PropertyProxy.py

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# File: AthenaCommon/python/PropertyProxy.py
# Author: Wim Lavrijsen (WLavrijsen@lbl.gov)
# Author: Martin Woudstra (Martin.Woudstra@cern.ch)

# data ---------------------------------------------------------------------
__all__ = ['PropertyProxy', 'GaudiHandlePropertyProxy',
           'GaudiHandleArrayPropertyProxy']

import os
import glob
from GaudiKernel.GaudiHandles import *
from GaudiKernel import ConfigurableDb
from GaudiKernel.DataObjectHandleBase import *

import logging
log = logging.getLogger('PropertyProxy')

# dictionary with configurable class : python module entries
#-->PM#from AthenaCommon import ConfigurableDb


def derives_from(derived, base):
    """A string version of isinstance().
    <derived> is either an object instance, or a type
    <base>    is a string containing the name of the base class (or <derived> class)"""
    if not isinstance(derived, type):
        derived = type(derived)
    if derived.__name__ == base:
        return True
    for b in derived.__bases__:
        if derives_from(b, base):
            return True

    return False


def _isCompatible(tp, value):
    errmsg = "received an instance of %s, but %s expected" % (type(value), tp)

    if derives_from(value, 'PropertyReference'):
        # TODO: implement type checking for references
        return value  # references are valid
    if (tp is str):
        if (type(value) is str) or derives_from(value, 'Configurable'):
            # we can set string properties only from strings or configurables
            return value
        else:
            raise ValueError(errmsg)
    elif (tp in [list, tuple, dict]):
        if (type(value) is tp):
            # We need to check that the types match for lists, tuples and
            # dictionaries (bug #34769).
            return value
        else:
            raise ValueError(errmsg)
    elif derives_from(tp, 'Configurable'):
        return value
    else:
        # all other types: accept if conversion allowed
        try:
            dummy = tp(value)
        except (TypeError, ValueError):
            raise ValueError(errmsg)

    return dummy         # in case of e.g. classes with __int__, __iter__, etc. implemented


class PropertyProxy(object):
    def __init__(self, descr, docString=None, default=None):
        self.history = {}
        self.descr = descr
        if docString:
            self.__doc__ = docString
        if default is not None:
            self.default = default

    def setDefault(self, value):
        self.__default = value

    def getDefault(self):
        return self.__default

    default = property(getDefault, setDefault)

    def fullPropertyName(self, obj):
        return (obj.getJobOptName() or obj.getName()) + '.' + self.descr.__name__

    def __get__(self, obj, type=None):
        try:
            return self.descr.__get__(obj, type)
        except AttributeError:
            # special case for lists and dictionaries:
            # allow default to work with on += and []
            if self.__default.__class__ in [list, dict]:
                self.descr.__set__(
                    obj, self.__default.__class__(self.__default))
                return self.descr.__get__(obj, type)
            else:
                # for non lists (or dicts) return a reference to the default
                # return self.__default
                raise

    def __set__(self, obj, value):
     # check value/property compatibility if possible
        proptype, allowcompat = None, False
        if hasattr(self, 'default'):
            proptype = type(self.default)
            if self.descr.__name__ == 'OutputLevel':      # old-style compat for Btag
                allowcompat = True
        elif obj in self.history:
            proptype = type(self.history[obj][0])
            allowcompat = True

     # check if type known; allow special initializer for typed instances
        # Do not perform the check for PropertyReference, should be delayed until
        # binding (if ever done)
        if proptype and proptype != type(None) and \
                not derives_from(value, 'PropertyReference'):
            try:
             # check value itself
                value = _isCompatible(proptype, value)

             # check element in case of list
                if proptype == list:
                    try:
                        oldvec = self.descr.__get__(obj, type)
                        if oldvec:
                            tpo = type(oldvec[0])
                            for v in value:
                                _isCompatible(tpo, v)
                    except AttributeError:
                     # value not yet set
                        pass
            except ValueError, e:
                if allowcompat:
                    log.error('inconsistent value types for %s.%s (%s)' %
                              (obj.getName(), self.descr.__name__, str(e)))
                else:
                    raise

