Add an early version of WIABlobReader

It can currently only read the first 0x80 bytes of a disc image,
which is enough for identifying it but not for doing anything else.

Source/Core/DiscIO/WIABlob.cpp

@@ -0,0 +1,92 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "DiscIO/WIABlob.h"
+
+#include <memory>
+
+#include "Common/CommonTypes.h"
+#include "Common/File.h"
+#include "Common/Logging/Log.h"
+#include "Common/StringUtil.h"
+#include "Common/Swap.h"
+
+#include "DiscIO/VolumeWii.h"
+
+namespace DiscIO
+{
+WIAFileReader::WIAFileReader(File::IOFile file, const std::string& path) : m_file(std::move(file))
+{
+  m_valid = Initialize(path);
+}
+
+WIAFileReader::~WIAFileReader() = default;
+
+bool WIAFileReader::Initialize(const std::string& path)
+{
+  if (!m_file.Seek(0, SEEK_SET) || !m_file.ReadArray(&m_header_1, 1))
+    return false;
+
+  if (m_header_1.magic != WIA_MAGIC)
+    return false;
+
+  const u32 version = Common::swap32(m_header_1.version);
+  const u32 version_compatible = Common::swap32(m_header_1.version_compatible);
+  if (WIA_VERSION < version_compatible || WIA_VERSION_READ_COMPATIBLE > version)
+  {
+    ERROR_LOG(DISCIO, "Unsupported WIA version %s in %s", VersionToString(version).c_str(),
+              path.c_str());
+    return false;
+  }
+
+  if (Common::swap64(m_header_1.wia_file_size) != m_file.GetSize())
+  {
+    ERROR_LOG(DISCIO, "File size is incorrect for %s", path.c_str());
+    return false;
+  }
+
+  if (Common::swap32(m_header_1.header_2_size) < sizeof(WIAHeader2))
+    return false;
+
+  if (!m_file.ReadArray(&m_header_2, 1))
+    return false;
+
+  const u32 chunk_size = Common::swap32(m_header_2.chunk_size);
+  if (chunk_size % VolumeWii::GROUP_TOTAL_SIZE != 0)
+    return false;
+
+  return true;
+}
+
+std::unique_ptr<WIAFileReader> WIAFileReader::Create(File::IOFile file, const std::string& path)
+{
+  std::unique_ptr<WIAFileReader> blob(new WIAFileReader(std::move(file), path));
+  return blob->m_valid ? std::move(blob) : nullptr;
+}
+
+bool WIAFileReader::Read(u64 offset, u64 size, u8* out_ptr)
+{
+  if (offset + size <= sizeof(WIAHeader2::disc_header))
+  {
+    std::memcpy(out_ptr, m_header_2.disc_header.data() + offset, size);
+    return true;
+  }
+
+  // Not implemented
+  return false;
+}
+
+std::string WIAFileReader::VersionToString(u32 version)
+{
+  const u8 a = version >> 24;
+  const u8 b = (version >> 16) & 0xff;
+  const u8 c = (version >> 8) & 0xff;
+  const u8 d = version & 0xff;
+
+  if (d == 0 || d == 0xff)
+    return StringFromFormat("%u.%02x.%02x", a, b, c);
+  else
+    return StringFromFormat("%u.%02x.%02x.beta%u", a, b, c, d);
+}
+}  // namespace DiscIO