CIber_prayer/cache_realisation_CPP
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ag 2024-09-13 12:14:00 +03:00
parent 3ef1bc3ab9
commit b1646952a5
9 changed files with 70 additions and 96 deletions
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85
2Q_cache.cpp
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@ -1,85 +0,0 @@
#include <unordered_map>
#include <list>
#include "2Q_cache.h"
class TwoCache {
private:
//2 LRU caches
size_t cpct_q1;
std::unordered_map<int, std::list<int>::iterator> umap1;
std::list <int> q1; //fast queue - the most popular pages
size_t cpct_q2;
std::unordered_map<int, std::list<int>::iterator> umap2;
std::list <int> q2; //slow queue - if page asked at the first time put it to q2, if itasked from q2 it put it to q1,
public:
TwoCache(size_t q1sz, size_t q2sz): cpct_q1(q1sz), cpct_q2(q2sz) {} //ctor
int get_page(int id) { //get_page(<int id>) - returns <int id> if page is found, and -1 if not
if(umap1.find(id) != umap1.end()) {
q1.splice(q1.begin(), q1, umap1[id]); //if page did not find in the end of fast(q1) queue - put it in the begin
return id;
}
if (umap2.find(id) != umap2.end()) { //if page was not found in the end of slow queue - put is from slow(q2) to begin fast(q1)
auto it = umap2[id];
q2.splice(q2.begin(), q2, it); //put this page from queue to the slow
umap2.erase(id); //delete it from slow queue
if (q1.size() == cpct_q1) { //if q1 is overflowed delete oldest element from fast(q1)
umap1.erase(q1.back());
q1.pop_back();
}
q1.push_front(id); //if it is not overflowed put it at the begin
umap2[id] = q1.begin();
return id;
} else return -1; //page was not found - return PAGE_DID_NOT_FOUND = -1
}
void put_page(int id) { //puts page in cache
if (umap1.find(id) != umap1.end()) { //if page is q1
return;
}
if (umap2.find(id) != umap2.end()) { //I know that in this case there will be 2 loops in get_page() i will think about it...
get_page(id);
return;
}
if (q1.size() == cpct_q1) { //if overflow
umap1.erase(q1.back());
q1.pop_back();
}
if (q2.size() == cpct_q2) {
umap2.erase(q2.back());
q2.pop_back();
}
q1.push_front(id); //in the end push page in cache
umap1[id] = q1.begin();
}
void info() {
std::cout << "q1 (the most usable): ";
for (auto i = q1.begin(); i != q1.end(); i++) {
std::cout << *i << " ";
}
std::cout << "\nq2(Less usable): ";
for (auto i = q2.begin(); i != q2.end(); i++) {
std::cout << *i << " ";
}
std::cout << "\ncapacity q1: " << cpct_q1
<< "\ncapacity q2: " << cpct_q2 << std::endl;
}
};

66
2Q_cache.h
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@ -4,11 +4,67 @@
#include <unordered_map>
#include <list>
class TwoCache {
class TwoCache {
private:
//2 LRU caches
size_t cpct_q1;
std::unordered_map<int, std::list<int>::iterator> umap1;
std::list <int> q1; //fast queue - the most popular pages
size_t cpct_q2;
std::unordered_map<int, std::list<int>::iterator> umap2;
std::list <int> q2; //slow queue - if page asked at the first time put it to q2, if itasked from q2 it put it to q1,
public:
TwoCache(size_t q1sz, size_t q2sz);
int get_page(int id);
void put_page(int id);
void info();
TwoCache(size_t q1sz, size_t q2sz): cpct_q1(q1sz), cpct_q2(q2sz) {} //ctor
void put_page(int id) {
if (umap1.find(id) != umap1.end()) { //page is in fast queue in the end, nothing to do (fast case)
std::cout<<"fast case\n";
return;
} else if (umap2.find(id) != umap2.end()) {
q2.erase(umap2[id]); //if page is in slow put it in fast
if (q1.size() < cpct_q1) {
q1.push_front(id);
umap1[id] = q1.begin();
} else {
int lru_page = q1.back(); //if fast is overflow - delete
q1.pop_back();
umap1.erase(lru_page);
q1.push_front(id);
umap1[id] = q1.begin();
}
return;
} else if (q2.size() < cpct_q2) { //if not in cache put it in slow
q2.push_front(id);
umap2[id] = q2.begin();
return;
} else { //if slow is overflow - pop
int lru_page = q2.back();
q2.pop_back();
umap2.erase(lru_page);
q2.push_front(id);
umap2[id] = q2.begin();
return;
}
}
void info() {
std::cout << "q1 (the most usable): ";
for (auto i = q1.begin(); i != q1.end(); i++) {
std::cout << *i << " ";
}
std::cout << "\nq2 (Less usable): ";
for (auto i = q2.begin(); i != q2.end(); i++) {
std::cout << *i << " ";
}
}
};
#endif

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git.ignore Normal file
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!*.*
!*o*
!**

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ideal_cache.cpp Normal file
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10
main.cpp
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int main() {
TwoCache cache(2, 4);
TwoCache cache(4, 4);
cache.put_page(1);
cache.put_page(2);
std::cout << cache.get_page(1) << std::endl; // Вывод: 1
cache.info();
cache.put_page(1);
cache.put_page(2);
cache.info();
cache.put_page(1);
cache.put_page(2);
cache.put_page(1);
cache.put_page(2);
cache.put_page(3);
std::cout << cache.get_page(2) << std::endl; // Вывод: 2
cache.put_page(4); // Теперь 4 будет в Q1
std::cout << cache.get_page(3) << std::endl; // Вывод: -1 (3 нет в кэше)
cache.info();
cache.put_page(4);
return 0;
}

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makefile
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@ -5,7 +5,7 @@ CXX = g++
CXXFLAGS = -Wall -Wextra -std=c++11
SRCS = 2Q_cache.cpp main.cpp
SRCS = main.cpp
OBJS = $(SRCS:.cpp=.o)

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tests Normal file
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