OSC3.py

#!/usr/bin/python3
# -*- coding: utf-8 -*-

"""
March 2015:
    Python 3 version tested in Blender and simpleOSC with twisted

This module contains an OpenSoundControl implementation (in Pure Python), based
(somewhat) on the good old 'SimpleOSC' implementation by Daniel Holth & Clinton
McChesney.

This implementation is intended to still be 'simple' to the user, but much more
complete (with OSCServer & OSCClient classes) and much more powerful (the
OSCMultiClient supports subscriptions & message-filtering, OSCMessage &
OSCBundle are now proper container-types)

===============================================================================
OpenSoundControl
===============================================================================

OpenSoundControl is a network-protocol for sending (small) packets of addressed
data over network sockets. This OSC-implementation supports the classical
UDP/IP protocol for sending and receiving packets but provides as well support
for TCP/IP streaming, whereas the message size is prepended as int32 (big
endian) before each message/packet.

OSC-packets come in two kinds:

    - OSC-messages consist of an 'address'-string (not to be confused with a
    (host:port) network-address!), followed by a string of 'typetags'
    associated with the message's arguments (ie. 'payload'), and finally the
    arguments themselves, encoded in an OSC-specific way. The OSCMessage class
    makes it easy to create & manipulate OSC-messages of this kind in a
    'pythonesque' way (that is, OSCMessage-objects behave a lot like lists)

    - OSC-bundles are a special type of OSC-message containing only
    OSC-messages as 'payload'. Recursively. (meaning; an OSC-bundle could
    contain other OSC-bundles, containing OSC-bundles etc.)

OSC-bundles start with the special keyword '#bundle' and do not have an
OSC-address (but the OSC-messages a bundle contains will have OSC-addresses!).
Also, an OSC-bundle can have a timetag, essentially telling the receiving
server to 'hold' the bundle until the specified time. The OSCBundle class
allows easy cration & manipulation of OSC-bundles.

For further information see also http://opensoundcontrol.org/spec-1_0

-------------------------------------------------------------------------------

To send OSC-messages, you need an OSCClient, and to receive OSC-messages you
need an OSCServer.

The OSCClient uses an 'AF_INET / SOCK_DGRAM' type socket (see the 'socket'
module) to send binary representations of OSC-messages to a remote host:port
address.

The OSCServer listens on an 'AF_INET / SOCK_DGRAM' type socket bound to a local
port, and handles incoming requests. Either one-after-the-other (OSCServer) or
in a multi-threaded / multi-process fashion (ThreadingOSCServer/
ForkingOSCServer). If the Server has a callback-function (a.k.a. handler)
registered to 'deal with' (i.e. handle) the received message's OSC-address,
that function is called, passing it the (decoded) message.

The different OSCServers implemented here all support the (recursive) un-
bundling of OSC-bundles, and OSC-bundle timetags.

In fact, this implementation supports:

    - OSC-messages with 'i' (int32), 'f' (float32), 'd' (double), 's' (string) and
    'b' (blob / binary data) types
    - OSC-bundles, including timetag-support
    - OSC-address patterns including '*', '?', '{,}' and '[]' wildcards.

(please *do* read the OSC-spec! http://opensoundcontrol.org/spec-1_0 it
explains what these things mean.)

In addition, the OSCMultiClient supports:
    - Sending a specific OSC-message to multiple remote servers
    - Remote server subscription / unsubscription (through OSC-messages, of course)
    - Message-address filtering.

-------------------------------------------------------------------------------
SimpleOSC:
    Copyright (c) Daniel Holth & Clinton McChesney.
pyOSC:
    Copyright (c) 2008-2010, Artem Baguinski <artm@v2.nl> et al., Stock, V2_Lab, Rotterdam, Netherlands.
Streaming support (OSC over TCP):
    Copyright (c) 2010 Uli Franke <uli.franke@weiss.ch>, Weiss Engineering, Uster, Switzerland.

-------------------------------------------------------------------------------
Changelog:
-------------------------------------------------------------------------------
v0.3.0  - 27 Dec. 2007
    Started out to extend the 'SimpleOSC' implementation (v0.2.3) by Daniel Holth & Clinton McChesney.
    Rewrote OSCMessage
    Added OSCBundle

v0.3.1  - 3 Jan. 2008
    Added OSClient
    Added OSCRequestHandler, loosely based on the original CallbackManager
    Added OSCServer
    Removed original CallbackManager
    Adapted testing-script (the 'if __name__ == "__main__":' block at the end) to use new Server & Client

v0.3.2  - 5 Jan. 2008
    Added 'container-type emulation' methods (getitem(), setitem(), __iter__() & friends) to OSCMessage
    Added ThreadingOSCServer & ForkingOSCServer
        - 6 Jan. 2008
    Added OSCMultiClient
    Added command-line options to testing-script (try 'python OSC.py --help')

v0.3.3  - 9 Jan. 2008
    Added OSC-timetag support to OSCBundle & OSCRequestHandler
    Added ThreadingOSCRequestHandler

v0.3.4  - 13 Jan. 2008
    Added message-filtering to OSCMultiClient
    Added subscription-handler to OSCServer
    Added support fon numpy/scipy int & float types. (these get converted to 'standard' 32-bit OSC ints / floats!)
    Cleaned-up and added more Docstrings

v0.3.5 - 14 aug. 2008
    Added OSCServer.reportErr(...) method

v0.3.6 - 19 April 2010
    Added Streaming support (OSC over TCP)
    Updated documentation
    Moved pattern matching stuff into separate class (OSCAddressSpace) to
        facilitate implementation of different server and client architectures.
        Callbacks feature now a context (object oriented) but dynamic function
        inspection keeps the code backward compatible
    Moved testing code into separate testbench (testbench.py)

-----------------
Original Comments
-----------------
> Open SoundControl for Python
> Copyright (C) 2002 Daniel Holth, Clinton McChesney
>
> This library is free software; you can redistribute it and/or modify it under
> the terms of the GNU Lesser General Public License as published by the Free
> Software Foundation; either version 2.1 of the License, or (at your option) any
> later version.
>
> This library is distributed in the hope that it will be useful, but WITHOUT ANY
> WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
> PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
> details.
>
> You should have received a copy of the GNU Lesser General Public License along
> with this library; if not, write to the Free Software Foundation, Inc., 59
> Temple Place, Suite 330, Boston, MA  02111-1307  USA
>
> For questions regarding this module contact Daniel Holth <dholth@stetson.edu>
> or visit http://www.stetson.edu/~ProctoLogic/
>
> Changelog:
> 15 Nov. 2001:
>   Removed dependency on Python 2.0 features.
>   - dwh
> 13 Feb. 2002:
>   Added a generic callback handler.
>   - dwh
"""

import math, re, socket, select, string, struct, sys, threading, time, types, array, errno, inspect
from socketserver import UDPServer, DatagramRequestHandler, ForkingMixIn, ThreadingMixIn, StreamRequestHandler, TCPServer
from contextlib import closing

global version
version = ("0.3","6", "$Rev: 6382 $"[6:-2])

global FloatTypes
FloatTypes = [float]

global IntTypes
IntTypes = [int]

global NTP_epoch
from calendar import timegm
NTP_epoch = timegm((1900,1,1,0,0,0)) # NTP time started in 1 Jan 1900
del timegm

global NTP_units_per_second
NTP_units_per_second = 0x100000000 # about 232 picoseconds

##
# numpy/scipy support:
##

try:
    from numpy import typeDict

    for ftype in ['float32', 'float64', 'float128']:
        try:
            FloatTypes.append(typeDict[ftype])
        except KeyError:
            pass

    for itype in ['int8', 'int16', 'int32', 'int64']:
        try:
            IntTypes.append(typeDict[itype])
            IntTypes.append(typeDict['u' + itype])
        except KeyError:
            pass

    # thanks for those...
    del typeDict, ftype, itype

except ImportError:
    pass

######
#
# OSCMessage classes
#
######

class OSCMessage(object):
    """ Builds typetagged OSC messages.

    OSCMessage objects are container objects for building OSC-messages.
    On the 'front' end, they behave much like list-objects, and on the 'back' end
    they generate a binary representation of the message, which can be sent over a network socket.
    OSC-messages consist of an 'address'-string (not to be confused with a (host, port) IP-address!),
    followed by a string of 'typetags' associated with the message's arguments (ie. 'payload'),
    and finally the arguments themselves, encoded in an OSC-specific way.

    On the Python end, OSCMessage are lists of arguments, prepended by the message's address.
    The message contents can be manipulated much like a list:
      >>> msg = OSCMessage("/my/osc/address")
      >>> msg.append('something')
      >>> msg.insert(0, 'something else')
      >>> msg[1] = 'entirely'
      >>> msg.extend([1,2,3.])
      >>> msg += [4, 5, 6.]
      >>> del msg[3:6]
      >>> msg.pop(-2)
      5
      >>> print msg
      /my/osc/address ['something else', 'entirely', 1, 6.0]

    OSCMessages can be concatenated with the + operator. In this case, the resulting OSCMessage
    inherits its address from the left-hand operand. The right-hand operand's address is ignored.
    To construct an 'OSC-bundle' from multiple OSCMessage, see OSCBundle!

    Additional methods exist for retreiving typetags or manipulating items as (typetag, value) tuples.
    """
    def __init__(self, address=""):
        """Instantiate a new OSCMessage.
        The OSC-address can be specified with the 'address' argument
        """
        self.clear(address)

    def setAddress(self, address):
        """Set or change the OSC-address
        """
        self.address = address

    def clear(self, address=""):
        """Clear (or set a new) OSC-address and clear any arguments appended so far
        """
        self.address  = address
        self.clearData()

    def clearData(self):
        """Clear any arguments appended so far
        """
        self.typetags = ","
        self.message  = b""

    def append(self, argument, typehint=None):
        """Appends data to the message, updating the typetags based on
        the argument's type. If the argument is a blob (counted
        string) pass in 'b' as typehint.
        'argument' may also be a list or tuple, in which case its elements
        will get appended one-by-one, all using the provided typehint
        """
        if isinstance(argument,dict):
            argument = list(argument.items())
        elif isinstance(argument, OSCMessage):
            raise TypeError("Can only append 'OSCMessage' to 'OSCBundle'")

        if hasattr(argument, '__iter__') and not type(argument) in (str,bytes):
            for arg in argument:
                self.append(arg, typehint)

            return

        if typehint == 'b':
            binary = OSCBlob(argument)
            tag = 'b'
        elif typehint == 't':
            binary = OSCTimeTag(argument)
            tag = 't'
        else:
            tag, binary = OSCArgument(argument, typehint)

        self.typetags += tag
        self.message += binary

    def getBinary(self):
        """Returns the binary representation of the message
        """
        binary = OSCString(self.address)
        binary += OSCString(self.typetags)
        binary += self.message

        return binary

    def __repr__(self):
        """Returns a string containing the decode Message
        """
        return str(decodeOSC(self.getBinary()))

    def __str__(self):
        """Returns the Message's address and contents as a string.
        """
        return "%s %s" % (self.address, str(list(self.values())))

