Separation of STFS, SVOD into different entities

src/xenia/vfs/devices/xcontent_container_file.cc

@@ -0,0 +1,71 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2023 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include <algorithm>
+#include <cmath>
+
+#include "xenia/base/math.h"
+#include "xenia/vfs/devices/xcontent_container_entry.h"
+#include "xenia/vfs/devices/xcontent_container_file.h"
+
+namespace xe {
+namespace vfs {
+
+XContentContainerFile::XContentContainerFile(uint32_t file_access,
+                                     XContentContainerEntry* entry)
+    : File(file_access, entry), entry_(entry) {}
+
+XContentContainerFile::~XContentContainerFile() = default;
+
+void XContentContainerFile::Destroy() { delete this; }
+
+X_STATUS XContentContainerFile::ReadSync(void* buffer, size_t buffer_length,
+                                     size_t byte_offset,
+                                     size_t* out_bytes_read) {
+  if (byte_offset >= entry_->size()) {
+    return X_STATUS_END_OF_FILE;
+  }
+
+  size_t src_offset = 0;
+  uint8_t* p = reinterpret_cast<uint8_t*>(buffer);
+  size_t remaining_length =
+      std::min(buffer_length, entry_->size() - byte_offset);
+
+  *out_bytes_read = 0;
+  for (size_t i = 0; i < entry_->block_list().size(); i++) {
+    auto& record = entry_->block_list()[i];
+    if (src_offset + record.length <= byte_offset) {
+      // Doesn't begin in this region. Skip it.
+      src_offset += record.length;
+      continue;
+    }
+
+    size_t read_offset =
+        (byte_offset > src_offset) ? byte_offset - src_offset : 0;
+    size_t read_length =
+        std::min(record.length - read_offset, remaining_length);
+
+    auto& file = entry_->files()->at(record.file);
+    xe::filesystem::Seek(file, record.offset + read_offset, SEEK_SET);
+    auto num_read = fread(p, 1, read_length, file);
+
+    *out_bytes_read += num_read;
+    p += num_read;
+    src_offset += record.length;
+    remaining_length -= read_length;
+    if (remaining_length == 0) {
+      break;
+    }
+  }
+
+  return X_STATUS_SUCCESS;
+}
+
+}  // namespace vfs
+}  // namespace xe