wangjia184 / mdbx.NET

.NET bindings of libmdbx, succeeder of LMDB(Lightning Memory-Mapped Database)

mdbx.NET

.NET bindings(.NET Standard 2.0) of libmdbx, succeeder of LMDB(Lightning Memory-Mapped Database).

License

This project is licensed under the Apache License, Version 2.0.

The libmdbx library is not shipped with this assembly. And the assembly will load libmdbx from the location below according to your platform and OS.

/mdbx.NET.dll
/native
  ├──/windows
  │   ├──/x86/mdbx.dll
  │   ├──/x64/mdbx.dll
  │   ├──/arm/mdbx.dll
  │   └──/arm64/mdbx.dll
  ├──/linux
  │   ├──/x86/libmdbx.so
  │   ├──/x64/libmdbx.so
  │   ├──/arm/libmdbx.so
  │   └──/arm64/libmdbx.so
  └──/osx
      ├──/x86/libmdbx.so
      ├──/x64/libmdbx.so
      ├──/arm/libmdbx.so
      └──/arm64/libmdbx.so

How to Use

NuGet package is available, first install.

Install-Package mdbx.NET

Here is an example of basic operations.

using MDBX;

using (MdbxEnvironment env = new MdbxEnvironment())
{
    env.SetMaxDatabases(10) /* allow us to use a different db for testing */
        .Open(path, EnvironmentFlag.NoTLS/* flags */, Convert.ToInt32("666", 8)/* permission */ );

    DatabaseOption option = DatabaseOption.Create /* needed to create a new db if not exists */
        | DatabaseOption.IntegerKey/* opitimized for fixed-size int/long key */;

    // mdbx_put
    using (MdbxTransaction tran = env.BeginTransaction())
    {
        MdbxDatabase db = tran.OpenDatabase("basic_op_test", option);
        db.Put(10L, "ten");
        db.Put(1000L, "thousand");
        db.Put(1000000000L, "billion");
        db.Put(1000000L, "million");
        db.Put(100L, "hundred");
        db.Put(1L, "one");
        tran.Commit();
    }


    // mdbx_get
    using (MdbxTransaction tran = env.BeginTransaction(TransactionOption.ReadOnly))
    {
        MdbxDatabase db = tran.OpenDatabase("basic_op_test", option);

        string text = db.Get<long, string>(1000000L);
        Assert.NotNull(text);
        Assert.Equal("million", text);
    }

    // mdbx_del
    using (MdbxTransaction tran = env.BeginTransaction())
    {
        MdbxDatabase db = tran.OpenDatabase("basic_op_test", option);
        bool deleted = db.Del(100L);
        Assert.True(deleted);
        deleted = db.Del(100L);
        Assert.False(deleted);
        tran.Commit();
    }


    // mdbx_get
    using (MdbxTransaction tran = env.BeginTransaction(TransactionOption.ReadOnly))
    {
        MdbxDatabase db = tran.OpenDatabase("basic_op_test", option);

        string text = db.Get<long, string>(100L);
        Assert.Null(text);
    }
}

Here is an example of using cursor

using (MdbxTransaction tran = env.BeginTransaction(TransactionOption.ReadOnly))
{
    MdbxDatabase db = tran.OpenDatabase("cursor_test1");
    using (MdbxCursor cursor = db.OpenCursor())
    {
        string key = null, value = null;
        cursor.Get(ref key, ref value, CursorOp.First);
        // ...
        
        while(cursor.Get(ref key, ref value, CursorOp.Next))
        {
            // ...
        }
    }
}

Please check unit test for more examples