     # allow a property to be set if we're in non-default mode, or if it
     # simply hasn't been set before
        if not obj._isInSetDefaults() or not obj in self.history:
            # by convention, 'None' for default is used to designate objects setting
            if hasattr(self, 'default') and self.default == None:
                obj.__iadd__(value, self.descr)     # to establish hierarchy
            else:
                self.descr.__set__(obj, value)
            self.history.setdefault(obj, []).append(value)

    def __delete__(self, obj):
        if obj in self.history:
            del self.history[obj]
        self.descr.__delete__(obj)


class GaudiHandlePropertyProxyBase(PropertyProxy):
    """A class with some utilities for GaudiHandles and GaudiHandleArrays"""

    def __init__(self, descr, docString, default, handleType, allowedType):
        """<descr>: the real property in the object instance (from __slots__)
        <docString>: the documentation string of this property
        <default>: default value from C++ (via python generated by genconf)
        <handleType>: real python handle type (e.g. PublicToolHandle, PrivateToolHandle, ...)
        <allowedType>: allowed instance type for default
        """
        # check that default is of allowed type for this proxy
        if not isinstance(default, allowedType):
            raise TypeError("%s: %s default: %r is not a %s" %
                            (descr.__name__, self.__class__.__name__, default, allowedType.__name__))
        PropertyProxy.__init__(self, descr, docString, default)
        self._handleType = handleType
        self._confTypeName = 'Configurable' + handleType.componentType
#      print "%s: %r (%s)" % (self.__class__.__name__,self._handleType,self._confTypeName)

    def __get__(self, obj, type=None):
        try:
            return self.descr.__get__(obj, type)
        except AttributeError:
            # Get default
            try:
                default = obj.__class__.getDefaultProperty(self.descr.__name__)
                default = self.convertDefaultToBeSet(obj, default)
                if default:
                    self.__set__(obj, default)
            except AttributeError, e:
                # change type of exception to avoid false error message
                raise RuntimeError(*e.args)

        return self.descr.__get__(obj, type)

    def __set__(self, obj, value):
     # allow a property to be set if we're in non-default mode, or if it
     # simply hasn't been set before
        if not obj._isInSetDefaults() or not obj in self.history:
            value = self.convertValueToBeSet(obj, value)
            # assign the value
            self.descr.__set__(obj, value)
            log.debug("Setting %s = %r", self.fullPropertyName(obj), value)
            self.history.setdefault(obj, []).append(value)

    def isHandle(self, value):
        """Check if <value> is a handle of the correct type"""
        return isinstance(value, self._handleType)

    def isConfig(self, value):
        """Check if <value> is a configurable of the correct type"""
        return derives_from(value, self._confTypeName)

    def getDefaultConfigurable(self, typeAndName, requester):
        """Return the configurable instance corresponding to the toolhandle if possible.
        Otherwise return None"""
        global log
        # find the module
        typeAndNameTuple = typeAndName.split('/')
        confType = typeAndNameTuple[0]
        confClass = ConfigurableDb.getConfigurable(confType)
        # check the type of the configurable
        if not derives_from(confClass, self._confTypeName):
            log.error("%s: Configurable %s is not a %s",
                      requester, confType, self._confTypeName)
            return None
        try:
            confName = typeAndNameTuple[1]
        except IndexError:
            return confClass()  # use default name
        else:
            return confClass(confName)

    def convertDefaultToBeSet(self, obj, default):
        # turn string into handle
        isString = type(default) == str
        if not isString and self.isConfig(default):
            #         print self.fullPropertyName(obj) + ": Setting default configurable: %r" % default
            return default
        elif isString or self.isHandle(default):
            if isString:
                # convert string into handle
                typeAndName = default
                default = self._handleType(typeAndName)
            else:
                typeAndName = default.typeAndName
            if not self._handleType.isPublic:
                if not typeAndName:
                    return None
                # Find corresponding default configurable of private handles
                try:
                    conf = self.getDefaultConfigurable(
                        typeAndName, self.fullPropertyName(obj))
#               print self.fullPropertyName(obj) + ": Setting default private configurable (from default handle): %r" % conf
                except AttributeError, e:
                    # change type of exception to avoid false error message
                    raise RuntimeError(*e.args)
                if conf is None:
                    raise RuntimeError("%s: Default configurable for class %s not found in ConfigurableDb.CfgDb" %
                                       (self.fullPropertyName(obj), default.getType()))
                return conf
        else:  # not a config, not a handle, not a string
            raise TypeError("%s: default value %r is not of type %s or %s" %
                            (self.fullPropertyName(obj), default, self._confTypeName, self._handleType.__name__))

