public void DetermineSequence()
{
try
{
// Find the newest chunk
ChunkIndex?newestChunkIndex = FindNewestChunkIndex();
if (newestChunkIndex == null)
{
CurrentSequence = null;
}
else
{
Logger.Instance.Trace(this, "Newest chunk: {0}", newestChunkIndex.Value);
int?currentSequence = CurrentSequence;
if (!currentSequence.HasValue || currentSequence.Value != newestChunkIndex?.numberOfChunks)
{
// Sequence has changed. Delete contacts
Logger.Instance.Trace(this, "Rechunked, deleting contacts");
ClearContacts();
// Determine new sequence
if (newestChunkIndex == null)
{
using (IStorageItem index = GetIndexItem())
{
if (index != null)
{
index.Delete();
}
}
}
else
{
int numberOfChunks = newestChunkIndex.Value.numberOfChunks;
using (IStorageItem index = GetIndexItem())
{
index.SetUserProperty(PROP_CURRENT_SEQUENCE, numberOfChunks);
index.SetUserProperty(PROP_LAST_PROCESSED, CreateChunkStateString(numberOfChunks));
index.Save();
}
}
}
}
}
catch (Exception e)
{
Logger.Instance.Trace(this, "Exception determining sequence: {0}", e);
// Delete the index item
using (IStorageItem index = GetIndexItem())
index?.Delete();
return;
}
Logger.Instance.Trace(this, "Current sequence: {0}", CurrentSequence);
}
private void SetChunkStateString(ChunkIndex index, string partState)
{
using (IStorageItem item = GetIndexItem())
{
string state = item.GetUserProperty <string>(PROP_LAST_PROCESSED);
string[] parts;
if (string.IsNullOrEmpty(state))
{
parts = new string[index.numberOfChunks];
}
else
{
parts = state.Split(';');
}
if (parts.Length != index.numberOfChunks)
{
Logger.Instance.Error(this, "Wrong number of chunks, got {0}, expected {1}: {2}",
parts.Length, index.numberOfChunks, state);
}
parts[index.chunk] = partState;
string combined = string.Join(";", parts);
item.SetUserProperty(PROP_LAST_PROCESSED, combined);
item.Save();
}
}