private string InnerGet(IntPtr readOptions, string key)
{
var keyData = Encoding.UTF8.GetBytes(key);
IntPtr error;
IntPtr lengthPtr;
var valuePtr = LevelDBInterop.leveldb_get(this.Database, readOptions, keyData, (IntPtr)keyData.Length, out lengthPtr, out error);
LevelDBException.Check(error);
if (valuePtr == IntPtr.Zero)
{
return(null);
}
try
{
return(GetValue(valuePtr, lengthPtr));
}
finally
{
LevelDBInterop.leveldb_free(valuePtr);
GC.KeepAlive(readOptions);
GC.KeepAlive(this);
}
}
/// <summary>
/// 获取指定键的值。
/// </summary>
/// <param name="key">键。</param>
/// <param name="options">读的选项。</param>
/// <returns>返回一个值，如果值不存在则返回 null 值。</returns>
public unsafe BinaryValue Get(BinaryValue key, ReadOptions options = null)
{
this.ThrowWhenDisposed();
if (options == null)
{
options = new ReadOptions();
}
var keyData = key.ByteArray;
IntPtr error;
IntPtr lengthPtr;
var valuePtr = LevelDBInterop.leveldb_get(this._handle, options._handle, keyData, (IntPtr)keyData.LongLength, out lengthPtr, out error);
LevelDBException.Check(error);
if (valuePtr == IntPtr.Zero)
{
return(null);
}
try
{
var length = (long)lengthPtr;
var value = new byte[length];
var valueNative = (byte *)valuePtr.ToPointer();
for (long i = 0; i < length; ++i)
{
value[i] = valueNative[i];
}
return(new BinaryValue(value));
}
finally
{
LevelDBInterop.leveldb_free(valuePtr);
GC.KeepAlive(options);
GC.KeepAlive(this);
}
}
