Another qfengine graft: resource management

DECOPYPASTA DECOPYPASTA DECOPYPASTA DECOPYPASTA

1 files changed, 129 insertions, 0 deletions

diff --git a/core/resource/resource.cc b/core/resource/resource.cc
new file mode 100644
index 0000000..600843f
--- /dev/null
+++ b/core/resource/resource.cc
@@ -0,0 +1,129 @@
+#include "core/pch.hh"
+
+#include "core/resource/resource.hh"
+
+struct ResourceLoader final {
+    ResourceLoadFunc load_func;
+    ResourceFreeFunc free_func;
+    emhash8::HashMap<std::string, std::shared_ptr<const void>> resources;
+    std::vector<std::shared_ptr<const void>> cache;
+    std::string class_name;
+};
+
+namespace
+{
+emhash8::HashMap<std::type_index, std::unique_ptr<ResourceLoader>> loaders;
+} // namespace
+
+void resource::detail::register_loader(const std::type_info& type, ResourceLoadFunc load_func, ResourceFreeFunc free_func)
+{
+    assert(load_func);
+    assert(free_func);
+
+    auto type_index = std::type_index(type);
+    auto loader = std::make_unique<ResourceLoader>();
+    loader->class_name = type.name();
+    loader->load_func = load_func;
+    loader->free_func = free_func;
+
+    assert(!loaders.contains(type_index));
+
+    loaders.insert_or_assign(type_index, std::move(loader));
+}
+
+std::shared_ptr<const void> resource::detail::load_resource(const std::type_info& type, std::string_view name, std::uint32_t flags)
+{
+    auto name_str = std::string(name);
+    auto type_index = std::type_index(type);
+    auto loader = loaders.find(type_index);
+
+    if(loader == loaders.cend()) {
+        spdlog::error("resource: no loader registered for type [{}]", type.name());
+        return nullptr;
+    }
+
+    auto resource_it = loader->second->resources.find(name_str);
+
+    if(resource_it == loader->second->resources.cend()) {
+        auto resource_raw = loader->second->load_func(name_str.c_str(), flags);
+
+        if(resource_raw == nullptr) {
+            spdlog::error("resource: {} [{}]: load failed", loader->second->class_name, name);
+            return nullptr;
+        }
+
+        std::shared_ptr<const void> resource_ptr(resource_raw, [](const void* ptr) { /* empty */ });
+        auto loaded_it = loader->second->resources.insert_or_assign(name_str, std::move(resource_ptr));
+
+        if(flags & RESOURCE_CACHE) {
+            loader->second->cache.push_back(loaded_it.first->second);
+        }
+
+        return loaded_it.first->second;
+    }
+
+    return resource_it->second;
+}
+
+std::shared_ptr<const void> resource::detail::find_resource(const std::type_info& type, std::string_view name)
+{
+    auto name_str = std::string(name);
+    auto type_index = std::type_index(type);
+    auto loader = loaders.find(type_index);
+
+    if(loader == loaders.cend()) {
+        spdlog::error("resource: no loader registered for type [{}]", type.name());
+        return nullptr;
+    }
+
+    auto resource_it = loader->second->resources.find(name_str);
+
+    if(resource_it == loader->second->resources.cend()) {
+        spdlog::error("resource: {} [{}]: not found", loader->second->class_name, name);
+        return nullptr;
+    }
+
+    return resource_it->second;
+}
+
+void resource::hard_cleanup(void)
+{
+    for(auto& [type_index, loader] : loaders) {
+        loader->cache.clear();
+
+        for(auto& [name, resource_ptr] : loader->resources) {
+            if(resource_ptr.use_count() > 1) {
+                spdlog::warn("resource: zombie resource: {} [{}] [use_count={}]", name, loader->class_name, resource_ptr.use_count());
+            }
+            else {
+                spdlog::debug("resource: releasing {} [{}]", name, loader->class_name);
+            }
+
+            loader->free_func(resource_ptr.get());
+        }
+
+        loader->resources.clear();
+    }
+
+    loaders.clear();
+}
+
+void resource::soft_cleanup(void)
+{
+    for(auto& [type_index, loader] : loaders) {
+        auto resource_it = loader->resources.begin();
+
+        while(resource_it != loader->resources.end()) {
+            if(resource_it->second.use_count() <= 1) {
+                spdlog::debug("resource: releasing {} [{}]", resource_it->first, loader->class_name);
+
+                loader->free_func(resource_it->second.get());
+                resource_it = loader->resources.erase(resource_it);
+
+                continue;
+            }
+
+            resource_it = std::next(resource_it);
+        }
+    }
+}