class DRAMCache:
    def __init__(self, size_mb=None):
        """Initialize DRAM cache with unlimited capacity"""
        self.cache = {}
        self.access_order = []
        self.is_unlimited = True

    def read(self, key):
        if key in self.cache:
            self.access_order.remove(key)
            self.access_order.append(key)
            return self.cache[key]
        return None

    def write(self, key, value):
        """Write to cache with unlimited capacity - no eviction needed"""
        if key in self.cache:
            self.access_order.remove(key)
        self.cache[key] = value
        self.access_order.append(key)

class Buffer:
    def __init__(self, size_mb=None):
        """Initialize buffer with unlimited capacity"""
        self.buffer = []
        self.is_unlimited = True

    def add(self, data):
        """Add data to buffer - no size restrictions"""
        self.buffer.append(data)

    def flush(self):
        """Flush buffer and return all data"""
        flushed = self.buffer[:]
        self.buffer = []
        return flushed