Fixed PathToExtents to FatFileSystem

LTRData · Nov 20, 2024 · eb1def3 · eb1def3
1 parent 1e35f07
commit eb1def3
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Showing 5 changed files with 35 additions and 5 deletions.
diff --git a/Library/DiscUtils.Fat/ClusterStream.cs b/Library/DiscUtils.Fat/ClusterStream.cs
@@ -638,5 +638,10 @@ public IEnumerable<Range<long, long>> EnumerateAllocatedClusters()
             firstCluster = null;
             lastCluster = null;
         }
+
+        if (firstCluster.HasValue && lastCluster.HasValue)
+        {
+            yield return new(firstCluster.Value, lastCluster.Value - firstCluster.Value + 1);
+        }
     }
 }
diff --git a/Library/DiscUtils.Fat/FatFileStream.cs b/Library/DiscUtils.Fat/FatFileStream.cs
@@ -177,5 +177,6 @@ private void FirstClusterAllocatedHandler(uint cluster)
         _dir.UpdateEntry(_dirId, dirEntry);
     }
 
-    public IEnumerable<Range<long, long>> EnumerateAllocatedClusters() => _stream.EnumerateAllocatedClusters();
+    public IEnumerable<Range<long, long>> EnumerateAllocatedClusters()
+        => _stream.EnumerateAllocatedClusters();
 }
diff --git a/Library/DiscUtils.Fat/FatFileSystem.cs b/Library/DiscUtils.Fat/FatFileSystem.cs
@@ -410,7 +410,13 @@ public override SparseStream OpenFile(string path, FileMode mode, FileAccess acc
     }
 
     public IEnumerable<StreamExtent> PathToExtents(string path)
-        => PathToClusters(path).Select(range => new StreamExtent(range.Offset * ClusterSize, range.Count * ClusterSize));
+    {
+        var stream = (FatFileStream)OpenFile(path, FileMode.Open, FileAccess.Read);
+
+        return stream
+            .EnumerateAllocatedClusters()
+            .Select(range => new StreamExtent(ClusterReader.GetBaseStreamPositionForCluster((uint)range.Offset), ClusterSize * range.Count));
+    }
 
     public IEnumerable<Range<long, long>> PathToClusters(string path)
     {

diff --git a/Tests/LibraryTests/Fat/FatFileSystemTest.cs b/Tests/LibraryTests/Fat/FatFileSystemTest.cs
@@ -477,6 +477,12 @@ public void TestFindPosition()
             file.Write(pattern);
         }
 
+        var firstExt = fs
+            .PathToExtents("Test.txt")
+            .FirstOrDefault();
+
+        Assert.NotEqual(0, firstExt.Start);
+
         long? locationOnDisk;
 
         Span<byte> buffer = stackalloc byte[pattern.Length];
@@ -492,7 +498,7 @@ public void TestFindPosition()
         }
 
         Assert.NotNull(locationOnDisk);
-        Assert.NotEqual(0, locationOnDisk.Value);
+        Assert.Equal(firstExt.Start, locationOnDisk.Value);
 
         diskStream.Position = locationOnDisk.Value;
         buffer.Clear();

diff --git a/Tests/LibraryTests/Ntfs/NtfsFileSystemTest.cs b/Tests/LibraryTests/Ntfs/NtfsFileSystemTest.cs
@@ -877,6 +877,12 @@ public void TestFindPositionSmallFile()
             file.Write(pattern);
         }
 
+        var firstExt = fs
+            .PathToExtents("Test.txt")
+            .FirstOrDefault();
+
+        Assert.NotEqual(0, firstExt.Start);
+
         long? locationOnDisk;
 
         Span<byte> buffer = stackalloc byte[pattern.Length];
@@ -892,7 +898,7 @@ public void TestFindPositionSmallFile()
         }
 
         Assert.NotNull(locationOnDisk);
-        Assert.NotEqual(0, locationOnDisk.Value);
+        Assert.Equal(firstExt.Start, locationOnDisk.Value);
 
         diskStream.Position = locationOnDisk.Value;
         buffer.Clear();
@@ -920,6 +926,12 @@ public void TestFindPositionBigFile()
             file.Write(pattern);
         }
 
+        var firstExt = fs
+            .PathToExtents("Test.txt")
+            .FirstOrDefault();
+
+        Assert.NotEqual(0, firstExt.Start);
+
         long? locationOnDisk;
 
         var buffer = new byte[pattern.Length];
@@ -935,7 +947,7 @@ public void TestFindPositionBigFile()
         }
 
         Assert.NotNull(locationOnDisk);
-        Assert.NotEqual(0, locationOnDisk.Value);
+        Assert.Equal(firstExt.Start, locationOnDisk.Value);
 
         diskStream.Position = locationOnDisk.Value;
         buffer.AsSpan().Clear();