Method llama_context

subprojects/llama.cpp/src/llama-context.cpp:21–358

//

llama_context::llama_context(
        const llama_model & model,
              llama_context_params params) :
    model(model),
    balloc(std::make_unique<llama_batch_allocr>(model.hparams.n_pos_per_embd())) {
    // TODO warning when creating llama_context with awkward ctx size that is not a power of 2,
    //     may need to be backend-dependent
    LLAMA_LOG_INFO("%s: constructing llama_context\n", __func__);

    t_start_us = model.t_start_us;
    t_load_us  = model.t_load_us;

    const auto & hparams = model.hparams;

    cparams.n_seq_max = std::max(1u, params.n_seq_max);
    if (cparams.n_seq_max > LLAMA_MAX_SEQ) {
        throw std::runtime_error("n_seq_max must be <= " + std::to_string(LLAMA_MAX_SEQ));
    }

    cparams.n_threads        = params.n_threads;
    cparams.n_threads_batch  = params.n_threads_batch;
    cparams.yarn_ext_factor  = params.yarn_ext_factor  >= 0.0f ? params.yarn_ext_factor  : hparams.yarn_ext_factor;
    cparams.yarn_attn_factor = params.yarn_attn_factor >= 0.0f ? params.yarn_attn_factor : hparams.yarn_attn_factor;
    cparams.yarn_beta_fast   = params.yarn_beta_fast   >= 0.0f ? params.yarn_beta_fast   : hparams.yarn_beta_fast;
    cparams.yarn_beta_slow   = params.yarn_beta_slow   >= 0.0f ? params.yarn_beta_slow   : hparams.yarn_beta_slow;
    cparams.embeddings       = params.embeddings;
    cparams.offload_kqv      = params.offload_kqv;
    cparams.no_perf          = params.no_perf;
    cparams.pooling_type     = params.pooling_type;
    cparams.warmup           = false;

    cparams.n_ctx            = params.n_ctx           == 0    ? hparams.n_ctx_train           : params.n_ctx;
    cparams.rope_freq_base   = params.rope_freq_base  == 0.0f ? hparams.rope_freq_base_train  : params.rope_freq_base;
    cparams.rope_freq_scale  = params.rope_freq_scale == 0.0f ? hparams.rope_freq_scale_train : params.rope_freq_scale;

    cparams.n_ctx_orig_yarn  = params.yarn_orig_ctx    != 0 ? params.yarn_orig_ctx    :
                               hparams.n_ctx_orig_yarn != 0 ? hparams.n_ctx_orig_yarn :
                                                              hparams.n_ctx_train;

    cparams.cb_eval           = params.cb_eval;
    cparams.cb_eval_user_data = params.cb_eval_user_data;

    // Initialize backend samplers here so they are part of the sampling graph
    // before the reserve passes run later in this function. This avoids a later
    // re-reserve when graph nodes change.
    if (params.samplers != nullptr && params.n_samplers > 0) {
        for (size_t i = 0; i < params.n_samplers; ++i) {
            const auto & config = params.samplers[i];

            if (llama_sampler_chain_get(config.sampler, -1) == nullptr) {
                throw std::runtime_error("the backend samplers must be of type llama_sampler_chain");
            }

            if (set_sampler(config.seq_id, config.sampler)) {
                const int n_samplers = llama_sampler_chain_n(config.sampler);

                LLAMA_LOG_INFO("%s: setting backend sampler for seq_id %d (n = %d)\n", __func__, config.seq_id, n_samplers);
            }