测试环境简单说明

Windows下测试

硬件环境如下：
处理器：Intel(R) Core(TM) i5-4460 CPU @ 3.20GHz
内 存：8GB
硬 盘：希捷 ST1000DM003
操作系统：Windows 10 企业版
编译说明：
两个都是使用VS2015编译的64位Release版本。运行时库采用动态多线程版本(MD)

Linux下测试

硬件环境如下：
处理器：Intel(R) Core(TM) i7-4500U CPU @ 1.80GHz
内 存：8GB
硬 盘：金士顿64G SSD
操作系统：ArchLinux (Linux version 4.8.13-1-ARCH)
编译说明：
两个都是使用Gcc 6.2.1编译的x64版本，使用-O2参数优化。

测试结果

对LevelDB和ForestDB进行简单的性能测试。
两个都在单线程下进行10000次的增删查改测试，共测试5次。（这里测试的次数有点少，应该测试十万次以上的）
测试的时候可以发现（设置断点），Forest每次操作都将数据缓存在内存了，内存占用比较大。而LevelDB在添加的时候并没有缓存，但是在数据获取和修改的时候内存会变大。
总体上LevelDB占用内存小一点，但是linux下速度不及ForestDB(非常接近)。易用程度上，LevelB简单得多。磁盘占用的情况的话，Forest对磁盘使用比较少，这10000条数据占了13MB左右，而LevelDB则占了120MB左右。

Windows下测试结果

测试结果平均值对比直方图：

LevelDB 测试结果截图

ForestDB 测试结果截图

Linux下测试结果

测试结果平均值对比直方图：

LevelDB 测试结果截图

ForestDB 测试结果截图

测试代码

LevelDB测试代码

#include <cassert>  
#include <string>  
#include <iostream>
#include <chrono>
#include "leveldb/db.h"  
#define TEST_FREQUENCY  (10000)
char* randomstr()
{
    static char buf[1024];
    int len = rand() % 768 + 255;
    for (int i = 0; i < len; ++i) {
        buf[i] = 'A' + rand() % 26;
    }
    buf[len] = '\0';
    return buf;
}
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, "./testdb", &db);
    assert(status.ok());
    srand(2017);
    std::string k[TEST_FREQUENCY];
    for (int i = 0; i < TEST_FREQUENCY; ++i) {
        k[i] = (randomstr());
    }
    std::string v("壹贰叁肆伍陆柒捌玖拾");
    v.append(v).append(v).append(v).append(v).append(v);
    // 测试添加
    {
        auto start = std::chrono::system_clock::now();
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = db->Put(leveldb::WriteOptions(), k[i], v);
            assert(status.ok());
        }
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次添加耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
    }
    // 测试获取
    {
        auto start = std::chrono::system_clock::now();
        std::string v2[TEST_FREQUENCY];
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = db->Get(leveldb::ReadOptions(), k[i], &v2[i]);
            assert(status.ok());
        }
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次获取耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
        // 验证获取结果是否正确
        std::string ss;
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            if (v2[i] != v) {
                std::cout << "第 " << i << " 个结果不正确" << std::endl;
                std::cout << v2[i] << std::endl;
            }
        }
    }
    // 测试修改
    {
        auto start = std::chrono::system_clock::now();
        v.append(v);
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = db->Put(leveldb::WriteOptions(), k[i], v);
            assert(status.ok());
        }
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次修改耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
    }
    // 测试删除
    {
        auto start = std::chrono::system_clock::now();
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = db->Delete(leveldb::WriteOptions(), k[i]);
            assert(status.ok());
        }
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次删除耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
    }
    delete db;
    return 0;
}

