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using list instead of bits/stdc++.h

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foo290
2021-08-12 14:07:22 +05:30
parent d361eb15de
commit 19d09e8590
1 changed files with 126 additions and 126 deletions
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252
others/lru_cache.cpp
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@@ -45,10 +45,10 @@
* @author [Nitin Sharma](https://github.com/foo290) * @author [Nitin Sharma](https://github.com/foo290)
* */ * */
#include <bits/stdc++.h> /// for std::list #include <list> /// for std::list
#include <cassert> /// for assert #include <cassert> /// for assert
#include <iostream> /// for IO Operations #include <iostream> /// for IO Operations
#include <unordered_map> /// for std::unordered_map
/** /**
* @namespace lru_cache * @namespace lru_cache
@@ -59,75 +59,75 @@ namespace lru_cache {
/** /**
* @brief LRU cache class * @brief LRU cache class
*/ */
class LRUCache { class LRUCache {
int pageFrame; ///< Page frame, or total size of the cache. int pageFrame; ///< Page frame, or total size of the cache.
std::list<int> cache; ///< Cache linked list (using the STL) std::list<int> cache; ///< Cache linked list (using the STL)
std::unordered_map<int, std::list<int>::iterator> std::unordered_map<int, std::list<int>::iterator>
pageMap; ///< Hash map containing pages and their addresses pageMap; ///< Hash map containing pages and their addresses
int hits = 0; ///< Total number of hits, or total number of times a page int hits = 0; ///< Total number of hits, or total number of times a page
///< was found in cache. ///< was found in cache.
int pageFault = 0; ///< Total number of miss/page fault, or total number of int pageFault = 0; ///< Total number of miss/page fault, or total number of
///< times a page was not found in cache ///< times a page was not found in cache
public: public:
/** /**
* @brief Constructor, Initialize thee LRU class with page frame. * @brief Constructor, Initialize thee LRU class with page frame.
* @param pf Page frame or total size of cache. * @param pf Page frame or total size of cache.
* */ * */
explicit LRUCache(int pf) { pageFrame = pf; } explicit LRUCache(int pf) { pageFrame = pf; }
/** /**
* @brief Refer to a page, or request a page from memory. * @brief Refer to a page, or request a page from memory.
* @param page The page that you are referring to. * @param page The page that you are referring to.
* @returns void * @returns void
* */ * */
void refer(int page) { void refer(int page) {
// If the page requested not in cache. // If the page requested not in cache.
if (pageMap.find(page) == pageMap.end()) { if (pageMap.find(page) == pageMap.end()) {
pageFault++; ///< Increase the page fault by one. pageFault++; ///< Increase the page fault by one.
// Check if the cache is full // Check if the cache is full
if (cache.size() == pageFrame) { if (cache.size() == pageFrame) {
// delete the last page from cache // delete the last page from cache
int lastPage = cache.back(); int lastPage = cache.back();
cache.pop_back(); cache.pop_back();
pageMap.erase(lastPage); pageMap.erase(lastPage);
}
} }
// The requested page is in the cache
else {
hits++;
// present in cache, erase from current position to bring in front
cache.erase(pageMap[page]);
}
// Push it in the front of the cache and update the page reference in
// page map.
cache.push_front(page);
pageMap[page] = cache.begin();
} }
// The requested page is in the cache
else {
hits++;
// present in cache, erase from current position to bring in front
cache.erase(pageMap[page]);
}
// Push it in the front of the cache and update the page reference in
// page map.
cache.push_front(page);
pageMap[page] = cache.begin();
}
/** /**
* @brief A function to display the current cache * @brief A function to display the current cache
* @returns Void * @returns Void
* */ * */
void display() { void display() {
for (int &it : cache) { for (int &it : cache) {
std::cout << it << " "; std::cout << it << " ";
}
std::cout << std::endl;
} }
std::cout << std::endl; /**
} * @brief A function to get page hits
/** * @returns int
* @brief A function to get page hits * */
* @returns int int getHits() const { return hits; }
* */ /**
int getHits() const { return hits; } * @brief A function to get page fault
/** * @returns int
* @brief A function to get page fault * */
* @returns int int getPageFault() const { return pageFault; }
* */ };
int getPageFault() const { return pageFault; }
};
} // namespace lru_cache } // namespace lru_cache
@@ -137,11 +137,11 @@ namespace lru_tests {
* @tparam T Type of the given message. * @tparam T Type of the given message.
