public override void Add(string path, T feature)
{
var cachedRecord = storage.GetFileRecordAsync(path).Result;
if (cachedRecord == null) //no cache record found
{
cachedRecord = PersistentFileRecord.Create(path);
}
cachedRecord.SetData(dataKey, feature);
storage.UpdateFileRecordAsync(path, cachedRecord).Wait();
//System.Diagnostics.Debug.WriteLine($"{System.IO.Path.GetFileName(path)}: cache updated");
base.Add(path, feature);
}
public override bool TryGetValue(string key, out T value)
{
if (base.TryGetValue(key, out value)) //cache is already loaded
{
return(true);
}
var cachedRecord = storage.GetFileRecordAsync(key).Result;
if (cachedRecord == null) //no cache record found
{
return(false);
}
var time = PersistentFileRecord.ReadModificationTime(key);
if (!time.HasValue) //current file can't be read - skip
{
return(false);
}
if (cachedRecord.Modified != time) //cached value expired
{
storage.RemoveFileRecordAsync(key).Wait();
return(false);
}
if (!cachedRecord.TryGetData <T>(dataKey, out T data)) //no cached Hash
{
return(false);
}
//success - use cached value
base.Add(key, data);
value = data;
return(true);
}