# Copyright 2001-2007 by Vinay Sajip. All Rights Reserved.

#

# Permission to use, copy, modify, and distribute this software and its

# documentation for any purpose and without fee is hereby granted,

# provided that the above copyright notice appear in all copies and that

# both that copyright notice and this permission notice appear in

# supporting documentation, and that the name of Vinay Sajip

# not be used in advertising or publicity pertaining to distribution

# of the software without specific, written prior permission.

# VINAY SAJIP DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING

# ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL

# VINAY SAJIP BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR

# ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER

# IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT

# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

"""

Additional handlers for the logging package for Python. The core package is

based on PEP 282 and comments thereto in comp.lang.python, and influenced by

Apache's log4j system.

Should work under Python versions >= 1.5.2, except that source line

information is not available unless 'sys._getframe()' is.

Copyright (C) 2001-2008 Vinay Sajip. All Rights Reserved.

To use, simply 'import logging' and log away!

"""

import logging, socket, types, os, string, cPickle, struct, time, re

from stat import ST_DEV, ST_INO

try:

    import codecs

except ImportError:

    codecs = None

#

# Some constants...

#

DEFAULT_TCP_LOGGING_PORT    = 9020

DEFAULT_UDP_LOGGING_PORT    = 9021

DEFAULT_HTTP_LOGGING_PORT   = 9022

DEFAULT_SOAP_LOGGING_PORT   = 9023

SYSLOG_UDP_PORT             = 514

_MIDNIGHT = 24 * 60 * 60  # number of seconds in a day

class BaseRotatingHandler(logging.FileHandler):

    """

    Base class for handlers that rotate log files at a certain point.

    Not meant to be instantiated directly.  Instead, use RotatingFileHandler

    or TimedRotatingFileHandler.

    """

    def __init__(self, filename, mode, encoding=None, delay=0):

        """

        Use the specified filename for streamed logging

        """

        if codecs is None:

            encoding = None

        logging.FileHandler.__init__(self, filename, mode, encoding, delay)

        self.mode = mode

        self.encoding = encoding

    def emit(self, record):

        """

        Emit a record.

        Output the record to the file, catering for rollover as described

        in doRollover().

        """

        try:

            if self.shouldRollover(record):

                self.doRollover()

            logging.FileHandler.emit(self, record)

        except (KeyboardInterrupt, SystemExit):

            raise

        except:

            self.handleError(record)

class RotatingFileHandler(BaseRotatingHandler):

    """

    Handler for logging to a set of files, which switches from one file

    to the next when the current file reaches a certain size.

    """

    def __init__(self, filename, mode='a', maxBytes=0, backupCount=0, encoding=None, delay=0):

        """

        Open the specified file and use it as the stream for logging.

        By default, the file grows indefinitely. You can specify particular

        values of maxBytes and backupCount to allow the file to rollover at

        a predetermined size.

        Rollover occurs whenever the current log file is nearly maxBytes in

        length. If backupCount is >= 1, the system will successively create

        new files with the same pathname as the base file, but with extensions

        ".1", ".2" etc. appended to it. For example, with a backupCount of 5

        and a base file name of "app.log", you would get "app.log",

        "app.log.1", "app.log.2", ... through to "app.log.5". The file being

        written to is always "app.log" - when it gets filled up, it is closed

        and renamed to "app.log.1", and if files "app.log.1", "app.log.2" etc.

        exist, then they are renamed to "app.log.2", "app.log.3" etc.

        respectively.

        If maxBytes is zero, rollover never occurs.

        """

        if maxBytes > 0:

            mode = 'a' # doesn't make sense otherwise!

        BaseRotatingHandler.__init__(self, filename, mode, encoding, delay)

        self.maxBytes = maxBytes

        self.backupCount = backupCount

    def doRollover(self):

        """

        Do a rollover, as described in __init__().

        """

        self.stream.close()

        if self.backupCount > 0:

            for i in range(self.backupCount - 1, 0, -1):

                sfn = "%s.%d" % (self.baseFilename, i)

                dfn = "%s.%d" % (self.baseFilename, i + 1)

                if os.path.exists(sfn):

                    #print "%s -> %s" % (sfn, dfn)

                    if os.path.exists(dfn):

                        os.remove(dfn)

                    os.rename(sfn, dfn)

            dfn = self.baseFilename + ".1"

            if os.path.exists(dfn):

                os.remove(dfn)

            os.rename(self.baseFilename, dfn)

            #print "%s -> %s" % (self.baseFilename, dfn)

        self.mode = 'w'

        self.stream = self._open()

    def shouldRollover(self, record):

        """

        Determine if rollover should occur.

        Basically, see if the supplied record would cause the file to exceed

        the size limit we have.

