NotifyFileSystemEventArgs() private method

private NotifyFileSystemEventArgs ( WatcherChangeTypes changeType, string name ) : void
changeType WatcherChangeTypes
name string
return void
            private unsafe void ProcessEvents(int numEvents,
                                              byte **eventPaths,
                                              FSEventStreamEventFlags *eventFlags,
                                              FSEventStreamEventId *eventIds,
                                              FileSystemWatcher watcher)
            {
                // Since renames come in pairs, when we find the first we need to search for the next one. Once we find it, we'll add it to this
                // list so when the for-loop comes across it, we'll skip it since it's already been processed as part of the original of the pair.
                List <FSEventStreamEventId> handledRenameEvents = null;

                Memory <char>[] events = new Memory <char> [numEvents];
                ParseEvents();

                for (int i = 0; i < numEvents; i++)
                {
                    ReadOnlySpan <char> path = events[i].Span;
                    Debug.Assert(path[path.Length - 1] != '/', "Trailing slashes on events is not supported");

                    // Match Windows and don't notify us about changes to the Root folder
                    if (_fullDirectory.Length >= path.Length && path.Equals(_fullDirectory.AsSpan(0, path.Length), StringComparison.OrdinalIgnoreCase))
                    {
                        continue;
                    }

                    WatcherChangeTypes eventType = 0;
                    // First, we should check if this event should kick off a re-scan since we can't really rely on anything after this point if that is true
                    if (ShouldRescanOccur(eventFlags[i]))
                    {
                        watcher.OnError(new ErrorEventArgs(new IOException(SR.FSW_BufferOverflow, (int)eventFlags[i])));
                        break;
                    }
                    else if ((handledRenameEvents != null) && (handledRenameEvents.Contains(eventIds[i])))
                    {
                        // If this event is the second in a rename pair then skip it
                        continue;
                    }
                    else if (CheckIfPathIsNested(path) && ((eventType = FilterEvents(eventFlags[i])) != 0))
                    {
                        // The base FileSystemWatcher does a match check against the relative path before combining with
                        // the root dir; however, null is special cased to signify the root dir, so check if we should use that.
                        ReadOnlySpan <char> relativePath = ReadOnlySpan <char> .Empty;
                        if (path.Length > _fullDirectory.Length && path.StartsWith(_fullDirectory, StringComparison.OrdinalIgnoreCase))
                        {
                            // Remove the root directory to get the relative path
                            relativePath = path.Slice(_fullDirectory.Length);
                        }

                        // Raise a notification for the event
                        if (((eventType & WatcherChangeTypes.Changed) > 0))
                        {
                            watcher.NotifyFileSystemEventArgs(WatcherChangeTypes.Changed, relativePath);
                        }
                        if (((eventType & WatcherChangeTypes.Created) > 0))
                        {
                            watcher.NotifyFileSystemEventArgs(WatcherChangeTypes.Created, relativePath);
                        }
                        if (((eventType & WatcherChangeTypes.Deleted) > 0))
                        {
                            watcher.NotifyFileSystemEventArgs(WatcherChangeTypes.Deleted, relativePath);
                        }
                        if (((eventType & WatcherChangeTypes.Renamed) > 0))
                        {
                            // Find the rename that is paired to this rename, which should be the next rename in the list
                            int pairedId = FindRenameChangePairedChange(i, eventFlags, numEvents);
                            if (pairedId == int.MinValue)
                            {
                                // Getting here means we have a rename without a pair, meaning it should be a create for the
                                // move from unwatched folder to watcher folder scenario or a move from the watcher folder out.
                                // Check if the item exists on disk to check which it is
                                // Don't send a new notification if we already sent one for this event.
                                if (DoesItemExist(path, IsFlagSet(eventFlags[i], FSEventStreamEventFlags.kFSEventStreamEventFlagItemIsFile)))
                                {
                                    if ((eventType & WatcherChangeTypes.Created) == 0)
                                    {
                                        watcher.NotifyFileSystemEventArgs(WatcherChangeTypes.Created, relativePath);
                                    }
                                }
                                else if ((eventType & WatcherChangeTypes.Deleted) == 0)
                                {
                                    watcher.NotifyFileSystemEventArgs(WatcherChangeTypes.Deleted, relativePath);
                                }
                            }
                            else
                            {
                                // Remove the base directory prefix and add the paired event to the list of
                                // events to skip and notify the user of the rename
                                ReadOnlySpan <char> newPathRelativeName = events[pairedId].Span;
                                if (newPathRelativeName.Length >= _fullDirectory.Length &&
                                    newPathRelativeName.StartsWith(_fullDirectory, StringComparison.OrdinalIgnoreCase))
                                {
                                    newPathRelativeName = newPathRelativeName.Slice(_fullDirectory.Length);
                                }
                                watcher.NotifyRenameEventArgs(WatcherChangeTypes.Renamed, newPathRelativeName, relativePath);

                                // Create a new list, if necessary, and add the event
                                if (handledRenameEvents == null)
                                {
                                    handledRenameEvents = new List <FSEventStreamEventId>();
                                }
                                handledRenameEvents.Add(eventIds[pairedId]);
                            }
                        }
                    }

                    ArraySegment <char> underlyingArray;
                    if (MemoryMarshal.TryGetArray(events[i], out underlyingArray))
                    {
                        ArrayPool <char> .Shared.Return(underlyingArray.Array);
                    }
                }

                this._context = ExecutionContext.Capture();

                void ParseEvents()
                {
                    for (int i = 0; i < events.Length; i++)
                    {
                        int byteCount = 0;
                        Debug.Assert(eventPaths[i] != null);
                        byte *temp = eventPaths[i];

                        // Finds the position of null character.
                        while (*temp != 0)
                        {
                            temp++;
                            byteCount++;
                        }

                        Debug.Assert(byteCount > 0, "Empty events are not supported");
                        events[i] = new Memory <char>(ArrayPool <char> .Shared.Rent(Encoding.UTF8.GetMaxCharCount(byteCount)));
                        int charCount;

                        // Converting an array of bytes to UTF-8 char array
                        charCount = Encoding.UTF8.GetChars(new ReadOnlySpan <byte>(eventPaths[i], byteCount), events[i].Span);
                        events[i] = events[i].Slice(0, charCount);
                    }
                }
            }