Add code for printing save FAT chains

src/LibHac/IO/Save/AllocationTableIterator.cs

@@ -16,7 +16,7 @@ namespace LibHac.IO.Save
 
             if (!BeginIteration(initialBlock))
             {
-                throw new ArgumentException($"Attempted to start FAT iteration from an invalid block. ({initialBlock}");
+                throw new ArgumentException($"Attempted to start FAT iteration from an invalid block. ({initialBlock})");
             }
         }
 
@@ -24,9 +24,9 @@ namespace LibHac.IO.Save
         {
             AllocationTableEntry tableEntry = Fat.Entries[initialBlock + 1];
 
-            if (!tableEntry.IsListStart())
+            if (!tableEntry.IsListStart() && initialBlock != -1)
             {
-                return false;
+               return false;
             }
 
             if (tableEntry.IsSingleBlockSegment())

src/LibHac/IO/Save/SaveDataFileSystemCore.cs

@@ -152,6 +152,7 @@ namespace LibHac.IO.Save
 
         public IStorage GetBaseStorage() => BaseStorage.AsReadOnly();
         public IStorage GetHeaderStorage() => HeaderStorage.AsReadOnly();
+        public SaveFileEntry GetFileEntry(string path) => FileDictionary[path];
 
         private void ReadFileInfo()
         {

src/LibHac/IO/Save/SaveExtensions.cs

@@ -0,0 +1,17 @@
+using System.Collections.Generic;
+
+namespace LibHac.IO.Save
+{
+    public static class SaveExtensions
+    {
+        public static IEnumerable<(int block, int length)> DumpChain(this AllocationTable table, int startBlock)
+        {
+            var iterator = new AllocationTableIterator(table, startBlock);
+
+            do
+            {
+                yield return (iterator.PhysicalBlock, iterator.CurrentSegmentSize);
+            } while (iterator.MoveNext());
+        }
+    }
+}

src/LibHac/LibHac.csproj

@@ -34,9 +34,10 @@
   </PropertyGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net46' ">
-    <PackageReference Include="System.Numerics.Vectors" Version="4.5.0" />
-    <PackageReference Include="System.Memory" Version="4.5.2" />
     <PackageReference Include="System.Buffers" Version="4.5.0" />
+    <PackageReference Include="System.Memory" Version="4.5.2" />
+    <PackageReference Include="System.Numerics.Vectors" Version="4.5.0" />
+    <PackageReference Include="System.ValueTuple" Version="4.5.0" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' ">

src/hactoolnet/ProcessSave.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -151,6 +152,87 @@ namespace hactoolnet
                 }
 
                 ctx.Logger.LogMessage(save.Print());
+                //ctx.Logger.LogMessage(PrintFatLayout(save));
+            }
+        }
+
+        // ReSharper disable once UnusedMember.Local
+        private static string PrintFatLayout(this SaveDataFileSystem save)
+        {
+            var sb = new StringBuilder();
+
+            foreach (DirectoryEntry entry in save.EnumerateEntries().Where(x => x.Type == DirectoryEntryType.File))
+            {
+                SaveFileEntry saveEntry = save.SaveDataFileSystemCore.GetFileEntry(entry.FullPath);
+
+                if (saveEntry.BlockIndex < 0) continue;
+
+                IEnumerable<(int block, int length)> chain = save.SaveDataFileSystemCore.AllocationTable.DumpChain(saveEntry.BlockIndex);
+
+                sb.AppendLine(entry.FullPath);
+                sb.AppendLine(PrintBlockChain(chain));
+            }
+
+            sb.AppendLine("Directory Table");
+            sb.AppendLine(PrintBlockChain(save.SaveDataFileSystemCore.AllocationTable.DumpChain(0)));
+
+            sb.AppendLine("File Table");
+            sb.AppendLine(PrintBlockChain(save.SaveDataFileSystemCore.AllocationTable.DumpChain(1)));
+
+            sb.AppendLine("Free blocks");
+            sb.AppendLine(PrintBlockChain(save.SaveDataFileSystemCore.AllocationTable.DumpChain(-1)));
+
+            return sb.ToString();
+        }
+
+        private static string PrintBlockChain(IEnumerable<(int block, int length)> chain)
+        {
+            var sb = new StringBuilder();
+            int segmentCount = 0;
+            int segmentStart = -1;
+            int segmentEnd = -1;
+
+            foreach ((int block, int length) in chain)
+            {
+                if (segmentStart == -1)
+                {
+                    segmentStart = block;
+                    segmentEnd = block + length - 1;
+                    continue;
+                }
+
+                if (block == segmentEnd + 1)
+                {
+                    segmentEnd += length;
+                    continue;
+                }
+
+                PrintSegment();
+
+                segmentStart = block;
+                segmentEnd = block + length - 1;
+            }
+
+            PrintSegment();
+
+            return sb.ToString();
+
+            void PrintSegment()
+            {
+                if (segmentCount > 0) sb.Append(", ");
+
+                if (segmentStart == segmentEnd)
+                {
+                    sb.Append(segmentStart);
+                }
+                else
+                {
+                    sb.Append($"{segmentStart}-{segmentEnd}");
+                }
+
+                segmentCount++;
+                segmentStart = -1;
+                segmentEnd = -1;
             }
         }