        """

        if self.maxBytes > 0:                   # are we rolling over?

            msg = "%s\n" % self.format(record)

            self.stream.seek(0, 2)  #due to non-posix-compliant Windows feature

            if self.stream.tell() + len(msg) >= self.maxBytes:

                return 1

        return 0

class TimedRotatingFileHandler(BaseRotatingHandler):

    """

    Handler for logging to a file, rotating the log file at certain timed

    intervals.

    If backupCount is > 0, when rollover is done, no more than backupCount

    files are kept - the oldest ones are deleted.

    """

    def __init__(self, filename, when='h', interval=1, backupCount=0, encoding=None, delay=0, utc=0):

        BaseRotatingHandler.__init__(self, filename, 'a', encoding, delay)

        self.when = string.upper(when)

        self.backupCount = backupCount

        self.utc = utc

        # Calculate the real rollover interval, which is just the number of

        # seconds between rollovers.  Also set the filename suffix used when

        # a rollover occurs.  Current 'when' events supported:

        # S - Seconds

        # M - Minutes

        # H - Hours

        # D - Days

        # midnight - roll over at midnight

        # W{0-6} - roll over on a certain day; 0 - Monday

        #

        # Case of the 'when' specifier is not important; lower or upper case

        # will work.

        currentTime = int(time.time())

        if self.when == 'S':

            self.interval = 1 # one second

            self.suffix = "%Y-%m-%d_%H-%M-%S"

            self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}-\d{2}$"

        elif self.when == 'M':

            self.interval = 60 # one minute

            self.suffix = "%Y-%m-%d_%H-%M"

            self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}-\d{2}$"

        elif self.when == 'H':

            self.interval = 60 * 60 # one hour

            self.suffix = "%Y-%m-%d_%H"

            self.extMatch = r"^\d{4}-\d{2}-\d{2}_\d{2}$"

        elif self.when == 'D' or self.when == 'MIDNIGHT':

            self.interval = 60 * 60 * 24 # one day

            self.suffix = "%Y-%m-%d"

            self.extMatch = r"^\d{4}-\d{2}-\d{2}$"

        elif self.when.startswith('W'):

            self.interval = 60 * 60 * 24 * 7 # one week

            if len(self.when) != 2:

                raise ValueError("You must specify a day for weekly rollover from 0 to 6 (0 is Monday): %s" % self.when)

            if self.when[1] < '0' or self.when[1] > '6':

                raise ValueError("Invalid day specified for weekly rollover: %s" % self.when)

            self.dayOfWeek = int(self.when[1])

            self.suffix = "%Y-%m-%d"

            self.extMatch = r"^\d{4}-\d{2}-\d{2}$"

        else:

            raise ValueError("Invalid rollover interval specified: %s" % self.when)

        self.extMatch = re.compile(self.extMatch)

        self.interval = self.interval * interval # multiply by units requested

        self.rolloverAt = currentTime + self.interval

        # If we are rolling over at midnight or weekly, then the interval is already known.

        # What we need to figure out is WHEN the next interval is.  In other words,

        # if you are rolling over at midnight, then your base interval is 1 day,

        # but you want to start that one day clock at midnight, not now.  So, we

        # have to fudge the rolloverAt value in order to trigger the first rollover

        # at the right time.  After that, the regular interval will take care of

        # the rest.  Note that this code doesn't care about leap seconds. :)

        if self.when == 'MIDNIGHT' or self.when.startswith('W'):

            # This could be done with less code, but I wanted it to be clear

            if utc:

                t = time.gmtime(currentTime)

            else:

                t = time.localtime(currentTime)

            currentHour = t[3]

            currentMinute = t[4]

            currentSecond = t[5]

            # r is the number of seconds left between now and midnight

            r = _MIDNIGHT - ((currentHour * 60 + currentMinute) * 60 +

                    currentSecond)

            self.rolloverAt = currentTime + r

            # If we are rolling over on a certain day, add in the number of days until

            # the next rollover, but offset by 1 since we just calculated the time

            # until the next day starts.  There are three cases:

            # Case 1) The day to rollover is today; in this case, do nothing

            # Case 2) The day to rollover is further in the interval (i.e., today is

            #         day 2 (Wednesday) and rollover is on day 6 (Sunday).  Days to

            #         next rollover is simply 6 - 2 - 1, or 3.

            # Case 3) The day to rollover is behind us in the interval (i.e., today

            #         is day 5 (Saturday) and rollover is on day 3 (Thursday).

            #         Days to rollover is 6 - 5 + 3, or 4.  In this case, it's the

            #         number of days left in the current week (1) plus the number

            #         of days in the next week until the rollover day (3).

            # The calculations described in 2) and 3) above need to have a day added.

            # This is because the above time calculation takes us to midnight on this

            # day, i.e. the start of the next day.

            if when.startswith('W'):

                day = t[6] # 0 is Monday

                if day != self.dayOfWeek:

                    if day < self.dayOfWeek:

