DiscIO: Deduplicate some VolumeGC/VolumeWii code

Source/Core/DiscIO/VolumeDisc.cpp

@@ -0,0 +1,87 @@
+// Copyright 2020 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "DiscIO/VolumeDisc.h"
+
+#include <optional>
+#include <string>
+
+#include "Common/CommonTypes.h"
+#include "DiscIO/Enums.h"
+
+namespace DiscIO
+{
+std::string VolumeDisc::GetGameID(const Partition& partition) const
+{
+  char id[6];
+
+  if (!Read(0, sizeof(id), reinterpret_cast<u8*>(id), partition))
+    return std::string();
+
+  return DecodeString(id);
+}
+
+Country VolumeDisc::GetCountry(const Partition& partition) const
+{
+  // The 0 that we use as a default value is mapped to Country::Unknown and Region::Unknown
+  const u8 country_byte = ReadSwapped<u8>(3, partition).value_or(0);
+  const Region region = GetRegion();
+  const std::optional<u16> revision = GetRevision();
+
+  if (CountryCodeToRegion(country_byte, GetVolumeType(), region, revision) != region)
+    return TypicalCountryForRegion(region);
+
+  return CountryCodeToCountry(country_byte, GetVolumeType(), region, revision);
+}
+
+Region VolumeDisc::RegionCodeToRegion(std::optional<u32> region_code) const
+{
+  if (!region_code)
+    return Region::Unknown;
+
+  const Region region = static_cast<Region>(*region_code);
+  return region <= Region::NTSC_K ? region : Region::Unknown;
+}
+
+std::string VolumeDisc::GetMakerID(const Partition& partition) const
+{
+  char maker_id[2];
+
+  if (!Read(0x4, sizeof(maker_id), reinterpret_cast<u8*>(&maker_id), partition))
+    return std::string();
+
+  return DecodeString(maker_id);
+}
+
+std::optional<u16> VolumeDisc::GetRevision(const Partition& partition) const
+{
+  std::optional<u8> revision = ReadSwapped<u8>(7, partition);
+  return revision ? *revision : std::optional<u16>();
+}
+
+std::string VolumeDisc::GetInternalName(const Partition& partition) const
+{
+  char name[0x60];
+  if (!Read(0x20, sizeof(name), reinterpret_cast<u8*>(&name), partition))
+    return std::string();
+
+  return DecodeString(name);
+}
+
+std::string VolumeDisc::GetApploaderDate(const Partition& partition) const
+{
+  char date[16];
+
+  if (!Read(0x2440, sizeof(date), reinterpret_cast<u8*>(&date), partition))
+    return std::string();
+
+  return DecodeString(date);
+}
+
+std::optional<u8> VolumeDisc::GetDiscNumber(const Partition& partition) const
+{
+  return ReadSwapped<u8>(6, partition);
+}
+
+}  // namespace DiscIO