server-context.cpp

#include "server-context.h"
#include "server-common.h"
#include "server-http.h"
#include "server-task.h"
#include "server-queue.h"

#include "arg.h"
#include "common.h"
#include "llama.h"
#include "log.h"
#include "sampling.h"
#include "speculative.h"
#include "mtmd.h"
#include "mtmd-helper.h"

#include <cstddef>
#include <cinttypes>
#include <memory>
#include <unordered_set>
#include <filesystem>

// fix problem with std::min and std::max
#if defined(_WIN32)
#define WIN32_LEAN_AND_MEAN
#ifndef NOMINMAX
# define NOMINMAX
#endif
#include <windows.h>
#endif

using json = nlohmann::ordered_json;

constexpr int HTTP_POLLING_SECONDS = 1;

// state diagram: https://github.com/ggml-org/llama.cpp/pull/9283
enum slot_state {
 SLOT_STATE_IDLE,
 SLOT_STATE_STARTED, // TODO: this state is only used for setting up the initial prompt processing; maybe merge it with launch_slot_with_task in the future
 SLOT_STATE_PROCESSING_PROMPT,
 SLOT_STATE_DONE_PROMPT,
 SLOT_STATE_GENERATING,
};

enum server_state {
 SERVER_STATE_LOADING_MODEL, // Server is starting up, model not fully loaded yet
 SERVER_STATE_READY, // Server is ready and model is loaded
};

static bool server_task_type_need_embd(server_task_type task_type) {
 switch (task_type) {
 case SERVER_TASK_TYPE_EMBEDDING:
 case SERVER_TASK_TYPE_RERANK:
 return true;
 default:
 return false;
 }
}

static bool server_task_type_need_logits(server_task_type task_type) {
 switch (task_type) {
 case SERVER_TASK_TYPE_COMPLETION:
 case SERVER_TASK_TYPE_INFILL:
 return true;
 default:
 return false;
 }
}

struct server_slot {
 int id;

 llama_batch batch_spec = {};

 // TODO: change to unique_ptrs for consistency:
 llama_context * ctx = nullptr;
 llama_context * ctx_dft = nullptr;

 // multimodal
 mtmd_context * mctx = nullptr;

 common_speculative * spec = nullptr;

 std::unique_ptr<const server_task> task;
 std::unique_ptr<const server_task> task_prev; // used for debugging

 // used to determine the slot that has been used the longest
 int64_t t_last_used = -1;

 // generation props
 int32_t n_ctx = 0; // context size per slot
 int32_t n_keep = 0;
 int32_t n_decoded = 0;
 int32_t n_remaining = -1;
 int32_t i_batch = -1;

 int32_t n_prompt_tokens_cache = 0;
 int32_t n_prompt_tokens_processed = 0;

 size_t last_nl_pos = 0;

 std::string generated_text;
 llama_tokens generated_tokens;

 common_chat_msg chat_msg;

 std::vector<completion_token_output> generated_token_probs;

 bool has_next_token = true;
 bool has_new_line = false;
 bool truncated = false;

 stop_type stop;

 std::string stopping_word;

 // state
 slot_state state = SLOT_STATE_IDLE;

 server_prompt prompt;

 void prompt_save(server_prompt_cache & prompt_cache) const {
 GGML_ASSERT(prompt.data.size() == 0);

 const size_t cur_size = llama_state_seq_get_size_ext(ctx, id, 0);

 SRV_WRN(" - saving prompt with length %d, total state size = %.3f MiB\n",
 (int) prompt.tokens.size(), cur_size / (1024.0 * 1024.0));

 auto * cur = prompt_cache.alloc(prompt, cur_size);
 if (cur == nullptr) {
 return;
 }

 llama_state_seq_get_data_ext(ctx, cur->data.data(), cur_size, id, 0);
 }

 bool prompt_load(server_prompt_cache & prompt_cache, const server_tokens & tokens) {
 bool res = prompt_cache.load(prompt, tokens, ctx, id);
 if (!res) {
 SLT_WRN(*this, "%s", "failed to load prompt from cache\n");
 }

 return res;
 }

 std::vector<common_adapter_lora_info> lora;
 int32_t alora_invocation_start = -1;