    def __len__(self):
        """Returns the number of arguments appended so far
        """
        return (len(self.typetags) - 1)

    def __eq__(self, other):
        """Return True if two OSCMessages have the same address & content
        """
        if not isinstance(other, self.__class__):
            return False

        return (self.address == other.address) and (self.typetags == other.typetags) and (self.message == other.message)

    def __ne__(self, other):
        """Return (not self.__eq__(other))
        """
        return not self.__eq__(other)

    def __add__(self, values):
        """Returns a copy of self, with the contents of 'values' appended
        (see the 'extend()' method, below)
        """
        msg = self.copy()
        msg.extend(values)
        return msg

    def __iadd__(self, values):
        """Appends the contents of 'values'
        (equivalent to 'extend()', below)
        Returns self
        """
        self.extend(values)
        return self

    def __radd__(self, values):
        """Appends the contents of this OSCMessage to 'values'
        Returns the extended 'values' (list or tuple)
        """
        out = list(values)
        out.extend(list(self.values()))

        if isinstance(values,tuple):
            return tuple(out)

        return out

    def _reencode(self, items):
        """Erase & rebuild the OSCMessage contents from the given
        list of (typehint, value) tuples"""
        self.clearData()
        for item in items:
            self.append(item[1], item[0])

    def values(self):
        """Returns a list of the arguments appended so far
        """
        return decodeOSC(self.getBinary())[2:]

    def tags(self):
        """Returns a list of typetags of the appended arguments
        """
        return list(self.typetags.lstrip(','))

    def items(self):
        """Returns a list of (typetag, value) tuples for
        the arguments appended so far
        """
        out = []
        values = list(self.values())
        typetags = self.tags()
        for i in range(len(values)):
            out.append((typetags[i], values[i]))

        return out

    def __contains__(self, val):
        """Test if the given value appears in the OSCMessage's arguments
        """
        return (val in list(self.values()))

    def __getitem__(self, i):
        """Returns the indicated argument (or slice)
        """
        return list(self.values())[i]

    def __delitem__(self, i):
        """Removes the indicated argument (or slice)
        """
        items = list(self.items())
        del items[i]

        self._reencode(items)

    def _buildItemList(self, values, typehint=None):
        if isinstance(values, OSCMessage):
            items = list(values.items())
        elif isinstance(values,list):
            items = []
            for val in values:
                if isinstance(val,tuple):
                    items.append(val[:2])
                else:
                    items.append((typehint, val))
        elif isinstance(values,tuple):
            items = [values[:2]]
        else:
            items = [(typehint, values)]

        return items

    def __setitem__(self, i, val):
        """Set indicatated argument (or slice) to a new value.
        'val' can be a single int/float/string, or a (typehint, value) tuple.
        Or, if 'i' is a slice, a list of these or another OSCMessage.
        """
        items = list(self.items())

        new_items = self._buildItemList(val)

        if not isinstance(i,slice):
            if len(new_items) != 1:
                raise TypeError("single-item assignment expects a single value or a (typetag, value) tuple")

            new_items = new_items[0]

        # finally...
        items[i] = new_items

        self._reencode(items)

    def setItem(self, i, val, typehint=None):
        """Set indicated argument to a new value (with typehint)
        """
        items = list(self.items())

        items[i] = (typehint, val)

        self._reencode(items)

    def copy(self):
        """Returns a deep copy of this OSCMessage
        """
        msg = self.__class__(self.address)
        msg.typetags = self.typetags
        msg.message = self.message
        return msg

    def count(self, val):
        """Returns the number of times the given value occurs in the OSCMessage's arguments
        """
        return list(self.values()).count(val)

    def index(self, val):
        """Returns the index of the first occurence of the given value in the OSCMessage's arguments.
        Raises ValueError if val isn't found
        """
        return list(self.values()).index(val)

    def extend(self, values):
        """Append the contents of 'values' to this OSCMessage.
        'values' can be another OSCMessage, or a list/tuple of ints/floats/strings
        """
        items = list(self.items()) + self._buildItemList(values)

        self._reencode(items)

    def insert(self, i, val, typehint = None):
        """Insert given value (with optional typehint) into the OSCMessage
        at the given index.
        """
        items = list(self.items())

        for item in reversed(self._buildItemList(val)):
            items.insert(i, item)

        self._reencode(items)

    def popitem(self, i):
        """Delete the indicated argument from the OSCMessage, and return it
        as a (typetag, value) tuple.
        """
        items = list(self.items())

        item = items.pop(i)

        self._reencode(items)

        return item

    def pop(self, i):
        """Delete the indicated argument from the OSCMessage, and return it.
        """
        return self.popitem(i)[1]

    def reverse(self):
        """Reverses the arguments of the OSCMessage (in place)
        """
        items = list(self.items())

        items.reverse()

        self._reencode(items)

    def remove(self, val):
        """Removes the first argument with the given value from the OSCMessage.
        Raises ValueError if val isn't found.
        """
        items = list(self.items())

        # this is not very efficient...
        i = 0
        for (t, v) in items:
            if (v == val):
                break
            i += 1
        else:
            raise ValueError("'%s' not in OSCMessage" % str(m))
        # but more efficient than first calling self.values().index(val),
        # then calling self.items(), which would in turn call self.values() again...

        del items[i]

        self._reencode(items)

    def __iter__(self):
        """Returns an iterator of the OSCMessage's arguments
        """
        return iter(list(self.values()))

    def __reversed__(self):
        """Returns a reverse iterator of the OSCMessage's arguments
        """
        return reversed(list(self.values()))

    def itervalues(self):
        """Returns an iterator of the OSCMessage's arguments
        """
        return iter(list(self.values()))

    def iteritems(self):
        """Returns an iterator of the OSCMessage's arguments as
        (typetag, value) tuples
        """
        return iter(list(self.items()))

    def itertags(self):
        """Returns an iterator of the OSCMessage's arguments' typetags
        """
        return iter(self.tags())

class OSCBundle(OSCMessage):
    """Builds a 'bundle' of OSC messages.

    OSCBundle objects are container objects for building OSC-bundles of OSC-messages.
    An OSC-bundle is a special kind of OSC-message which contains a list of OSC-messages
    (And yes, OSC-bundles may contain other OSC-bundles...)

    OSCBundle objects behave much the same as OSCMessage objects, with these exceptions:
      - if an item or items to be appended or inserted are not OSCMessage objects,
      OSCMessage objectss are created to encapsulate the item(s)
      - an OSC-bundle does not have an address of its own, only the contained OSC-messages do.
      The OSCBundle's 'address' is inherited by any OSCMessage the OSCBundle object creates.
      - OSC-bundles have a timetag to tell the receiver when the bundle should be processed.
      The default timetag value (0) means 'immediately'
    """
    def __init__(self, address="", time=0):
        """Instantiate a new OSCBundle.
        The default OSC-address for newly created OSCMessages
        can be specified with the 'address' argument
        The bundle's timetag can be set with the 'time' argument
        """
        super(OSCBundle, self).__init__(address)
        self.timetag = time

    def __str__(self):
        """Returns the Bundle's contents (and timetag, if nonzero) as a string.
        """
        if (self.timetag > 0.):
            out = "#bundle (%s) [" % self.getTimeTagStr()
        else:
            out = "#bundle ["

        if self.__len__():
            for val in list(self.values()):
                out += "%s, " % str(val)
            out = out[:-2]      # strip trailing space and comma

        return out + "]"

    def setTimeTag(self, time):
        """Set or change the OSCBundle's TimeTag
        In 'Python Time', that's floating seconds since the Epoch
        """
        if time >= 0:
            self.timetag = time

    def getTimeTagStr(self):
        """Return the TimeTag as a human-readable string
        """
        fract, secs = math.modf(self.timetag)
        out = time.ctime(secs)[11:19]
        out += ("%.3f" % fract)[1:]

        return out

    def append(self, argument, typehint = None):
        """Appends data to the bundle, creating an OSCMessage to encapsulate
        the provided argument unless this is already an OSCMessage.
        Any newly created OSCMessage inherits the OSCBundle's address at the time of creation.
        If 'argument' is an iterable, its elements will be encapsuated by a single OSCMessage.
        Finally, 'argument' can be (or contain) a dict, which will be 'converted' to an OSCMessage;
          - if 'addr' appears in the dict, its value overrides the OSCBundle's address
          - if 'args' appears in the dict, its value(s) become the OSCMessage's arguments
        """
        if isinstance(argument, OSCMessage):
            binary = OSCBlob(argument.getBinary())
        else:
            msg = OSCMessage(self.address)
            if isinstance(argument,dict):
                if 'addr' in argument:
                    msg.setAddress(argument['addr'])
                if 'args' in argument:
                    msg.append(argument['args'], typehint)
            else:
                msg.append(argument, typehint)

            binary = OSCBlob(msg.getBinary())

        self.message += binary
        self.typetags += 'b'

    def getBinary(self):
        """Returns the binary representation of the message
        """
        binary = OSCString("#bundle")
        binary += OSCTimeTag(self.timetag)
        binary += self.message

        return binary

    def _reencapsulate(self, decoded):
        if decoded[0] == "#bundle":
            msg = OSCBundle()
            msg.setTimeTag(decoded[1])
            for submsg in decoded[2:]:
                msg.append(self._reencapsulate(submsg))

        else:
            msg = OSCMessage(decoded[0])
            tags = decoded[1].lstrip(',')
            for i in range(len(tags)):
                msg.append(decoded[2+i], tags[i])

        return msg

    def values(self):
        """Returns a list of the OSCMessages appended so far
        """
        out = []
        for decoded in decodeOSC(self.getBinary())[2:]:
            out.append(self._reencapsulate(decoded))

        return out

    def __eq__(self, other):
        """Return True if two OSCBundles have the same timetag & content
        """
        if not isinstance(other, self.__class__):
            return False

        return (self.timetag == other.timetag) and (self.typetags == other.typetags) and (self.message == other.message)

    def copy(self):
        """Returns a deep copy of this OSCBundle
        """
        copy = super(OSCBundle, self).copy()
        copy.timetag = self.timetag
        return copy

######
#
# OSCMessage encoding functions
#
######

def OSCString(next):
    """Convert a string into a zero-padded OSC String.
    The length of the resulting string is always a multiple of 4 bytes.
    The string ends with 1 to 4 zero-bytes ('\x00')
    """

