1])
        except OSError:
            continue

        contact = get_contact(get)
        description = get("web", "description")
        seenrepos.add(name)
        name = get("web", "name", name)
        labels = u.configlist('web', 'labels', untrusted=True)
        row = {'contact': contact or "unknown",
               'contact_sort': contact.upper() or "unknown",
               'name': name,
               'name_sort': name,
               'url': url,
               'description': description or "unknown",
               'description_sort': description.upper() or "unknown",
               'lastchange': d,
               'lastchange_sort': d[1] - d[0],
               'archives': webutil.archivelist(u, "tip", url),
               'isdirectory': None,
               'labels': templateutil.hybridlist(labels, name='label'),
               }

        yield row

def _indexentriesgen(context, ui, repos, req, stripecount, sortcolumn,
                     descending, subdir):
    rows = rawindexentries(ui, repos, req, subdir=subdir)

    sortdefault = None, False

    if sortcolumn and sortdefault != (sortcolumn, descending):
        sortkey = '%s_sort' % sortcolumn
        rows = sorted(rows, key=lambda x: x[sortkey],
                      reverse=descending)

    for row, parity in zip(rows, paritygen(stripecount)):
        row['parity'] = parity
        yield row

def indexentries(ui, repos, req, stripecount, sortcolumn='',
                 descending=False, subdir=''):
    args = (ui, repos, req, stripecount, sortcolumn, descending, subdir)
    return templateutil.mappinggenerator(_indexentriesgen, args=args)

class hgwebdir(object):
    """HTTP server for multiple repositories.

    Given a configuration, different repositories will be served depending
    on the request path.

    Instances are typically used as WSGI applications.
    """
    def __init__(self, conf, baseui=None):
        self.conf = conf
        self.baseui = baseui
        self.ui = None
        self.lastrefresh = 0
        self.motd = None
        self.refresh()

    def refresh(self):
        if self.ui:
            refreshinterval = self.ui.configint('web', 'refreshinterval')
        else:
            item = configitems.coreitems['web']['refreshinterval']
            refreshinterval = item.default

        # refreshinterval <= 0 means to always refresh.
        if (refreshinterval > 0 and
            self.lastrefresh + refreshinterval > time.time()):
            return

        if self.baseui:
            u = self.baseui.copy()
        else:
            u = uimod.ui.load()
            u.setconfig('ui', 'report_untrusted', 'off', 'hgwebdir')
            u.setconfig('ui', 'nontty', 'true', 'hgwebdir')
            # displaying bundling progress bar while serving feels wrong and may
            # break some wsgi implementations.
            u.setconfig('progress', 'disable', 'true', 'hgweb')

        if not isinstance(self.conf, (dict, list, tuple)):
            map = {'paths': 'hgweb-paths'}
            if not os.path.exists(self.conf):
                raise error.Abort(_('config file %s not found!') % self.conf)
            u.readconfig(self.conf, remap=map, trust=True)
            paths = []
            for name, ignored in u.configitems('hgweb-paths'):
                for path in u.configlist('hgweb-paths', name):
                    paths.append((name, path))
        elif isinstance(self.conf, (list, tuple)):
            paths = self.conf
        elif isinstance(self.conf, dict):
            paths = self.conf.items()

        repos = findrepos(paths)
        for prefix, root in u.configitems('collections'):
            prefix = util.pconvert(prefix)
            for path in scmutil.walkrepos(root, followsym=True):
                repo = os.path.normpath(path)
                name = util.pconvert(repo)
                if name.startswith(prefix):
                    name = name[len(prefix):]
                repos.append((name.lstrip('/'), repo))

        self.repos = repos
        self.ui = u
        encoding.encoding = self.ui.config('web', 'encoding')
        self.style = self.ui.config('web', 'style')
        self.templatepath = self.ui.config('web', 'templates', untrusted=False)
        self.stripecount = self.ui.config('web', 'stripes')
        if self.stripecount:
            self.stripecount = int(self.stripecount)
        prefix = self.ui.config('web', 'prefix')
        if prefix.startswith('/'):
            prefix = prefix[1:]
        if prefix.endswith('/'):
            prefix = prefix[:-1]
        self.prefix = prefix
        self.lastrefresh = time.time()

    def run(self):
        if not encoding.environ.get('GATEWAY_INTERFACE',
                                    '').startswith("CGI/1."):
            raise RuntimeError("This function is only intended to be "
                               "called while running as a CGI script.")
        wsgicgi.launch(self)

    def __call__(self, env, respond):
        baseurl = self.ui.config('web', 'baseurl')
        req = requestmod.parserequestfromenv(env, altbaseurl=baseurl)
        res = requestmod.wsgiresponse(req, respond)

        return self.run_wsgi(req, res)

    def run_wsgi(self, req, res):
        profile = self.ui.configbool('profiling', 'enabled')
        with profiling.profile(self.ui, enabled=profile):
            try:
                for r in self._runwsgi(req, res):
                    yield r
            finally:
                # There are known cycles in localrepository that prevent
                # those objects (and tons of held references) from being
                # collected through normal refcounting. We mitigate those
                # leaks by performing an explicit GC on every request.
                # TODO remove this once leaks are fixed.
                # TODO only run this on requests that create localrepository
                # instances instead of every request.
                gc.collect()

    def _runwsgi(self, req, res):
        try:
            self.refresh()

            csp, nonce = cspvalues(self.ui)
            if csp:
                res.headers['Content-Security-Policy'] = csp

            virtual = req.dispatchpath.strip('/')
            tmpl = self.templater(req, nonce)
            ctype = tmpl.render('mimetype', {'encoding': encoding.encoding})

