view hgext/blackbox.py @ 36858:01f6bba64424

hgweb: remove support for POST form data (BC)

Previously, we called out to cgi.parse(), which for POST requests
parsed multipart/form-data and application/x-www-form-urlencoded
Content-Type requests for form data, combined it with query string
parameters, returned a union of the values.

As far as I know, nothing in Mercurial actually uses this mechanism
to submit data to the HTTP server. The wire protocol has its own
mechanism for passing parameters. And the web interface only does
GET requests. Removing support for parsing POST data doesn't break
any tests.

Another reason to not like this feature is that cgi.parse() may
modify the QUERY_STRING environment variable as a side-effect.
In addition, it merges both POST data and the query string into
one data structure. This prevents consumers from knowing whether
a variable came from the query string or POST data. That can matter
for some operations.

I suspect we use cgi.parse() because back when this code was
initially implemented, it was the function that was readily
available. In other words, I don't think there was conscious
choice to support POST data: we just got it because cgi.parse()
supported it.

Since nothing uses the feature and it is untested, let's remove
support for parsing POST form data. We can add it back in easily
enough if we need it in the future.

.. bc::

   Hgweb no longer reads form data in POST requests from
   multipart/form-data and application/x-www-form-urlencoded
   requests. Arguments should be specified as URL path components
   or in the query string in the URL instead.

Differential Revision: https://phab.mercurial-scm.org/D2774

# blackbox.py - log repository events to a file for post-mortem debugging
#
# Copyright 2010 Nicolas Dumazet
# 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.

"""log repository events to a blackbox for debugging

Logs event information to .hg/blackbox.log to help debug and diagnose problems.
The events that get logged can be configured via the blackbox.track config key.

Examples::

  [blackbox]
  track = *
  # dirty is *EXPENSIVE* (slow);
  # each log entry indicates `+` if the repository is dirty, like :hg:`id`.
  dirty = True
  # record the source of log messages
  logsource = True

  [blackbox]
  track = command, commandfinish, commandexception, exthook, pythonhook

  [blackbox]
  track = incoming

  [blackbox]
  # limit the size of a log file
  maxsize = 1.5 MB
  # rotate up to N log files when the current one gets too big
  maxfiles = 3

"""

from __future__ import absolute_import

import errno
import re

from mercurial.i18n import _
from mercurial.node import hex

from mercurial import (
    encoding,
    registrar,
    ui as uimod,
    util,
)
from mercurial.utils import dateutil

# 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'

cmdtable = {}
command = registrar.command(cmdtable)

configtable = {}
configitem = registrar.configitem(configtable)

configitem('blackbox', 'dirty',
    default=False,
)
configitem('blackbox', 'maxsize',
    default='1 MB',
)
configitem('blackbox', 'logsource',
    default=False,
)
configitem('blackbox', 'maxfiles',
    default=7,
)
configitem('blackbox', 'track',
    default=lambda: ['*'],
)

lastui = None

def _openlogfile(ui, vfs):
    def rotate(oldpath, newpath):
        try:
            vfs.unlink(newpath)
        except OSError as err:
            if err.errno != errno.ENOENT:
                ui.debug("warning: cannot remove '%s': %s\n" %
                         (newpath, err.strerror))
        try:
            if newpath:
                vfs.rename(oldpath, newpath)
        except OSError as err:
            if err.errno != errno.ENOENT:
                ui.debug("warning: cannot rename '%s' to '%s': %s\n" %
                         (newpath, oldpath, err.strerror))

    maxsize = ui.configbytes('blackbox', 'maxsize')
    name = 'blackbox.log'
    if maxsize > 0:
        try:
            st = vfs.stat(name)
        except OSError:
            pass
        else:
            if st.st_size >= maxsize:
                path = vfs.join(name)
                maxfiles = ui.configint('blackbox', 'maxfiles')
                for i in xrange(maxfiles - 1, 1, -1):
                    rotate(oldpath='%s.%d' % (path, i - 1),
                           newpath='%s.%d' % (path, i))
                rotate(oldpath=path,
                       newpath=maxfiles > 0 and path + '.1')
    return vfs(name, 'a')

def wrapui(ui):
    class blackboxui(ui.__class__):
        @property
        def _bbvfs(self):
            vfs = None
            repo = getattr(self, '_bbrepo', None)
            if repo:
                vfs = repo.vfs
                if not vfs.isdir('.'):
                    vfs = None
            return vfs