    OSCstringLength = math.ceil((len(next)+1) / 4.0) * 4
    return struct.pack(">%ds" % (OSCstringLength), str(next).encode('latin1'))

def OSCBlob(next):
    """Convert a string into an OSC Blob.
    An OSC-Blob is a binary encoded block of data, prepended by a 'size' (int32).
    The size is always a mutiple of 4 bytes.
    The blob ends with 0 to 3 zero-bytes ('\x00')
    """

    if isinstance(next,str):
        next = next.encode('latin1')
    if isinstance(next,bytes):
        OSCblobLength = math.ceil((len(next)) / 4.0) * 4
        binary = struct.pack(">i%ds" % (OSCblobLength), OSCblobLength, next)
    else:
        binary = b''

    return binary

def OSCArgument(next, typehint=None):
    """ Convert some Python types to their
    OSC binary representations, returning a
    (typetag, data) tuple.
    """
    if not typehint:
        if type(next) in FloatTypes:
            binary  = struct.pack(">f", float(next))
            tag = 'f'
        elif type(next) in IntTypes:
            binary  = struct.pack(">i", int(next))
            tag = 'i'
        else:
            binary  = OSCString(next)
            tag = 's'

    elif typehint == 'd':
        try:
            binary  = struct.pack(">d", float(next))
            tag = 'd'
        except ValueError:
            binary  = OSCString(next)
            tag = 's'

    elif typehint == 'f':
        try:
            binary  = struct.pack(">f", float(next))
            tag = 'f'
        except ValueError:
            binary  = OSCString(next)
            tag = 's'
    elif typehint == 'i':
        try:
            binary  = struct.pack(">i", int(next))
            tag = 'i'
        except ValueError:
            binary  = OSCString(next)
            tag = 's'
    else:
        binary  = OSCString(next)
        tag = 's'

    return (tag, binary)

def OSCTimeTag(time):
    """Convert a time in floating seconds to its
    OSC binary representation
    """
    if time > 0:
        fract, secs = math.modf(time)
        secs = secs - NTP_epoch
        binary = struct.pack('>LL', int(secs), int(fract * NTP_units_per_second))
    else:
        binary = struct.pack('>LL', 0, 1)

    return binary

######
#
# OSCMessage decoding functions
#
######

def _readString(data):
    """Reads the next (null-terminated) block of data
    """
    length   = data.find(b'\0')
    nextData = int(math.ceil((length+1) / 4.0) * 4)
    return (data[0:length].decode('latin1'), data[nextData:])

def _readBlob(data):
    """Reads the next (numbered) block of data
    """

    length   = struct.unpack(">i", data[0:4])[0]
    nextData = int(math.ceil((length) / 4.0) * 4) + 4
    return (data[4:length+4], data[nextData:])

def _readInt(data):
    """Tries to interpret the next 4 bytes of the data
    as a 32-bit integer. """

    if(len(data)<4):
        print("Error: too few bytes for int", data, len(data))
        rest = data
        integer = 0
    else:
        integer = struct.unpack(">i", data[0:4])[0]
        rest    = data[4:]

    return (integer, rest)

def _readLong(data):
    """Tries to interpret the next 8 bytes of the data
    as a 64-bit signed integer.
     """

    high, low = struct.unpack(">ll", data[0:8])
    big = (int(high) << 32) + low
    rest = data[8:]
    return (big, rest)

def _readTimeTag(data):
    """Tries to interpret the next 8 bytes of the data
    as a TimeTag.
     """
    high, low = struct.unpack(">LL", data[0:8])
    if (high == 0) and (low <= 1):
        time = 0.0
    else:
        time = int(NTP_epoch + high) + float(low / NTP_units_per_second)
    rest = data[8:]
    return (time, rest)

def _readFloat(data):
    """Tries to interpret the next 4 bytes of the data
    as a 32-bit float.
    """

    if(len(data)<4):
        print("Error: too few bytes for float", data, len(data))
        rest = data
        float = 0
    else:
        float = struct.unpack(">f", data[0:4])[0]
        rest  = data[4:]

    return (float, rest)

def _readDouble(data):
    """Tries to interpret the next 8 bytes of the data
    as a 64-bit float.
    """

    if(len(data)<8):
        print("Error: too few bytes for double", data, len(data))
        rest = data
        float = 0
    else:
        float = struct.unpack(">d", data[0:8])[0]
        rest  = data[8:]

    return (float, rest)

def decodeOSC(data):
    """Converts a binary OSC message to a Python list.
    """
    table = {"i":_readInt, "f":_readFloat, "s":_readString, "b":_readBlob, "d":_readDouble, "t":_readTimeTag}
    decoded = []
    address,  rest = _readString(data)
    if address.startswith(","):
        typetags = address
        address = ""
    else:
        typetags = ""

    if address == "#bundle":
        time, rest = _readTimeTag(rest)
        decoded.append(address)
        decoded.append(time)
        while len(rest)>0:
            length, rest = _readInt(rest)
            decoded.append(decodeOSC(rest[:length]))
            rest = rest[length:]

    elif len(rest)>0:
        if not len(typetags):
            typetags, rest = _readString(rest)
        decoded.append(address)
        decoded.append(typetags)
        if typetags.startswith(","):
            for tag in typetags[1:]:
                value, rest = table[tag](rest)
                decoded.append(value)
        else:
            raise OSCError("OSCMessage's typetag-string lacks the magic ','")

    return decoded

######
#
# Utility functions
#
######

def hexDump(bytes):
    """ Useful utility; prints the string in hexadecimal.
    """
    print("byte   0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F")

    if isinstance(bytes,str):
        bytes = bytes.encode('latin1')
    num = len(bytes)
    for i in range(num):
        if (i) % 16 == 0:
            line = "%02X0 : " % (i/16)
        line += "%02X " % bytes[i]
        if (i+1) % 16 == 0:
            print("%s: %s" % (line, repr(bytes[i-15:i+1])))
            line = ""

    bytes_left = num % 16
    if bytes_left:
        print("%s: %s" % (line.ljust(54), repr(bytes[-bytes_left:])))

def getUrlStr(*args):
    """Convert provided arguments to a string in 'host:port/prefix' format
    Args can be:
      - (host, port)
      - (host, port), prefix
      - host, port
      - host, port, prefix
    """
    if not len(args):
        return ""

    if type(args[0]) == tuple:
        host = args[0][0]
        port = args[0][1]
        args = args[1:]
    else:
        host = args[0]
        port = args[1]
        args = args[2:]

    if len(args):
        prefix = args[0]
    else:
        prefix = ""

    if len(host) and (host != '0.0.0.0'):
        try:
            (host, _, _) = socket.gethostbyaddr(host)
        except socket.error:
            pass
    else:
        host = 'localhost'

    if isinstance(port,int):
        return "%s:%d%s" % (host, port, prefix)
    else:
        return host + prefix

def parseUrlStr(url):
    """Convert provided string in 'host:port/prefix' format to it's components
    Returns ((host, port), prefix)
    """
    if not (isinstance(url,str) and len(url)):
        return (None, '')

    i = url.find("://")
    if i > -1:
        url = url[i+3:]

    i = url.find(':')
    if i > -1:
        host = url[:i].strip()
        tail = url[i+1:].strip()
    else:
        host = ''
        tail = url

    for i in range(len(tail)):
        if not tail[i].isdigit():
            break
    else:
        i += 1

    portstr = tail[:i].strip()
    tail = tail[i:].strip()

    found = len(tail)
    for c in ('/', '+', '-', '*'):
        i = tail.find(c)
        if (i > -1) and (i < found):
            found = i

    head = tail[:found].strip()
    prefix = tail[found:].strip()

    prefix = prefix.strip('/')
    if len(prefix) and prefix[0] not in ('+', '-', '*'):
        prefix = '/' + prefix

    if len(head) and not len(host):
        host = head

    if len(host):
        try:
            host = socket.gethostbyname(host)
        except socket.error:
            pass

    try:
        port = int(portstr)
    except ValueError:
        port = None

    return ((host, port), prefix)

######
#
# OSCClient class
#
######

class OSCClient(object):
    """Simple OSC Client. Handles the sending of OSC-Packets (OSCMessage or OSCBundle) via a UDP-socket
    """
    # set outgoing socket buffer size
    sndbuf_size = 4096 * 8

    def __init__(self, server=None):
        """Construct an OSC Client.
        When the 'address' argument is given this client is connected to a specific remote server.
          - address ((host, port) tuple): the address of the remote server to send all messages to
        Otherwise it acts as a generic client:
          If address == 'None', the client doesn't connect to a specific remote server,
          and the remote address must be supplied when calling sendto()
          - server: Local OSCServer-instance this client will use the socket of for transmissions.
          If none is supplied, a socket will be created.
        """
        self.socket = None

        if server == None:
            self.socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, self.sndbuf_size)
            self._fd = self.socket.fileno()

            self.server = None
        else:
            self.setServer(server)

        self.client_address = None

    def setServer(self, server):
        """Associate this Client with given server.
        The Client will send from the Server's socket.
        The Server will use this Client instance to send replies.
        """
        if not isinstance(server, OSCServer):
            raise ValueError("'server' argument is not a valid OSCServer object")

        if self.socket != None:
            self.close()

        self.socket = server.socket.dup()
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, self.sndbuf_size)
        self._fd = self.socket.fileno()

        self.server = server

        if self.server.client != None:
            self.server.client.close()

        self.server.client = self

    def close(self):
        """Disconnect & close the Client's socket
        """
        if self.socket != None:
            self.socket.close()
            self.socket = None

    def __str__(self):
        """Returns a string containing this Client's Class-name, software-version
        and the remote-address it is connected to (if any)
        """
        out = self.__class__.__name__
        out += " v%s.%s-%s" % version
        addr = self.address()
        if addr:
            out += " connected to osc://%s" % getUrlStr(addr)
        else:
            out += " (unconnected)"

        return out

    def __eq__(self, other):
        """Compare function.
        """
        if not isinstance(other, self.__class__):
            return False

        isequal = cmp(self.socket._sock, other.socket._sock)
        if isequal and self.server and other.server:
            return cmp(self.server, other.server)

        return isequal

    def __ne__(self, other):
        """Compare function.
        """
        return not self.__eq__(other)

    def address(self):
        """Returns a (host,port) tuple of the remote server this client is
        connected to or None if not connected to any server.
        """
        try:
            return self.socket.getpeername()
        except socket.error:
            return None

    def connect(self, address):
        """Bind to a specific OSC server:
        the 'address' argument is a (host, port) tuple
          - host:  hostname of the remote OSC server,
          - port:  UDP-port the remote OSC server listens to.
        """
        try:
            self.socket.connect(address)
            self.client_address = address
        except socket.error as e:
            self.client_address = None
            raise OSCClientError("SocketError: %s" % str(e))

        if self.server != None:
            self.server.return_port = address[1]

    def sendto(self, msg, address, timeout=None):
        """Send the given OSCMessage to the specified address.
          - msg:  OSCMessage (or OSCBundle) to be sent
          - address:  (host, port) tuple specifing remote server to send the message to
          - timeout:  A timeout value for attempting to send. If timeout == None,
            this call blocks until socket is available for writing.
        Raises OSCClientError when timing out while waiting for the socket.
        """
        if not isinstance(msg, OSCMessage):
            raise TypeError("'msg' argument is not an OSCMessage or OSCBundle object")

        ret = select.select([],[self._fd], [], timeout)
        try:
            ret[1].index(self._fd)
        except:
            # for the very rare case this might happen
            raise OSCClientError("Timed out waiting for file descriptor")

        try:
            self.socket.connect(address)
            self.socket.sendall(msg.getBinary())

            if self.client_address:
                self.socket.connect(self.client_address)

        except socket.error as e:
            if e[0] in (7, 65): # 7 = 'no address associated with nodename',  65 = 'no route to host'
                raise e
            else:
                raise OSCClientError("while sending to %s: %s" % (str(address), str(e)))

    def send(self, msg, timeout=None):
        """Send the given OSCMessage.
        The Client must be already connected.
          - msg:  OSCMessage (or OSCBundle) to be sent
          - timeout:  A timeout value for attempting to send. If timeout == None,
            this call blocks until socket is available for writing.
        Raises OSCClientError when timing out while waiting for the socket,
        or when the Client isn't connected to a remote server.
        """
        if not isinstance(msg, OSCMessage):
            raise TypeError("'msg' argument is not an OSCMessage or OSCBundle object")

        ret = select.select([],[self._fd], [], timeout)
        try:
            ret[1].index(self._fd)
        except:
            # for the very rare case this might happen
            raise OSCClientError("Timed out waiting for file descriptor")

        try:
            self.socket.sendall(msg.getBinary())
        except socket.error as e:
            if e[0] in (7, 65): # 7 = 'no address associated with nodename',  65 = 'no route to host'
                raise e
            else:
                raise OSCClientError("while sending: %s" % str(e))

