/// <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);
}
private void CheckCacheSize()
{
while (this.maxSize > 0 &&
this.cacheSize >= this.maxSize &&
this.cacheMetadata.Count > 0)
{
ICacheRecordMetadata metadata = this.cacheMetadata[0];
this.RemoveFile(metadata.FileName);
this.cacheMetadataDictionary.Remove(metadata.FileName);
this.cacheMetadata.Remove(metadata);
this.cacheSize -= metadata.FileStorageLength;
}
}
private Stream GetStorageStream(string fileName)
{
ICacheRecordMetadata metaData = this.LoadFileMetadata(fileName);
if (metaData != null && metaData.Expires >= DateTime.Now)
{
Stream stream = this.OpenCacheStream(fileName);
if (stream.Length == 0)
{
stream.Dispose();
return(null);
}
this.SaveFileMetadata(metaData);
return(stream);
}
return(null);
}
private int CompareMetadata(ICacheRecordMetadata a, ICacheRecordMetadata b)
{
DateTime now = DateTime.Now;
if (a == null && b == null)
{
return(0);
}
if (a == null)
{
return(-1);
}
if (a == b)
{
return(0);
}
if (a.Expires < now && b.Expires < now)
{
return(0);
}
if (a.Expires < now)
{
return(-1);
}
if (b.Expires < now)
{
return(1);
}
if (a.LastAccess < b.LastAccess)
{
return(-1);
}
return(1);
}
private void GetMetadata()
{
string[] files = this.GetFiles(this.threadSafetyCachePath, "*");
Regex fileNameRegex = new Regex(@"\\([^\\]+)$");
foreach (string file in files)
{
Match match = fileNameRegex.Match(file);
if (match.Success)
{
ICacheRecordMetadata metadata = this.GetFileMetadataSafety(match.Groups[0].Value);
if (metadata != null)
{
this.AddMetadata(metadata);
}
}
}
this.cacheMetadata.Sort(this.CompareMetadata);
}
private void AddMetadata(ICacheRecordMetadata metadata)
{
this.cacheMetadataDictionary.Add(metadata.FileName, metadata);
this.cacheMetadata.Add(metadata);
this.cacheSize += metadata.FileStorageLength;
}
/// <summary> /// Saves file metadata. /// </summary> /// <param name="cacheRecord">Cache record metadata.</param> protected abstract void SaveFileMetadata(ICacheRecordMetadata cacheRecord);