* @returns void * @returns void
* */ * */
template <typename T> template <typename T>
void log(T msg) { void log(T msg) {
// It's just to avoid writing cout and endl // It's just to avoid writing cout and endl
std::cout << "[TESTS] : ---> " << msg << std::endl; std::cout << "[TESTS] : ---> " << msg << std::endl;
} }
/** /**
* @brief A simple test case * @brief A simple test case
@@ -149,26 +149,26 @@ void log(T msg) {
* miss * miss
* @returns void * @returns void
* */ * */
static void test_1() { static void test_1() {
int expected_hits = 2; int expected_hits = 2;
int expected_pageFault = 4; int expected_pageFault = 4;
log("Running Test-1..."); log("Running Test-1...");
lru_cache::LRUCache cache(4); lru_cache::LRUCache cache(4);
cache.refer(1); cache.refer(1);
cache.refer(2); cache.refer(2);
cache.refer(5); cache.refer(5);
cache.refer(1); cache.refer(1);
cache.refer(4); cache.refer(4);
cache.refer(5); cache.refer(5);
log("Checking assert statement..."); log("Checking assert statement...");
assert(cache.getHits() == expected_hits && assert(cache.getHits() == expected_hits &&
cache.getPageFault() == expected_pageFault); cache.getPageFault() == expected_pageFault);
log("Assert successful!"); log("Assert successful!");
log("Test-1 complete!"); log("Test-1 complete!");
} }
/** /**
* @brief A test case contains hits more than cache size * @brief A test case contains hits more than cache size
@@ -176,26 +176,26 @@ static void test_1() {
* miss * miss
* @returns void * @returns void
* */ * */
static void test_2() { static void test_2() {
int expected_hits = 4; int expected_hits = 4;
int expected_pageFault = 2; int expected_pageFault = 2;
log("Running Test-2..."); log("Running Test-2...");
lru_cache::LRUCache cache(4); lru_cache::LRUCache cache(4);
cache.refer(1); cache.refer(1);
cache.refer(1); cache.refer(1);
cache.refer(1); cache.refer(1);
cache.refer(1); cache.refer(1);
cache.refer(1); cache.refer(1);
cache.refer(5); cache.refer(5);
log("Checking assert statement..."); log("Checking assert statement...");
assert(cache.getHits() == expected_hits && assert(cache.getHits() == expected_hits &&
cache.getPageFault() == expected_pageFault); cache.getPageFault() == expected_pageFault);
log("Assert successful!"); log("Assert successful!");
log("Test-2 complete!"); log("Test-2 complete!");
} }
/** /**
* @brief A simple test case * @brief A simple test case
@@ -203,38 +203,38 @@ static void test_2() {
* miss * miss
* @returns void * @returns void
* */ * */
static void test_3() { static void test_3() {
int expected_hits = 1; int expected_hits = 1;
int expected_pageFault = 5; int expected_pageFault = 5;
log("Running Test-3..."); log("Running Test-3...");
lru_cache::LRUCache cache(4); lru_cache::LRUCache cache(4);
cache.refer(1); cache.refer(1);
cache.refer(2); cache.refer(2);
cache.refer(3); cache.refer(3);
cache.refer(4); cache.refer(4);
cache.refer(5); cache.refer(5);
cache.refer(5); cache.refer(5);
log("Checking assert statement..."); log("Checking assert statement...");
assert(cache.getHits() == expected_hits && assert(cache.getHits() == expected_hits &&
cache.getPageFault() == expected_pageFault); cache.getPageFault() == expected_pageFault);
log("Assert successful!"); log("Assert successful!");
log("Test-3 complete!"); log("Test-3 complete!");
} }
/** /**
* @brief A function to invoke all test cases * @brief A function to invoke all test cases
* @returns void * @returns void
* */ * */
static void run_tests() { static void run_tests() {
test_1(); test_1();
test_2(); test_2();
test_3(); test_3();
log(""); log("");
log("TESTS COMPLETED!"); log("TESTS COMPLETED!");
} }
} // namespace lru_tests } // namespace lru_tests
/** /**