/// <summary>
/// Loaded file from a cache to event arguments.
/// </summary>
/// <param name="fileName">File name.</param>
/// <param name="callback">Callback which should be called to return tile if it is available or null.</param>
public override void LoadAsync(string fileName, Action <byte[]> callback)
{
CacheRecord record = this.GetCacheRecord(fileName);
byte[] tile = null;
if (record == null)
{
ICacheRecordMetadata metaData = this.LoadFileMetadata(fileName);
if (metaData != null && metaData.Expires >= DateTime.Now)
{
Stream stream = this.OpenCacheStream(fileName);
if (stream.Length == 0)
{
stream.Dispose();
}
else
{
AsyncStreamOperations.LoadAsync(stream, callback);
return;
}
}
}
else
{
tile = record.TileBody;
}
callback(tile);
}
/// <summary>
/// Saves byte array asynchronously to the stream.
/// </summary>
/// <param name="stream">Stream.</param>
/// <param name="tile">Byte array.</param>
/// <param name="callback">Callback.</param>
/// <param name="userState">User state.</param>
public static void SaveAsync(Stream stream, byte[] tile, Action <object> callback, object userState)
{
AsyncStreamOperations writer = new AsyncStreamOperations(stream);
writer.writerCallback = callback;
writer.userState = userState;
writer.tileBodyPart = tile;
writer.stream.BeginWrite(writer.tileBodyPart, 0, writer.tileBodyPart.Length, WriteCallback, writer);
}
/// <summary>
/// Loads stream asynchronously to byte array.
/// </summary>
/// <param name="stream">Stream.</param>
/// <param name="callback">Callback.</param>
public static void LoadAsync(Stream stream, Action <byte[]> callback)
{
AsyncStreamOperations loader = new AsyncStreamOperations(stream);
loader.readerCallback = callback;
loader.memoryStream = new MemoryStream();
loader.tileBodyPart = new byte[TileBodyPartLength];
loader.stream.BeginRead(loader.tileBodyPart, 0, TileBodyPartLength, ReadCallback, loader);
}
private static void WriteCallback(IAsyncResult asyncResult)
{
AsyncStreamOperations writer = (AsyncStreamOperations)asyncResult.AsyncState;
writer.stream.EndWrite(asyncResult);
writer.Dispose();
if (writer.writerCallback != null)
{
writer.writerCallback(writer.userState);
}
writer = null;
}
private static void ReadCallback(IAsyncResult asyncResult)
{
AsyncStreamOperations loader = (AsyncStreamOperations)asyncResult.AsyncState;
int loaded = loader.stream.EndRead(asyncResult);
if (asyncResult.IsCompleted && loaded > 0)
{
loader.memoryStream.Write(loader.tileBodyPart, 0, loaded);
loader.stream.BeginRead(loader.tileBodyPart, 0, TileBodyPartLength, ReadCallback, loader);
return;
}
byte[] tile = loader.memoryStream.ToArray();
loader.Dispose();
loader.readerCallback(tile);
loader = null;
}
private void SaveCacheFile(CacheRecord cacheRecord)
{
Stream cacheStream = null;
try
{
cacheStream = this.CreateCacheStream(cacheRecord.FileName);
}
catch
{
}
if (cacheStream != null)
{
AsyncStreamOperations.SaveAsync(cacheStream, cacheRecord.TileBody, this.SaveFileMetadataCallback, cacheRecord);
}
else
{
cacheRecord.CompeleEvent.Set();
}
}