feat(Resources): 添加资源系统基础框架

- ResourceTypes: 资源类型枚举、ResourceGUID生成
- IResource: 资源基类接口
- ResourceHandle: 资源句柄智能指针
- IResourceLoader: 加载器接口
- ResourceManager: 资源管理器(单例模式)
- ResourceCache: LRU缓存实现
- AsyncLoader: 异步加载器
- 测试框架: test_resource_types, test_resource_guid

Note: 当前与现有容器API存在编译差异,需要后续修复

engine/src/Resources/AsyncLoader.cpp

@@ -0,0 +1,103 @@
+#include "Resources/AsyncLoader.h"
+#include "Resources/ResourceManager.h"
+#include "Resources/ResourceTypes.h"
+
+namespace XCEngine {
+namespace Resources {
+
+Core::uint64 LoadRequest::GenerateRequestId() {
+    static std::atomic<Core::uint64> s_requestId{0};
+    return ++s_requestId;
+}
+
+AsyncLoader& AsyncLoader::Get() {
+    static AsyncLoader instance;
+    return instance;
+}
+
+void AsyncLoader::Initialize(Core::uint32 workerThreadCount) {
+    (void)workerThreadCount;
+}
+
+void AsyncLoader::Shutdown() {
+    CancelAll();
+}
+
+void AsyncLoader::Submit(const Containers::String& path, ResourceType type,
+                        std::function<void(LoadResult)> callback) {
+    Submit(path, type, nullptr, std::move(callback));
+}
+
+void AsyncLoader::Submit(const Containers::String& path, ResourceType type, ImportSettings* settings,
+                        std::function<void(LoadResult)> callback) {
+    LoadRequest request(path, type, std::move(callback), settings);
+    SubmitInternal(request);
+}
+
+void AsyncLoader::SubmitInternal(LoadRequest& request) {
+    IResourceLoader* loader = FindLoader(request.type);
+    
+    if (!loader) {
+        if (request.callback) {
+            LoadResult result(Containers::String("No loader for type: ") + 
+                           GetResourceTypeName(request.type));
+            request.callback(result);
+        }
+        return;
+    }
+    
+    {
+        std::lock_guard lock(m_queueMutex);
+        m_pendingQueue.PushBack(request);
+        m_pendingCount++;
+        m_totalRequested++;
+    }
+}
+
+void AsyncLoader::Update() {
+    Containers::Array<LoadRequest> completed;
+    
+    {
+        std::lock_guard lock(m_completedMutex);
+        completed = std::move(m_completedQueue);
+        m_completedQueue.Clear();
+    }
+    
+    for (auto& request : completed) {
+        m_pendingCount--;
+        
+        if (request.callback) {
+            LoadResult result(true);
+            request.callback(result);
+        }
+    }
+}
+
+float AsyncLoader::GetProgress() const {
+    if (m_totalRequested == 0) return 1.0f;
+    return static_cast<float>(m_totalRequested - m_pendingCount.load()) / m_totalRequested;
+}
+
+void AsyncLoader::CancelAll() {
+    std::lock_guard lock(m_queueMutex);
+    m_pendingQueue.Clear();
+    m_pendingCount = 0;
+}
+
+void AsyncLoader::Cancel(Core::uint64 requestId) {
+    std::lock_guard lock(m_queueMutex);
+    (void)requestId;
+}
+
+IResourceLoader* AsyncLoader::FindLoader(ResourceType type) const {
+    return ResourceManager::Get().GetLoader(type);
+}
+
+void AsyncLoader::QueueCompleted(LoadRequest request, LoadResult result) {
+    std::lock_guard lock(m_completedMutex);
+    (void)request;
+    (void)result;
+}
+
+} // namespace Resources
+} // namespace XCEngine

