refactor: move photomaker into generation extension (#1618)

src/extensions/generation_extension.h

@@ -0,0 +1,73 @@
+#ifndef __SD_EXTENSIONS_GENERATION_EXTENSION_H__
+#define __SD_EXTENSIONS_GENERATION_EXTENSION_H__
+
+#include <functional>
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+
+#include "conditioning/conditioner.hpp"
+#include "core/ggml_extend_backend.h"
+#include "model.h"
+#include "stable-diffusion.h"
+
+struct GenerationExtensionInitContext {
+    const sd_ctx_params_t* params;
+    SDVersion version;
+    const String2TensorStorage& tensor_storage_map;
+    ModelLoader& model_loader;
+    int n_threads;
+    std::function<bool(SDBackendModule)> ensure_backend_pair;
+    std::function<ggml_backend_t(SDBackendModule)> backend_for;
+    std::function<ggml_backend_t(SDBackendModule)> params_backend_for;
+};
+
+struct GenerationExtensionTensorContext {
+    std::map<std::string, ggml_tensor*>& tensors;
+    std::map<std::string, ggml_tensor*>& mmap_able_tensors;
+    std::function<bool(SDBackendModule)> module_can_mmap;
+};
+
+struct GenerationExtensionConditionContext {
+    Conditioner* conditioner;
+    ConditionerParams& condition_params;
+    const sd_pm_params_t& pm_params;
+    std::map<std::string, ggml_tensor*>& tensors;
+    SDVersion version;
+    int n_threads;
+    int total_steps;
+    bool free_params_immediately;
+};
+
+struct GenerationExtension {
+    virtual ~GenerationExtension() = default;
+
+    virtual const char* name() const = 0;
+    virtual bool is_enabled() const {
+        return false;
+    }
+    virtual bool init(const GenerationExtensionInitContext&) {
+        return true;
+    }
+    virtual void collect_param_tensors(GenerationExtensionTensorContext&) {}
+    virtual void add_ignore_tensors(std::set<std::string>&) const {}
+    virtual bool alloc_params_buffer() {
+        return true;
+    }
+    virtual size_t get_params_buffer_size() const {
+        return 0;
+    }
+    virtual void reset_runtime_condition() {}
+    virtual bool prepare_condition(GenerationExtensionConditionContext&) {
+        return false;
+    }
+    virtual const SDCondition& before_condition(int step,
+                                                const SDCondition& condition) const {
+        return condition;
+    }
+};
+
+std::shared_ptr<GenerationExtension> create_photomaker_extension();
+
+#endif