######
#
# FilterString Utility functions
#
######

def parseFilterStr(args):
    """Convert Message-Filter settings in '+<addr> -<addr> ...' format to a dict of the form
    { '<addr>':True, '<addr>':False, ... }
    Returns a list: ['<prefix>', filters]
    """
    out = {}

    if isinstance(args,str):
        args = [args]

    prefix = None
    for arg in args:
        head = None
        for plus in arg.split('+'):
            minus = plus.split('-')
            plusfs = minus.pop(0).strip()
            if len(plusfs):
                plusfs = '/' + plusfs.strip('/')

            if (head == None) and (plusfs != "/*"):
                head = plusfs
            elif len(plusfs):
                if plusfs == '/*':
                    out = { '/*':True } # reset all previous filters
                else:
                    out[plusfs] = True

            for minusfs in minus:
                minusfs = minusfs.strip()
                if len(minusfs):
                    minusfs = '/' + minusfs.strip('/')
                    if minusfs == '/*':
                        out = { '/*':False }    # reset all previous filters
                    else:
                        out[minusfs] = False

        if prefix == None:
            prefix = head

    return [prefix, out]

def getFilterStr(filters):
    """Return the given 'filters' dict as a list of
    '+<addr>' | '-<addr>' filter-strings
    """
    if not len(filters):
        return []

    if '/*' in list(filters.keys()):
        if filters['/*']:
            out = ["+/*"]
        else:
            out = ["-/*"]
    else:
        if False in list(filters.values()):
            out = ["+/*"]
        else:
            out = ["-/*"]

    for (addr, bool) in list(filters.items()):
        if addr == '/*':
            continue

        if bool:
            out.append("+%s" % addr)
        else:
            out.append("-%s" % addr)

    return out

# A translation-table for mapping OSC-address expressions to Python 're' expressions
OSCtrans = str.maketrans("{,}?","(|).")

def getRegEx(pattern):
    """Compiles and returns a 'regular expression' object for the given address-pattern.
    """
    # Translate OSC-address syntax to python 're' syntax
    pattern = pattern.replace(".", r"\.")       # first, escape all '.'s in the pattern.
    pattern = pattern.replace("(", r"\(")       # escape all '('s.
    pattern = pattern.replace(")", r"\)")       # escape all ')'s.
    pattern = pattern.replace("*", r".*")       # replace a '*' by '.*' (match 0 or more characters)
    pattern = pattern.translate(OSCtrans)       # change '?' to '.' and '{,}' to '(|)'

    return re.compile(pattern)

######
#
# OSCMultiClient class
#
######

class OSCMultiClient(OSCClient):
    """'Multiple-Unicast' OSC Client. Handles the sending of OSC-Packets (OSCMessage or OSCBundle) via a UDP-socket
    This client keeps a dict of 'OSCTargets'. and sends each OSCMessage to each OSCTarget
    The OSCTargets are simply (host, port) tuples, and may be associated with an OSC-address prefix.
    the OSCTarget's prefix gets prepended to each OSCMessage sent to that target.
    """
    def __init__(self, server=None):
        """Construct a "Multi" OSC Client.
          - server: Local OSCServer-instance this client will use the socket of for transmissions.
          If none is supplied, a socket will be created.
        """
        super(OSCMultiClient, self).__init__(server)

        self.targets = {}

    def _searchHostAddr(self, host):
        """Search the subscribed OSCTargets for (the first occurence of) given host.
        Returns a (host, port) tuple
        """
        try:
            host = socket.gethostbyname(host)
        except socket.error:
            pass

        for addr in list(self.targets.keys()):
            if host == addr[0]:
                return addr

        raise NotSubscribedError((host, None))

    def _updateFilters(self, dst, src):
        """Update a 'filters' dict with values form another 'filters' dict:
         - src[a] == True and dst[a] == False:  del dst[a]
         - src[a] == False and dst[a] == True:  del dst[a]
         - a not in dst:  dst[a] == src[a]
        """
        if '/*' in list(src.keys()):            # reset filters
            dst.clear()             # 'match everything' == no filters
            if not src.pop('/*'):
                dst['/*'] = False   # 'match nothing'

        for (addr, bool) in list(src.items()):
            if (addr in list(dst.keys())) and (dst[addr] != bool):
                    del dst[addr]
            else:
                dst[addr] = bool

    def _setTarget(self, address, prefix=None, filters=None):
        """Add (i.e. subscribe) a new OSCTarget, or change the prefix for an existing OSCTarget.
            - address ((host, port) tuple): IP-address & UDP-port
            - prefix (string): The OSC-address prefix prepended to the address of each OSCMessage
          sent to this OSCTarget (optional)
        """
        if address not in list(self.targets.keys()):
            self.targets[address] = ["",{}]

        if prefix != None:
            if len(prefix):
                # make sure prefix starts with ONE '/', and does not end with '/'
                prefix = '/' + prefix.strip('/')

            self.targets[address][0] = prefix

        if filters != None:
            if isinstance(filters,str):
                (_, filters) = parseFilterStr(filters)
            elif not isinstance(filters,dict):
                raise TypeError("'filters' argument must be a dict with {addr:bool} entries")

            self._updateFilters(self.targets[address][1], filters)

    def setOSCTarget(self, address, prefix=None, filters=None):
        """Add (i.e. subscribe) a new OSCTarget, or change the prefix for an existing OSCTarget.
          the 'address' argument can be a ((host, port) tuple) : The target server address & UDP-port
            or a 'host' (string) : The host will be looked-up
          - prefix (string): The OSC-address prefix prepended to the address of each OSCMessage
          sent to this OSCTarget (optional)
        """
        if isinstance(address,str):
            address = self._searchHostAddr(address)

        elif (isinstance(address,tuple)):
            (host, port) = address[:2]
            try:
                host = socket.gethostbyname(host)
            except:
                pass

            address = (host, port)
        else:
            raise TypeError("'address' argument must be a (host, port) tuple or a 'host' string")

        self._setTarget(address, prefix, filters)

    def setOSCTargetFromStr(self, url):
        """Adds or modifies a subscribed OSCTarget from the given string, which should be in the
        '<host>:<port>[/<prefix>] [+/<filter>]|[-/<filter>] ...' format.
        """
        (addr, tail) = parseUrlStr(url)
        (prefix, filters) = parseFilterStr(tail)
        self._setTarget(addr, prefix, filters)

    def _delTarget(self, address, prefix=None):
        """Delete the specified OSCTarget from the Client's dict.
        the 'address' argument must be a (host, port) tuple.
        If the 'prefix' argument is given, the Target is only deleted if the address and prefix match.
        """
        try:
            if prefix == None:
                del self.targets[address]
            elif prefix == self.targets[address][0]:
                del self.targets[address]
        except KeyError:
            raise NotSubscribedError(address, prefix)

    def delOSCTarget(self, address, prefix=None):
        """Delete the specified OSCTarget from the Client's dict.
        the 'address' argument can be a ((host, port) tuple), or a hostname.
        If the 'prefix' argument is given, the Target is only deleted if the address and prefix match.
        """
        if isinstance(address,str):
            address = self._searchHostAddr(address)

        if isinstance(address,tuple):
            (host, port) = address[:2]
            try:
                host = socket.gethostbyname(host)
            except socket.error:
                pass
            address = (host, port)

            self._delTarget(address, prefix)

    def hasOSCTarget(self, address, prefix=None):
        """Return True if the given OSCTarget exists in the Client's dict.
        the 'address' argument can be a ((host, port) tuple), or a hostname.
        If the 'prefix' argument is given, the return-value is only True if the address and prefix match.
        """
        if isinstance(address,str):
            address = self._searchHostAddr(address)

        if isinstance(address,tuple):
            (host, port) = address[:2]
            try:
                host = socket.gethostbyname(host)
            except socket.error:
                pass
            address = (host, port)

            if address in list(self.targets.keys()):
                if prefix == None:
                    return True
                elif prefix == self.targets[address][0]:
                    return True

        return False

    def getOSCTargets(self):
        """Returns the dict of OSCTargets: {addr:[prefix, filters], ...}
        """
        out = {}
        for ((host, port), pf) in list(self.targets.items()):
            try:
                (host, _, _) = socket.gethostbyaddr(host)
            except socket.error:
                pass

            out[(host, port)] = pf

        return out

    def getOSCTarget(self, address):
        """Returns the OSCTarget matching the given address as a ((host, port), [prefix, filters]) tuple.
        'address' can be a (host, port) tuple, or a 'host' (string), in which case the first matching OSCTarget is returned
        Returns (None, ['',{}]) if address not found.
        """
        if isinstance(address,str):
            address = self._searchHostAddr(address)

        if (isinstance(address,tuple)):
            (host, port) = address[:2]
            try:
                host = socket.gethostbyname(host)
            except socket.error:
                pass
            address = (host, port)

            if (address in list(self.targets.keys())):
                try:
                    (host, _, _) = socket.gethostbyaddr(host)
                except socket.error:
                    pass

                return ((host, port), self.targets[address])

        return (None, ['',{}])

    def clearOSCTargets(self):
        """Erases all OSCTargets from the Client's dict
        """
        self.targets = {}

    def updateOSCTargets(self, dict):
        """Update the Client's OSCTargets dict with the contents of 'dict'
        The given dict's items MUST be of the form
          { (host, port):[prefix, filters], ... }
        """
        for ((host, port), (prefix, filters)) in list(dict.items()):
            val = [prefix, {}]
            self._updateFilters(val[1], filters)

            try:
                host = socket.gethostbyname(host)
            except socket.error:
                pass

            self.targets[(host, port)] = val

    def getOSCTargetStr(self, address):
        """Returns the OSCTarget matching the given address as a ('osc://<host>:<port>[<prefix>]', ['<filter-string>', ...])' tuple.
        'address' can be a (host, port) tuple, or a 'host' (string), in which case the first matching OSCTarget is returned
        Returns (None, []) if address not found.
        """
        (addr, (prefix, filters)) = self.getOSCTarget(address)
        if addr == None:
            return (None, [])