        @util.propertycache
        def track(self):
            return self.configlist('blackbox', 'track')

        def debug(self, *msg, **opts):
            super(blackboxui, self).debug(*msg, **opts)
            if self.debugflag:
                self.log('debug', '%s', ''.join(msg))

        def log(self, event, *msg, **opts):
            global lastui
            super(blackboxui, self).log(event, *msg, **opts)

            if not '*' in self.track and not event in self.track:
                return

            if self._bbvfs:
                ui = self
            else:
                # certain ui instances exist outside the context of
                # a repo, so just default to the last blackbox that
                # was seen.
                ui = lastui

            if not ui:
                return
            vfs = ui._bbvfs
            if not vfs:
                return

            repo = getattr(ui, '_bbrepo', None)
            if not lastui or repo:
                lastui = ui
            if getattr(ui, '_bbinlog', False):
                # recursion and failure guard
                return
            ui._bbinlog = True
            default = self.configdate('devel', 'default-date')
            date = dateutil.datestr(default, '%Y/%m/%d %H:%M:%S')
            user = util.getuser()
            pid = '%d' % util.getpid()
            formattedmsg = msg[0] % msg[1:]
            rev = '(unknown)'
            changed = ''
            if repo:
                ctx = repo[None]
                parents = ctx.parents()
                rev = ('+'.join([hex(p.node()) for p in parents]))
                if (ui.configbool('blackbox', 'dirty') and
                    ctx.dirty(missing=True, merge=False, branch=False)):
                    changed = '+'
            if ui.configbool('blackbox', 'logsource'):
                src = ' [%s]' % event
            else:
                src = ''
            try:
                fmt = '%s %s @%s%s (%s)%s> %s'
                args = (date, user, rev, changed, pid, src, formattedmsg)
                with _openlogfile(ui, vfs) as fp:
                    fp.write(fmt % args)
            except (IOError, OSError) as err:
                self.debug('warning: cannot write to blackbox.log: %s\n' %
                           encoding.strtolocal(err.strerror))
                # do not restore _bbinlog intentionally to avoid failed
                # logging again
            else:
                ui._bbinlog = False

        def setrepo(self, repo):
            self._bbrepo = repo

    ui.__class__ = blackboxui
    uimod.ui = blackboxui

def uisetup(ui):
    wrapui(ui)

def reposetup(ui, repo):
    # During 'hg pull' a httppeer repo is created to represent the remote repo.
    # It doesn't have a .hg directory to put a blackbox in, so we don't do
    # the blackbox setup for it.
    if not repo.local():
        return

    if util.safehasattr(ui, 'setrepo'):
        ui.setrepo(repo)

        # Set lastui even if ui.log is not called. This gives blackbox a
        # fallback place to log.
        global lastui
        if lastui is None:
            lastui = ui

    repo._wlockfreeprefix.add('blackbox.log')

@command('^blackbox',
    [('l', 'limit', 10, _('the number of events to show')),
    ],
    _('hg blackbox [OPTION]...'))
def blackbox(ui, repo, *revs, **opts):
    '''view the recent repository events
    '''

    if not repo.vfs.exists('blackbox.log'):
        return

    limit = opts.get(r'limit')
    fp = repo.vfs('blackbox.log', 'r')
    lines = fp.read().split('\n')

    count = 0
    output = []
    for line in reversed(lines):
        if count >= limit:
            break

        # count the commands by matching lines like: 2013/01/23 19:13:36 root>
        if re.match('^\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} .*> .*', line):
            count += 1
        output.append(line)

    ui.status('\n'.join(reversed(output)))