Source Code for Module envi.pagelookup

 1  ''' 
 2  A home for the page lookup construct.  Basically it is a 
 3  python object which implements a similar lookup mechanism 
 4  to the i386 page table lookups... 
 5  ''' 
 6   
 7  # FIXME move functions in here too so there is procedural "speed" way 
 8  # and objecty pythonic way... 
 9   
10 -class PageLookup: 
11      ''' 
12      An object capable of rapid lookups across a sparse address 
13      space which will also NOT eat *all* the RAMS like a straight 
14      dictionary full of millions of entries would. 
15      ''' 
16   
17 -    def __init__(self): 
18          self._page_dict = {} 
19   
20 -    def getPageLookup(self, va): 
21          base = va >> 16 
22          offs = va & 0xffff 
23          page = self._page_dict.get(base) 
24          if page == None: 
25              return None 
26          return page[offs] 
27   
28 -    def setPageLookup(self, va, size, obj): 
29          vamax = va+size 
30          while va < vamax: 
31              base = va >> 16 
32              offs = va & 0xffff 
33              page = self._page_dict.get(base) 
34              if page == None: 
35                  page = [None] * 0xffff 
36                  self._page_dict[base] = page 
37              page[offs] = obj 
38              va += 1 
39   
40      # __getitem__ 
41      # __getslice__ 
42      # __setslice__ 
43   
44 -class MapLookup: 
45   
46      ''' 
47      A specialized lookup object for large densely populated ranges 
48      which are layed out in a sparse field space themselves... 
49      ''' 
50   
51 -    def __init__(self): 
52          self._maps_list = [] 
53   
54 -    def initMapLookup(self, va, size, obj=None): 
55          marray = [obj] * size 
56          # FIXME optimize by size! 
57          self._maps_list.append((va, va+size, marray)) 
58   
59 -    def setMapLookup(self, va, size, obj): 
60          for mva, mvamax, marray in self._maps_list: 
61              if va >= mva and va < mvamax: 
62                  off = va - mva 
63                  s = [obj] * size 
64                  marray[off:off+size] = s 
65                  return 
66          raise Exception('Address (0x%.8x) not in maps!' % va) 
67   
68 -    def getMapLookup(self, va): 
69          for mva, mvamax, marray in self._maps_list: 
70              if va >= mva and va < mvamax: 
71                  off = va - mva 
72                  return marray[off] 
73          return None 
74   
75 -    def __getslice__(self, start, end): 
76          print 'GET SLICE' 
77