OSC.py

#!/usr/bin/python
#
# 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
#
# Updated June 2007 by Hans Huebner (hans.huebner@gmail.com)
#   Improved bundle support, API cleanup

import sys
import struct
import math
import string
import time

from Logger import log

def hexDump(bytes):
    """Useful utility; prints the string in hexadecimal"""
    for i in range(len(bytes)):
        sys.stdout.write("%2x " % (ord(bytes[i])))
        if (i+1) % 8 == 0:
            print repr(bytes[i-7:i+1])

    if(len(bytes) % 8 != 0):
        print string.rjust("", 11), repr(bytes[i-7:i+1])

class OSCMessage:
    """Builds typetagged OSC messages."""
    def __init__(self, address='', msg=()):
        self.address  = address
        self.typetags = ","
        self.message  = ""

        if type(msg) in (str, int, float):
           self.append(msg)
        elif type(msg) in (list,tuple):
             for m in msg:
                if type(m) not in (str,int,float):
                    log("don't know how to encode message element " + str(m) + " " + str(type(m)))
                    return
                self.append(m)
        else:
            log("don't know how to encode message " + str(m) + " " + str(type(m)))
            return

    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."""

        if typehint == 'b':
            binary = OSCBlob(argument)
        else:
            binary = OSCArgument(argument)

        self.typetags = self.typetags + binary[0]
        self.message = self.message + binary[1]

    def getBinary(self):
        """Returns the binary message (so far) with typetags."""
        address  = OSCArgument(self.address)[1]
        typetags = OSCArgument(self.typetags)[1]
        return address + typetags + self.message

    def __repr__(self):
        return self.getBinary()

JAN_1970 = 2208988800L
SECS_TO_PICOS = 4294967296L
def abs_to_timestamp(abs):
    """ since 1970 => since 1900 64b OSC """
    sec_1970 = long(abs)
    sec_1900 = sec_1970 + JAN_1970

    sec_frac = float(abs - sec_1970)
    picos = long(sec_frac * SECS_TO_PICOS)

    total_picos = (abs + JAN_1970) * SECS_TO_PICOS
    return struct.pack('!LL', sec_1900, picos)

class OSCBundle:
    """Builds OSC bundles"""
    def __init__(self, when=None):
        self.items = []
        if when == None:
            when = time.time()
        self.when = when

    def append(self, address, msg = None):
        if isinstance(address, str):
            self.items.append(OSCMessage(address, msg))
        elif isinstance(address, OSCMessage):
            # address really is an OSCMessage
            self.items.append(address)
        else:
            raise Exception('invalid type of first argument to OSCBundle.append(), need address string or OSCMessage, not ', str(type(address)))

    def getBinary(self):
        retval = OSCArgument('#bundle')[1] + abs_to_timestamp(self.when)
        for item in self.items:
            binary = item.getBinary()
            retval = retval + OSCArgument(len(binary))[1] + binary
        return retval

def readString(data):
    length   = string.find(data,"\0")
    nextData = int(math.ceil((length+1) / 4.0) * 4)
    return (data[0:length], data[nextData:])

def readBlob(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):
    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 = (long(high) << 32) + low
    rest = data[8:]
    return (big, rest)

def readFloat(data):
    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 OSCBlob(next):
    """Convert a string into an OSC Blob,
    returning a (typetag, data) tuple."""

    if type(next) == type(""):
        length = len(next)
        padded = math.ceil((len(next)) / 4.0) * 4
        binary = struct.pack(">i%ds" % (padded), length, next)
        tag    = 'b'
    else:
        tag    = ''
        binary = ''
    
    return (tag, binary)

def OSCArgument(next):
    """Convert some Python types to their
    OSC binary representations, returning a
    (typetag, data) tuple."""
    