                        daysToWait = self.dayOfWeek - day

                    else:

                        daysToWait = 6 - day + self.dayOfWeek + 1

                    newRolloverAt = self.rolloverAt + (daysToWait * (60 * 60 * 24))

                    if not utc:

                        dstNow = t[-1]

                        dstAtRollover = time.localtime(newRolloverAt)[-1]

                        if dstNow != dstAtRollover:

                            if not dstNow:  # DST kicks in before next rollover, so we need to deduct an hour

                                newRolloverAt = newRolloverAt - 3600

                            else:           # DST bows out before next rollover, so we need to add an hour

                                newRolloverAt = newRolloverAt + 3600

                    self.rolloverAt = newRolloverAt

        #print "Will rollover at %d, %d seconds from now" % (self.rolloverAt, self.rolloverAt - currentTime)

    def shouldRollover(self, record):

        """

        Determine if rollover should occur.

        record is not used, as we are just comparing times, but it is needed so

        the method signatures are the same

        """

        t = int(time.time())

        if t >= self.rolloverAt:

            return 1

        #print "No need to rollover: %d, %d" % (t, self.rolloverAt)

        return 0

    def getFilesToDelete(self):

        """

        Determine the files to delete when rolling over.

        More specific than the earlier method, which just used glob.glob().

        """

        dirName, baseName = os.path.split(self.baseFilename)

        fileNames = os.listdir(dirName)

        result = []

        prefix = baseName + "."

        plen = len(prefix)

        for fileName in fileNames:

            if fileName[:plen] == prefix:

                suffix = fileName[plen:]

                if self.extMatch.match(suffix):

                    result.append(os.path.join(dirName, fileName))

        result.sort()

        if len(result) < self.backupCount:

            result = []

        else:

            result = result[:len(result) - self.backupCount]

        return result

    def doRollover(self):

        """

        do a rollover; in this case, a date/time stamp is appended to the filename

        when the rollover happens.  However, you want the file to be named for the

        start of the interval, not the current time.  If there is a backup count,

        then we have to get a list of matching filenames, sort them and remove

        the one with the oldest suffix.

        """

        self.stream.close()

        # get the time that this sequence started at and make it a TimeTuple

        t = self.rolloverAt - self.interval

        if self.utc:

            timeTuple = time.gmtime(t)

        else:

            timeTuple = time.localtime(t)

        dfn = self.baseFilename + "." + time.strftime(self.suffix, timeTuple)

        if os.path.exists(dfn):

            os.remove(dfn)

        os.rename(self.baseFilename, dfn)

        if self.backupCount > 0:

            # find the oldest log file and delete it

            #s = glob.glob(self.baseFilename + ".20*")

            #if len(s) > self.backupCount:

            #    s.sort()

            #    os.remove(s[0])

            for s in self.getFilesToDelete():

                os.remove(s)

        #print "%s -> %s" % (self.baseFilename, dfn)

        self.mode = 'w'

        self.stream = self._open()

        newRolloverAt = self.rolloverAt + self.interval

        currentTime = int(time.time())

        while newRolloverAt <= currentTime:

            newRolloverAt = newRolloverAt + self.interval

        #If DST changes and midnight or weekly rollover, adjust for this.

        if (self.when == 'MIDNIGHT' or self.when.startswith('W')) and not self.utc:

            dstNow = time.localtime(currentTime)[-1]

            dstAtRollover = time.localtime(newRolloverAt)[-1]

            if dstNow != dstAtRollover:

                if not dstNow:  # DST kicks in before next rollover, so we need to deduct an hour

                    newRolloverAt = newRolloverAt - 3600

                else:           # DST bows out before next rollover, so we need to add an hour

                    newRolloverAt = newRolloverAt + 3600

        self.rolloverAt = newRolloverAt

class WatchedFileHandler(logging.FileHandler):

    """

    A handler for logging to a file, which watches the file

    to see if it has changed while in use. This can happen because of

    usage of programs such as newsyslog and logrotate which perform

    log file rotation. This handler, intended for use under Unix,

    watches the file to see if it has changed since the last emit.

    (A file has changed if its device or inode have changed.)

    If it has changed, the old file stream is closed, and the file

    opened to get a new stream.

    This handler is not appropriate for use under Windows, because

    under Windows open files cannot be moved or renamed - logging

    opens the files with exclusive locks - and so there is no need

    for such a handler. Furthermore, ST_INO is not supported under

    Windows; stat always returns zero for this value.

    This handler is based on a suggestion and patch by Chad J.

    Schroeder.

