/// <summary>
/// Saves block contents to index file
/// </summary>
/// <param name="data">Block object</param>
/// <param name="offset">Desired offset of block in index file, default in null, that means append to the end of file</param>
/// <returns>offset of the written block in index file</returns>
public long Write(ISerializableIndexData data, long?offset = null)
{
var length = data.SerializedLength;
var buffer = new byte[length];
data.Serialize(buffer, 0);
lock (fileStreamLock)
{
var newOffset = fileStream.Seek(offset ?? fileStream.Length, SeekOrigin.Begin);
fileStream.Write(buffer, 0, length);
fileStream.Flush();
return(newOffset);
}
}
/// <summary>
/// Loads block contents from index file
/// </summary>
/// <param name="data">Block object</param>
/// <param name="offset">Offset of block in index file</param>
/// <param name="length">Length of block in index file</param>
/// <exception cref="IOException">not enough data in index file to fill the block</exception>
public void Read(ISerializableIndexData data, long offset, int length)
{
var buffer = new byte[length];
lock (fileStreamLock)
{
fileStream.Seek(offset, SeekOrigin.Begin);
var bytesRead = fileStream.Read(buffer, 0, length);
if (bytesRead != length)
{
throw new IOException(IndexBlockReadErrorMessage);
}
}
data.Deserialize(buffer, 0);
}