        return default

    def convertValueToBeSet(self, obj, value):
        if value is None:
            value = ''
        isString = type(value) == str
        if isString:
            # create an new handle
            return self._handleType(value)
        elif self.isHandle(value):
            # make a copy of the handle
            return self._handleType(value.toStringProperty())
        elif self.isConfig(value):
            if self._handleType.isPublic:
             # A public tool must be registered to ToolSvc before assigning it
                if derives_from(value, 'ConfigurableAlgTool'):
                    if not value.isInToolSvc():
                        suggestion = 'You may need to add jobOptions lines something like:' + os.linesep + \
                                     'from AthenaCommon.AppMgr import ToolSvc' + os.linesep + \
                                     'ToolSvc += '
                        if value.getName() == value.getType():  # using default name
                            suggestion += '%s()' % value.__class__.__name__
                        else:  # using user-defined name
                            suggestion += '%s(%r)' % (value.__class__.__name__,
                                                      value.getName())
                        raise RuntimeError(self.fullPropertyName(obj) +
                                           ': Public tool %s is not yet in ToolSvc. %s' %
                                           (value.getJobOptName(), suggestion))
             # make it read-only
                return self._handleType(value.toStringProperty())
            elif value.hasParent(obj.getJobOptName()):
             # is already a child, keep as-is
                return value
            else:
             # make a copy of the configurable
                value = obj.copyChildAndSetParent(value, obj.getJobOptName())
                # ensure that the new object is in allConfigurables
                obj.allConfigurables[value.name()] = value
                return value
        else:
            raise TypeError("Property %s value %r is not a %s nor a %s nor a string" %
                            (self.fullPropertyName(obj), value, self._confTypeName, self._handleType.__name__))

        return value


class GaudiHandlePropertyProxy(GaudiHandlePropertyProxyBase):
    def __init__(self, descr, docString, default):
        GaudiHandlePropertyProxyBase.__init__(
            self, descr, docString, default, type(default), GaudiHandle)


class GaudiHandleArrayPropertyProxy(GaudiHandlePropertyProxyBase):
    def __init__(self, descr, docString, default):
        """<descr>: the real property in the object instance (from __slots__)
        <confTypeName>: string indicating the (base) class of allowed Configurables to be assigned.
        <handleType>: real python handle type (e.g. PublicToolHandle, PrivateToolHandle, ...)
        """
        GaudiHandlePropertyProxyBase.__init__(
            self, descr, docString, default, type(default).handleType, GaudiHandleArray)
        self.arrayType = type(default)

    def checkType(self, obj, value):
        if not isinstance(value, list) and not isinstance(value, self.arrayType):
            raise TypeError("%s: Value %r is not a list nor a %s" %
                            (self.fullPropertyName(obj), value, self.arrayType.__name__))

    def convertDefaultToBeSet(self, obj, default):
        self.checkType(obj, default)
        newDefault = self.arrayType()
        for d in default:
            cd = GaudiHandlePropertyProxyBase.convertDefaultToBeSet(
                self, obj, d)
            if cd:
                newDefault.append(cd)

        return newDefault

    def convertValueToBeSet(self, obj, value):
        self.checkType(obj, value)
        newValue = self.arrayType()
        for v in value:
            cv = GaudiHandlePropertyProxyBase.convertValueToBeSet(self, obj, v)
            if cv:
                newValue.append(cv)

        return newValue


class DataObjectHandleBasePropertyProxy(PropertyProxy):

    def __init__(self, descr, docString, default):
        PropertyProxy.__init__(self, descr, docString, default)

    def __get__(self, obj, type=None):
        try:
            return self.descr.__get__(obj, type)
        except AttributeError:
            # Get default
            try:
                default = obj.__class__.getDefaultProperty(self.descr.__name__)
                default = self.convertValueToBeSet(obj, default)
                if default:
                    self.__set__(obj, default)
            except AttributeError, e:
                # change type of exception to avoid false error message
                raise RuntimeError(*e.args)

        return self.descr.__get__(obj, type)

    def __set__(self, obj, value):
        if not obj._isInSetDefaults() or not obj in self.history:
            value = self.convertValueToBeSet(obj, value)
            # assign the value
            self.descr.__set__(obj, value)
            log.debug("Setting %s = %r", self.fullPropertyName(obj), value)
            self.history.setdefault(obj, []).append(value)

    def convertValueToBeSet(self, obj, value):
        if value is None:
            value = ''

        if type(value) == str:
            return DataObjectHandleBase(value)
        elif isinstance(value, DataObjectHandleBase):
            return DataObjectHandleBase(value.__str__())


def PropertyProxyFactory(descr, doc, default):
    #   print "PropertyProxyFactory( %s, %r )" % (descr.__name__,default)

    if isinstance(default, GaudiHandleArray):
        return GaudiHandleArrayPropertyProxy(descr, doc, default)

    if isinstance(default, GaudiHandle):
        return GaudiHandlePropertyProxy(descr, doc, default)

    if isinstance(default, DataObjectHandleBase):
        return DataObjectHandleBasePropertyProxy(descr, doc, default)

    return PropertyProxy(descr, doc, default)