engine/src/Resources/ResourceCache.cpp

@@ -0,0 +1,141 @@
+#include "Resources/ResourceCache.h"
+#include "Resources/ResourceManager.h"
+
+namespace XCEngine {
+namespace Resources {
+
+static Core::uint64 g_currentTick = 0;
+
+Core::uint64 CacheEntry::GetCurrentTick() {
+    return ++g_currentTick;
+}
+
+CacheEntry::CacheEntry(IResource* res, size_t size)
+    : resource(res), guid(res->GetGUID()), memorySize(size),
+      lastAccessTime(GetCurrentTick()), accessCount(1) {}
+
+ResourceCache::ResourceCache() = default;
+ResourceCache::~ResourceCache() = default;
+
+void ResourceCache::Add(ResourceGUID guid, IResource* resource) {
+    std::lock_guard lock(m_mutex);
+    
+    if (m_cache.Contains(guid)) {
+        return;
+    }
+    
+    CacheEntry entry(resource, resource->GetMemorySize());
+    m_cache.Insert(guid, entry);
+    m_lruOrder.PushBack(guid);
+    m_memoryUsage += entry.memorySize;
+}
+
+void ResourceCache::Remove(ResourceGUID guid) {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_cache.Find(guid);
+    if (it != nullptr) {
+        m_memoryUsage -= it->memorySize;
+        m_cache.Erase(guid);
+        
+        // Simple workaround: rebuild LRU list without the guid
+        Containers::Array<ResourceGUID> newList;
+        for (size_t i = 0; i < m_lruOrder.Size(); ++i) {
+            if (m_lruOrder[i] != guid) {
+                newList.PushBack(m_lruOrder[i]);
+            }
+        }
+        m_lruOrder = std::move(newList);
+    }
+}
+
+IResource* ResourceCache::Find(ResourceGUID guid) const {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_cache.Find(guid);
+    return it != nullptr ? it->resource : nullptr;
+}
+
+void ResourceCache::Touch(ResourceGUID guid) {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_cache.Find(guid);
+    if (it != nullptr) {
+        it->lastAccessTime = CacheEntry::GetCurrentTick();
+        it->accessCount++;
+    }
+}
+
+void ResourceCache::SetMemoryBudget(size_t bytes) {
+    std::lock_guard lock(m_mutex);
+    m_memoryBudget = bytes;
+}
+
+void ResourceCache::OnMemoryPressure(size_t requiredBytes) {
+    std::lock_guard lock(m_mutex);
+    
+    if (m_memoryUsage + requiredBytes <= m_memoryBudget) {
+        return;
+    }
+    
+    size_t targetRelease = (m_memoryUsage + requiredBytes) - m_memoryBudget;
+    Evict(targetRelease);
+}
+
+void ResourceCache::OnZeroRefCount(ResourceGUID guid) {
+    
+}
+
+void ResourceCache::Evict(size_t requiredBytes) {
+    size_t released = 0;
+    
+    // Simple eviction: remove from end of LRU list
+    while (released < requiredBytes && m_lruOrder.Size() > 0) {
+        ResourceGUID guid = m_lruOrder.Back();
+        m_lruOrder.PopBack();
+        
+        auto* it = m_cache.Find(guid);
+        if (it != nullptr) {
+            m_memoryUsage -= it->memorySize;
+            released += it->memorySize;
+            it->resource->Release();
+            m_cache.Erase(guid);
+        }
+    }
+}
+
+void ResourceCache::Flush() {
+    std::lock_guard lock(m_mutex);
+    
+    // Release all resources
+    for (size_t i = 0; i < m_cache.Size(); ++i) {
+        // Would need iteration support
+    }
+    
+    m_cache.Clear();
+    m_lruOrder.Clear();
+    m_memoryUsage = 0;
+}
+
+void ResourceCache::Clear() {
+    std::lock_guard lock(m_mutex);
+    m_cache.Clear();
+    m_lruOrder.Clear();
+    m_memoryUsage = 0;
+}
+
+Containers::Array<ResourceGUID> ResourceCache::GetLRUList(size_t count) const {
+    std::lock_guard lock(m_mutex);
+    
+    Containers::Array<ResourceGUID> result;
+    size_t n = std::min(count, static_cast<size_t>(m_lruOrder.Size()));
+    
+    for (size_t i = 0; i < n; i++) {
+        result.PushBack(m_lruOrder[i]);
+    }
+    
+    return result;
+}
+
+} // namespace Resources
+} // namespace XCEngine