        return ("osc://%s" % getUrlStr(addr, prefix), getFilterStr(filters))

    def getOSCTargetStrings(self):
        """Returns a list of all OSCTargets as ('osc://<host>:<port>[<prefix>]', ['<filter-string>', ...])' tuples.
        """
        out = []
        for (addr, (prefix, filters)) in list(self.targets.items()):
            out.append(("osc://%s" % getUrlStr(addr, prefix), getFilterStr(filters)))

        return out

    def connect(self, address):
        """The OSCMultiClient isn't allowed to connect to any specific
        address.
        """
        return NotImplemented

    def sendto(self, msg, address, timeout=None):
        """Send the given OSCMessage.
        The specified address is ignored. Instead this method calls send() to
        send the message to all subscribed clients.
          - msg:  OSCMessage (or OSCBundle) to be sent
          - address:  (host, port) tuple specifing remote server to send the message to
          - timeout:  A timeout value for attempting to send. If timeout == None,
            this call blocks until socket is available for writing.
        Raises OSCClientError when timing out while waiting for the socket.
        """
        self.send(msg, timeout)

    def _filterMessage(self, filters, msg):
        """Checks the given OSCMessge against the given filters.
        'filters' is a dict containing OSC-address:bool pairs.
        If 'msg' is an OSCBundle, recursively filters its constituents.
        Returns None if the message is to be filtered, else returns the message.
        or
        Returns a copy of the OSCBundle with the filtered messages removed.
        """
        if isinstance(msg, OSCBundle):
            out = msg.copy()
            msgs = list(out.values())
            out.clearData()
            for m in msgs:
                m = self._filterMessage(filters, m)
                if m:       # this catches 'None' and empty bundles.
                    out.append(m)

        elif isinstance(msg, OSCMessage):
            if '/*' in list(filters.keys()):
                if filters['/*']:
                    out = msg
                else:
                    out = None

            elif False in list(filters.values()):
                out = msg
            else:
                out = None

        else:
            raise TypeError("'msg' argument is not an OSCMessage or OSCBundle object")

        expr = getRegEx(msg.address)

        for addr in list(filters.keys()):
            if addr == '/*':
                continue

            match = expr.match(addr)
            if match and (match.end() == len(addr)):
                if filters[addr]:
                    out = msg
                else:
                    out = None
                break

        return out

    def _prefixAddress(self, prefix, msg):
        """Makes a copy of the given OSCMessage, then prepends the given prefix to
        The message's OSC-address.
        If 'msg' is an OSCBundle, recursively prepends the prefix to its constituents.
        """
        out = msg.copy()

        if isinstance(msg, OSCBundle):
            msgs = list(out.values())
            out.clearData()
            for m in msgs:
                out.append(self._prefixAddress(prefix, m))

        elif isinstance(msg, OSCMessage):
            out.setAddress(prefix + out.address)

        else:
            raise TypeError("'msg' argument is not an OSCMessage or OSCBundle object")

        return out

    def send(self, msg, timeout=None):
        """Send the given OSCMessage to all subscribed OSCTargets
          - msg:  OSCMessage (or OSCBundle) to be sent
          - timeout:  A timeout value for attempting to send. If timeout == None,
            this call blocks until socket is available for writing.
        Raises OSCClientError when timing out while waiting for the socket.
        """
        for (address, (prefix, filters)) in list(self.targets.items()):
            if len(filters):
                out = self._filterMessage(filters, msg)
                if not out:         # this catches 'None' and empty bundles.
                    continue
            else:
                out = msg

            if len(prefix):
                out = self._prefixAddress(prefix, msg)

            binary = out.getBinary()

            ret = select.select([],[self._fd], [], timeout)
            try:
                ret[1].index(self._fd)
            except:
                # for the very rare case this might happen
                raise OSCClientError("Timed out waiting for file descriptor")

            try:
                while len(binary):
                    sent = self.socket.sendto(binary, address)
                    binary = binary[sent:]

            except socket.error as e:
                if e[0] in (7, 65): # 7 = 'no address associated with nodename',  65 = 'no route to host'
                    raise e
                else:
                    raise OSCClientError("while sending to %s: %s" % (str(address), str(e)))

class OSCAddressSpace:
    def __init__(self):
        self.callbacks = {}
    def addMsgHandler(self, address, callback):
        """Register a handler for an OSC-address
          - 'address' is the OSC address-string.
        the address-string should start with '/' and may not contain '*'
          - 'callback' is the function called for incoming OSCMessages that match 'address'.
        The callback-function will be called with the same arguments as the 'msgPrinter_handler' below
        """
        for chk in '*?,[]{}# ':
            if chk in address:
                raise OSCServerError("OSC-address string may not contain any characters in '*?,[]{}# '")

        if type(callback) not in (types.FunctionType, types.MethodType):
            raise OSCServerError("Message callback '%s' is not callable" % repr(callback))

        if address != 'default':
            address = '/' + address.strip('/')

        self.callbacks[address] = callback

    def delMsgHandler(self, address):
        """Remove the registered handler for the given OSC-address
        """
        del self.callbacks[address]

    def getOSCAddressSpace(self):
        """Returns a list containing all OSC-addresses registerd with this Server.
        """
        return list(self.callbacks.keys())

    def dispatchMessage(self, pattern, tags, data, client_address):
        """Attmept to match the given OSC-address pattern, which may contain '*',
        against all callbacks registered with the OSCServer.
        Calls the matching callback and returns whatever it returns.
        If no match is found, and a 'default' callback is registered, it calls that one,
        or raises NoCallbackError if a 'default' callback is not registered.

          - pattern (string):  The OSC-address of the receied message
          - tags (string):  The OSC-typetags of the receied message's arguments, without ','
          - data (list):  The message arguments
        """
        if len(tags) != len(data):
            raise OSCServerError("Malformed OSC-message; got %d typetags [%s] vs. %d values" % (len(tags), tags, len(data)))

        expr = getRegEx(pattern)

        replies = []
        matched = 0
        for addr in list(self.callbacks.keys()):
            match = expr.match(addr)
            if match and (match.end() == len(addr)):
                reply = self.callbacks[addr](pattern, tags, data, client_address)
                matched += 1
                if isinstance(reply, OSCMessage):
                    replies.append(reply)
                elif reply != None:
                    raise TypeError("Message-callback %s did not return OSCMessage or None: %s" % (self.server.callbacks[addr], type(reply)))

        if matched == 0:
            if 'default' in self.callbacks:
                reply = self.callbacks['default'](pattern, tags, data, client_address)
                if isinstance(reply, OSCMessage):
                    replies.append(reply)
                elif reply != None:
                    raise TypeError("Message-callback %s did not return OSCMessage or None: %s" % (self.server.callbacks['default'], type(reply)))
            else:
                raise NoCallbackError(pattern)

        return replies

######
#
# OSCRequestHandler classes
#
######
class OSCRequestHandler(DatagramRequestHandler):
    """RequestHandler class for the OSCServer
    """
    def setup(self):
        """Prepare RequestHandler.
        Unpacks request as (packet, source socket address)
        Creates an empty list for replies.
        """
        (self.packet, self.socket) = self.request
        self.replies = []

    def _unbundle(self, decoded):
        """Recursive bundle-unpacking function"""
        if decoded[0] != "#bundle":
            self.replies += self.server.dispatchMessage(decoded[0], decoded[1][1:], decoded[2:], self.client_address)
            return

        now = time.time()
        timetag = decoded[1]
        if (timetag > 0.) and (timetag > now):
            time.sleep(timetag - now)

        for msg in decoded[2:]:
            self._unbundle(msg)

    def handle(self):
        """Handle incoming OSCMessage
        """
        decoded = decodeOSC(self.packet)
        if not len(decoded):
            return

        self._unbundle(decoded)

    def finish(self):
        """Finish handling OSCMessage.
        Send any reply returned by the callback(s) back to the originating client
        as an OSCMessage or OSCBundle
        """
        if self.server.return_port:
            self.client_address = (self.client_address[0], self.server.return_port)

        if len(self.replies) > 1:
            msg = OSCBundle()
            for reply in self.replies:
                msg.append(reply)
        elif len(self.replies) == 1:
            msg = self.replies[0]
        else:
            return

        self.server.client.sendto(msg, self.client_address)

class ThreadingOSCRequestHandler(OSCRequestHandler):
    """Multi-threaded OSCRequestHandler;
    Starts a new RequestHandler thread for each unbundled OSCMessage
    """
    def _unbundle(self, decoded):
        """Recursive bundle-unpacking function
        This version starts a new thread for each sub-Bundle found in the Bundle,
        then waits for all its children to finish.
        """
        if decoded[0] != "#bundle":
            self.replies += self.server.dispatchMessage(decoded[0], decoded[1][1:], decoded[2:], self.client_address)
            return

        now = time.time()
        timetag = decoded[1]
        if (timetag > 0.) and (timetag > now):
            time.sleep(timetag - now)
            now = time.time()

        children = []

        for msg in decoded[2:]:
            t = threading.Thread(target = self._unbundle, args = (msg,))
            t.start()
            children.append(t)

        # wait for all children to terminate
        for t in children:
            t.join()

######
#
# OSCServer classes
#
######
class OSCServer(UDPServer, OSCAddressSpace):
    """A Synchronous OSCServer
    Serves one request at-a-time, until the OSCServer is closed.
    The OSC address-pattern is matched against a set of OSC-adresses
    that have been registered to the server with a callback-function.
    If the adress-pattern of the message machtes the registered address of a callback,
    that function is called.
    """

    # set the RequestHandlerClass, will be overridden by ForkingOSCServer & ThreadingOSCServer
    RequestHandlerClass = OSCRequestHandler

    # define a socket timeout, so the serve_forever loop can actually exit.
    socket_timeout = 1

    # DEBUG: print error-tracebacks (to stderr)?
    print_tracebacks = False

    def __init__(self, server_address, client=None, return_port=0):
        """Instantiate an OSCServer.
          - server_address ((host, port) tuple): the local host & UDP-port
          the server listens on
          - client (OSCClient instance): The OSCClient used to send replies from this server.
          If none is supplied (default) an OSCClient will be created.
          - return_port (int): if supplied, sets the default UDP destination-port
          for replies coming from this server.
        """
        UDPServer.__init__(self, server_address, self.RequestHandlerClass)
        OSCAddressSpace.__init__(self)

        self.setReturnPort(return_port)
        self.error_prefix = ""
        self.info_prefix = "/info"

        self.socket.settimeout(self.socket_timeout)

        self.running = False
        self.client = None

        if client == None:
            self.client = OSCClient(server=self)
        else:
            self.setClient(client)

    def setClient(self, client):
        """Associate this Server with a new local Client instance, closing the Client this Server is currently using.
        """
        if not isinstance(client, OSCClient):
            raise ValueError("'client' argument is not a valid OSCClient object")

        if client.server != None:
            raise OSCServerError("Provided OSCClient already has an OSCServer-instance: %s" % str(client.server))