 // sampling
 json json_schema;

 struct common_sampler * smpl = nullptr;

 llama_token sampled;

 common_chat_format chat_format = COMMON_CHAT_FORMAT_CONTENT_ONLY;
 std::vector<std::string> generated_tool_call_ids;

 // stats
 size_t n_sent_text = 0; // number of sent text character

 int64_t t_start_process_prompt;
 int64_t t_start_generation;

 double t_prompt_processing; // ms
 double t_token_generation; // ms

 std::function<void(int)> callback_on_release;

 // Speculative decoding stats
 int32_t n_draft_total = 0; // Total draft tokens generated
 int32_t n_draft_accepted = 0; // Draft tokens actually accepted

 void reset() {
 SLT_DBG(*this, "%s", "\n");

 n_prompt_tokens_cache = 0;

 last_nl_pos = 0;
 generated_text = "";
 has_new_line = false;
 truncated = false;
 stop = STOP_TYPE_NONE;
 stopping_word = "";
 n_sent_text = 0;
 chat_format = COMMON_CHAT_FORMAT_CONTENT_ONLY;

 generated_tokens.clear();
 generated_token_probs.clear();
 chat_msg = {};
 json_schema = json();
 generated_tool_call_ids.clear();

 // clear speculative decoding stats
 n_draft_total = 0;
 n_draft_accepted = 0;

 task.reset();
 task_prev.reset();

 // clear alora start
 alora_invocation_start = -1;
 }

 bool need_embd() const {
 GGML_ASSERT(task);

 return server_task_type_need_embd(task->type);
 }

 bool need_logits() const {
 GGML_ASSERT(task);

 return server_task_type_need_logits(task->type);
 }

 // if the context does not have a memory module then all embeddings have to be computed within a single ubatch
 // also we cannot split if the pooling would require any past tokens
 bool can_split() const {
 return
 !need_embd() ||
 (llama_get_memory(ctx) && llama_pooling_type(ctx) == LLAMA_POOLING_TYPE_LAST);
 }

 bool can_batch_with(server_slot & other_slot) const {
 GGML_ASSERT(task);

 return task->type == other_slot.task->type && are_lora_equal(lora, other_slot.lora);
 }

 bool has_budget(const common_params & global_params) {
 GGML_ASSERT(task);

 if (task->params.n_predict == -1 && global_params.n_predict == -1) {
 return true; // limitless
 }

 n_remaining = -1;

 if (task->params.n_predict != -1) {
 n_remaining = task->params.n_predict - n_decoded;
 } else if (global_params.n_predict != -1) {
 n_remaining = global_params.n_predict - n_decoded;
 }

 return n_remaining > 0; // no budget
 }

 bool is_processing() const {
 return state != SLOT_STATE_IDLE;
 }

 bool can_speculate() const {
 return ctx_dft;
 }

 void add_token(const completion_token_output & token) {
 if (!is_processing()) {
 SLT_WRN(*this, "%s", "slot is not processing\n");
 return;
 }
 generated_token_probs.push_back(token);
 }

 void release() {
 if (is_processing()) {
 GGML_ASSERT(task);

 SLT_INF(*this, "stop processing: n_tokens = %d, truncated = %d\n", prompt.n_tokens(), truncated);

 t_last_used = ggml_time_us();
 t_token_generation = (ggml_time_us() - t_start_generation) / 1e3;
 state = SLOT_STATE_IDLE;

 task_prev = std::move(task);
 task.reset();

 callback_on_release(id);
 }
 }

 result_timings get_timings() const {
 result_timings timings;
 timings.cache_n = n_prompt_tokens_cache;

 timings.prompt_n = n_prompt_tokens_processed;
 timings.prompt_ms = t_prompt_processing;
 timings.prompt_per_token_ms = t_prompt_processing / n_prompt_tokens_processed;
 timings.prompt_per_second = 1e3 / t_prompt_processing * n_prompt_tokens_processed;

 timings.predicted_n = n_decoded;
 timings.predicted_ms = t_token_generation;
 timings.predicted_per_token_ms = t_token_generation / n_decoded;
 timings.predicted_per_second = 1e3 / t_token_generation * n_decoded;

