private bool CacheChunk(long chunkIndex)
{
lock (_lock)
{
if (_decryptedChunkByChunkIndex.Contains(chunkIndex))
{
return(false);
}
//log.Info(string.Format("{0}: Going to add chunk #{1} to cache", new object[] { DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss.fff"), chunkIndex }));
DecryptedChunk DecryptedChunk = new DecryptedChunk(this, chunkIndex);
_decryptedChunkByChunkIndex.Add(chunkIndex, DecryptedChunk);
_decryptedChunkIndexSortedByCreationTime.Add(chunkIndex);
RemoveOldCachedItems();
// Cached
return(true);
}
}
private DecryptedChunk GetOrAddDecryptedChunk(long chunkIndex)
{
lock (_lock)
{
if (_decryptedChunkByChunkIndex.Contains(chunkIndex))
{
//Logger.Log(string.Format("{0}: Chunk #{1} already cached", new object[] { DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss.fff"), chunkIndex }));
return((DecryptedChunk)_decryptedChunkByChunkIndex[chunkIndex]);
}
//Logger.Log(string.Format("{0}: Chunk #{1} is NOT yet available", new object[] { DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss.fff"), chunkIndex }));
DecryptedChunk DecryptedChunk = new DecryptedChunk(this, chunkIndex);
_decryptedChunkByChunkIndex.Add(chunkIndex, DecryptedChunk);
_decryptedChunkIndexSortedByCreationTime.Add(chunkIndex);
RemoveOldCachedItems();
return(DecryptedChunk);
}
}
public byte[] GetDecryptedChunk(long chunkIndex)
{
//log.Info(string.Format("{0}: Asked for chunk #{1}, thread = {2}", new object[] { DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ss.fff"), chunkIndex, Thread.CurrentThread.ManagedThreadId }));
DecryptedChunk DecryptedChunk = GetOrAddDecryptedChunk(chunkIndex);
// Start caching some next chunks
int cachedChunks = 0;
for (long AdditionalCachedChunkIndex = chunkIndex + 1;
cachedChunks < _additionalChunkToCache && // Cache some number of next chunks
AdditionalCachedChunkIndex < _chunkCount &&
_decryptedChunkByChunkIndex.Count < _maxDecryptedChunkCount; // Doesn't occupy entire cache
AdditionalCachedChunkIndex++)
{
if (CacheChunk(AdditionalCachedChunkIndex))
{
cachedChunks++;
}
}
return(DecryptedChunk.DecryptedData);
}
