/// <summary>
/// Load a tile from the store, and add it to the display container and dictionary
/// If no tile is available in the store at this position, we put an empty proxy in place.
/// </summary>
private void AddToCache(PositionKey key)
{
if (key == null)
{
return;
}
var pos = VisualRectangleNative(key);
var tile = new CachedTile(_displayContainer, key, pos.X, pos.Y); // calls down to "Win2dCanvasManager.Employ"
tile.SetState(TileState.Locked);
lock (_reflowLock)
{
_tileCache.Add(key, tile);
_loadQueue.Enqueue(tile);
}
}
private void WriteTileToBackingStoreSync(PositionKey key, CachedTile tile)
{
if (key == null)
{
return;
}
if (tile == null)
{
return;
}
if (tile.State == TileState.Locked)
{
return;
}
var red = RawDataPool.Capture();
var green = RawDataPool.Capture();
var blue = RawDataPool.Capture();
try
{
var name = key.ToString();
if (tile.ImageIsBlank())
{
_tileStore.Delete(name, "img");
tile.SetState(TileState.Empty);
}
else
{
var packed = tile.GetTileData();
if (packed == null)
{
return;
}
var end = TileImageSize * TileImageSize;
for (int i = 0; i < end; i++)
{
blue[i] = packed[4 * i + 0];
green[i] = packed[4 * i + 1];
red[i] = packed[4 * i + 2];
}
using (var ms = new MemoryStream())
{
WaveletCompress.Compress(red, green, blue, tile.Width, tile.Height).WriteToStream(ms);
ms.Seek(0, SeekOrigin.Begin);
var ok = _tileStore.Store(name, "img", ms);
if (ok.IsFailure)
{
throw new Exception("Storage error: DB might be corrupt.", ok.FailureCause);
}
}
}
}
finally
{
RawDataPool.Release(red);
RawDataPool.Release(green);
RawDataPool.Release(blue);
}
}