            # Global defaults. These can be overridden by any handler.
            res.status = '200 Script output follows'
            res.headers['Content-Type'] = ctype

            # a static file
            if virtual.startswith('static/') or 'static' in req.qsparams:
                if virtual.startswith('static/'):
                    fname = virtual[7:]
                else:
                    fname = req.qsparams['static']
                static = self.ui.config("web", "static", None,
                                        untrusted=False)
                if not static:
                    tp = self.templatepath or templater.templatepaths()
                    if isinstance(tp, str):
                        tp = [tp]
                    static = [os.path.join(p, 'static') for p in tp]

                staticfile(static, fname, res)
                return res.sendresponse()

            # top-level index

            repos = dict(self.repos)

            if (not virtual or virtual == 'index') and virtual not in repos:
                return self.makeindex(req, res, tmpl)

            # nested indexes and hgwebs

            if virtual.endswith('/index') and virtual not in repos:
                subdir = virtual[:-len('index')]
                if any(r.startswith(subdir) for r in repos):
                    return self.makeindex(req, res, tmpl, subdir)

            def _virtualdirs():
                # Check the full virtual path, each parent, and the root ('')
                if virtual != '':
                    yield virtual

                    for p in util.finddirs(virtual):
                        yield p

                yield ''

            for virtualrepo in _virtualdirs():
                real = repos.get(virtualrepo)
                if real:
                    # Re-parse the WSGI environment to take into account our
                    # repository path component.
                    uenv = req.rawenv
                    if pycompat.ispy3:
                        uenv = {k.decode('latin1'): v for k, v in
                                uenv.iteritems()}
                    req = requestmod.parserequestfromenv(
                        uenv, reponame=virtualrepo,
                        altbaseurl=self.ui.config('web', 'baseurl'),
                        # Reuse wrapped body file object otherwise state
                        # tracking can get confused.
                        bodyfh=req.bodyfh)
                    try:
                        # ensure caller gets private copy of ui
                        repo = hg.repository(self.ui.copy(), real)
                        return hgweb_mod.hgweb(repo).run_wsgi(req, res)
                    except IOError as inst:
                        msg = encoding.strtolocal(inst.strerror)
                        raise ErrorResponse(HTTP_SERVER_ERROR, msg)
                    except error.RepoError as inst:
                        raise ErrorResponse(HTTP_SERVER_ERROR, bytes(inst))

            # browse subdirectories
            subdir = virtual + '/'
            if [r for r in repos if r.startswith(subdir)]:
                return self.makeindex(req, res, tmpl, subdir)

            # prefixes not found
            res.status = '404 Not Found'
            res.setbodygen(tmpl.generate('notfound', {'repo': virtual}))
            return res.sendresponse()

        except ErrorResponse as e:
            res.status = statusmessage(e.code, pycompat.bytestr(e))
            res.setbodygen(tmpl.generate('error', {'error': e.message or ''}))
            return res.sendresponse()
        finally:
            tmpl = None

    def makeindex(self, req, res, tmpl, subdir=""):
        self.refresh()
        sortable = ["name", "description", "contact", "lastchange"]
        sortcolumn, descending = None, False
        if 'sort' in req.qsparams:
            sortcolumn = req.qsparams['sort']
            descending = sortcolumn.startswith('-')
            if descending:
                sortcolumn = sortcolumn[1:]
            if sortcolumn not in sortable:
                sortcolumn = ""

        sort = [("sort_%s" % column,
                 "%s%s" % ((not descending and column == sortcolumn)
                            and "-" or "", column))
                for column in sortable]

        self.refresh()

        entries = indexentries(self.ui, self.repos, req,
                               self.stripecount, sortcolumn=sortcolumn,
                               descending=descending, subdir=subdir)

        mapping = {
            'entries': entries,
            'subdir': subdir,
            'pathdef': hgweb_mod.makebreadcrumb('/' + subdir, self.prefix),
            'sortcolumn': sortcolumn,
            'descending': descending,
        }
        mapping.update(sort)
        res.setbodygen(tmpl.generate('index', mapping))
        return res.sendresponse()

    def templater(self, req, nonce):

        def config(section, name, default=uimod._unset, untrusted=True):
            return self.ui.config(section, name, default, untrusted)

        vars = {}
        styles, (style, mapfile) = hgweb_mod.getstyle(req, config,
                                                      self.templatepath)
        if style == styles[0]:
            vars['style'] = style

        sessionvars = webutil.sessionvars(vars, r'?')
        logourl = config('web', 'logourl')
        logoimg = config('web', 'logoimg')
        staticurl = (config('web', 'staticurl')
                     or req.apppath.rstrip('/') + '/static/')
        if not staticurl.endswith('/'):
            staticurl += '/'

        defaults = {
            "encoding": encoding.encoding,
            "url": req.apppath + '/',
            "logourl": logourl,
            "logoimg": logoimg,
            "staticurl": staticurl,
            "sessionvars": sessionvars,
            "style": style,
            "nonce": nonce,
        }
        templatekeyword = registrar.templatekeyword(defaults)
        @templatekeyword('motd', requires=())
        def motd(context, mapping):
            if self.motd is not None:
                yield self.motd
            else:
                yield config('web', 'motd')

        tmpl = templater.templater.frommapfile(mapfile, defaults=defaults)
        return tmpl