private void ListAndFilterFiles()

in src/Ingestor.cs [634:682]
42 lines of code
5 McCabe index (conditional complexity)

        private void ListAndFilterFiles(string sourcePath, string pattern, int filesToTake, ITargetBlock<DataSource> targetBlock)
        {
            try
            {
                m_logger.LogVerbose($"ListAndFilterFiles: enumerating files under '{sourcePath}'");

                // sourcePath is a file path
                if (File.Exists(sourcePath))
                {
                    m_logger.LogVerbose($"ListAndFilterFiles: found 1 file: '{sourcePath}'");
                    Interlocked.Increment(ref m_objectsListed);
                    Interlocked.Increment(ref m_objectsAccepted);
                    targetBlock.SendAsync(new DataSource { FileSystemPath = sourcePath, SizeInBytes = Utilities.TryGetFileSize(sourcePath, m_estimatedCompressionRatio) });
                    return;
                }

                // sourcePath is a directory path
                var files = Directory.EnumerateFiles(sourcePath, pattern, SearchOption.AllDirectories);
                if (files.SafeFastNone())
                {
                    m_logger.LogWarning($"ListAndFilterFiles: files matching the pattern '{pattern}' found under '{sourcePath}' path.");
                    throw new FileNotFoundException($"No files matching the pattern '{pattern}' found under '{sourcePath}' path.");
                }

                int fileCount = (int)files.SafeFastCount();
                Interlocked.Add(ref m_objectsListed, fileCount);

                filesToTake = (filesToTake >= 0 ? Math.Min(filesToTake, fileCount) : fileCount);

                files.SafeFastTake(filesToTake).ForEach((f) =>
                {
                    long fileSize = Utilities.TryGetFileSize(f, m_estimatedCompressionRatio);
                    DateTime? fileCreationTime = Utilities.InferFileCreationTimeUtc(f, m_creationTimeInNamePattern);

                    targetBlock.SendAsync(new DataSource
                    {
                        FileSystemPath = f,
                        SizeInBytes = fileSize,
                        CreationTimeUtc = fileCreationTime
                    });

                    Interlocked.Increment(ref m_objectsAccepted);
                });
            }
            catch (Exception ex)
            {
                m_logger.LogError($"ListAndFilterFiles failed: {ex.Message}");
            }
        }