Cache模拟

建立一个Cache类来模拟Cache的行为，包括缓存块的状态、标记位、指针等成员变量，并定义对应的方法来模拟Cache的读取、写入和替换等行为。

代码示例：

class Cache:
    def __init__(self, block_size, cache_size):
        self.block_size = block_size   # 缓存块大小
        self.cache_size = cache_size   # 缓存大小
        self.blocks = []               # 缓存块列表
        self.num_hits = 0              # 命中次数
        self.num_misses = 0            # 未命中次数
        self.num_writes = 0            # 写入次数

        # 初始化缓存块
        for i in range(cache_size // block_size):
            self.blocks.append({'valid': False, 'tag': None, 'data': None})

    def read(self, address):
        block_offset = address % self.block_size
        block_address = address - block_offset
        index = block_address // self.block_size % len(self.blocks)
        tag = block_address // self.block_size // len(self.blocks)

        # 检查是否命中缓存
        if self.blocks[index]['valid'] and self.blocks[index]['tag'] == tag:
            self.num_hits += 1
            return self.blocks[index]['data'][block_offset]
        else:
            self.num_misses += 1
            # 从内存中读取数据
            data = self.read_from_memory(block_address, self.block_size)
            # 写入缓存
            self.blocks[index]['valid'] = True
            self.blocks[index]['tag'] = tag
            self.blocks[index]['data'] = data
            return data[block_offset]

    def write(self, address, value):
        block_offset = address % self.block_size
        block_address = address - block_offset
        index = block_address // self.block_size % len(self.blocks)
        tag = block_address // self.block_size // len(self.blocks)

        # 检查是否命中缓存
        if self.blocks[index]['valid'] and self.blocks[index]['tag'] == tag:
            self.num_hits += 1
            self.blocks[index]['data'][block_offset] = value
        else:
            self.num_misses += 1
            self.num_writes += 1
            # 从内存中读取块数据
            data = self.read_from_memory(block_address, self.block_size)
            # 修改缓存块
            self.blocks[index]['valid'] = True
            self.blocks[index]['tag']