 // Add speculative metrics
 if (n_draft_total > 0) {
 timings.draft_n = n_draft_total;
 timings.draft_n_accepted = n_draft_accepted;
 }

 return timings;
 }

 const common_chat_msg & update_chat_msg(std::vector<common_chat_msg_diff> & diffs) {
 GGML_ASSERT(task);

 auto previous_msg = chat_msg;
 SRV_DBG("Parsing chat message: %s\n", generated_text.c_str());
 auto new_msg = common_chat_parse(
 generated_text,
 /* is_partial= */ stop != STOP_TYPE_EOS,
 task->params.oaicompat_chat_syntax);
 if (!new_msg.empty()) {
 new_msg.set_tool_call_ids(generated_tool_call_ids, gen_tool_call_id);
 chat_msg = new_msg;
 diffs = common_chat_msg_diff::compute_diffs(previous_msg, new_msg.empty() ? previous_msg : new_msg);
 }
 return chat_msg;
 }

 size_t find_stopping_strings(const std::string & text, const size_t last_token_size, bool is_full_stop) {
 GGML_ASSERT(task);

 size_t stop_pos = std::string::npos;

 for (const std::string & word : task->params.antiprompt) {
 size_t pos;

 if (is_full_stop) {
 const size_t tmp = word.size() + last_token_size;
 const size_t from_pos = text.size() > tmp ? text.size() - tmp : 0;

 pos = text.find(word, from_pos);
 } else {
 // otherwise, partial stop
 pos = string_find_partial_stop(text, word);
 }

 if (pos != std::string::npos && (stop_pos == std::string::npos || pos < stop_pos)) {
 if (is_full_stop) {
 stop = STOP_TYPE_WORD;
 stopping_word = word;
 has_next_token = false;
 }
 stop_pos = pos;
 }
 }

 return stop_pos;
 }

 void print_timings() const {
 const double t_prompt = t_prompt_processing / n_prompt_tokens_processed;
 const double n_prompt_second = 1e3 / t_prompt_processing * n_prompt_tokens_processed;

 const double t_gen = t_token_generation / n_decoded;
 const double n_gen_second = 1e3 / t_token_generation * n_decoded;

 SLT_INF(*this,
 "\n"
 "prompt eval time = %10.2f ms / %5d tokens (%8.2f ms per token, %8.2f tokens per second)\n"
 " eval time = %10.2f ms / %5d tokens (%8.2f ms per token, %8.2f tokens per second)\n"
 " total time = %10.2f ms / %5d tokens\n",
 t_prompt_processing, n_prompt_tokens_processed, t_prompt, n_prompt_second,
 t_token_generation, n_decoded, t_gen, n_gen_second,
 t_prompt_processing + t_token_generation, n_prompt_tokens_processed + n_decoded);

 if (n_draft_total > 0) {
 const float draft_ratio = (float) n_draft_accepted / n_draft_total;
 SLT_INF(*this,
 "\n"
 "draft acceptance rate = %0.5f (%5d accepted / %5d generated)\n",
 draft_ratio, n_draft_accepted, n_draft_total
 );
 }
 }

 json to_json(bool only_metrics = false) const {
 json res;

 res = {
 {"id", id},
 {"n_ctx", n_ctx},
 {"speculative", can_speculate()},
 {"is_processing", is_processing()},
 };

 const auto & ptask = task ? task : task_prev;

 if (ptask) {
 res["id_task"] = ptask->id;
 res["params"] = ptask->params.to_json(only_metrics);
 res["next_token"] = {
 {
 {"has_next_token", has_next_token},
 {"has_new_line", has_new_line},
 {"n_remain", n_remaining},
 {"n_decoded", n_decoded},
 }
 };

 if (!only_metrics) {
 res["prompt"] = ptask->tokens.detokenize(ctx, true);
 res["generated"] = generated_text;
 }
 }

 return res;
 }
};