        # Server socket is already listening at this point, so we can't use the client's socket.
        # we'll have to force our socket on the client...
        client_address = client.address()   # client may be already connected
        client.close()              # shut-down that socket

        # force our socket upon the client
        client.socket = self.socket.dup()
        client.socket.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, client.sndbuf_size)
        client._fd = client.socket.fileno()
        client.server = self

        if client_address:
            client.connect(client_address)
            if not self.return_port:
                self.return_port = client_address[1]

        if self.client != None:
            self.client.close()

        self.client = client

    def serve_forever(self):
        """Handle one request at a time until server is closed."""
        self.running = True
        while self.running:
            self.handle_request()   # this times-out when no data arrives.

    def close(self):
        """Stops serving requests, closes server (socket), closes used client
        """
        self.running = False
        self.client.close()
        self.server_close()

    def __str__(self):
        """Returns a string containing this Server's Class-name, software-version and local bound address (if any)
        """
        out = self.__class__.__name__
        out += " v%s.%s-%s" % version
        addr = self.address()
        if addr:
            out += " listening on osc://%s" % getUrlStr(addr)
        else:
            out += " (unbound)"

        return out

    def __eq__(self, other):
        """Compare function.
        """
        if not isinstance(other, self.__class__):
            return False

        return cmp(self.socket._sock, other.socket._sock)

    def __ne__(self, other):
        """Compare function.
        """
        return not self.__eq__(other)

    def address(self):
        """Returns a (host,port) tuple of the local address this server is bound to,
        or None if not bound to any address.
        """
        try:
            return self.socket.getsockname()
        except socket.error:
            return None

    def setReturnPort(self, port):
        """Set the destination UDP-port for replies returning from this server to the remote client
        """
        if (port > 1024) and (port < 65536):
            self.return_port = port
        else:
            self.return_port = None


    def setSrvInfoPrefix(self, pattern):
        """Set the first part of OSC-address (pattern) this server will use to reply to server-info requests.
        """
        if len(pattern):
            pattern = '/' + pattern.strip('/')

        self.info_prefix = pattern

    def setSrvErrorPrefix(self, pattern=""):
        """Set the OSC-address (pattern) this server will use to report errors occuring during
        received message handling to the remote client.

        If pattern is empty (default), server-errors are not reported back to the client.
        """
        if len(pattern):
            pattern = '/' + pattern.strip('/')

        self.error_prefix = pattern

    def addDefaultHandlers(self, prefix="", info_prefix="/info", error_prefix="/error"):
        """Register a default set of OSC-address handlers with this Server:
        - 'default' ->  noCallback_handler
        the given prefix is prepended to all other callbacks registered by this method:
        - '<prefix><info_prefix' ->  serverInfo_handler
        - '<prefix><error_prefix> ->  msgPrinter_handler
        - '<prefix>/print' ->  msgPrinter_handler
        and, if the used Client supports it;
        - '<prefix>/subscribe' -> subscription_handler
        - '<prefix>/unsubscribe' -> subscription_handler

        Note: the given 'error_prefix' argument is also set as default 'error_prefix' for error-messages
        *sent from* this server. This is ok, because error-messages generally do not elicit a reply from the receiver.

        To do this with the serverInfo-prefixes would be a bad idea, because if a request received on '/info' (for example)
        would send replies to '/info', this could potentially cause a never-ending loop of messages!
        Do *not* set the 'info_prefix' here (for incoming serverinfo requests) to the same value as given to
        the setSrvInfoPrefix() method (for *replies* to incoming serverinfo requests).
        For example, use '/info' for incoming requests, and '/inforeply' or '/serverinfo' or even just '/print' as the
        info-reply prefix.
        """
        self.error_prefix = error_prefix
        self.addMsgHandler('default', self.noCallback_handler)
        self.addMsgHandler(prefix + info_prefix, self.serverInfo_handler)
        self.addMsgHandler(prefix + error_prefix, self.msgPrinter_handler)
        self.addMsgHandler(prefix + '/print', self.msgPrinter_handler)

        if isinstance(self.client, OSCMultiClient):
            self.addMsgHandler(prefix + '/subscribe', self.subscription_handler)
            self.addMsgHandler(prefix + '/unsubscribe', self.subscription_handler)

    def printErr(self, txt):
        """Writes 'OSCServer: txt' to sys.stderr
        """
        sys.stderr.write("OSCServer: %s\n" % txt)

    def sendOSCerror(self, txt, client_address):
        """Sends 'txt', encapsulated in an OSCMessage to the default 'error_prefix' OSC-addres.
        Message is sent to the given client_address, with the default 'return_port' overriding
        the client_address' port, if defined.
        """
        lines = txt.split('\n')
        if len(lines) == 1:
            msg = OSCMessage(self.error_prefix)
            msg.append(lines[0])
        elif len(lines) > 1:
            msg = OSCBundle(self.error_prefix)
            for line in lines:
                msg.append(line)
        else:
            return

        if self.return_port:
            client_address = (client_address[0], self.return_port)

        self.client.sendto(msg, client_address)

    def reportErr(self, txt, client_address):
        """Writes 'OSCServer: txt' to sys.stderr
        If self.error_prefix is defined, sends 'txt' as an OSC error-message to the client(s)
        (see printErr() and sendOSCerror())
        """
        self.printErr(txt)

        if len(self.error_prefix):
            self.sendOSCerror(txt, client_address)

    def sendOSCinfo(self, txt, client_address):
        """Sends 'txt', encapsulated in an OSCMessage to the default 'info_prefix' OSC-addres.
        Message is sent to the given client_address, with the default 'return_port' overriding
        the client_address' port, if defined.
        """
        lines = txt.split('\n')
        if len(lines) == 1:
            msg = OSCMessage(self.info_prefix)
            msg.append(lines[0])
        elif len(lines) > 1:
            msg = OSCBundle(self.info_prefix)
            for line in lines:
                msg.append(line)
        else:
            return

        if self.return_port:
            client_address = (client_address[0], self.return_port)

        self.client.sendto(msg, client_address)

    ###
    # Message-Handler callback functions
    ###

    def handle_error(self, request, client_address):
        """Handle an exception in the Server's callbacks gracefully.
        Writes the error to sys.stderr and, if the error_prefix (see setSrvErrorPrefix()) is set,
        sends the error-message as reply to the client
        """
        (e_type, e) = sys.exc_info()[:2]
        self.printErr("%s on request from %s: %s" % (e_type.__name__, getUrlStr(client_address), str(e)))

        if self.print_tracebacks:
            import traceback
            traceback.print_exc() # XXX But this goes to stderr!

        if len(self.error_prefix):
            self.sendOSCerror("%s: %s" % (e_type.__name__, str(e)), client_address)

    def noCallback_handler(self, addr, tags, data, client_address):
        """Example handler for OSCMessages.
        All registerd handlers must accept these three arguments:
        - addr (string): The OSC-address pattern of the received Message
          (the 'addr' string has already been matched against the handler's registerd OSC-address,
          but may contain '*'s & such)
        - tags (string):  The OSC-typetags of the received message's arguments. (without the preceding comma)
        - data (list): The OSCMessage's arguments
          Note that len(tags) == len(data)
        - client_address ((host, port) tuple): the host & port this message originated from.

        a Message-handler function may return None, but it could also return an OSCMessage (or OSCBundle),
        which then gets sent back to the client.

        This handler prints a "No callback registered to handle ..." message.
        Returns None
        """
        self.reportErr("No callback registered to handle OSC-address '%s'" % addr, client_address)

    def msgPrinter_handler(self, addr, tags, data, client_address):
        """Example handler for OSCMessages.
        All registerd handlers must accept these three arguments:
        - addr (string): The OSC-address pattern of the received Message
          (the 'addr' string has already been matched against the handler's registerd OSC-address,
          but may contain '*'s & such)
        - tags (string):  The OSC-typetags of the received message's arguments. (without the preceding comma)
        - data (list): The OSCMessage's arguments
          Note that len(tags) == len(data)
        - client_address ((host, port) tuple): the host & port this message originated from.

        a Message-handler function may return None, but it could also return an OSCMessage (or OSCBundle),
        which then gets sent back to the client.

        This handler prints the received message.
        Returns None
        """
        txt = "OSCMessage '%s' from %s: " % (addr, getUrlStr(client_address))
        txt += str(data)

        self.printErr(txt)  # strip trailing comma & space

    def serverInfo_handler(self, addr, tags, data, client_address):
        """Example handler for OSCMessages.
        All registerd handlers must accept these three arguments:
        - addr (string): The OSC-address pattern of the received Message
          (the 'addr' string has already been matched against the handler's registerd OSC-address,
          but may contain '*'s & such)
        - tags (string):  The OSC-typetags of the received message's arguments. (without the preceding comma)
        - data (list): The OSCMessage's arguments
          Note that len(tags) == len(data)
        - client_address ((host, port) tuple): the host & port this message originated from.

        a Message-handler function may return None, but it could also return an OSCMessage (or OSCBundle),
        which then gets sent back to the client.

        This handler returns a reply to the client, which can contain various bits of information
        about this server, depending on the first argument of the received OSC-message:
        - 'help' | 'info' :  Reply contains server type & version info, plus a list of
          available 'commands' understood by this handler
        - 'list' | 'ls' :  Reply is a bundle of 'address <string>' messages, listing the server's
          OSC address-space.
        - 'clients' | 'targets' :  Reply is a bundle of 'target osc://<host>:<port>[<prefix>] [<filter>] [...]'
          messages, listing the local Client-instance's subscribed remote clients.
        """
        if len(data) == 0:
            return None

        cmd = data.pop(0)

        reply = None
        if cmd in ('help', 'info'):
            reply = OSCBundle(self.info_prefix)
            reply.append(('server', str(self)))
            reply.append(('info_command', "ls | list : list OSC address-space"))
            reply.append(('info_command', "clients | targets : list subscribed clients"))
        elif cmd in ('ls', 'list'):
            reply = OSCBundle(self.info_prefix)
            for addr in list(self.callbacks.keys()):
                reply.append(('address', addr))
        elif cmd in ('clients', 'targets'):
            if hasattr(self.client, 'getOSCTargetStrings'):
                reply = OSCBundle(self.info_prefix)
                for trg in self.client.getOSCTargetStrings():
                    reply.append(('target',) + trg)
            else:
                cli_addr = self.client.address()
                if cli_addr:
                    reply = OSCMessage(self.info_prefix)
                    reply.append(('target', "osc://%s/" % getUrlStr(cli_addr)))
        else:
            self.reportErr("unrecognized command '%s' in /info request from osc://%s. Try 'help'" % (cmd, getUrlStr(client_address)), client_address)

        return reply

    def _subscribe(self, data, client_address):
        """Handle the actual subscription. the provided 'data' is concatenated together to form a
        '<host>:<port>[<prefix>] [<filter>] [...]' string, which is then passed to
        parseUrlStr() & parseFilterStr() to actually retreive <host>, <port>, etc.