Forest 测试代码

#include <cassert>  
#include <string>  
#include <iostream>
#include <chrono>
#include "libforestdb/forestdb.h"
#define TEST_FREQUENCY  (10000)
char* randomstr()
{
    static char buf[1024];
    int len = rand() % 768 + 255;
    for (int i = 0; i < len; ++i) {
        buf[i] = 'A' + rand() % 26;
    }
    buf[len] = '\0';
    return buf;
}
int main()
{
    fdb_file_handle* fdbFileHandle = nullptr;
    fdb_kvs_handle* fdbKvsHandle = nullptr;
    fdb_status status;
    // 初始化ForestDB
    // 1、文件配置设置配置
    fdb_config fileConfig = fdb_get_default_config();
    {// WAL阈值4K
        fileConfig.wal_threshold = 4096;
        // 缓存大小64MB
        fileConfig.buffercache_size = 64 * 1024 * 1024;
        // 设置使用默认的kvs
        fileConfig.multi_kv_instances = false;
        // 关闭循环块复用
        fileConfig.block_reusing_threshold = 100;
        // 使用序列树
        fileConfig.seqtree_opt = FDB_SEQTREE_USE;
    }
    // 2、使用设置的配置进行初始化
    status = fdb_init(&fileConfig);
    assert(status == FDB_RESULT_SUCCESS);
    // 打开数据库
    status = fdb_open(&fdbFileHandle, "./testdb", &fileConfig);
    assert(status == FDB_RESULT_SUCCESS);
    // 打开kvs
    fdb_kvs_config kvsConfig = fdb_get_default_kvs_config();
    status = fdb_kvs_open_default(fdbFileHandle, &fdbKvsHandle, &kvsConfig);
    assert(status == FDB_RESULT_SUCCESS);
    srand(2017);
    std::string k[TEST_FREQUENCY];
    for (int i = 0; i < TEST_FREQUENCY; ++i) {
        k[i] = (randomstr());
    }
    std::string v("壹贰叁肆伍陆柒捌玖拾");
    v.append(v).append(v).append(v).append(v).append(v);
    // 测试添加
    {
        auto start = std::chrono::system_clock::now();
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = fdb_set_kv(fdbKvsHandle, k[i].data(), k[i].size(), v.data(), v.size());
            assert(status == FDB_RESULT_SUCCESS);
        }
        // 提交操作到磁盘(这里必须commit才能实际写入到磁盘)
        fdb_commit(fdbFileHandle, FDB_COMMIT_NORMAL);
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次添加耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
    }
    // 测试获取
    {
        auto start = std::chrono::system_clock::now();
        void* v2[TEST_FREQUENCY]; size_t v2len[TEST_FREQUENCY];
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = fdb_get_kv(fdbKvsHandle, k[i].data(), k[i].size(), &v2[i], &v2len[i]);
            assert(status == FDB_RESULT_SUCCESS);
        }
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次获取耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
        // 验证获取结果是否正确
        std::string ss;
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            ss.assign((const char*)v2[i], v2len[i]);
            if (ss != v) {
                std::cout << "第 " << i << " 个结果不正确" << std::endl;
                std::cout << ss << std::endl;
            }
            free(v2[i]);
        }
    }
    // 测试修改
    {
        auto start = std::chrono::system_clock::now();
        v.append(v);
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = fdb_set_kv(fdbKvsHandle, k[i].data(), k[i].size(), v.data(), v.size());
            assert(status == FDB_RESULT_SUCCESS);
        }
        // 提交操作到磁盘(这里必须commit才能实际写入到磁盘)
        fdb_commit(fdbFileHandle, FDB_COMMIT_NORMAL);
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次修改耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
    }
    // 测试删除
    {
        auto start = std::chrono::system_clock::now();
        for (int i = 0; i < TEST_FREQUENCY; ++i) {
            status = fdb_del_kv(fdbKvsHandle, k[i].data(), k[i].size());
            assert(status == FDB_RESULT_SUCCESS);
        }
        // 提交操作到磁盘(这里必须commit才能实际写入到磁盘)
        fdb_commit(fdbFileHandle, FDB_COMMIT_NORMAL);
        auto end = std::chrono::system_clock::now();
        auto duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start);
        std::cout << TEST_FREQUENCY <<"次删除耗时: "
            << double(duration.count()) * std::chrono::microseconds::period::num / std::chrono::microseconds::period::den
            << "秒" << std::endl;
    }
    // 关闭数据库
    status = fdb_kvs_close(fdbKvsHandle);
    assert(status == FDB_RESULT_SUCCESS);
    status = fdb_close(fdbFileHandle);
    assert(status == FDB_RESULT_SUCCESS);
    status = fdb_shutdown();
    assert(status == FDB_RESULT_SUCCESS);
    return 0;
}

参考资料

• https://www.cnblogs.com/oloroso/p/6306352.html