#!/usr/bin/env python

#-*- coding:utf-8 -*-

SHIFT = 5  # 如果计算机为32位,SHIFT为5;如果计算机为64位,SHIFT为6

MASK = 0x1F  # 如果计算机为32位,MASK为0x1F;如果计算机为64位,MASK为0x3F

class BitBucket(object):

    def __init__(self):

        self._unique_key_count = 0   # 唯一的key有多少个

        self._total_key_count = 0    # 加入的key有多少个

        self._bit = {}

    def set(self, value):

        """return last bit"""

        self._total_key_count += 1

        if not self._has_key(value):

            self._unique_key_count += 1

            key = value >> SHIFT

            self._bit[key] = self._bit.get(key, 0) | (1 << (value & MASK))

            return 0

        return 1

    def exist(self, value):

        if self._has_key(value):

            return True

        return False

    def clear(self, value):

        if self._has_key(value):

            self._unique_key_count -= 1

            self._total_key_count -= 1

            key = value >> SHIFT

            self._bit[key] = self._bit[key] & (~(1 << (value & MASK)))

            return True

        return False

    def get_total_count(self):

        return self._total_key_count

    def get_bit_count(self):

        return self._unique_key_count

    def _has_key(self, value):

        key = value >> SHIFT

        return self._bit.get(key, 0) & (1 << (value & MASK))

if __name__ == '__main__':

    bitBucket = BitBucket()

    for i in range(1, 27):

        bitBucket.set(i)

    print bitBucket.get_total_count()

    print bitBucket.get_bit_count()

    count = 0

    for i in range(1, 30):

        if bitBucket.exist(i):

            count += 1

    assert count == bitBucket.get_bit_count()