Add non-system BCAT mount shim

src/LibHac/Fs/Shim/BcatSaveData.cs

@@ -0,0 +1,56 @@
+using System;
+using LibHac.Common;
+using LibHac.FsService;
+using LibHac.Ncm;
+
+namespace LibHac.Fs.Shim
+{
+    public static class BcatSaveData
+    {
+        public static Result MountBcatSaveData(this FileSystemClient fs, U8Span mountName, TitleId applicationId)
+        {
+            Result rc;
+
+            if (fs.IsEnabledAccessLog(AccessLogTarget.System))
+            {
+                TimeSpan startTime = fs.Time.GetCurrent();
+                rc = MountBcatSaveDataImpl(fs, mountName, applicationId);
+                TimeSpan endTime = fs.Time.GetCurrent();
+
+                string logMessage = $", name: \"{mountName.ToString()}\", applicationid: 0x{applicationId}\"";
+
+                fs.OutputAccessLog(rc, startTime, endTime, logMessage);
+            }
+            else
+            {
+                rc = MountBcatSaveDataImpl(fs, mountName, applicationId);
+            }
+
+            if (rc.IsFailure()) return rc;
+
+            if (fs.IsEnabledAccessLog(AccessLogTarget.System))
+            {
+                fs.EnableFileSystemAccessorAccessLog(mountName);
+            }
+
+            return Result.Success;
+        }
+
+        private static Result MountBcatSaveDataImpl(FileSystemClient fs, U8Span mountName, TitleId applicationId)
+        {
+            Result rc = MountHelpers.CheckMountName(mountName);
+            if (rc.IsFailure()) return rc;
+
+            IFileSystemProxy fsProxy = fs.GetFileSystemProxyServiceObject();
+
+            SaveDataAttribute attribute = default;
+            attribute.TitleId = applicationId;
+            attribute.Type = SaveDataType.Bcat;
+
+            rc = fsProxy.OpenSaveDataFileSystem(out IFileSystem fileSystem, SaveDataSpaceId.User, ref attribute);
+            if (rc.IsFailure()) return rc;
+
+            return fs.Register(mountName, fileSystem);
+        }
+    }
+}

tests/LibHac.Tests/Fs/FileSystemClientTests/ShimTests/BcatSaveData.cs

@@ -0,0 +1,51 @@
+using LibHac.Common;
+using LibHac.Fs;
+using LibHac.Fs.Shim;
+using LibHac.Ncm;
+using Xunit;
+
+namespace LibHac.Tests.Fs.FileSystemClientTests.ShimTests
+{
+    public class BcatSaveData
+    {
+        [Fact]
+        public void MountBcatSaveData_SaveDoesNotExist_ReturnsTargetNotFound()
+        {
+            var applicationId = new TitleId(1);
+            FileSystemClient fs = FileSystemServerFactory.CreateClient(true);
+
+            Assert.Result(ResultFs.TargetNotFound, fs.MountBcatSaveData("bcat_test".ToU8Span(), applicationId));
+        }
+
+        [Fact]
+        public void MountBcatSaveData_SaveExists_ReturnsSuccess()
+        {
+            var applicationId = new TitleId(1);
+            FileSystemClient fs = FileSystemServerFactory.CreateClient(true);
+
+            Assert.Success(fs.CreateBcatSaveData(applicationId, 0x400000));
+            Assert.Success(fs.MountBcatSaveData("bcat_test".ToU8Span(), applicationId));
+        }
+
+        [Fact]
+        public void MountBcatSaveData_WrittenDataPersists()
+        {
+            var applicationId = new TitleId(1);
+            FileSystemClient fs = FileSystemServerFactory.CreateClient(true);
+
+            Assert.Success(fs.CreateBcatSaveData(applicationId, 0x400000));
+            Assert.Success(fs.MountBcatSaveData("bcat_test".ToU8Span(), applicationId));
+
+            // Check that the path doesn't exist
+            Assert.Result(ResultFs.PathNotFound, fs.GetEntryType(out _, "bcat_test:/file".ToU8Span()));
+
+            fs.CreateFile("bcat_test:/file".ToU8Span(), 0);
+            fs.Commit("bcat_test".ToU8Span());
+            fs.Unmount("bcat_test".ToU8Span());
+
+            Assert.Success(fs.MountBcatSaveData("bcat_test".ToU8Span(), applicationId));
+            Assert.Success(fs.GetEntryType(out DirectoryEntryType type, "bcat_test:/file".ToU8Span()));
+            Assert.Equal(DirectoryEntryType.File, type);
+        }
+    }
+}

tests/LibHac.Tests/Fs/FileSystemClientTests/ShimTests/SaveData.cs

@@ -36,6 +36,7 @@ namespace LibHac.Tests.Fs.FileSystemClientTests.ShimTests
             Assert.Success(fs.GetEntryType(out DirectoryEntryType type, "cache:/file".ToU8Span()));
             Assert.Equal(DirectoryEntryType.File, type);
         }
+
         [Fact]
         public void MountCacheStorage_SdCardIsPreferredOverBis()
         {

tests/LibHac.Tests/Fs/FileSystemClientTests/ShimTests/SaveDataManagement.cs

@@ -84,5 +84,33 @@ namespace LibHac.Tests.Fs.FileSystemClientTests.ShimTests
 
             Assert.Equal(expectedIndexes, actualIndexes);
         }
+
+        [Fact]
+        public void CreateBcatSaveData_DoesNotExist_SaveIsCreated()
+        {
+            var applicationId = new TitleId(1);
+            FileSystemClient fs = FileSystemServerFactory.CreateClient(true);
+
+            Assert.Success(fs.CreateBcatSaveData(applicationId, 0x400000));
+
+            fs.OpenSaveDataIterator(out SaveDataIterator iterator, SaveDataSpaceId.User);
+
+            var info = new SaveDataInfo[2];
+            iterator.ReadSaveDataInfo(out long entriesRead, info);
+
+            Assert.Equal(1, entriesRead);
+            Assert.Equal(applicationId, info[0].TitleId);
+            Assert.Equal(SaveDataType.Bcat, info[0].Type);
+        }
+
+        [Fact]
+        public void CreateBcatSaveData_AlreadyExists_ReturnsPathAlreadyExists()
+        {
+            var applicationId = new TitleId(1);
+            FileSystemClient fs = FileSystemServerFactory.CreateClient(true);
+
+            Assert.Success(fs.CreateBcatSaveData(applicationId, 0x400000));
+            Assert.Result(ResultFs.PathAlreadyExists, fs.CreateBcatSaveData(applicationId, 0x400000));
+        }
     }
 }