145     def _find_block(self, val):  argument
177             if val < pair[0]:
180             elif val > pair[1]:
191     def alloc(self, val=None):  argument
205             if val is None:
206                 val = self.last + 1 if self.last is not None else self.min_val
207             if val is None or val > self.max_val or val < self.min_val:
208                 val = self.min_val
209             i, pair = self._find_block(val)
225                 val = pair[0]
234             assert pair[0] <= val <= pair[1]
235             if pair[0] == val:
237                 if val == pair[1]:
240                     pair[0] = val + 1
243                 if val == pair[1]:
244                     pair[1] = val - 1
246                     newpair = [val + 1, pair[1]]
247                     pair[1] = val - 1
249             self.last = val
250             return val
252     def free(self, val):  argument
254         self._free_multi('free', [val])
274                 val = highval
275                 while len(values) and values[-1] == val - 1:
276                     val = values.pop()
277                 self._free_range(how, val, highval)
279     def _maybe_increase_max(self, how, val):  argument
285         if val <= self.max_val:
288             self.max_val = val
290         raise ValueError('{0}: {1} is outside range limit'.format(how, val))
292     def _maybe_decrease_min(self, how, val):  argument
298         if val >= self.min_val:
301             self.min_val = val
303         raise ValueError('{0}: {1} is outside range limit'.format(how, val))
305     def _free_range(self, how, val, highval):  argument
314         i, pair = self._find_block(val)
316             raise ValueError('{0}: {1} already available'.format(how, val))
319         if highval > val and i < len(self.avail):
322                                  'available'.format(how, val, highval))
329             abuts_below = self.avail[i - 1][1] + 1 == val
353                 self._maybe_decrease_min(how, val)
354                 self.avail[i][0] = val
357                 self._maybe_decrease_min(how, val)
359                 newblock = [val, highval]