public static List <FileComparisonResult> Go(SortFilesSettings settings)
{
// first, just make an index that simply maps filesizes to filenames.
// we don't need to compute any content-hashes yet, because if there
// is only one file with that filesize, we know it's not a duplicate.
var results = new List <FileComparisonResult>();
var di = new DirectoryInfo(settings.LeftDirectory);
var index = SortFilesSearchDuplicates.MapFilesizesToFilenames(
settings.LeftDirectory,
di.EnumerateFiles("*", SearchOption.AllDirectories));
foreach (var list in index.Values)
{
if (list.Count > 1)
{
// if there's more than one file with the same filesize,
// compute hashes of contents to look for duplicates.
for (int i = 0; i < list.Count; i++)
{
list[i].ContentHash = Utils.GetSha512(
settings.LeftDirectory + list[i].Filename);
// have we seen this hash before? this is an n-squared loop, but
// basically amortized by the cost of computing hashes.
for (int j = 0; j < i; j++)
{
if (list[j].ContentHash == list[i].ContentHash)
{
// consistently put the first-appearing file on the 'left' side
// so that the user can conveniently safely delete all on 'right'.
results.Add(new FileComparisonResult(
list[j], list[i], FileComparisonResultType.Same_Contents));
break;
}
}
}
}
}
return(results);
}
static void TestMethod_MapFilesizesToFilenames()
{
var dirTest = TestUtil.GetTestSubDirectory("testMapFilesizesToFilenames");
File.WriteAllText(Path.Combine(dirTest, "a.txt"), "abcd");
File.WriteAllText(Path.Combine(dirTest, "b.txt"), "abcde");
File.WriteAllText(Path.Combine(dirTest, "c.txt"), "1234");
// adjust the lmt of c.txt
File.SetLastWriteTimeUtc(Path.Combine(dirTest, "c.txt"), DateTime.Now.AddDays(1));
var map = SortFilesSearchDuplicates.MapFilesizesToFilenames(dirTest,
new DirectoryInfo(dirTest).EnumerateFiles("*"));
var mapSorted = (from item in map[4] orderby item.Filename select item).ToArray();
TestUtil.IsEq(2, map.Count);
TestUtil.IsEq(2, map[4].Count);
TestUtil.IsEq(1, map[5].Count);
// test that FileInfoForComparison was set correctly
TestUtil.IsEq(Utils.Sep + "a.txt", mapSorted[0].Filename);
TestUtil.IsEq(null, mapSorted[0].ContentHash);
TestUtil.IsEq(4L, mapSorted[0].FileSize);
TestUtil.IsEq(File.GetLastWriteTimeUtc(Path.Combine(dirTest, "a.txt")),
mapSorted[0].LastModifiedTime);
TestUtil.IsEq(Utils.Sep + "b.txt", map[5][0].Filename);
TestUtil.IsEq(null, map[5][0].ContentHash);
TestUtil.IsEq(5L, map[5][0].FileSize);
TestUtil.IsEq(File.GetLastWriteTimeUtc(Path.Combine(dirTest, "b.txt")),
map[5][0].LastModifiedTime);
TestUtil.IsEq(Utils.Sep + "c.txt", mapSorted[1].Filename);
TestUtil.IsEq(null, mapSorted[1].ContentHash);
TestUtil.IsEq(4L, mapSorted[1].FileSize);
TestUtil.IsEq(File.GetLastWriteTimeUtc(Path.Combine(dirTest, "c.txt")),
mapSorted[1].LastModifiedTime);
}
