proxy.py revision 9280:fda147c035b3
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 36import copy 37 38class 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 122class 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 184class 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 193class AllProxy(BaseProxy): 194 def find(self, obj): 195 return obj.find_all(self._pdesc.ptype) 196 197 def path(self): 198 return 'all' 199 200def 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 209class 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 225Parent = ProxyFactory(search_self = False, search_up = True) 226Self = 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. 232import params # for EthernetAddr 233