X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=trunk%2FPLC%2FAPI.py;fp=trunk%2FPLC%2FAPI.py;h=7fcfa09451324cc51fdc0c2fdaa7e4cfa5de1eff;hb=5a4c1b1278ffa01e630fde47f7c54888ed20a576;hp=0000000000000000000000000000000000000000;hpb=cee5ab52df1c9f38b6eaff2dd354cb22f59028c7;p=plcapi.git diff --git a/trunk/PLC/API.py b/trunk/PLC/API.py new file mode 100644 index 0000000..7fcfa09 --- /dev/null +++ b/trunk/PLC/API.py @@ -0,0 +1,174 @@ +# +# PLCAPI XML-RPC and SOAP interfaces +# +# Aaron Klingaman +# Mark Huang +# +# Copyright (C) 2004-2006 The Trustees of Princeton University +# $Id$ +# + +import sys +import traceback +import string + +import xmlrpclib + +# See "2.2 Characters" in the XML specification: +# +# #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] +# avoiding +# [#x7F-#x84], [#x86-#x9F], [#xFDD0-#xFDDF] + +invalid_xml_ascii = map(chr, range(0x0, 0x8) + [0xB, 0xC] + range(0xE, 0x1F)) +xml_escape_table = string.maketrans("".join(invalid_xml_ascii), "?" * len(invalid_xml_ascii)) + +def xmlrpclib_escape(s, replace = string.replace): + """ + xmlrpclib does not handle invalid 7-bit control characters. This + function augments xmlrpclib.escape, which by default only replaces + '&', '<', and '>' with entities. + """ + + # This is the standard xmlrpclib.escape function + s = replace(s, "&", "&") + s = replace(s, "<", "<") + s = replace(s, ">", ">",) + + # Replace invalid 7-bit control characters with '?' + return s.translate(xml_escape_table) + +def xmlrpclib_dump(self, value, write): + """ + xmlrpclib cannot marshal instances of subclasses of built-in + types. This function overrides xmlrpclib.Marshaller.__dump so that + any value that is an instance of one of its acceptable types is + marshalled as that type. + + xmlrpclib also cannot handle invalid 7-bit control characters. See + above. + """ + + # Use our escape function + args = [self, value, write] + if isinstance(value, (str, unicode)): + args.append(xmlrpclib_escape) + + try: + # Try for an exact match first + f = self.dispatch[type(value)] + except KeyError: + # Try for an isinstance() match + for Type, f in self.dispatch.iteritems(): + if isinstance(value, Type): + f(*args) + return + raise TypeError, "cannot marshal %s objects" % type(value) + else: + f(*args) + +# You can't hide from me! +xmlrpclib.Marshaller._Marshaller__dump = xmlrpclib_dump + +# SOAP support is optional +try: + import SOAPpy + from SOAPpy.Parser import parseSOAPRPC + from SOAPpy.Types import faultType + from SOAPpy.NS import NS + from SOAPpy.SOAPBuilder import buildSOAP +except ImportError: + SOAPpy = None + +from PLC.Config import Config +from PLC.Faults import * +import PLC.Methods + +class PLCAPI: + methods = PLC.Methods.methods + + def __init__(self, config = "/etc/planetlab/plc_config", encoding = "utf-8"): + self.encoding = encoding + + # Better just be documenting the API + if config is None: + return + + # Load configuration + self.config = Config(config) + + # Initialize database connection + if self.config.PLC_DB_TYPE == "postgresql": + from PLC.PostgreSQL import PostgreSQL + self.db = PostgreSQL(self) + + else: + raise PLCAPIError, "Unsupported database type " + self.config.PLC_DB_TYPE + + def callable(self, method): + """ + Return a new instance of the specified method. + """ + + # Look up method + if method not in self.methods: + raise PLCInvalidAPIMethod, method + + # Get new instance of method + try: + classname = method.split(".")[-1] + module = __import__("PLC.Methods." + method, globals(), locals(), [classname]) + return getattr(module, classname)(self) + except ImportError, AttributeError: + raise PLCInvalidAPIMethod, method + + def call(self, source, method, *args): + """ + Call the named method from the specified source with the + specified arguments. + """ + + function = self.callable(method) + function.source = source + return function(*args) + + def handle(self, source, data): + """ + Handle an XML-RPC or SOAP request from the specified source. + """ + + # Parse request into method name and arguments + try: + interface = xmlrpclib + (args, method) = xmlrpclib.loads(data) + methodresponse = True + except Exception, e: + if SOAPpy is not None: + interface = SOAPpy + (r, header, body, attrs) = parseSOAPRPC(data, header = 1, body = 1, attrs = 1) + method = r._name + args = r._aslist() + # XXX Support named arguments + else: + raise e + + try: + result = self.call(source, method, *args) + except PLCFault, fault: + # Handle expected faults + if interface == xmlrpclib: + result = fault + methodresponse = None + elif interface == SOAPpy: + result = faultParameter(NS.ENV_T + ":Server", "Method Failed", method) + result._setDetail("Fault %d: %s" % (fault.faultCode, fault.faultString)) + + # Return result + if interface == xmlrpclib: + if not isinstance(result, PLCFault): + result = (result,) + data = xmlrpclib.dumps(result, methodresponse = True, encoding = self.encoding, allow_none = 1) + elif interface == SOAPpy: + data = buildSOAP(kw = {'%sResponse' % method: {'Result': result}}, encoding = self.encoding) + + return data