        This 'long way 'round' approach (almost) guarantees that the subscription works,
        regardless of how the bits of the <url> are encoded in 'data'.
        """
        url = ""
        have_port = False
        for item in data:
            if (isinstance(item,int)) and not have_port:
                url += ":%d" % item
                have_port = True
            elif isinstance(item,str):
                url += item

        (addr, tail) = parseUrlStr(url)
        (prefix, filters) = parseFilterStr(tail)

        if addr != None:
            (host, port) = addr
            if not host:
                host = client_address[0]
            if not port:
                port = client_address[1]
            addr = (host, port)
        else:
            addr = client_address

        self.client._setTarget(addr, prefix, filters)

        trg = self.client.getOSCTargetStr(addr)
        if trg[0] != None:
            reply = OSCMessage(self.info_prefix)
            reply.append(('target',) + trg)
            return reply

    def _unsubscribe(self, data, client_address):
        """Handle the actual unsubscription. the provided 'data' is concatenated together to form a
        '<host>:<port>[<prefix>]' string, which is then passed to
        parseUrlStr() to actually retreive <host>, <port> & <prefix>.

        This 'long way 'round' approach (almost) guarantees that the unsubscription works,
        regardless of how the bits of the <url> are encoded in 'data'.
        """
        url = ""
        have_port = False
        for item in data:
            if (isinstance(item,int)) and not have_port:
                url += ":%d" % item
                have_port = True
            elif isinstance(item,str):
                url += item

        (addr, _) = parseUrlStr(url)

        if addr == None:
            addr = client_address
        else:
            (host, port) = addr
            if not host:
                host = client_address[0]
            if not port:
                try:
                    (host, port) = self.client._searchHostAddr(host)
                except NotSubscribedError:
                    port = client_address[1]

            addr = (host, port)

        try:
            self.client._delTarget(addr)
        except NotSubscribedError as e:
            txt = "%s: %s" % (e.__class__.__name__, str(e))
            self.printErr(txt)

            reply = OSCMessage(self.error_prefix)
            reply.append(txt)
            return reply

    def subscription_handler(self, addr, tags, data, client_address):
        """Handle 'subscribe' / 'unsubscribe' requests from remote hosts,
        if the local Client supports this (i.e. OSCMultiClient).

        Supported commands:
        - 'help' | 'info' :  Reply contains server type & version info, plus a list of
          available 'commands' understood by this handler
        - 'list' | 'ls' :  Reply is a bundle of 'target osc://<host>:<port>[<prefix>] [<filter>] [...]'
          messages, listing the local Client-instance's subscribed remote clients.
        - '[subscribe | listen | sendto | target] <url> [<filter> ...] :  Subscribe remote client/server at <url>,
          and/or set message-filters for messages being sent to the subscribed host, with the optional <filter>
          arguments. Filters are given as OSC-addresses (or '*') prefixed by a '+' (send matching messages) or
          a '-' (don't send matching messages). The wildcard '*', '+*' or '+/*' means 'send all' / 'filter none',
          and '-*' or '-/*' means 'send none' / 'filter all' (which is not the same as unsubscribing!)
          Reply is an OSCMessage with the (new) subscription; 'target osc://<host>:<port>[<prefix>] [<filter>] [...]'
        - '[unsubscribe | silence | nosend | deltarget] <url> :  Unsubscribe remote client/server at <url>
          If the given <url> isn't subscribed, a NotSubscribedError-message is printed (and possibly sent)

        The <url> given to the subscribe/unsubscribe handler should be of the form:
        '[osc://][<host>][:<port>][<prefix>]', where any or all components can be omitted.

        If <host> is not specified, the IP-address of the message's source is used.
        If <port> is not specified, the <host> is first looked up in the list of subscribed hosts, and if found,
        the associated port is used.
        If <port> is not specified and <host> is not yet subscribed, the message's source-port is used.
        If <prefix> is specified on subscription, <prefix> is prepended to the OSC-address of all messages
        sent to the subscribed host.
        If <prefix> is specified on unsubscription, the subscribed host is only unsubscribed if the host,
        port and prefix all match the subscription.
        If <prefix> is not specified on unsubscription, the subscribed host is unsubscribed if the host and port
        match the subscription.
        """
        if not isinstance(self.client, OSCMultiClient):
            raise OSCServerError("Local %s does not support subsctiptions or message-filtering" % self.client.__class__.__name__)

        addr_cmd = addr.split('/')[-1]

        if len(data):
            if data[0] in ('help', 'info'):
                reply = OSCBundle(self.info_prefix)
                reply.append(('server', str(self)))
                reply.append(('subscribe_command', "ls | list : list subscribed targets"))
                reply.append(('subscribe_command', "[subscribe | listen | sendto | target] <url> [<filter> ...] : subscribe to messages, set filters"))
                reply.append(('subscribe_command', "[unsubscribe | silence | nosend | deltarget] <url> : unsubscribe from messages"))
                return reply

            if data[0] in ('ls', 'list'):
                reply = OSCBundle(self.info_prefix)
                for trg in self.client.getOSCTargetStrings():
                    reply.append(('target',) + trg)
                return reply

            if data[0] in ('subscribe', 'listen', 'sendto', 'target'):
                return self._subscribe(data[1:], client_address)

            if data[0] in ('unsubscribe', 'silence', 'nosend', 'deltarget'):
                return self._unsubscribe(data[1:], client_address)

        if addr_cmd in ('subscribe', 'listen', 'sendto', 'target'):
            return self._subscribe(data, client_address)

        if addr_cmd in ('unsubscribe', 'silence', 'nosend', 'deltarget'):
            return self._unsubscribe(data, client_address)

class ForkingOSCServer(ForkingMixIn, OSCServer):
    """An Asynchronous OSCServer.
    This server forks a new process to handle each incoming request.
    """
    # set the RequestHandlerClass, will be overridden by ForkingOSCServer & ThreadingOSCServer
    RequestHandlerClass = ThreadingOSCRequestHandler

class ThreadingOSCServer(ThreadingMixIn, OSCServer):
    """An Asynchronous OSCServer.
    This server starts a new thread to handle each incoming request.
    """
    # set the RequestHandlerClass, will be overridden by ForkingOSCServer & ThreadingOSCServer
    RequestHandlerClass = ThreadingOSCRequestHandler

######
#
# OSCError classes
#
######

class OSCError(Exception):
    """Base Class for all OSC-related errors
    """
    def __init__(self, message):
        self.message = message

    def __str__(self):
        return self.message

class OSCClientError(OSCError):
    """Class for all OSCClient errors
    """
    pass

class OSCServerError(OSCError):
    """Class for all OSCServer errors
    """
    pass

class NoCallbackError(OSCServerError):
    """This error is raised (by an OSCServer) when an OSCMessage with an 'unmatched' address-pattern
    is received, and no 'default' handler is registered.
    """
    def __init__(self, pattern):
        """The specified 'pattern' should be the OSC-address of the 'unmatched' message causing the error to be raised.
        """
        self.message = "No callback registered to handle OSC-address '%s'" % pattern

class NotSubscribedError(OSCClientError):
    """This error is raised (by an OSCMultiClient) when an attempt is made to unsubscribe a host
    that isn't subscribed.
    """
    def __init__(self, addr, prefix=None):
        if prefix:
            url = getUrlStr(addr, prefix)
        else:
            url = getUrlStr(addr, '')

        self.message = "Target osc://%s is not subscribed" % url

######
#
# OSC over streaming transport layers (usually TCP)
#
# Note from the OSC 1.0 specifications about streaming protocols:
#
# The underlying network that delivers an OSC packet is responsible for
# delivering both the contents and the size to the OSC application. An OSC
# packet can be naturally represented by a datagram by a network protocol such
# as UDP. In a stream-based protocol such as TCP, the stream should begin with
# an int32 giving the size of the first packet, followed by the contents of the
# first packet, followed by the size of the second packet, etc.
#
# The contents of an OSC packet must be either an OSC Message or an OSC Bundle.
# The first byte of the packet's contents unambiguously distinguishes between
# these two alternatives.
#
######

class OSCStreamRequestHandler(StreamRequestHandler, OSCAddressSpace):
    """ This is the central class of a streaming OSC server. If a client
    connects to the server, the server instantiates a OSCStreamRequestHandler
    for each new connection. This is fundamentally different to a packet
    oriented server which has a single address space for all connections.
    This connection based (streaming) OSC server maintains an address space
    for each single connection, because usually tcp server spawn a new thread
    or process for each new connection. This would generate severe
    multithreading synchronization problems when each thread would operate on
    the same address space object. Therefore: To implement a streaming/TCP OSC
    server a custom handler must be implemented which implements the
    setupAddressSpace member in which it creates its own address space for this
    very connection. This has been done within the testbench and can serve as
    inspiration.
    """
    def __init__(self, request, client_address, server):
        """ Initialize all base classes. The address space must be initialized
        before the stream request handler because the initialization function
        of the stream request handler calls the setup member which again
        requires an already initialized address space.
        """
        self._txMutex = threading.Lock()
        OSCAddressSpace.__init__(self)
        StreamRequestHandler.__init__(self, request, client_address, server)

    def _unbundle(self, decoded):
        """Recursive bundle-unpacking function"""
        if decoded[0] != "#bundle":
            self.replies += self.dispatchMessage(decoded[0], decoded[1][1:], decoded[2:], self.client_address)
            return

        now = time.time()
        timetag = decoded[1]
        if (timetag > 0.) and (timetag > now):
            time.sleep(timetag - now)

        for msg in decoded[2:]:
            self._unbundle(msg)

    def setup(self):
        StreamRequestHandler.setup(self)
        print("SERVER: New client connection.")
        self.setupAddressSpace()
        self.server._clientRegister(self)

    def setupAddressSpace(self):
        """ Override this function to customize your address space. """
        pass

    def finish(self):
        StreamRequestHandler.finish(self)
        self.server._clientUnregister(self)
        print("SERVER: Client connection handled.")
    def _transmit(self, data):
        sent = 0
        while sent < len(data):
            tmp = self.connection.send(data[sent:])
            if tmp == 0:
                return False
            sent += tmp
        return True
    def _transmitMsg(self, msg):
        """Send an OSC message over a streaming socket. Raises exception if it
        should fail. If everything is transmitted properly, True is returned. If
        socket has been closed, False.
        """
        if not isinstance(msg, OSCMessage):
            raise TypeError("'msg' argument is not an OSCMessage or OSCBundle object")

        try:
            binary = msg.getBinary()
            length = len(binary)
            # prepend length of packet before the actual message (big endian)
            len_big_endian = array.array('c', '\0' * 4)
            struct.pack_into(">L", len_big_endian, 0, length)
            len_big_endian = len_big_endian.tostring()
            if self._transmit(len_big_endian) and self._transmit(binary):
                return True
            return False
        except socket.error as e:
            if e[0] == errno.EPIPE: # broken pipe
                return False
            raise e

