34   def __init__(self, simg_fn, file_map_fn=None, clobbered_blocks=None):  argument
35     self.simg_f = f = open(simg_fn, "rb")
45     self.blocksize = blk_sz = header[5]
46     self.total_blocks = total_blks = header[6]
66     self.offset_map = offset_map = []
67     self.clobbered_blocks = rangelib.RangeSet(data=clobbered_blocks)
110     self.care_map = rangelib.RangeSet(care_data)
111     self.offset_index = [i[0] for i in offset_map]
119     extended = self.care_map.extend(512)
120     all_blocks = rangelib.RangeSet(data=(0, self.total_blocks))
121     extended = extended.intersect(all_blocks).subtract(self.care_map)
122     self.extended = extended
125       self.LoadFileBlockMap(file_map_fn, self.clobbered_blocks)
127       self.file_map = {"__DATA": self.care_map}
129   def ReadRangeSet(self, ranges):  argument
130     return [d for d in self._GetRangeData(ranges)]
132   def TotalSha1(self, include_clobbered_blocks=False):  argument
137     ranges = self.care_map
139       ranges = ranges.subtract(self.clobbered_blocks)
141     for d in self._GetRangeData(ranges):
145   def _GetRangeData(self, ranges):  argument
155     f = self.simg_f
158       idx = bisect.bisect_right(self.offset_index, s) - 1
159       chunk_start, chunk_len, filepos, fill_data = self.offset_map[idx]
165         p = filepos + ((s - chunk_start) * self.blocksize)
167         yield f.read(this_read * self.blocksize)
169         yield fill_data * (this_read * (self.blocksize >> 2))
175         chunk_start, chunk_len, filepos, fill_data = self.offset_map[idx]
179           yield f.read(this_read * self.blocksize)
181           yield fill_data * (this_read * (self.blocksize >> 2))
184   def LoadFileBlockMap(self, fn, clobbered_blocks):  argument
185     remaining = self.care_map
186     self.file_map = out = {}
211     reference = '\0' * self.blocksize
213     f = self.simg_f
216         idx = bisect.bisect_right(self.offset_index, b) - 1
217         chunk_start, _, filepos, fill_data = self.offset_map[idx]
219           filepos += (b-chunk_start) * self.blocksize
221           data = f.read(self.blocksize)
244   def ResetFileMap(self):  argument
247     self.file_map = {"__DATA": self.care_map}