src/python/m5/proxy.py

   1 # Copyright (c) 2004-2006 The Regents of The University of Michigan
   2 # All rights reserved.
   3 #
   4 # Redistribution and use in source and binary forms, with or without
   5 # modification, are permitted provided that the following conditions are
   6 # met: redistributions of source code must retain the above copyright
   7 # notice, this list of conditions and the following disclaimer;
   8 # redistributions in binary form must reproduce the above copyright
   9 # notice, this list of conditions and the following disclaimer in the
  10 # documentation and/or other materials provided with the distribution;
  11 # neither the name of the copyright holders nor the names of its
  12 # contributors may be used to endorse or promote products derived from
  13 # this software without specific prior written permission.
  14 #
  15 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  17 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  18 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  19 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  20 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  21 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  25 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 #
  27 # Authors: Steve Reinhardt
  28 #          Nathan Binkert
  29
  30 #####################################################################
  31 #
  32 # Proxy object support.
  33 #
  34 #####################################################################
  35
  36 import copy
  37
  38 class BaseProxy(object):
  39     def __init__(self, search_self, search_up):
  40         self._search_self = search_self
  41         self._search_up = search_up
  42         self._multiplier = None
  43
  44     def __str__(self):
  45         if self._search_self and not self._search_up:
  46             s = 'Self'
  47         elif not self._search_self and self._search_up:
  48             s = 'Parent'
  49         else:
  50             s = 'ConfusedProxy'
  51         return s + '.' + self.path()
  52
  53     def __setattr__(self, attr, value):
  54         if not attr.startswith('_'):
  55             raise AttributeError, \
  56                   "cannot set attribute '%s' on proxy object" % attr
  57         super(BaseProxy, self).__setattr__(attr, value)
  58
  59     # support multiplying proxies by constants
  60     def __mul__(self, other):
  61         if not isinstance(other, (int, long, float)):
  62             raise TypeError, "Proxy multiplier must be integer"
  63         if self._multiplier == None:
  64             self._multiplier = other
  65         else:
  66             # support chained multipliers
  67             self._multiplier *= other
  68         return self
  69
  70     __rmul__ = __mul__
  71
  72     def _mulcheck(self, result):
  73         if self._multiplier == None:
  74             return result
  75         return result * self._multiplier
  76
  77     def unproxy(self, base):
  78         obj = base
  79         done = False
  80
  81         if self._search_self:
  82             result, done = self.find(obj)
  83
  84         if self._search_up:
  85             while not done:
  86                 obj = obj._parent
  87                 if not obj:
  88                     break
  89                 result, done = self.find(obj)
  90
  91         if not done:
  92             raise AttributeError, \
  93                   "Can't resolve proxy '%s' of type '%s' from '%s'" % \
  94                   (self.path(), self._pdesc.ptype_str, base.path())
  95
  96         if isinstance(result, BaseProxy):
  97             if result == self:
  98                 raise RuntimeError, "Cycle in unproxy"
  99             result = result.unproxy(obj)
 100
 101         return self._mulcheck(result)
 102
 103     def getindex(obj, index):
 104         if index == None:
 105             return obj
 106         try:
 107             obj = obj[index]
 108         except TypeError:
 109             if index != 0:
 110                 raise
 111             # if index is 0 and item is not subscriptable, just
 112             # use item itself (so cpu[0] works on uniprocessors)
 113         return obj
 114     getindex = staticmethod(getindex)
 115
 116     # This method should be called once the proxy is assigned to a
 117     # particular parameter or port to set the expected type of the
 118     # resolved proxy
 119     def set_param_desc(self, pdesc):
 120         self._pdesc = pdesc
 121
 122 class AttrProxy(BaseProxy):
 123     def __init__(self, search_self, search_up, attr):
 124         super(AttrProxy, self).__init__(search_self, search_up)
 125         self._attr = attr
 126         self._modifiers = []
 127
 128     def __getattr__(self, attr):
 129         # python uses __bases__ internally for inheritance
 130         if attr.startswith('_'):
 131             return super(AttrProxy, self).__getattr__(self, attr)
 132         if hasattr(self, '_pdesc'):
 133             raise AttributeError, "Attribute reference on bound proxy"
 134         # Return a copy of self rather than modifying self in place
 135         # since self could be an indirect reference via a variable or
 136         # parameter
 137         new_self = copy.deepcopy(self)
 138         new_self._modifiers.append(attr)
 139         return new_self
 140
 141     # support indexing on proxies (e.g., Self.cpu[0])
 142     def __getitem__(self, key):
 143         if not isinstance(key, int):
 144             raise TypeError, "Proxy object requires integer index"
 145         if hasattr(self, '_pdesc'):
 146             raise AttributeError, "Index operation on bound proxy"
 147         new_self = copy.deepcopy(self)
 148         new_self._modifiers.append(key)
 149         return new_self
 150
 151     def find(self, obj):
 152         try:
 153             val = getattr(obj, self._attr)
 154             # for any additional unproxying to be done, pass the
 155             # current, rather than the original object so that proxy
 156             # has the right context
 157             obj = val
 158         except:
 159             return None, False
 160         while isproxy(val):
 161             val = val.unproxy(obj)
 162         for m in self._modifiers:
 163             if isinstance(m, str):
 164                 val = getattr(val, m)
 165             elif isinstance(m, int):
 166                 val = val[m]
 167             else:
 168                 assert("Item must be string or integer")
 169             while isproxy(val):
 170                 val = val.unproxy(obj)
 171         return val, True
 172
 173     def path(self):
 174         p = self._attr
 175         for m in self._modifiers:
 176             if isinstance(m, str):
 177                 p += '.%s' % m
 178             elif isinstance(m, int):
 179                 p += '[%d]' % m
 180             else:
 181                 assert("Item must be string or integer")
 182         return p
 183
 184 class AnyProxy(BaseProxy):
 185     def find(self, obj):
 186         return obj.find_any(self._pdesc.ptype)
 187
 188     def path(self):
 189         return 'any'
 190
 191 # The AllProxy traverses the entire sub-tree (not only the children)
 192 # and adds all objects of a specific type
 193 class AllProxy(BaseProxy):
 194     def find(self, obj):
 195         return obj.find_all(self._pdesc.ptype)
 196
 197     def path(self):
 198         return 'all'
 199
 200 def isproxy(obj):
 201     if isinstance(obj, (BaseProxy, params.EthernetAddr)):
 202         return True
 203     elif isinstance(obj, (list, tuple)):
 204         for v in obj:
 205             if isproxy(v):
 206                 return True
 207     return False
 208
 209 class ProxyFactory(object):
 210     def __init__(self, search_self, search_up):
 211         self.search_self = search_self
 212         self.search_up = search_up
 213
 214     def __getattr__(self, attr):
 215         if attr == 'any':
 216             return AnyProxy(self.search_self, self.search_up)
 217         elif attr == 'all':
 218             if self.search_up:
 219                 assert("Parant.all is not supported")
 220             return AllProxy(self.search_self, self.search_up)
 221         else:
 222             return AttrProxy(self.search_self, self.search_up, attr)
 223
 224 # global objects for handling proxies
 225 Parent = ProxyFactory(search_self = False, search_up = True)
 226 Self = ProxyFactory(search_self = True, search_up = False)
 227
 228 # limit exports on 'from proxy import *'
 229 __all__ = ['Parent', 'Self']
 230
 231 # see comment on imports at end of __init__.py.
 232 import params # for EthernetAddr