# 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.

If you want to record whether the repository is dirty (a `+` sign, as you'd

get when using :hg:`id`), you can set the blackbox.dirty config key.

Examples::

  [blackbox]

  track = *

  dirty = 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 (

    cmdutil,

    util,

)

cmdtable = {}

command = cmdutil.command(cmdtable)

# Note for extension authors: ONLY specify testedwith = 'internal' 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 = 'internal'

lastui = None

filehandles = {}

def _openlog(vfs):

    path = vfs.join('blackbox.log')

    if path in filehandles:

        return filehandles[path]

    filehandles[path] = fp = vfs('blackbox.log', 'a')

    return fp

def _closelog(vfs):

    path = vfs.join('blackbox.log')

    fp = filehandles[path]

    del filehandles[path]

    fp.close()

def hexfn(node):

    if node is None:

        return None

    else:

        return hex(node)

def wrapui(ui):

    class blackboxui(ui.__class__):

        @util.propertycache

        def track(self):

            return self.configlist('blackbox', 'track', ['*'])

        def _openlogfile(self):

            def rotate(oldpath, newpath):

                try:

                    self._bbvfs.unlink(newpath)

                except OSError as err:

                    if err.errno != errno.ENOENT:

                        self.debug("warning: cannot remove '%s': %s\n" %

                                   (newpath, err.strerror))

                try:

                    if newpath:

                        self._bbvfs.rename(oldpath, newpath)

                except OSError as err:

                    if err.errno != errno.ENOENT:

                        self.debug("warning: cannot rename '%s' to '%s': %s\n" %

                                   (newpath, oldpath, err.strerror))

            fp = _openlog(self._bbvfs)

            maxsize = self.configbytes('blackbox', 'maxsize', 1048576)

            if maxsize > 0:

                st = self._bbvfs.fstat(fp)

                if st.st_size >= maxsize:

                    path = fp.name

                    _closelog(self._bbvfs)

                    maxfiles = self.configint('blackbox', 'maxfiles', 7)

                    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')

                    fp = _openlog(self._bbvfs)

            return fp

        def _bbwrite(self, fmt, *args):

            self._bbfp.write(fmt % args)

            self._bbfp.flush()

        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

                ui = self

                try:

                    self._bbfp = self._openlogfile()

                except (IOError, OSError) as err:

                    self.debug('warning: cannot write to blackbox.log: %s\n' %

                               err.strerror)

                    del self._bbvfs

                    self._bbfp = None

                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

                date = util.datestr(None, '%Y/%m/%d %H:%M:%S')

                user = util.getuser()

                pid = str(util.getpid())

                formattedmsg = msg[0] % msg[1:]

                rev = '(unknown)'

                changed = ''

                    ctx = ui._bbrepo[None]

                    if ctx.rev() is not None:

                        rev = hexfn(ctx.node())

                    else:

                        parents = ctx.parents()

                        rev = ('+'.join([hexfn(p.node()) for p in parents]))

                        if (ui.configbool('blackbox', 'dirty', False) and (

                            any(ui._bbrepo.status()) or

                            any(ctx.sub(s).dirty() for s in ctx.substate)

                        )):

                            changed = '+'

                try:

                    ui._bbwrite('%s %s @%s%s (%s)> %s',

                        date, user, rev, changed, pid, formattedmsg)

                except IOError as err:

                    self.debug('warning: cannot write to blackbox.log: %s\n' %

                               err.strerror)

                    lastui = ui

        def setrepo(self, repo):

            self._bbvfs = repo.vfs

    ui.__class__ = 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)

@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('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)))