    """

    def __init__(self, filename, mode='a', encoding=None, delay=0):

        logging.FileHandler.__init__(self, filename, mode, encoding, delay)

        if not os.path.exists(self.baseFilename):

            self.dev, self.ino = -1, -1

        else:

            stat = os.stat(self.baseFilename)

            self.dev, self.ino = stat[ST_DEV], stat[ST_INO]

    def emit(self, record):

        """

        Emit a record.

        First check if the underlying file has changed, and if it

        has, close the old stream and reopen the file to get the

        current stream.

        """

        if not os.path.exists(self.baseFilename):

            stat = None

            changed = 1

        else:

            stat = os.stat(self.baseFilename)

            changed = (stat[ST_DEV] != self.dev) or (stat[ST_INO] != self.ino)

        if changed and self.stream is not None:

            self.stream.flush()

            self.stream.close()

            self.stream = self._open()

            if stat is None:

                stat = os.stat(self.baseFilename)

            self.dev, self.ino = stat[ST_DEV], stat[ST_INO]

        logging.FileHandler.emit(self, record)

class SocketHandler(logging.Handler):

    """

    A handler class which writes logging records, in pickle format, to

    a streaming socket. The socket is kept open across logging calls.

    If the peer resets it, an attempt is made to reconnect on the next call.

    The pickle which is sent is that of the LogRecord's attribute dictionary

    (__dict__), so that the receiver does not need to have the logging module

    installed in order to process the logging event.

    To unpickle the record at the receiving end into a LogRecord, use the

    makeLogRecord function.

    """

    def __init__(self, host, port):

        """

        Initializes the handler with a specific host address and port.

        The attribute 'closeOnError' is set to 1 - which means that if

        a socket error occurs, the socket is silently closed and then

        reopened on the next logging call.

        """

        logging.Handler.__init__(self)

        self.host = host

        self.port = port

        self.sock = None

        self.closeOnError = 0

        self.retryTime = None

        #

        # Exponential backoff parameters.

        #

        self.retryStart = 1.0

        self.retryMax = 30.0

        self.retryFactor = 2.0

    def makeSocket(self, timeout=1):

        """

        A factory method which allows subclasses to define the precise

        type of socket they want.

        """

        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

        if hasattr(s, 'settimeout'):

            s.settimeout(timeout)

        s.connect((self.host, self.port))

        return s

    def createSocket(self):

        """

        Try to create a socket, using an exponential backoff with

        a max retry time. Thanks to Robert Olson for the original patch

        (SF #815911) which has been slightly refactored.

        """

        now = time.time()

        # Either retryTime is None, in which case this

        # is the first time back after a disconnect, or

        # we've waited long enough.

        if self.retryTime is None:

            attempt = 1

        else:

            attempt = (now >= self.retryTime)

        if attempt:

            try:

                self.sock = self.makeSocket()

                self.retryTime = None # next time, no delay before trying

            except socket.error:

                #Creation failed, so set the retry time and return.

                if self.retryTime is None:

                    self.retryPeriod = self.retryStart

                else:

                    self.retryPeriod = self.retryPeriod * self.retryFactor

                    if self.retryPeriod > self.retryMax:

                        self.retryPeriod = self.retryMax

                self.retryTime = now + self.retryPeriod

    def send(self, s):

        """

        Send a pickled string to the socket.

        This function allows for partial sends which can happen when the

        network is busy.

        """

        if self.sock is None:

            self.createSocket()

        #self.sock can be None either because we haven't reached the retry

        #time yet, or because we have reached the retry time and retried,

        #but are still unable to connect.

        if self.sock:

            try:

                if hasattr(self.sock, "sendall"):

                    self.sock.sendall(s)

                else:

                    sentsofar = 0

                    left = len(s)

                    while left > 0:

                        sent = self.sock.send(s[sentsofar:])

                        sentsofar = sentsofar + sent

                        left = left - sent

            except socket.error:

                self.sock.close()

                self.sock = None  # so we can call createSocket next time

    def makePickle(self, record):

        """

        Pickles the record in binary format with a length prefix, and

        returns it ready for transmission across the socket.

        """

        ei = record.exc_info

        if ei:

            dummy = self.format(record) # just to get traceback text into record.exc_text

            record.exc_info = None  # to avoid Unpickleable error

        s = cPickle.dumps(record.__dict__, 1)

        if ei:

            record.exc_info = ei  # for next handler

        slen = struct.pack(">L", len(s))

        return slen + s

    def handleError(self, record):

        """

        Handle an error during logging.

        An error has occurred during logging. Most likely cause -

        connection lost. Close the socket so that we can retry on the

        next event.

        """

        if self.closeOnError and self.sock:

            self.sock.close()

            self.sock = None        #try to reconnect next time

        else:

            logging.Handler.handleError(self, record)

    def emit(self, record):

        """

        Emit a record.