public void CacheMap_GetOneMisingChunk()
{
var cm = new CacheMap();
cm.SetCached(0, 32);
var missing = cm.GetMissingChunks(33, 10);
Assert.AreEqual(1, missing.Count);
Assert.AreEqual(new CachedFileChunk(33, 10), missing[0]);
}
/// <summary>
/// Reads buffer from backing stream
/// </summary>
/// <param name="buffer">Buffer that will hold </param>
/// <param name="offset">Offset in a backing stream to start reading from</param>
/// <param name="count">Maximum bytes to be read from stream</param>
/// <returns>Number of bytes actually read</returns>
public override int Read(byte[] buffer, int offset, int count)
{
// make sure we're not reading beyond the end of file
if (offset > Length)
{
_log.Trace("Trying to read beyond the end of file.");
return(0);
}
if (offset <= Length && (offset + count - 1) > Length)
{
count = (int)Length - offset;
_log.Trace("This chunk is longer than our file stream. Trimed it down to {0} ({1}).", offset, count);
}
if (!_cacheMap.IsCached(offset, count))
{
_log.Trace(String.Format("Chunk {0} ({1}) is not cached", offset, count));
var chunkList = _cacheMap.GetMissingChunks(offset, count);
_log.Trace(String.Format("Will download {0} chunks", chunkList.Count));
foreach (var chunk in chunkList)
{
_log.Trace("Chunk #{0}", chunk);
}
var doneEvents = new ManualResetEvent[chunkList.Count];
for (var i = 0; i < chunkList.Count; i++)
{
var cachedFileChunk = chunkList[i];
doneEvents[i] = cachedFileChunk.DoneEvent;
ThreadPool.QueueUserWorkItem(DownloadChunk, cachedFileChunk);
}
do
{
DokanNet.DokanResetTimeout(15000, _dokanInfo); // keep extending our time so OS will know we're still alive
} while (!WaitHandle.WaitAll(doneEvents, 5000));
}
else
{
_log.Trace(String.Format("Chunk {0} ({1}) is cached, reading it", offset, count));
}
lock (_innerStream)
{
_innerStream.Position = _readPosition;
_innerStream.Seek(offset, SeekOrigin.Begin);
var read = _innerStream.Read(buffer, 0, count);
_readPosition = _innerStream.Position;
return(read);
}
}
public void CacheMap_GetMisingChunks()
{
var cm = new CacheMap();
cm.SetCached(5, 4); // overlaps with the second one
cm.SetCached(1, 9); // overlaps with previous one
cm.SetCached(20, 10); // has a gap before
cm.SetCached(15, 1); // is adjascent to the next one
cm.SetCached(16, 1); // is adjascent to the next one
var missing = cm.GetMissingChunks(0, 31);
Assert.AreEqual(4, missing.Count);
Assert.AreEqual(new CachedFileChunk(new Range <int>(0, 0)), missing[0]);
Assert.AreEqual(new CachedFileChunk(new Range <int>(10, 14)), missing[1]);
Assert.AreEqual(new CachedFileChunk(new Range <int>(17, 19)), missing[2]);
Assert.AreEqual(new CachedFileChunk(new Range <int>(30, 30)), missing[3]);
}