[SharedCache] Warn when loading BNDB with different shared cache metadata version

This does not actually give the user control to exit early, that looks to need core changes.

Author: emesare

view/sharedcache/core/DSCView.cpp

@@ -195,6 +195,14 @@ bool DSCView::Init()
 	if (m_parseOnly)
 		return true;
 
+	// Check the metadata version if there is one, so we can alert the user to why they have no loaded images.
+	// TODO: Once the view is able to be exited early we should offer to close the view if the user does not want to upgrade.
+	auto metadataVersion = SharedCacheCore::SharedCacheMetadata::ViewMetadataVersion(GetParentView());
+	if (metadataVersion.has_value() && metadataVersion.value() != METADATA_VERSION)
+	{
+		ShowMessageBox("Invalid Shared Cache Metadata!", "The BNDB shared cache metadata was created with a different version of the Shared Cache view, to continue the metadata has to be recreated. You will need to add your images back again.");
+	}
+
 	// Add Mach-O file header type info
 	EnumerationBuilder cpuTypeBuilder;
 	cpuTypeBuilder.AddMemberWithValue("CPU_TYPE_ANY", MACHO_CPU_TYPE_ANY);

view/sharedcache/core/SharedCache.cpp

@@ -3594,6 +3594,21 @@ bool SharedCacheMetadata::ViewHasMetadata(BinaryView* view)
 	return view->QueryMetadata(Tag);
 }
 
+std::optional<unsigned int> SharedCacheMetadata::ViewMetadataVersion(BinaryView* view)
+{
+	// Whether the view has compatible metadata. I.e. if the version differs.
+	Ref<Metadata> viewMetadata = view->QueryMetadata(Tag);
+	if (!viewMetadata)
+		return std::nullopt;
+	DeserializationContext context;
+	rapidjson::ParseResult result = context.doc.Parse(viewMetadata->GetString().c_str());
+	if (!result)
+		return std::nullopt;
+	if (!context.doc.HasMember("metadataVersion"))
+		return std::nullopt;
+	return context.doc["metadataVersion"].GetUint();
+}
+
 // static
 std::optional<SharedCacheMetadata> SharedCacheMetadata::LoadFromView(BinaryView* view)
 {

view/sharedcache/core/SharedCache.h

@@ -668,6 +668,7 @@ namespace SharedCacheCore {
 	public:
 		static std::optional<SharedCacheMetadata> LoadFromView(BinaryView*);
 		static bool ViewHasMetadata(BinaryView*);
+		static std::optional<unsigned int> ViewMetadataVersion(BinaryView*);
 
 		const std::unordered_map<uint64_t, std::shared_ptr<std::unordered_map<uint64_t, Ref<Symbol>>>>& ExportInfos() const;
 		std::string InstallNameForImageBaseAddress(uint64_t baseAddress) const;