private Task ProcessFiles()
{
return(Task.Run(async() =>
{
var fileInfos = new DirectoryInfo(FilePath).GetFiles(FilePattern);
foreach (var fileInfo in fileInfos)
{
var newNumLines = await GetLineCount(fileInfo.FullName);
var oldFileInfoPair = FileLineMap.FirstOrDefault(fi => fi.Key.Name == fileInfo.Name);
if (!oldFileInfoPair.Equals(default(KeyValuePair <FileInfo, int>)) && oldFileInfoPair.Key.LastWriteTime != fileInfo.LastWriteTime)
{
// update the # of lines (other FileInfo properties will be refreshed in RemoveDeletedFiles)
if (FileLineMap.TryUpdate(oldFileInfoPair.Key, newNumLines, oldFileInfoPair.Value))
{
OutputFunction.Invoke($"Changed: {fileInfo.Name}, {newNumLines - oldFileInfoPair.Value}");
}
}
// new file
else
{
if (oldFileInfoPair.Key?.Name != fileInfo.Name && FileLineMap.TryAdd(fileInfo, newNumLines))
{
OutputFunction.Invoke($"Created: {fileInfo.Name}, {newNumLines}");
}
}
}
// no need to wait for this
Task.Factory.StartNew(RemoveDeletedFiles, CancellationToken);
},
CancellationToken));
}
protected void RemoveDeletedFiles()
{
Parallel.ForEach(FileLineMap,
async kvp =>
{
// new to wait on refresh to determine if the file still exists
await Task.Run(() => kvp.Key.Refresh(), CancellationToken);
if (!kvp.Key.Exists && FileLineMap.TryRemove(kvp.Key, out _))
{
OutputFunction.Invoke($"Deleted: {kvp.Key.Name}");
}
});
}
private async void FileEventHandler(object sender, FileSystemEventArgs args)
{
await Task.Factory.StartNew(async() =>
{
var numLines = 0;
var changeType = WatcherChangeTypes.Deleted;
if (args.ChangeType == WatcherChangeTypes.Changed)
{
changeType = WatcherChangeTypes.Created;
var oldNumLines = 0;
var newNumLines = await GetLineCount(args.FullPath);
var kvp = FileLineMap.FirstOrDefault(i => i.Key.Name == args.FullPath);
if (kvp.Key != default(FileInfo))
{
oldNumLines = kvp.Value;
changeType = WatcherChangeTypes.Changed;
}
numLines = newNumLines - oldNumLines;
FileLineMap[new FileInfo(args.FullPath)] = newNumLines;
}
var sb = new StringBuilder($"{changeType}: {args.Name}");
if (changeType != WatcherChangeTypes.Deleted)
{
sb.Append($", {numLines}");
}
OutputFunction.Invoke(sb.ToString());
},
CancellationToken);
}