    if type(next) == type(""):        
        OSCstringLength = math.ceil((len(next)+1) / 4.0) * 4
        binary  = struct.pack(">%ds" % (OSCstringLength), next)
        tag = "s"
    elif type(next) == type(42.5):
        binary  = struct.pack(">f", next)
        tag = "f"
    elif type(next) == type(13):
        binary  = struct.pack(">i", next)
        tag = "i"
    else:
        raise Exception("don't know how to encode " + str(next) + " as OSC argument, type=" + str(type(next)))

    return (tag, binary)

def parseArgs(args):
    """Given a list of strings, produces a list
    where those strings have been parsed (where
    possible) as floats or integers."""
    parsed = []
    for arg in args:
        print arg
        arg = arg.strip()
        interpretation = None
        try:
            interpretation = float(arg)
            if string.find(arg, ".") == -1:
                interpretation = int(interpretation)
        except:
            # Oh - it was a string.
            interpretation = arg
        parsed.append(interpretation)
    return parsed

def decodeOSC(data):
    """Converts a typetagged OSC message to a Python list."""
    table = {"i":readInt, "f":readFloat, "s":readString, "b":readBlob}
    decoded = []
    address,  rest = readString(data)
    typetags = ""

    if address == "#bundle":
        time, rest = readLong(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:
        typetags, rest = readString(rest)
        decoded.append(address)
        decoded.append(typetags)
        if(typetags[0] == ","):
            for tag in typetags[1:]:
                value, rest = table[tag](rest)                
                decoded.append(value)
        else:
            print "Oops, typetag lacks the magic ,"
    else:
        decoded.append(address)
        decoded.append(',')

    # return only the data
    return decoded

class CallbackManager:
    """This utility class maps OSC addresses to callables.

    The CallbackManager calls its callbacks with a list
    of decoded OSC arguments, including the address and
    the typetags as the first two arguments."""

    def __init__(self):
        self.callbacks = {}
        self.add("#bundle", self.unbundler)

    def handle(self, data, source):
        """Given OSC data, tries to call the callback with the right address."""
        decoded = decodeOSC(data)
        self.dispatch(decoded, source)

    def dispatch(self, message, source):
        """Sends decoded OSC data to an appropriate calback"""
        address = message[0]
        self.callbacks[address](message, source)

    def add(self, address, callback):
        """Adds a callback to our set of callbacks,
        or removes the callback with name if callback
        is None."""
        if callback == None:
            del self.callbacks[address]
        else:
            self.callbacks[address] = callback

    def unbundler(self, messages, source):
        """Dispatch the messages in a decoded bundle."""
        # first two elements are #bundle and the time tag, rest are messages.
        for message in messages[2:]:
            self.dispatch(message, source)

if __name__ == "__main__":
    hexDump("Welcome to the OSC testing program.")
    print
    message = OSCMessage("/foo/play")
    message.append(44)
    message.append(11)
    message.append(4.5)
    message.append("the white cliffs of dover")
    hexDump(message.getBinary())

    print "Making and unmaking a message.."

    strings = OSCMessage()
    strings.append("Mary had a little lamb")
    strings.append("its fleece was white as snow")
    strings.append("and everywhere that Mary went,")
    strings.append("the lamb was sure to go.")
    strings.append(14.5)
    strings.append(14.5)
    strings.append(-400)

    raw  = strings.getBinary()

    hexDump(raw)
    
    print "Retrieving arguments..."
    data = raw
    for i in range(6):
        text, data = readString(data)
        print text

    number, data = readFloat(data)
    print number

    number, data = readFloat(data)
    print number

    number, data = readInt(data)
    print number

    hexDump(raw)
    print decodeOSC(raw)
    print decodeOSC(message.getBinary())

    print "Testing Blob types."
   
    blob = OSCMessage()
    blob.append("","b")
    blob.append("b","b")
    blob.append("bl","b")
    blob.append("blo","b")
    blob.append("blob","b")
    blob.append("blobs","b")
    blob.append(42)

    hexDump(blob.getBinary())

    print decodeOSC(blob.getBinary())

    def printingCallback(stuff, source):
        sys.stdout.write("Got: ")
        for i in stuff:
            sys.stdout.write(str(i) + " ")
        sys.stdout.write("\n")

    print "Testing bundles"

    print1 = OSCMessage("/print")
    print1.append("Hey man, that's cool.")
    print1.append(42)
    print1.append(3.1415926)

    bundle = OSCBundle()
    bundle.append(print1)
    bundle.append('/foo', (123, 456))
    bundlebinary = bundle.getBinary()
    hexDump(bundlebinary)
    print decodeOSC(bundlebinary)

    print "Testing the callback manager."
    
    c = CallbackManager()
    c.add("/print", printingCallback)
    
    c.handle(message.getBinary(), None)
    
    c.handle(print1.getBinary(), None)

    print "sending a bundle to the callback manager"
    c.handle(bundlebinary, None)