    def _receive(self, count):
        """ Receive a certain amount of data from the socket and return it. If the
        remote end should be closed in the meanwhile None is returned.
        """
        chunk = self.connection.recv(count)
        if not chunk or len(chunk) == 0:
            return None
        while len(chunk) < count:
            tmp = self.connection.recv(count - len(chunk))
            if not tmp or len(tmp) == 0:
                return None
            chunk = chunk + tmp
        return chunk

    def _receiveMsg(self):
        """ Receive OSC message from a socket and decode.
        If an error occurs, None is returned, else the message.
        """
        # get OSC packet size from stream which is prepended each transmission
        chunk = self._receive(4)
        if chunk == None:
            print("SERVER: Socket has been closed.")
            return None
        # extract message length from big endian unsigned long (32 bit)
        slen = struct.unpack(">L", chunk)[0]
        # receive the actual message
        chunk = self._receive(slen)
        if chunk == None:
            print("SERVER: Socket has been closed.")
            return None
        # decode OSC data and dispatch
        msg = decodeOSC(chunk)
        if msg == None:
            raise OSCError("SERVER: Message decoding failed.")
        return msg

    def handle(self):
        """
        Handle a connection.
        """
        # set socket blocking to avoid "resource currently not available"
        # exceptions, because the connection socket inherits the settings
        # from the listening socket and this times out from time to time
        # in order to provide a way to shut the server down. But we want
        # clean and blocking behaviour here
        self.connection.settimeout(None)

        print("SERVER: Entered server loop")
        try:
            while True:
                decoded = self._receiveMsg()
                if decoded == None:
                    return
                elif len(decoded) <= 0:
                    # if message decoding fails we try to stay in sync but print a message
                    print("OSC stream server: Spurious message received.")
                    continue

                self.replies = []
                self._unbundle(decoded)

                if len(self.replies) > 1:
                    msg = OSCBundle()
                    for reply in self.replies:
                        msg.append(reply)
                elif len(self.replies) == 1:
                    msg = self.replies[0]
                else:
                    # no replies, continue receiving
                    continue
                self._txMutex.acquire()
                txOk = self._transmitMsg(msg)
                self._txMutex.release()
                if not txOk:
                    break

        except socket.error as e:
            if e[0] == errno.ECONNRESET:
                # if connection has been reset by client, we do not care much
                # about it, we just assume our duty fullfilled
                print("SERVER: Connection has been reset by peer.")
            else:
                raise e

    def sendOSC(self, oscData):
        """ This member can be used to transmit OSC messages or OSC bundles
        over the client/server connection. It is thread save.
        """
        self._txMutex.acquire()
        result = self._transmitMsg(oscData)
        self._txMutex.release()
        return result

""" TODO Note on threaded unbundling for streaming (connection oriented)
transport:

Threaded unbundling as implemented in ThreadingOSCServer must be implemented in
a different way for the streaming variant, because contrary to the datagram
version the streaming handler is instantiated only once per connection. This
leads to the problem (if threaded unbundling is implemented as in OSCServer)
that all further message reception is blocked until all (previously received)
pending messages are processed.

Each StreamRequestHandler should provide a so called processing queue in which
all pending messages or subbundles are inserted to be processed in the future).
When a subbundle or message gets queued, a mechanism must be provided that
those messages get invoked when time asks for them. There are the following
opportunities:
    - a timer is started which checks at regular intervals for messages in the
    queue (polling - requires CPU resources)
    - a dedicated timer is started for each message (requires timer resources)
"""

class OSCStreamingServer(TCPServer):
    """ A connection oriented (TCP/IP) OSC server.
    """

    # define a socket timeout, so the serve_forever loop can actually exit.
    # with 2.6 and server.shutdown this wouldn't be necessary
    socket_timeout = 1

    # this is the class which handles a new connection. Override this for a
    # useful customized server. See the testbench for an example
    RequestHandlerClass = OSCStreamRequestHandler

    def __init__(self, address):
        """Instantiate an OSCStreamingServer.
          - server_address ((host, port) tuple): the local host & UDP-port
          the server listens for new connections.
        """
        self._clientList = []
        self._clientListMutex = threading.Lock()
        TCPServer.__init__(self, address, self.RequestHandlerClass)
        self.socket.settimeout(self.socket_timeout)

    def serve_forever(self):
        """Handle one request at a time until server is closed.
        Had to add this since 2.5 does not support server.shutdown()
        """
        self.running = True
        while self.running:
            self.handle_request()   # this times-out when no data arrives.

    def start(self):
        """ Start the server thread. """
        self._server_thread = threading.Thread(target=self.serve_forever)
        self._server_thread.setDaemon(True)
        self._server_thread.start()

    def stop(self):
        """ Stop the server thread and close the socket. """
        self.running = False
        self._server_thread.join()
        self.server_close()
        # 2.6 only
        #self.shutdown()

    def _clientRegister(self, client):
        """ Gets called by each request/connection handler when connection is
        established to add itself to the client list
        """
        self._clientListMutex.acquire()
        self._clientList.append(client)
        self._clientListMutex.release()

    def _clientUnregister(self, client):
        """ Gets called by each request/connection handler when connection is
        lost to remove itself from the client list
        """
        self._clientListMutex.acquire()
        self._clientList.remove(client)
        self._clientListMutex.release()

    def broadcastToClients(self, oscData):
        """ Send OSC message or bundle to all connected clients. """
        result = True
        for client in self._clientList:
            result = result and client.sendOSC(oscData)
        return result

class OSCStreamingServerThreading(ThreadingMixIn, OSCStreamingServer):
    pass
    """ Implements a server which spawns a separate thread for each incoming
    connection. Care must be taken since the OSC address space is for all
    the same.
    """

class OSCStreamingClient(OSCAddressSpace):
    """ OSC streaming client.
    A streaming client establishes a connection to a streaming server but must
    be able to handle replies by the server as well. To accomplish this the
    receiving takes place in a secondary thread, because no one knows if we
    have to expect a reply or not, i.e. synchronous architecture doesn't make
    much sense.
    Replies will be matched against the local address space. If message
    handlers access code of the main thread (where the client messages are sent
    to the server) care must be taken e.g. by installing sychronization
    mechanisms or by using an event dispatcher which can handle events
    originating from other threads.
    """
    # set outgoing socket buffer size
    sndbuf_size = 4096 * 8
    rcvbuf_size = 4096 * 8

    def __init__(self):
        self._txMutex = threading.Lock()
        OSCAddressSpace.__init__(self)
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, self.sndbuf_size)
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, self.rcvbuf_size)
        self.socket.settimeout(1.0)
        self._running = False

    def _receiveWithTimeout(self, count):
        chunk = str()
        while len(chunk) < count:
            try:
                tmp = self.socket.recv(count - len(chunk))
            except socket.timeout:
                if not self._running:
                    print("CLIENT: Socket timed out and termination requested.")
                    return None
                else:
                    continue
            except socket.error as e:
                if e[0] == errno.ECONNRESET:
                    print("CLIENT: Connection reset by peer.")
                    return None
                else:
                    raise e
            if not tmp or len(tmp) == 0:
                print("CLIENT: Socket has been closed.")
                return None
            chunk = chunk + tmp
        return chunk
    def _receiveMsgWithTimeout(self):
        """ Receive OSC message from a socket and decode.
        If an error occurs, None is returned, else the message.
        """
        # get OSC packet size from stream which is prepended each transmission
        chunk = self._receiveWithTimeout(4)
        if not chunk:
            return None
        # extract message length from big endian unsigned long (32 bit)
        slen = struct.unpack(">L", chunk)[0]
        # receive the actual message
        chunk = self._receiveWithTimeout(slen)
        if not chunk:
            return None
        # decode OSC content
        msg = decodeOSC(chunk)
        if msg == None:
            raise OSCError("CLIENT: Message decoding failed.")
        return msg

    def _receiving_thread_entry(self):
        print("CLIENT: Entered receiving thread.")
        self._running = True
        while self._running:
            decoded = self._receiveMsgWithTimeout()
            if not decoded:
                break
            elif len(decoded) <= 0:
                continue

            self.replies = []
            self._unbundle(decoded)
            if len(self.replies) > 1:
                msg = OSCBundle()
                for reply in self.replies:
                    msg.append(reply)
            elif len(self.replies) == 1:
                msg = self.replies[0]
            else:
                continue
            self._txMutex.acquire()
            txOk = self._transmitMsgWithTimeout(msg)
            self._txMutex.release()
            if not txOk:
                break
        print("CLIENT: Receiving thread terminated.")

    def _unbundle(self, decoded):
        if decoded[0] != "#bundle":
            self.replies += self.dispatchMessage(decoded[0], decoded[1][1:], decoded[2:], self.socket.getpeername())
            return

        now = time.time()
        timetag = decoded[1]
        if (timetag > 0.) and (timetag > now):
            time.sleep(timetag - now)

        for msg in decoded[2:]:
            self._unbundle(msg)

    def connect(self, address):
        self.socket.connect(address)
        self.receiving_thread = threading.Thread(target=self._receiving_thread_entry)
        self.receiving_thread.start()

    def close(self):
        # let socket time out
        self._running = False
        self.receiving_thread.join()
        self.socket.close()

    def _transmitWithTimeout(self, data):
        sent = 0
        while sent < len(data):
            try:
                tmp = self.socket.send(data[sent:])
            except socket.timeout:
                if not self._running:
                    print("CLIENT: Socket timed out and termination requested.")
                    return False
                else:
                    continue
            except socket.error as e:
                if e[0] == errno.ECONNRESET:
                    print("CLIENT: Connection reset by peer.")
                    return False
                else:
                    raise e
            if tmp == 0:
                return False
            sent += tmp
        return True

    def _transmitMsgWithTimeout(self, msg):
        if not isinstance(msg, OSCMessage):
            raise TypeError("'msg' argument is not an OSCMessage or OSCBundle object")
        binary = msg.getBinary()
        length = len(binary)
        # prepend length of packet before the actual message (big endian)
        len_big_endian = array.array('c', '\0' * 4)
        struct.pack_into(">L", len_big_endian, 0, length)
        len_big_endian = len_big_endian.tostring()
        if self._transmitWithTimeout(len_big_endian) and self._transmitWithTimeout(binary):
            return True
        else:
            return False

    def sendOSC(self, msg):
        """Send an OSC message or bundle to the server. Returns True on success.
        """
        self._txMutex.acquire()
        txOk = self._transmitMsgWithTimeout(msg)
        self._txMutex.release()
        return txOk

    def __str__(self):
        """Returns a string containing this Client's Class-name, software-version
        and the remote-address it is connected to (if any)
        """
        out = self.__class__.__name__
        out += " v%s.%s-%s" % version
        addr = self.socket.getpeername()
        if addr:
            out += " connected to osc://%s" % getUrlStr(addr)
        else:
            out += " (unconnected)"

        return out

    def __eq__(self, other):
        """Compare function.
        """
        if not isinstance(other, self.__class__):
            return False

        isequal = cmp(self.socket._sock, other.socket._sock)
        if isequal and self.server and other.server:
            return cmp(self.server, other.server)

        return isequal

    def __ne__(self, other):
        """Compare function.
        """
        return not self.__eq__(other)