Libation/FileManager/FileUtility.cs

124 lines
4.6 KiB
C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Dinah.Core;
using Polly;
using Polly.Retry;
namespace FileManager
{
public static class FileUtility
{
private const int MAX_FILENAME_LENGTH = 255;
private const int MAX_DIRECTORY_LENGTH = 247;
public static string GetValidFilename(string dirFullPath, string filename, string extension, string metadataSuffix)
{
if (string.IsNullOrWhiteSpace(dirFullPath))
throw new ArgumentException($"{nameof(dirFullPath)} may not be null or whitespace", nameof(dirFullPath));
filename ??= "";
// sanitize. omit invalid characters. exception: colon => underscore
filename = filename.Replace(':', '_');
filename = PathLib.ToPathSafeString(filename);
if (filename.Length > 50)
filename = filename.Substring(0, 50) + "[...]";
if (!string.IsNullOrWhiteSpace(metadataSuffix))
filename += $" [{metadataSuffix}]";
// extension is null when this method is used for directory names
if (!string.IsNullOrWhiteSpace(extension))
extension = '.' + extension.Trim('.');
// ensure uniqueness
var fullfilename = Path.Combine(dirFullPath, filename + extension);
var i = 0;
while (File.Exists(fullfilename))
fullfilename = Path.Combine(dirFullPath, filename + $" ({++i})" + extension);
return fullfilename;
}
public static string GetMultipartFileName(string originalPath, int partsPosition, int partsTotal, string suffix)
{
// 1-9 => 1-9
// 10-99 => 01-99
// 100-999 => 001-999
var chapterCountLeadingZeros = partsPosition.ToString().PadLeft(partsTotal.ToString().Length, '0');
string extension = Path.GetExtension(originalPath);
var filenameBase = $"{Path.GetFileNameWithoutExtension(originalPath)} - {chapterCountLeadingZeros} - {suffix}";
// Replace illegal path characters with spaces
var filenameBaseSafe = PathLib.ToPathSafeString(filenameBase, " ");
var fileName = filenameBaseSafe.Truncate(MAX_FILENAME_LENGTH - extension.Length);
var path = Path.Combine(Path.GetDirectoryName(originalPath), fileName + extension);
return path;
}
public static string Move(string source, string destination)
{
// TODO: destination must be valid path. Use: " (#)" when needed
SaferMove(source, destination);
return destination;
}
public static string GetValidFilename(string path)
{
// TODO: destination must be valid path. Use: " (#)" when needed
return path;
}
private static int maxRetryAttempts { get; } = 3;
private static TimeSpan pauseBetweenFailures { get; } = TimeSpan.FromMilliseconds(100);
private static RetryPolicy retryPolicy { get; } =
Policy
.Handle<Exception>()
.WaitAndRetry(maxRetryAttempts, i => pauseBetweenFailures);
/// <summary>Delete file. No error when source does not exist. Retry up to 3 times.</summary>
public static void SaferDelete(string source)
=> retryPolicy.Execute(() =>
{
try
{
if (!File.Exists(source))
{
File.Delete(source);
Serilog.Log.Logger.Information("File successfully deleted", new { source });
}
}
catch (Exception e)
{
Serilog.Log.Logger.Error(e, "Failed to delete file", new { source });
throw;
}
});
/// <summary>Move file. No error when source does not exist. Retry up to 3 times.</summary>
public static void SaferMove(string source, string target)
=> retryPolicy.Execute(() =>
{
try
{
if (!File.Exists(source))
{
SaferDelete(target);
File.Move(source, target);
Serilog.Log.Logger.Information("File successfully moved", new { source, target });
}
}
catch (Exception e)
{
Serilog.Log.Logger.Error(e, "Failed to move file", new { source, target });
throw;
}
});
}
}