protected override void Dispose(bool disposing)
{
_db = null;
_dir = null;
_file = null;
_file_block = null;
}
private void ResetProperties()
{
// Reset properties.
_buffer_position = 0;
_buffer_start = 0;
_buffer_length = 0;
_block_index = -1;
_file_block = null;
}
protected override void Dispose(bool disposing)
{
if (_isDisposed)
{
return;
}
if (disposing)
{
Flush();
_db = null;
_dir = null;
_file = null;
_file_block = null;
}
_isDisposed = true;
}
private void SwitchBlock()
{
// Keep oldBlock
DbFileBlock oldBlock = null;
if (_file_block != null)
{
_file_block.ComputeSHA();
oldBlock = _file_block;
}
long maxBlock = _file.BlockSet.Count();
if (_block_index == maxBlock)
{
// Add a new block.
DbFileBlock block = new DbFileBlock(_file.BufferSize);
block.Order = _block_index;
_file.BlockSet.Add(block);
_file_block = block;
_db.SaveChanges();
}
else if (_block_index >= 0 && _block_index < maxBlock)
{
// Switch to existed block.
_file_block = _file.BlockSet.SingleOrDefault(obj => obj.Order == _block_index);
Debug.Assert(_file_block != null);
}
else
{
//
throw new System.IO.IOException("Failed to write due to invalid file block index.");
}
// Reset buffer positions, buffer length, ...
_buffer_start = _block_index * _file.BufferSize;
_buffer_position = 0;
_buffer_length = _file_block.Length;
if (_file_block != oldBlock && oldBlock != null)
{
// Let GC have chance to free the memory space of oldBlock.
//_db.Detach(oldBlock);
oldBlock = null;
}
}
private void SwitchBlock(bool enforceEOF)
{
DbFileBlock oldBlock = null;
if (_file_block != null)
{
oldBlock = _file_block;
}
long maxBlock = _file.BlockSet.Count();
if (_block_index >= maxBlock)
{
if (enforceEOF)
{
throw new System.IO.IOException("Read past EOF");
}
else
{
_block_index -= 1;
_buffer_length = _file.BufferSize;
}
}
else
{
_file_block = _file.BlockSet.SingleOrDefault(obj => obj.Order == _block_index);
_buffer_start = _block_index * _file.BufferSize;
_buffer_position = 0;
long bufLen = _file.Length - _buffer_start;
_buffer_length = (bufLen > _file.BufferSize) ? _file.BufferSize : bufLen;
}
if (oldBlock != _file_block && oldBlock != null)
{
//_db.Detach(oldBlock);
oldBlock = null;
}
}
public void TestDBSchema()
{
Guid guid = Guid.NewGuid();
using (DbFileContext db = new DbFileContext()) {
DbDirectory dir = new DbDirectory()
{
Name = "a_dir_" + guid.ToString(),
};
db.DirectorySet.Add(dir);
DbFileInfo file = new DbFileInfo("a_file");
dir.FileSet.Add(file);
DbFileBlock block = new DbFileBlock(100);
byte[] bytes = Encoding.UTF8.GetBytes("Hello World");
Array.Copy(bytes, block.RawData, bytes.Length);
file.BlockSet.Add(block);
db.SaveChanges();
}
}
