/// <summary>
/// Moves the cursor to the specified position.
/// </summary>
/// <param name="op"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public bool MoveCursor(CursorOp op, int x, int y)
{
lock (tn)
{
return(tn.Controller.MoveCursor(op, x, y));
}
}
public bool MoveCursor(CursorOp op, int x, int y)
{
lock (tn)
{
return(tn.tnctlr.MoveCursor(op, x, y));
}
}
/// <summary>
/// Get items from a database.
/// </summary>
/// <typeparam name="K"></typeparam>
/// <typeparam name="V"></typeparam>
/// <param name="key"></param>
/// <param name="value"></param>
/// <param name="op"></param>
/// <returns>false if not found.</returns>
public bool Get <K, V>(ref K key, ref V value, CursorOp op)
{
ISerializer <K> keySerializer = SerializerRegistry.Get <K>();
ISerializer <V> valueSerializer = SerializerRegistry.Get <V>();
byte[] keyBytes = keySerializer.Serialize(key);
byte[] valueBytes = valueSerializer.Serialize(value);
bool found = Get(ref keyBytes, ref valueBytes, op);
if (found)
{
if (keyBytes != null)
{
key = keySerializer.Deserialize(keyBytes);
}
else
{
key = default(K);
}
if (valueBytes != null)
{
value = valueSerializer.Deserialize(valueBytes);
}
else
{
value = default(V);
}
}
return(found);
}
internal static void Get(IntPtr cursor, ref DbValue key, ref DbValue value, CursorOp op)
{
int err = _getDelegate(cursor, ref key, ref value, op);
if (err != 0)
{
throw new MdbxException("mdbx_cursor_get", err);
}
}
/// <summary>
/// Get items from a database.
/// </summary>
/// <param name="key"></param>
/// <param name="value"></param>
/// <param name="op"></param>
public bool Get(ref byte[] key, ref byte[] value, CursorOp op)
{
IntPtr keyPtr = IntPtr.Zero;
IntPtr valuePtr = IntPtr.Zero;
if (key != null)
{
keyPtr = Marshal.AllocHGlobal(key.Length);
}
if (value != null)
{
valuePtr = Marshal.AllocHGlobal(key.Length);
}
try
{
if (key != null && key.Length > 0)
{
Marshal.Copy(key, 0, keyPtr, key.Length);
}
if (value != null && value.Length > 0)
{
Marshal.Copy(value, 0, valuePtr, value.Length);
}
DbValue dbKey = new DbValue(keyPtr, key == null ? 0 : key.Length);
DbValue dbValue = new DbValue(valuePtr, value == null ? 0 : value.Length);
Cursor.Get(_cursorPtr, ref dbKey, ref dbValue, op);
if (dbKey.Address != IntPtr.Zero)
{
if (key == null || key.Length != dbKey.Length)
{
key = new byte[dbKey.Length];
}
Marshal.Copy(dbKey.Address, key, 0, key.Length);
}
else
{
key = null;
}
if (dbValue.Address != IntPtr.Zero)
{
if (value == null || value.Length != dbValue.Length)
{
value = new byte[dbValue.Length];
}
Marshal.Copy(dbValue.Address, value, 0, value.Length);
}
else
{
value = null;
}
}
catch (MdbxException ex)
{
if (ex.ErrorNumber == MdbxCode.MDBX_NOTFOUND)
{
return(false);
}
throw;
}
finally
{
if (keyPtr != IntPtr.Zero)
{
Marshal.FreeHGlobal(keyPtr);
}
if (valuePtr != IntPtr.Zero)
{
Marshal.FreeHGlobal(valuePtr);
}
}
return(true);
}