fusee: read from emuSD, if enabled

fusee/program/source/fs/fusee_multi_file_storage.cpp

@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 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 <exosphere.hpp>
+#include "fusee_fs_storage.hpp"
+
+namespace ams::fs {
+
+        void MultiFileStorage::EnsureFile(int id) {
+            if (!m_open[id]) {
+                /* Update path. */
+                m_base_path[m_file_path_ofs + 1] = '0' + (id % 10);
+                m_base_path[m_file_path_ofs + 0] = '0' + (id / 10);
+
+                /* Open new file. */
+                const Result result = fs::OpenFile(m_handles + id, m_base_path, fs::OpenMode_Read);
+                if (R_FAILED(result)) {
+                    nxboot::ShowFatalError("Failed to open part %02d (%s): 0x%08" PRIx32 "!\n", id, m_base_path, result.GetValue());
+                }
+
+                m_open[id] = true;
+            }
+        }
+
+        MultiFileStorage::MultiFileStorage(const char *base_path) {
+            util::Strlcpy(m_base_path, base_path, sizeof(m_base_path) - 2);
+            m_file_path_ofs = strlen(m_base_path);
+
+            for (size_t i = 0; i < util::size(m_handles); i++) {
+                m_open[i] = false;
+            }
+
+            std::memcpy(m_base_path + m_file_path_ofs, "00", 3);
+            Result r;
+            if (R_FAILED(r = fs::OpenFile(std::addressof(m_handles[0]), m_base_path, fs::OpenMode_Read))) {
+                nxboot::ShowFatalError("Failed to open part %02d (%s): 0x%08" PRIx32 "!\n", 0, m_base_path, r.GetValue());
+            }
+
+            m_open[0] = true;
+        }
+
+        Result MultiFileStorage::Read(s64 offset, void *buffer, size_t size) {
+            int file   = offset / m_file_size;
+            s64 subofs = offset % m_file_size;
+
+            u8 *cur_dst = static_cast<u8 *>(buffer);
+
+            for (/* ... */; size > 0; ++file) {
+                /* Ensure the current file is open. */
+                EnsureFile(file);
+
+                /* Perform the current read. */
+                const size_t cur_size = std::min<size_t>(m_file_size - subofs, size);
+                R_TRY(fs::ReadFile(m_handles[file], subofs, cur_dst, cur_size));
+
+                /* Advance. */
+                cur_dst += cur_size;
+                size -= cur_size;
+                subofs = 0;
+            }
+
+            R_SUCCEED();
+        }
+
+        Result MultiFileStorage::Flush() {
+            R_THROW(fs::ResultUnsupportedOperation());
+        }
+
+        Result MultiFileStorage::GetSize(s64 *out) {
+            R_THROW(fs::ResultUnsupportedOperation());
+        }
+
+        Result MultiFileStorage::Write(s64 offset, const void *buffer, size_t size) {
+            int file   = offset / m_file_size;
+            s64 subofs = offset % m_file_size;
+
+            const u8 *cur_src = static_cast<const u8 *>(buffer);
+
+            for (/* ... */; size > 0; ++file) {
+                /* Ensure the current file is open. */
+                EnsureFile(file);
+
+                /* Perform the current read. */
+                const size_t cur_size = std::min<size_t>(m_file_size - subofs, size);
+                R_TRY(fs::WriteFile(m_handles[file], subofs, cur_src, cur_size, fs::WriteOption::Flush));
+
+                /* Advance. */
+                cur_src += cur_size;
+                size -= cur_size;
+                subofs = 0;
+            }
+
+            R_SUCCEED();
+        }
+
+        Result MultiFileStorage::SetSize(s64 size) {
+            R_THROW(fs::ResultUnsupportedOperation());
+        }
+
+}