Method SaveModifiedStateToKCView

view/kernelcache/core/KernelCache.cpp:1982–2051

bool KernelCache::SaveModifiedStateToKCView(std::lock_guard<std::mutex>&)
{
	if (!m_kcView)
		return false;
	
	{
		std::lock_guard lock(m_viewSpecificState->stateMutex);

		uint64_t modificationNumber = m_viewSpecificState->savedModifications++;
		if (modificationNumber == 0)
		{
			// The cached state in the view-specific state has not yet been saved.
			// For the initial load of a shared cache this will be empty, but if
			// the shared cache has been loaded from a database then this will
			// contain the full state that was saved.
			std::string metadataKey = KernelCacheMetadata::ModifiedStateTagPrefix + std::to_string(modificationNumber);
			auto data = m_viewSpecificState->state.AsMetadata(m_viewSpecificState->viewState);

			m_kcView->StoreMetadata(metadataKey, data);
			m_kcView->GetParentView()->StoreMetadata(metadataKey, data);
			modificationNumber = m_viewSpecificState->savedModifications++;
		}

		std::string metadataKey = KernelCacheMetadata::ModifiedStateTagPrefix + std::to_string(modificationNumber);
		auto data = m_modifiedState->AsMetadata();

		m_kcView->StoreMetadata(metadataKey, data);
		m_kcView->GetParentView()->StoreMetadata(metadataKey, data);

		Ref<Metadata> count = new Metadata(m_viewSpecificState->savedModifications);
		m_kcView->StoreMetadata(KernelCacheMetadata::ModifiedStateCountTag, count);
		m_kcView->GetParentView()->StoreMetadata(KernelCacheMetadata::ModifiedStateCountTag, count);

		m_viewSpecificState->state.loadedImages.merge(m_modifiedState->loadedImages);
		// `merge` will move a node to the target map if the corresponding key does not yet exist.
		// If we've redundantly loaded images, we may be left with symbols in the source maps.
		m_modifiedState->loadedImages.clear();

		// Clean up any metadata entries past the current modification number.
		// These can happen after being loaded from a database as all modifications are
		// merged into a single state object and the modification count is reset to zero.
		for (size_t i = modificationNumber + 1; i < std::numeric_limits<size_t>::max(); ++i)
		{
			std::string modifiedStateMetadataKey = KernelCacheMetadata::ModifiedStateTagPrefix + std::to_string(i);
			bool done = true;
			if (m_kcView->QueryMetadata(modifiedStateMetadataKey))
			{
				done = false;
				m_kcView->RemoveMetadata(modifiedStateMetadataKey);
			}
			if (m_kcView->GetParentView()->QueryMetadata(modifiedStateMetadataKey))
			{
				done = false;
				m_kcView->GetParentView()->RemoveMetadata(modifiedStateMetadataKey);
			}
			if (done)
				break;
		}