windows下编译leveldb(动态库+静态库)

环境准备

1）下载cmake并安装

下载路径: https://cmake.org/download/

2）下载leveldb源码

git clone https://github.com/google/leveldb.git

3）下载googletest和benchmark，cmake编译时需要

# 进入leveldb源码路径下的third_party
cd leveldb/third_party# 下载googletest
git clone https://github.com/google/googletest.git# 下载benchmark
git clone https://github.com/google/benchmark.git

生成工程文件

1）进入leveldb源码目录，以管理员方式打开cmd.exe，执行

cmake CMakeLists.txt

生成工程文件如下所示：

静态库编译

配置

无需任何配置，使用visual studio打开工程文件leveldb.sln直接编译即可。

生成

如编译debug版本，编译完成后在源码根目录的Debug文件夹下会生成对应的静态库。

测试

#include <iostream>
#include "leveldb/db.h"
#include "leveldb/write_batch.h"
using namespace std;int main()
{leveldb::DB* dbptr = nullptr;leveldb::Options options;options.create_if_missing = true;// open leveldb::Status status = leveldb::DB::Open(options, "./leveldb.db", &dbptr);if (!status.ok()) {// 失败返回状态字符串cout << "Open db failed, status: " << status.ToString() << endl;return -1;}assert(nullptr != dbptr);cout << "Open db success" << endl;// putleveldb::WriteOptions putOptions;putOptions.sync = true;status = dbptr->Put(putOptions, "TEST1", "RESULT1");if (!status.ok()) {cout << "Put failed, status: " << status.ToString() << endl;return -1;}cout << "Put success" << endl;// write leveldb::WriteBatch writeBatch;writeBatch.Put("name", "lucas");writeBatch.Put("age", "12");writeBatch.Put("sex", "boy");status = dbptr->Write(leveldb::WriteOptions(), &writeBatch);if (!status.ok()) {cout << "Write failed, status: " << status.ToString() << endl;return -1;}cout << "Write success" << endl;// getleveldb::ReadOptions getOptions;std::string value;status = dbptr->Get(getOptions, "TEST1", &value);if (!status.ok()) {cout << "Get failed, status: " << status.ToString() << std::endl;return -1;}cout << "Get success, value: " << value << std::endl;// iterleveldb::Iterator* it = dbptr->NewIterator(leveldb::ReadOptions());if (!it) {cout << "NewIterator failed" << endl;return -1;}cout << "Iterator test start" << endl;it->SeekToFirst();while (it->Valid()) {leveldb::Slice sKey = it->key();leveldb::Slice sVal = it->value();cout << "key:" << sKey.ToString() << " value:" << sVal.ToString() << endl;it->Next();}cout << "Iterator test finish" << endl;if (it) {delete (it);it = nullptr;}// deletestatus = dbptr->Delete(putOptions, "TEST1");if (!status.ok()) {cout << "Delete failed, status: " << status.ToString() << endl;return -1;}cout << "Delete success, key: " << "TEST1" << endl;if (dbptr) {delete dbptr;dbptr = nullptr;}cout << "test finished" << endl;system("pause");return 0; 
}

