Function query_backend_memory

src/framework/core/backend.cpp:247–296

    BackendMemorySnapshot snapshot;
    if (backend == nullptr) {
        return snapshot;
    }
    ggml_backend_dev_t device = ggml_backend_get_device(backend);
    if (device != nullptr) {
        size_t free_bytes = 0;
        size_t total_bytes = 0;
        ggml_backend_dev_memory(device, &free_bytes, &total_bytes);
        if (total_bytes > 0 && free_bytes <= total_bytes) {
            snapshot.available = true;
            snapshot.total_bytes = static_cast<int64_t>(total_bytes);
            snapshot.free_bytes = static_cast<int64_t>(free_bytes);
            snapshot.used_bytes = static_cast<int64_t>(total_bytes - free_bytes);
        }
    }
    (void)device_hint;
    return snapshot;
}

BackendMemorySnapshot query_backend_memory(const BackendConfig & config) {
    BackendMemorySnapshot snapshot;
    switch (config.type) {
        case BackendType::Cpu:
            return snapshot;
        case BackendType::BestAvailable:
            return snapshot;
        default:
            break;
    }
    ggml_backend_dev_t device = find_device_by_backend_type(config.type, config.device);
    if (device != nullptr) {
        size_t free_bytes = 0;
        size_t total_bytes = 0;
        ggml_backend_dev_memory(device, &free_bytes, &total_bytes);
        if (total_bytes > 0 && free_bytes <= total_bytes) {
            snapshot.available = true;
            snapshot.total_bytes = static_cast<int64_t>(total_bytes);
            snapshot.free_bytes = static_cast<int64_t>(free_bytes);
            snapshot.used_bytes = static_cast<int64_t>(total_bytes - free_bytes);
        }
    }
    return snapshot;
}

ggml_backend_graph_plan_t create_backend_graph_plan_if_host(ggml_backend_t backend, ggml_cgraph * graph) {
    if (backend == nullptr || graph == nullptr || !is_host_backend(backend)) {
        return nullptr;
    }
    return ggml_backend_graph_plan_create(backend, graph);
}

void free_backend_graph_plan(ggml_backend_t backend, ggml_backend_graph_plan_t & plan) {
    if (plan != nullptr) {
        ggml_backend_graph_plan_free(backend, plan);