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 # Search up the tree but mark ourself
86 # as visited to avoid a self-reference
87 self._visited = True
88 obj._visited = True
89 while not done:
90 obj = obj._parent
91 if not obj:
92 break
93 result, done = self.find(obj)
94
95 self._visited = False
96 base._visited = False
97
98 if not done:
99 raise AttributeError, \
100 "Can't resolve proxy '%s' of type '%s' from '%s'" % \
101 (self.path(), self._pdesc.ptype_str, base.path())
102
103 if isinstance(result, BaseProxy):
104 if result == self:
105 raise RuntimeError, "Cycle in unproxy"
106 result = result.unproxy(obj)
107
108 return self._mulcheck(result)
109
110 def getindex(obj, index):
111 if index == None:
112 return obj
113 try:
114 obj = obj[index]
115 except TypeError:
116 if index != 0:
117 raise
118 # if index is 0 and item is not subscriptable, just
119 # use item itself (so cpu[0] works on uniprocessors)
120 return obj
121 getindex = staticmethod(getindex)
122
123 # This method should be called once the proxy is assigned to a
124 # particular parameter or port to set the expected type of the
125 # resolved proxy
126 def set_param_desc(self, pdesc):
127 self._pdesc = pdesc
128
129class AttrProxy(BaseProxy):
130 def __init__(self, search_self, search_up, attr):
131 super(AttrProxy, self).__init__(search_self, search_up)
132 self._attr = attr
133 self._modifiers = []
134
135 def __getattr__(self, attr):
136 # python uses __bases__ internally for inheritance
137 if attr.startswith('_'):
138 return super(AttrProxy, self).__getattr__(self, attr)
139 if hasattr(self, '_pdesc'):
140 raise AttributeError, "Attribute reference on bound proxy"
141 # Return a copy of self rather than modifying self in place
142 # since self could be an indirect reference via a variable or
143 # parameter
144 new_self = copy.deepcopy(self)
145 new_self._modifiers.append(attr)
146 return new_self
147
148 # support indexing on proxies (e.g., Self.cpu[0])
149 def __getitem__(self, key):
150 if not isinstance(key, int):
151 raise TypeError, "Proxy object requires integer index"
152 if hasattr(self, '_pdesc'):
153 raise AttributeError, "Index operation on bound proxy"
154 new_self = copy.deepcopy(self)
155 new_self._modifiers.append(key)
156 return new_self
157
158 def find(self, obj):
159 try:
160 val = getattr(obj, self._attr)
161 visited = False
162 if hasattr(val, '_visited'):
163 visited = getattr(val, '_visited')
164
165 if not visited:
166 # for any additional unproxying to be done, pass the
167 # current, rather than the original object so that proxy
168 # has the right context
169 obj = val
170 else:
171 return None, False
172 except:
173 return None, False
174 while isproxy(val):
175 val = val.unproxy(obj)
176 for m in self._modifiers:
177 if isinstance(m, str):
178 val = getattr(val, m)
179 elif isinstance(m, int):
180 val = val[m]
181 else:
182 assert("Item must be string or integer")
183 while isproxy(val):
184 val = val.unproxy(obj)
185 return val, True
186
187 def path(self):
188 p = self._attr
189 for m in self._modifiers:
190 if isinstance(m, str):
191 p += '.%s' % m
192 elif isinstance(m, int):
193 p += '[%d]' % m
194 else:
195 assert("Item must be string or integer")
196 return p
197
198class AnyProxy(BaseProxy):
199 def find(self, obj):
200 return obj.find_any(self._pdesc.ptype)
201
202 def path(self):
203 return 'any'
204
205# The AllProxy traverses the entire sub-tree (not only the children)
206# and adds all objects of a specific type
207class AllProxy(BaseProxy):
208 def find(self, obj):
209 return obj.find_all(self._pdesc.ptype)
210
211 def path(self):
212 return 'all'
213
214def isproxy(obj):
215 if isinstance(obj, (BaseProxy, params.EthernetAddr)):
216 return True
217 elif isinstance(obj, (list, tuple)):
218 for v in obj:
219 if isproxy(v):
220 return True
221 return False
222
223class ProxyFactory(object):
224 def __init__(self, search_self, search_up):
225 self.search_self = search_self
226 self.search_up = search_up
227
228 def __getattr__(self, attr):
229 if attr == 'any':
230 return AnyProxy(self.search_self, self.search_up)
231 elif attr == 'all':
232 if self.search_up:
233 assert("Parant.all is not supported")
234 return AllProxy(self.search_self, self.search_up)
235 else:
236 return AttrProxy(self.search_self, self.search_up, attr)
237
238# global objects for handling proxies
239Parent = ProxyFactory(search_self = False, search_up = True)
240Self = ProxyFactory(search_self = True, search_up = False)
241
242# limit exports on 'from proxy import *'
243__all__ = ['Parent', 'Self']
244
245# see comment on imports at end of __init__.py.
246import params # for EthernetAddr