测试结果：

动态库编译

配置

1）修改位置1（配置属性——常规——配置类型）：

2）修改位置2（配置属性——高级——目标文件扩展名）：

3）修改位置3（配置属性——C/C++——预处理器，增加LEVELDB_SHARED_LIBRARY）：

生成

如生成Debug版本，编译完成后在源码根目录的Debug文件夹下会生成对应的动态库。

测试

采用手动加载动态库，这样具有良好的向下兼容性。

#include <iostream>
#include <stdio.h>
#include <windows.h>
#include <tchar.h>
#include "leveldb/c.h"
using namespace std;typedef leveldb_t* (*LevelDBOpen)(const leveldb_options_t*, const char*, char**);
typedef leveldb_options_t* (*LevelDBCreate)(void);
typedef leveldb_writeoptions_t* (*LevelDBWriteOptionsCreate)(void);
typedef leveldb_readoptions_t* (*LevelDBReadOptionsCreate)(void);
typedef void (*LevelDBReadOptionsDestroy)(leveldb_readoptions_t*);
typedef void (*LevelDBPut)(leveldb_t*, const leveldb_writeoptions_t*,const char*, size_t, const char*,size_t, char**);
typedef char* (*LevelDBGet)(leveldb_t*, const leveldb_readoptions_t*,const char*, size_t, size_t*, char**);
typedef void (*LevelDBWrite)(leveldb_t*,const leveldb_writeoptions_t*,leveldb_writebatch_t*, char**);
typedef void (*LevelDBDelete)(leveldb_t*,const leveldb_writeoptions_t*,const char*, size_t, char**);
typedef void (*LevelDBClose)(leveldb_t*);
typedef void (*LevelDBDestroy)(const leveldb_options_t*,const char*, char**);
typedef void (*LevelDBSetCreateIfMissing)(leveldb_options_t*, uint8_t);
typedef void (*LevelDBFree)(void*);
typedef leveldb_writebatch_t* (*LevelDBWriteBatchCreate)(void);
typedef void (*LevelDBWriteBatchDestroy)(leveldb_writebatch_t*);
typedef void (*LevelDBWriteBatchPut)(leveldb_writebatch_t*, const char*,size_t, const char*, size_t);int main()
{HMODULE handle = ::LoadLibrary(_T("./leveldb.dll"));if (!handle) {cout << "Load failed!" << endl;return -1;}cout << "Load success" << endl;// get funcLevelDBOpen func_open = (LevelDBOpen)GetProcAddress(handle, "leveldb_open");LevelDBCreate func_options_create = (LevelDBCreate)GetProcAddress(handle, "leveldb_options_create");LevelDBWriteOptionsCreate func_write_options_create =(LevelDBWriteOptionsCreate)GetProcAddress(handle, "leveldb_writeoptions_create");LevelDBReadOptionsCreate func_read_options_create =(LevelDBReadOptionsCreate)GetProcAddress(handle, "leveldb_readoptions_create");LevelDBReadOptionsDestroy func_read_options_destroy =(LevelDBReadOptionsDestroy)GetProcAddress(handle, "leveldb_readoptions_destroy");LevelDBPut func_put = (LevelDBPut)GetProcAddress(handle, "leveldb_put");LevelDBGet func_get = (LevelDBGet)GetProcAddress(handle, "leveldb_get");LevelDBWrite func_write =(LevelDBWrite)GetProcAddress(handle, "leveldb_write");LevelDBDelete func_delete =(LevelDBDelete)GetProcAddress(handle, "leveldb_delete");LevelDBClose func_close =(LevelDBClose)GetProcAddress(handle, "leveldb_close");LevelDBDestroy func_destroy =(LevelDBDestroy)GetProcAddress(handle, "leveldb_destroy_db");LevelDBSetCreateIfMissing func_options_set_create_if_missing =(LevelDBSetCreateIfMissing)GetProcAddress(handle, "leveldb_options_set_create_if_missing");LevelDBFree func_free = (LevelDBFree)GetProcAddress(handle, "leveldb_free");LevelDBWriteBatchCreate func_writebatch_create =(LevelDBWriteBatchCreate)GetProcAddress(handle, "leveldb_writebatch_create");LevelDBWriteBatchDestroy func_writebatch_destroy =(LevelDBWriteBatchDestroy)GetProcAddress(handle, "leveldb_writebatch_destroy");LevelDBWriteBatchPut func_writebatch_put =(LevelDBWriteBatchPut)GetProcAddress(handle, "leveldb_writebatch_put");if (nullptr == func_open|| nullptr == func_options_create || nullptr == func_write_options_create || nullptr == func_read_options_create || nullptr == func_read_options_destroy|| nullptr == func_put|| nullptr == func_get|| nullptr == func_delete|| nullptr == func_close|| nullptr == func_destroy|| nullptr == func_options_set_create_if_missing|| nullptr == func_free || nullptr == func_writebatch_create|| nullptr == func_writebatch_destroy|| nullptr == func_writebatch_put) {DWORD dw = GetLastError();cout << "Get func failed, err: " << dw << endl;return -1;}cout << "Open func success" << endl;// Openchar* err = nullptr;leveldb_options_t* options = nullptr;options = func_options_create();func_options_set_create_if_missing(options, 1);leveldb_t* db = func_open(options, "./leveldb.db", &err);if (nullptr != err) {cout << "Open failed, err: " << err << endl;return -1;}func_free(err);err = nullptr;cout << "Open success" << endl;// Putleveldb_writeoptions_t* woptions = nullptr;woptions = func_write_options_create();func_put(db, woptions, "key", 5, "value", 5, &err);if (nullptr != err) {cout << "Put failed, err: " << err << endl;return -1;}func_free(err);err = nullptr;cout << "Put success" << endl;leveldb_writebatch_t* batch = func_writebatch_create();func_writebatch_put(batch, "foo", 3, "a", 1);func_writebatch_put(batch, "bar", 3, "b", 1);func_writebatch_put(batch, "box", 3, "c", 1);func_write(db, woptions, batch, &err);if (nullptr != err) {cout << "Write failed, err: " << err << endl;return -1;}func_free(err);err = nullptr;func_writebatch_destroy(batch);cout << "Write success" << endl;// Readsize_t read_len = 0;leveldb_readoptions_t* roptions = func_read_options_create();char* read = func_get(db, roptions, "key", 5, &read_len, &err);if (nullptr != err) {cout << "Read failed!" << endl;return -1;}func_free(err);err = nullptr;func_read_options_destroy(roptions);cout << "Read success" << endl;// Deletefunc_delete(db, woptions, "key", 3, &err);if (nullptr != err) {cout << "Delete failed!" << endl;return -1;}func_free(err);err = nullptr;cout << "Delete success" << endl;// Closefunc_close(db);cout << "Close success" << endl;// Destroyfunc_destroy(options, "./leveldb.db", &err);if (nullptr != err) {cout << "Destroy failed!" << endl;return -1;}func_free(err);err = nullptr;cout << "Destroy success" << endl;FreeLibrary(handle);system("pause");return 0;
}

测试结果：

参考：

leveldb介绍：https://blog.csdn.net/joelcat/article/details/89240584

linux下安装leveldb：https://blog.csdn.net/www_dong/article/details/107307944