//ProcessFiles method called every 1 sec
//Duplicate events are generated but are not getting executed in this case
//However it may happen that the events gets duplicated before this function is even called (that in less than 1000ms)
//Hence we can use MemoryCache as a workaround
public static void ProcessFiles(object stateInfo)
{
foreach (var fileName in FilesToProcess.Keys)
{
// as we don't need the out param, hence out _
if (FilesToProcess.TryRemove(fileName, out _))
{
var fileProcessor = new FileProcessor(fileName);
fileProcessor.Process();
}
}
}
//Called when a cache item expires and item not accessed till two seconds
//Note: This method also can raise exceptions if there are too many operations and multiple two operations are changing
//one file from diffrent threads
private static void ProcessFile(CacheEntryRemovedArguments args)
{
WriteLine($"Cache item removed: {args.CacheItem.Key} becayse {args.RemovedReason}");
if (args.RemovedReason == CacheEntryRemovedReason.Expired)
{
var fileProcessor = new FileProcessor(args.CacheItem.Key);
fileProcessor.Process();
}
else
{
WriteLine($"Warning: {args.CacheItem.Key} was removed unexpectedly and may not");
}
}
//Creating event handler methods
public static void FileCreated(object sender, FileSystemEventArgs e)
{
WriteLine($"File created: {e.Name} - type: {e.ChangeType}");
if (_applicationRunningMethod == (int)ApplicationRunningMethod.Normally)
{
var fileProcessor = new FileProcessor(e.FullPath);
fileProcessor.Process();
}
else if (_applicationRunningMethod == (int)ApplicationRunningMethod.UsingConcurrentDictionary)
{
//Hence instead of calling the Process method directly like above, we're using TryAdd method of concurrent dictionary
//and it will only add the event if there's not one already present
FilesToProcess.TryAdd(e.FullPath, e.FullPath);
}
else
{
AddToCache(e.FullPath);
}
}