Infrastructure/Files/InputFileScanner.cs - master - rezvich/Prik

Infrastructure/Files/InputFileScanner.cs
70 строк2 KB
waweda299
Прик
08 июн 2026, 15:52
08 июн 2026, 15:529ddc25e
//prik/Infrastructure/Files/InputFileScanner.cs
using System.Collections.Concurrent;

namespace prik.Infrastructure.Files
{
    public interface IInputFileScanner
    {
        IReadOnlyList<FileInfo> ListReadyCsv(string inputDir, int settleSeconds);
    }

    public sealed class InputFileScanner : IInputFileScanner
    {
        private sealed record Obs(long Size, DateTime MTimeUtc, DateTime FirstSeenUtc);

        private readonly ConcurrentDictionary<string, Obs> _obs = new(StringComparer.OrdinalIgnoreCase);

        public IReadOnlyList<FileInfo> ListReadyCsv(string inputDir, int settleSeconds)
        {
            var now = DateTime.UtcNow;
            var dir = new DirectoryInfo(inputDir);
            if (!dir.Exists)
            {
                return Array.Empty<FileInfo>();
            }

            var candidates = dir.EnumerateFiles("*", SearchOption.TopDirectoryOnly)
                    .Where(f => !f.Name.StartsWith("~") && !f.Name.StartsWith("."))
                    .Where(f => string.Equals(f.Extension, ".csv", StringComparison.OrdinalIgnoreCase))
                    .ToList();

            // purge disappeared
            var present = new HashSet<string>(candidates.Select(f => f.FullName), StringComparer.OrdinalIgnoreCase);
            foreach (var k in _obs.Keys)
            {
                if (!present.Contains(k))
                {
                    _obs.TryRemove(k, out _);
                }
            }

            var ready = new List<FileInfo>();

            foreach (var f in candidates)
            {
                var key = f.FullName;
                var size = f.Length;
                var mtime = f.LastWriteTimeUtc;

                if (!_obs.TryGetValue(key, out var prev))
                {
                    _obs[key] = new Obs(size, mtime, now);
                    continue;
                }

                if (size != prev.Size || mtime != prev.MTimeUtc)
                {
                    _obs[key] = new Obs(size, mtime, now);
                    continue;
                }

                if ((now - prev.FirstSeenUtc).TotalSeconds >= settleSeconds && size > 0)
                {
                    ready.Add(f);
                }
            }

            return ready.OrderBy(f => f.Name, StringComparer.OrdinalIgnoreCase).ToList();
        }
    }
}