git subrepo clone https://github.com/Atmosphere-NX/Atmosphere-libs libraries

subrepo:
  subdir:   "libraries"
  merged:   "07af583b"
upstream:
  origin:   "https://github.com/Atmosphere-NX/Atmosphere-libs"
  branch:   "master"
  commit:   "07af583b"
git-subrepo:
  version:  "0.4.0"
  origin:   "https://github.com/ingydotnet/git-subrepo"
  commit:   "5d6aba9"

libraries/libstratosphere/source/fs/fs_file_storage.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+
+namespace ams::fs {
+
+    Result FileStorage::UpdateSize() {
+        R_UNLESS(this->size == InvalidSize, ResultSuccess());
+        return this->base_file->GetSize(&this->size);
+    }
+
+    Result FileStorage::Read(s64 offset, void *buffer, size_t size) {
+        /* Immediately succeed if there's nothing to read. */
+        R_UNLESS(size > 0, ResultSuccess());
+
+        /* Validate buffer. */
+        R_UNLESS(buffer != nullptr, fs::ResultNullptrArgument());
+
+        /* Ensure our size is valid. */
+        R_TRY(this->UpdateSize());
+
+        /* Ensure our access is valid. */
+        R_UNLESS(IStorage::IsRangeValid(offset, size, this->size), fs::ResultOutOfRange());
+
+        size_t read_size;
+        return this->base_file->Read(&read_size, offset, buffer, size);
+    }
+
+    Result FileStorage::Write(s64 offset, const void *buffer, size_t size) {
+        /* Immediately succeed if there's nothing to write. */
+        R_UNLESS(size > 0, ResultSuccess());
+
+        /* Validate buffer. */
+        R_UNLESS(buffer != nullptr, fs::ResultNullptrArgument());
+
+        /* Ensure our size is valid. */
+        R_TRY(this->UpdateSize());
+
+        /* Ensure our access is valid. */
+        R_UNLESS(IStorage::IsRangeValid(offset, size, this->size), fs::ResultOutOfRange());
+
+        return this->base_file->Write(offset, buffer, size, fs::WriteOption());
+    }
+
+    Result FileStorage::Flush() {
+        return this->base_file->Flush();
+    }
+
+    Result FileStorage::GetSize(s64 *out_size) {
+        R_TRY(this->UpdateSize());
+        *out_size = this->size;
+        return ResultSuccess();
+    }
+
+    Result FileStorage::SetSize(s64 size) {
+        this->size = InvalidSize;
+        return this->base_file->SetSize(size);
+    }
+
+    Result FileStorage::OperateRange(void *dst, size_t dst_size, OperationId op_id, s64 offset, s64 size, const void *src, size_t src_size) {
+        switch (op_id) {
+            case OperationId::InvalidateCache:
+            case OperationId::QueryRange:
+                if (size == 0) {
+                    if (op_id == OperationId::QueryRange) {
+                        R_UNLESS(dst != nullptr,                     fs::ResultNullptrArgument());
+                        R_UNLESS(dst_size == sizeof(QueryRangeInfo), fs::ResultInvalidSize());
+                        reinterpret_cast<QueryRangeInfo *>(dst)->Clear();
+                    }
+                    return ResultSuccess();
+                }
+                R_TRY(this->UpdateSize());
+                R_UNLESS(IStorage::IsOffsetAndSizeValid(offset, size), fs::ResultOutOfRange());
+                return this->base_file->OperateRange(dst, dst_size, op_id, offset, size, src, src_size);
+            default:
+                return fs::ResultUnsupportedOperation();
+        }
+    }
+
+}