engine/src/Resources/ResourceManager.cpp

@@ -0,0 +1,190 @@
+#include "Resources/ResourceManager.h"
+#include "Resources/ResourceHandle.h"
+#include "Resources/ResourceTypes.h"
+
+namespace XCEngine {
+namespace Resources {
+
+ResourceManager& ResourceManager::Get() {
+    static ResourceManager instance;
+    return instance;
+}
+
+void ResourceManager::Initialize() {
+    m_asyncLoader = Core::MakeUnique<AsyncLoader>();
+    m_asyncLoader->Initialize(2);
+}
+
+void ResourceManager::Shutdown() {
+    UnloadAll();
+    m_asyncLoader->Shutdown();
+    m_asyncLoader.reset();
+}
+
+void ResourceManager::SetResourceRoot(const Containers::String& rootPath) {
+    m_resourceRoot = rootPath;
+}
+
+const Containers::String& ResourceManager::GetResourceRoot() const {
+    return m_resourceRoot;
+}
+
+void ResourceManager::AddRef(ResourceGUID guid) {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_refCounts.Find(guid);
+    if (it == nullptr) {
+        m_refCounts.Insert(guid, 1);
+    } else {
+        (*it)++;
+    }
+    
+    if (!m_resourceCache.Contains(guid)) {
+        ReloadResource(guid);
+    }
+}
+
+void ResourceManager::Release(ResourceGUID guid) {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_refCounts.Find(guid);
+    if (it != nullptr) {
+        (*it)--;
+        
+        if (*it == 0) {
+            m_refCounts.Erase(guid);
+            m_cache.OnZeroRefCount(guid);
+        }
+    }
+}
+
+Core::uint32 ResourceManager::GetRefCount(ResourceGUID guid) const {
+    auto* it = m_refCounts.Find(guid);
+    return it != nullptr ? *it : 0;
+}
+
+void ResourceManager::RegisterLoader(IResourceLoader* loader) {
+    std::lock_guard lock(m_mutex);
+    m_loaders.Insert(loader->GetResourceType(), Core::MakeUnique<IResourceLoader>(loader));
+}
+
+IResourceLoader* ResourceManager::GetLoader(ResourceType type) const {
+    auto* it = m_loaders.Find(type);
+    return it != nullptr ? it->get() : nullptr;
+}
+
+IResourceLoader* ResourceManager::FindLoader(ResourceType type) {
+    return GetLoader(type);
+}
+
+IResource* ResourceManager::FindInCache(ResourceGUID guid) {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_resourceCache.Find(guid);
+    return it != nullptr ? *it : nullptr;
+}
+
+void ResourceManager::AddToCache(ResourceGUID guid, IResource* resource) {
+    std::lock_guard lock(m_mutex);
+    
+    m_resourceCache.Insert(guid, resource);
+    m_memoryUsage += resource->GetMemorySize();
+    m_cache.Add(guid, resource);
+    
+    if (m_memoryUsage > m_memoryBudget) {
+        m_cache.OnMemoryPressure(m_memoryUsage - m_memoryBudget);
+    }
+}
+
+void ResourceManager::Unload(ResourceGUID guid) {
+    std::lock_guard lock(m_mutex);
+    
+    auto* it = m_resourceCache.Find(guid);
+    if (it != nullptr) {
+        IResource* resource = *it;
+        m_resourceCache.Erase(guid);
+        m_memoryUsage -= resource->GetMemorySize();
+        resource->Release();
+    }
+}
+
+void ResourceManager::UnloadAll() {
+    std::lock_guard lock(m_mutex);
+    
+    for (size_t i = 0; i < m_resourceCache.Size(); ++i) {
+        // This is a simplified approach - we'd need a way to iterate
+        // For now, just clear everything
+    }
+    m_resourceCache.Clear();
+    m_refCounts.Clear();
+    m_memoryUsage = 0;
+}
+
+void ResourceManager::SetMemoryBudget(size_t bytes) {
+    m_memoryBudget = bytes;
+}
+
+size_t ResourceManager::GetMemoryUsage() const {
+    return m_memoryUsage;
+}
+
+size_t ResourceManager::GetMemoryBudget() const {
+    return m_memoryBudget;
+}
+
+void ResourceManager::FlushCache() {
+    m_cache.Flush();
+}
+
+IResource* ResourceManager::Find(const Containers::String& path) {
+    return Find(ResourceGUID::Generate(path));
+}
+
+IResource* ResourceManager::Find(ResourceGUID guid) {
+    return FindInCache(guid);
+}
+
+bool ResourceManager::Exists(const Containers::String& path) const {
+    return Exists(ResourceGUID::Generate(path));
+}
+
+bool ResourceManager::Exists(ResourceGUID guid) const {
+    return m_resourceCache.Contains(guid);
+}
+
+Containers::String ResourceManager::ResolvePath(const Containers::String& relativePath) const {
+    return m_resourceRoot + "/" + relativePath;
+}
+
+void ResourceManager::LoadAsync(const Containers::String& path, ResourceType type,
+                               std::function<void(LoadResult)> callback) {
+    LoadAsync(path, type, nullptr, callback);
+}
+
+void ResourceManager::LoadAsync(const Containers::String& path, ResourceType type, 
+                               ImportSettings* settings,
+                               std::function<void(LoadResult)> callback) {
+    m_asyncLoader->Submit(path, type, settings, callback);
+}
+
+void ResourceManager::Unload(const Containers::String& path) {
+    Unload(ResourceGUID::Generate(path));
+}
+
+void ResourceManager::UnloadUnused() {
+    
+}
+
+void ResourceManager::UnregisterLoader(ResourceType type) {
+    m_loaders.Erase(type);
+}
+
+void ResourceManager::ReloadResource(ResourceGUID guid) {
+    auto* pathIt = m_guidToPath.Find(guid);
+    if (pathIt == nullptr) {
+        return;
+    }
+}
+
+} // namespace Resources
+} // namespace XCEngine

engine/src/Resources/ResourceTypes.cpp

@@ -0,0 +1,29 @@
+#include "Resources/ResourceTypes.h"
+
+namespace XCEngine {
+namespace Resources {
+
+ResourceGUID ResourceGUID::Generate(const char* path) {
+    Core::uint64 hash = 14695981039346656037ULL;
+    
+    while (*path) {
+        hash ^= static_cast<Core::uint64>(*path);
+        hash *= 1099511628211ULL;
+        path++;
+    }
+    
+    return ResourceGUID(hash);
+}
+
+ResourceGUID ResourceGUID::Generate(const Containers::String& path) {
+    return Generate(path.CStr());
+}
+
+Containers::String ResourceGUID::ToString() const {
+    char buffer[17];
+    snprintf(buffer, sizeof(buffer), "%016llx", value);
+    return Containers::String(buffer);
+}
+
+} // namespace Resources
+} // namespace XCEngine