bst vs heap: move in fully from cpp-cheat

2026-01-23 10:15:57 +01:00 · 2019-06-26 00:00:00 +00:00
parent d37344ac11
commit 178a6681df
7 changed files with 266 additions and 91 deletions
--- a/userland/cpp/bst_vs_heap_vs_hashmap.cpp
+++ b/userland/cpp/bst_vs_heap_vs_hashmap.cpp
@@ -0,0 +1,154 @@
+// https://github.com/cirosantilli/linux-kernel-module-cheat#bst-vs-heap-vs-hashmap
+
+//#include <algorithm>
+//#include <iostream>
+//#include <queue>
+//#include <random>
+//#include <set>
+//
+//#include <lkmc/m5ops.h>
+//
+//int main(int argc, char **argv) {
+//    typedef uint64_t I;
+//    std::vector<I> randoms;
+//    size_t i, n;
+//    std::priority_queue<I> heap;
+//    std::set<I> bst;
+//    unsigned int seed = std::random_device()();
+//
+//    // CLI arguments.
+//    if (argc > 1) {
+//        n = std::stoi(argv[1]);
+//    } else {
+//        n = 1;
+//    }
+//
+//    // Action.
+//    for (i = 0; i < n; ++i) {
+//        randoms.push_back(i);
+//    }
+//    std::shuffle(randoms.begin(), randoms.end(), std::mt19937(seed));
+//    for (i = 0; i < n; ++i) {
+//        auto random = randoms[i];
+//
+//        // Heap.
+//        LKMC_M5OPS_RESETSTATS;
+//        heap.emplace(random);
+//        LKMC_M5OPS_DUMPSTATS;
+//
+//        // BST.
+//        LKMC_M5OPS_RESETSTATS;
+//        bst.insert(random);
+//        LKMC_M5OPS_DUMPSTATS;
+//    }
+//}
+
+#include <algorithm>
+#include <cassert>
+#include <chrono>
+#include <iostream>
+#include <queue>
+#include <random>
+#include <set>
+#include <unordered_set>
+
+#include <lkmc/m5ops.h>
+
+int main(int argc, char **argv) {
+    typedef uint64_t I;
+    std::vector<I> randoms;
+    size_t i, j, n, granule, base;
+    std::priority_queue<I> heap;
+    std::set<I> bst;
+    std::unordered_set<I> hashmap;
+    unsigned int seed = std::random_device()();
+
+    // CLI arguments.
+    if (argc > 1) {
+        n = std::stoi(argv[1]);
+    } else {
+        n = 10000000;
+    }
+#ifdef LKMC_M5OPS_ENABLE
+    // Let's comment useless stuff out to speed up gem5 simulations.
+    granule = 1;
+    j = 0;
+#else
+    if (argc > 2) {
+        granule = std::stoi(argv[2]);
+    } else {
+        granule = 10000;
+    }
+#endif
+
+    // Action.
+    for (i = 0; i < n; ++i) {
+        randoms.push_back(i);
+    }
+    std::shuffle(randoms.begin(), randoms.end(), std::mt19937(seed));
+    for (i = 0; i < n / granule; ++i) {
+#ifndef LKMC_M5OPS_ENABLE
+        using clk = std::chrono::high_resolution_clock;
+        decltype(clk::now()) start, end;
+#endif
+        base = i * granule;
+
+        // Heap.
+#ifndef LKMC_M5OPS_ENABLE
+        start = clk::now();
+        for (j = 0; j < granule; ++j) {
+#endif
+            LKMC_M5OPS_RESETSTATS;
+            heap.emplace(randoms[base + j]);
+            LKMC_M5OPS_DUMPSTATS;
+#ifndef LKMC_M5OPS_ENABLE
+        }
+        end = clk::now();
+        auto dt_heap = (end - start) / granule;
+#endif
+
+        // BST.
+#ifndef LKMC_M5OPS_ENABLE
+        start = clk::now();
+        for (j = 0; j < granule; ++j) {
+#endif
+            LKMC_M5OPS_RESETSTATS;
+            bst.insert(randoms[base + j]);
+            LKMC_M5OPS_DUMPSTATS;
+#ifndef LKMC_M5OPS_ENABLE
+        }
+        end = clk::now();
+        auto dt_bst = (end - start) / granule;
+#endif
+
+        // Hashmap.
+#ifndef LKMC_M5OPS_ENABLE
+        start = clk::now();
+        for (j = 0; j < granule; ++j) {
+#endif
+            LKMC_M5OPS_RESETSTATS;
+            hashmap.insert(randoms[base + j]);
+            LKMC_M5OPS_DUMPSTATS;
+#ifndef LKMC_M5OPS_ENABLE
+        }
+        end = clk::now();
+        auto dt_hashmap = (end - start) / granule;
+#endif
+
+#ifndef LKMC_M5OPS_ENABLE
+        // Output.
+        std::cout
+            << base << " "
+            << std::chrono::duration_cast<std::chrono::nanoseconds>(dt_heap).count() << " "
+            << std::chrono::duration_cast<std::chrono::nanoseconds>(dt_bst).count() << " "
+            << std::chrono::duration_cast<std::chrono::nanoseconds>(dt_hashmap).count() << std::endl
+        ;
+#endif
+    }
+
+    // Sanity check.
+    for (auto it = bst.rbegin(); it != bst.rend(); ++it) {
+        assert(*it == heap.top());
+        heap.pop();
+    }
+}