add benchmark for version_0

CMakeLists.txt

@@ -517,3 +517,7 @@ if(LEVELDB_INSTALL)
     DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}"
   )
 endif(LEVELDB_INSTALL)
+add_executable(db_test_bench
+"${PROJECT_SOURCE_DIR}/test/benchmark_4leveldb.cpp"
+      )
+target_link_libraries(db_test_bench PRIVATE leveldb gtest)

test/benchmark_4leveldb.cpp

@@ -0,0 +1,138 @@
+#include <cassert>
+#include <string>
+#include <iostream>
+#include <iomanip>
+#include <cmath>
+#include <chrono>
+#include "leveldb/db.h"
+// 配置
+const int TEST_EXPONENT = 5;
+const int TEST_FREQUENCY = static_cast<int>(std::pow(10, TEST_EXPONENT));
+const int MIN_STR_LEN = 255;
+const int MAX_STR_LEN = 1024;
+const std::string DB_PATH = "db_benchmark";
+const std::string CHARSET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+// 多语言
+const std::string BASE_VALUE = "こんにちは世界！Hello World! Привет, мир! ¡Hola Mundo! 你好，世界！Bonjour le monde! Hallo Welt!";
+// 莎士比亚
+// const std::string BASE_VALUE = "To be, or not to be, that is the question: Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune, or to take arms against a sea of troubles and by opposing end them.";
+// 超长字符
+// const std::string BASE_VALUE = []() {
+//     std::string base = "壹贰叁肆伍陆柒捌玖拾";
+//     std::string long_text;
+//     for (int i = 0; i < 100; ++i) { // 重复 100 次
+//         long_text += base;
+//     }
+//     return long_text;
+// }();
+
+// 随机字符串生成
+std::string randomStr() {
+    int len = rand() % (MAX_STR_LEN - MIN_STR_LEN + 1) + MIN_STR_LEN;
+    std::string str(len, '\0');
+    for (int i = 0; i < len; ++i) {
+        str[i] = CHARSET[rand() % CHARSET.size()];
+    }
+    return str;
+}
+
+// 计算并输出耗时的模板函数
+template<typename Func>
+void measureTime(const std::string& operation, Func func) {
+    auto start = std::chrono::system_clock::now();
+    func();
+    auto end = std::chrono::system_clock::now();
+    auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
+    
+    double seconds = double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den;
+
+    // 输出格式化信息
+    std::cout << "Operation: " << operation << "\n";
+    std::cout << "Number of operations: " << TEST_FREQUENCY << "\n";
+    std::cout << "Total time: " 
+              << std::fixed << std::setprecision(6) << seconds << " seconds\n";
+    std::cout << "Average time per operation: " 
+              << std::fixed << std::setprecision(6) 
+              << (seconds / TEST_FREQUENCY) * 1e6 << " microseconds\n";
+    std::cout << "========================================\n";
+}
+
+int main() {
+    leveldb::DB* db;
+    leveldb::Options options;
+    options.create_if_missing = true;
+
+    // 打开数据库
+    leveldb::Status status = leveldb::DB::Open(options, DB_PATH, &db);
+    assert(status.ok());
+    std::cout << "db open: " << DB_PATH << std::endl;
+
+    srand(2017);
+
+    // 生成测试数据
+    std::string keys[TEST_FREQUENCY];
+    for (int i = 0; i < TEST_FREQUENCY; ++i) {
+        keys[i] = randomStr();
+    }
+    std::string value = BASE_VALUE;
+    for (int i = 0; i < 4; ++i) {
+        value += value; // 扩展 base value
+    }
+
+    // 测试添加
+    measureTime("ADD", [&]() {
+        for (int i = 0; i < TEST_FREQUENCY; ++i) {
+            status = db->Put(leveldb::WriteOptions(), keys[i], value);
+            assert(status.ok());
+        }
+    });
+
+    // 测试获取
+    measureTime("GET", [&]() {
+        std::string retrievedValues[TEST_FREQUENCY];
+        for (int i = 0; i < TEST_FREQUENCY; ++i) {
+            status = db->Get(leveldb::ReadOptions(), keys[i], &retrievedValues[i]);
+            assert(status.ok());
+            assert(retrievedValues[i] == value); // 验证获取结果
+        }
+    });
+
+    // 测试修改
+    measureTime("UPDATE", [&]() {
+        std::string newValue = value + value;
+        for (int i = 0; i < TEST_FREQUENCY; ++i) {
+            status = db->Put(leveldb::WriteOptions(), keys[i], newValue);
+            assert(status.ok());
+        }
+    });
+
+    // 测试删除
+    measureTime("DELETE", [&]() {
+        for (int i = 0; i < TEST_FREQUENCY; ++i) {
+            status = db->Delete(leveldb::WriteOptions(), keys[i]);
+            assert(status.ok());
+        }
+    });
+
+    if (db) {
+    delete db;
+    db = nullptr;
+    }
+    std::cout << "Test completed, database has been closed." << std::endl;
+
+    // Delete database directory
+    #ifdef _WIN32
+        std::string command = "rd /s /q \"" + DB_PATH + "\""; // Windows delete directory
+    #else
+        std::string command = "rm -rf \"" + DB_PATH + "\""; // Linux/macOS delete directory
+    #endif
+    if (std::system(command.c_str()) == 0) {
+        std::cout << "Database directory has been successfully deleted" << std::endl;
+    } else {
+        std::cerr << "Warning: Failed to delete the database directory. Please check manually!" << std::endl;
+    }
+
+    
+    return 0;
+}