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#ifndef CACHE_H
#define CACHE_H
#include "definitions.h"
#include "storage.h"
#include <array>
#include <cmath>
#include <functional>
#include <ostream>
/**
* Parse an address into a tag, index into the cache table, and a line
* offset.
* @param the address to be parsed
* @param the resulting tag
* @param the resulting index
* @param the resulting offset
*/
// clang-format off
#define GET_FIELDS(a, t, i, o) \
*(t) = GET_MID_BITS(a, this->size + LINE_SPEC, MEM_WORD_SPEC); \
*(i) = GET_MID_BITS(a, LINE_SPEC, this->size + LINE_SPEC); \
*(o) = GET_LS_BITS(a, LINE_SPEC)
// clang-format on
class Cache : public Storage
{
public:
/**
nn * Constructor.
* @param The number of `lines` contained in memory. The total number of
* words is this number multiplied by LINE_SIZE.
* @param The next lowest level in storage. Methods from this object are
* called in case of a cache miss.
* @param The number of bits required to specify a line in this level of cache.
* @param The number of clock cycles each access takes.
* @return A new cache object.
*/
Cache(Storage *lower, unsigned int size, int delay);
~Cache();
int write_word(void *, signed int, int) override;
int write_line(void *, std::array<signed int, LINE_SIZE>, int) override;
int read_line(void *, int, std::array<signed int, LINE_SIZE> &) override;
int read_word(void *, int, signed int &) override;
private:
/**
* Helper for all access methods.
* Calls `request_handler` when `id` is allowed to complete its
* request cycle.
* @param the source making the request
* @param the address to write to
* @param the function to call when an access should be completed
*/
int process(void *id, int address, std::function<void(int index, int offset)> request_handler);
/**
* Helper for process.
* Fetches `address` from a lower level of storage if it is not already
* present. The victim line is chosen/written back.
* @param the address that must be present in cache.
* @param 0 if the address is currently in cache, 1 if it is being fetched.
*/
int is_address_missing(int address);
/**
* The number of bits required to specify a line in this level of cache.
*/
unsigned int size;
/**
* An array of metadata about elements in `data`.
* If the first value of an element is negative, the corresponding
* element in `data` is invalid. If the most second value of an element
* is nonzero, the corresponding element in `data` is dirty.
*/
std::vector<std::array<signed int, 2>> meta;
};
#endif /* CACHE_H_INCLUDED */
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