Benchmarks

.github/workflows/cmake-multi-platform.yml

@@ -24,7 +24,7 @@ jobs:
       # To add more build types (Release, Debug, RelWithDebInfo, etc.) customize the build_type list.
       matrix:
         os: [ubuntu-latest, windows-latest]
-        build_type: [Debug]
+        build_type: [Release]
         c_compiler: [gcc, clang, cl]
         include:
           - os: windows-latest

CMakeLists.txt

@@ -11,6 +11,7 @@ add_subdirectory(main)
 add_subdirectory(LRU)
 add_subdirectory(LFU)
 add_subdirectory(perfect)
+add_subdirectory(benchmark)
 
 
 include(CTest)

README.md

@@ -1,24 +1,34 @@
-# cpp_proj
+# HWC Caches. LRU, LFU, Belady's optimal cache
 
-How to run
+## How to run
 
 ```bash
 ./build/main/main <<< "2 6 3 3 1 2 1 2" # cache_size Nelem elem1 elem2 ...
 ```
 output is 
 ```bash
 Cache type   N hits
+Belady       3
 LRU          3
 LFU          1
 ```
 
+### Benchmark
+input : uniform random integers [0: 100) with input size 100'000
 
+![statistics](./benchmark/cache_hit_statistics.png)
 
-# Tips
+To reproduce benchmarks one needs to build the project and run
+```bash
+./build/benchmark/benchmark
+cd benchmark
+gnuplot script.gp
+open cache_hit_statistics.png
+```
 
-## CMAKE
 
 
+## How to build: CMAKE
 ```bash
 cmake -S . -B build -G Ninja \
   -DCMAKE_C_COMPILER=gcc-14 \

benchmark/CMakeLists.txt

@@ -0,0 +1,18 @@
+add_executable(benchmark)
+target_sources(benchmark
+  PRIVATE
+    benchmark.cpp
+)
+
+target_compile_options(benchmark
+  PRIVATE
+    $<$<CXX_COMPILER_ID:MSVC>:/W4 /WX>
+    $<$<CXX_COMPILER_ID:GNU,Clang>:-Wall -Wextra -Werror>
+)
+
+target_link_libraries(benchmark
+  PRIVATE
+    LRU 
+    LFU
+    perfect
+)

benchmark/benchmark.cpp

@@ -0,0 +1,68 @@
+#include "LFU.hpp"
+#include "LRU.hpp"
+#include "perfect.hpp"
+#include <algorithm>
+#include <cassert>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <map>
+#include <string>
+#include <utility>
+
+int slow_get_page(int key) { return key; }
+
+std::vector<int> generate_rnd_keys(size_t n, int mod = 100) {
+  std::vector<int> keys(n);
+  std::generate(keys.begin(), keys.end(),
+                [&]() { return static_cast<int>(rand() % mod); });
+  return keys;
+}
+
+int main() {
+  size_t input_sz = 100'000;
+  int rnd_mod = 100;
+  std::vector<int> keys = generate_rnd_keys(input_sz, rnd_mod);
+
+  std::map<size_t, std::map<std::string, int>> cache_sizes_vs_strategy_hits;
+  std::cout << "Cache type\tN hits\n";
+  for (size_t cache_sz = 10; cache_sz < 101; cache_sz += 10) {
+    std::map<std::string, int> cache_hits;
+    cache::perfect_t<int> perfect_cache(cache_sz, keys);
+    cache::LRU_t<int> lru{cache_sz};
+    cache::LFU_t<int> lfu{cache_sz};
+
+    for (const auto key : keys) {
+      if (perfect_cache.lookup_update(key, slow_get_page))
+        cache_hits["Belady"] += 1;
+
+      if (lru.lookup_update(key, slow_get_page))
+        cache_hits["LRU"] += 1;
+
+      if (lfu.lookup_update(key, slow_get_page))
+        cache_hits["LFU"] += 1;
+    }
+    cache_sizes_vs_strategy_hits[cache_sz] = cache_hits;
+
+    std::cout << "cache size: " << cache_sz << '\n';
+    for (auto [cache_type, nhits] : cache_hits) {
+      std::cout << cache_type << "\t" << nhits << '\n';
+    }
+    std::cout << std::endl;
+  }
+
+  // output to a file
+  std::ofstream file("benchmark/cache_hits.dat");
+  if (file.is_open()) {
+    file << "#Number of keys = " << input_sz << "\n";
+    file << "#input keys: uniform distribution [0:" << rnd_mod << ")\n";
+    file << "#Cache_size\tLRU\tLFU\tBelady\n";
+    for (auto &[sz, cache_stats] : cache_sizes_vs_strategy_hits) {
+      file << sz << '\t' << cache_stats["LRU"] << '\t' << cache_stats["LFU"]
+           << '\t' << cache_stats["Belady"] << '\n';
+    }
+    file.close();
+  }
+
+  return 0;
+}

benchmark/cache_hits.dat

@@ -0,0 +1,13 @@
+#Number of keys = 100000
+#input keys: uniform distribution [0:100)
+#Cache_size	LRU	LFU	Belady
+10	10015	9828	35205
+20	19947	19849	51756
+30	29887	29907	63218
+40	39921	39898	72054
+50	49944	49914	79207
+60	59924	59805	85109
+70	69960	69747	90046
+80	79974	79703	94157
+90	89939	89828	97468
+100	99900	99900	99900

benchmark/script.gp

@@ -0,0 +1,11 @@
+set terminal pngcairo size 800,600 enhanced font "Helvetica,12"
+set output 'cache_hit_statistics.png'
+
+set title "Cache statistics for uniform random integers [0:100)"
+set xlabel "Cache size"
+set ylabel "Cache hits"
+set key bottom right
+
+plot "cache_hits.dat" u 1:2 title "LRU",\
+      "" u 1:3 title "LFU",\
+      "" u 1:4 title "Belady"\

main/main.cpp

@@ -27,7 +27,7 @@ int main() {
   std::map<std::string, int> cache_hits;
   for (const auto key : keys) {
     if (perfect_cache.lookup_update(key, slow_get_page))
-      cache_hits["perfect_cache"] += 1;
+      cache_hits["Belady"] += 1;
 
     if (lru.lookup_update(key, slow_get_page))
       cache_hits["LRU"] += 1;

tests/LFU_test.cpp

@@ -87,9 +87,7 @@ TEST(LFU, eviction_LRU) {
 
 size_t nhits(const std::vector<int> &input) {
   size_t cache_sz = input[0];
-  size_t nelem = input[1];
   std::vector<int> page_ids(input.begin() + 2, input.end());
-  assert(page_ids.size() == nelem);
 
   cache::LFU_t<page_t> lfu{cache_sz};
   size_t hits{};

tests/LRU_test.cpp

@@ -67,9 +67,7 @@ TEST(LRU, eviction) {
 
 size_t nhits(const std::vector<int> &input) {
   size_t cache_sz = input[0];
-  size_t nelem = input[1];
   std::vector<int> page_ids(input.begin() + 2, input.end());
-  assert(page_ids.size() == nelem);
 
   cache::LRU_t<page_t> lru{cache_sz};
   size_t hits{};

tests/perfect_test.cpp

@@ -86,9 +86,7 @@ TEST(Perfect_cache, eviction_2) {
 
 size_t nhits(const std::vector<int> &input) {
   size_t cache_sz = input[0];
-  size_t nelem = input[1];
   std::vector<int> page_ids(input.begin() + 2, input.end());
-  assert(page_ids.size() == nelem);
 
   cache::perfect_t<page_t> perf_cache{cache_sz, page_ids};
   size_t hits{};