text-generation-inference/backends/llamacpp/csrc/backend.cpp

//
// Created by Morgan Funtowicz on 9/28/2024.
//

#include <arg.h>
#include <common.h>
#include <fmt/format.h>
#include <spdlog/spdlog.h>
#include "backend.hpp"

namespace huggingface::tgi::backends::llama {

    std::unique_ptr<huggingface::tgi::backends::llama::TgiLlamaCppBackend>
    CreateLlamaCppBackend(std::string_view root) {
        SPDLOG_INFO(FMT_STRING("Loading model from {}"), root);
        gpt_init();

        // Fake argv
        std::vector<std::string_view> args = {"tgi_llama_cpp_backend", "--model", root};
        std::vector<char *> argv;
        for (const auto &arg: args) {
            argv.push_back(const_cast<char *>(arg.data()));
        }
        argv.push_back(nullptr);

        // Create the GPT parameters
        gpt_params params;
        if (!gpt_params_parse(args.size(), argv.data(), params, LLAMA_EXAMPLE_SERVER)) {
            throw std::runtime_error("Failed to create GPT Params from model");
        }


        // Create the inference engine
        SPDLOG_INFO("Allocating llama.cpp model from gpt_params");
        auto result = llama_init_from_gpt_params(params);

        // Unpack all the inference engine components
        auto model = result.model;
        auto context = result.context;
        auto loras = result.lora_adapters;

        // Make sure everything is correctly initialized
        if (model == nullptr)
            throw std::runtime_error(fmt::format("Failed to load model from {}", root));

        return std::make_unique<huggingface::tgi::backends::llama::TgiLlamaCppBackend>(model, context);
    }

    huggingface::tgi::backends::llama::TgiLlamaCppBackend::TgiLlamaCppBackend(llama_model *const model,
                                                                              llama_context *const ctx)
            : model(model), ctx(ctx), batch() {
        char modelName[128];
        llama_model_meta_val_str(model, "general.name", modelName, sizeof(modelName));
        SPDLOG_DEBUG(FMT_STRING("Created llama.cpp backend for model: '{}'"), std::string_view(modelName));
    }

    huggingface::tgi::backends::llama::TgiLlamaCppBackend::~TgiLlamaCppBackend() {
        if (model) {
            SPDLOG_DEBUG("Freeing llama.cpp model");
            llama_free_model(model);
        }

        if (ctx) {
            SPDLOG_DEBUG("Freeing llama.cpp context");
            llama_free(ctx);
        }
    }

    void huggingface::tgi::backends::llama::TgiLlamaCppBackend::schedule() {
        std::vector<llama_token> tokens;
    }

    namespace impl {
        class LlamaCppBackendImpl {

        };
    }
}