//
// server_metrics
//

struct server_metrics {
 int64_t t_start = 0;

 uint64_t n_prompt_tokens_processed_total = 0;
 uint64_t t_prompt_processing_total = 0;
 uint64_t n_tokens_predicted_total = 0;
 uint64_t t_tokens_generation_total = 0;

 uint64_t n_tokens_max = 0;

 uint64_t n_prompt_tokens_processed = 0;
 uint64_t t_prompt_processing = 0;

 uint64_t n_tokens_predicted = 0;
 uint64_t t_tokens_generation = 0;

 uint64_t n_decode_total = 0;
 uint64_t n_busy_slots_total = 0;

 void init() {
 t_start = ggml_time_us();
 }

 void on_prompt_eval(const server_slot & slot) {
 n_prompt_tokens_processed_total += slot.n_prompt_tokens_processed;
 n_prompt_tokens_processed += slot.n_prompt_tokens_processed;
 t_prompt_processing += slot.t_prompt_processing;
 t_prompt_processing_total += slot.t_prompt_processing;

 n_tokens_max = std::max(n_tokens_max, (uint64_t) slot.prompt.n_tokens());
 }

 void on_prediction(const server_slot & slot) {
 n_tokens_predicted_total += slot.n_decoded;
 n_tokens_predicted += slot.n_decoded;
 t_tokens_generation += slot.t_token_generation;
 t_tokens_generation_total += slot.t_token_generation;
 }

 void on_decoded(const std::vector<server_slot> & slots) {
 n_decode_total++;
 for (const auto & slot : slots) {
 if (slot.is_processing()) {
 n_busy_slots_total++;
 }
 n_tokens_max = std::max(n_tokens_max, (uint64_t) slot.prompt.n_tokens());
 }
 }

 void reset_bucket() {
 n_prompt_tokens_processed = 0;
 t_prompt_processing = 0;
 n_tokens_predicted = 0;
 t_tokens_generation = 0;
 }
};


//
// server_context_impl (private implementation)
//

struct server_context_impl {
 common_params params_base;

 // note: keep these alive - they determine the lifetime of the model, context, etc.
 common_init_result llama_init;
 common_init_result llama_init_dft;

 llama_model * model = nullptr;
 llama_context * ctx = nullptr;

 // multimodal
 mtmd_context * mctx = nullptr;

 const llama_vocab * vocab = nullptr;
 bool vocab_dft_compatible = true;

 llama_model * model_dft = nullptr;

 llama_context_params cparams_dft;

 llama_batch batch {};

 bool add_bos_token = true;

 int32_t n_ctx; // total context for all clients / slots

 // slots / clients
 std::vector<server_slot> slots;

 int slots_debug = 0;

 server_queue queue_tasks;
 server_response queue_results;

 std::unique_ptr<server_prompt_cache> prompt_cache;

 server_metrics metrics;

 // Necessary similarity of prompt for slot selection
 float slot_prompt_similarity = 0.0f;

 std::string model_name; // name of the loaded model, to be used by API

 common_chat_templates_ptr chat_templates;
 oaicompat_parser_options oai_parser_opt;

 ~server_context_impl() {
 mtmd_free(mctx);

 // Clear any sampling context
 for (server_slot & slot : slots) {
 common_sampler_free(slot.smpl);
 slot.smpl = nullptr;

 llama_free(slot.ctx_dft);
 slot.ctx_dft = nullptr;

 common_speculative_free(slot.spec);
 slot.spec = nullptr;

 llama_batch_free(slot.batch_spec);
 }

 llama_batch_free(batch);
 }

 // load the model and initialize llama_context
 bool load_model(const common_params & params) {
 SRV_INF("loading model '%s'\n", params.model.path.c_str());

 params_base = params;

 llama_init = common_init_from_params(params_base);

 model = llama_init.model.get();
 ctx = llama_init.context.get();

 if (model == nullptr) {
 SRV_ERR("failed to load model, '%s'\n", params_base.model.path.c_str());
 return false;
 }

 vocab = llama_model_get_vocab(model);

 n_ctx = llama_n_ctx(ctx);

 add_bos_token = llama_vocab_get_add_bos(vocab);

 if (params_base.has_speculative()) {
 SRV_INF("loading draft model '%s'\n", params_base.speculative.model.path.c_str());

 auto params_dft = params_base;

 params_dft.devices = params_base.speculative.devices;
 params_dft.model = params_base.speculative.model;
 params_dft.n_ctx = params_base.speculative.n_ctx == 0 ? llama_n_ctx_seq(ctx) : params_base.speculative.n_ctx;
 params_dft.n_gpu_layers = params_base.speculative.n_gpu_layers;
 params_dft.n_parallel = 1;
 params_dft.cache_type_k = params_base.speculative.cache_type_k;
 params_dft.cache_type_v = params_base.speculative.cache_type_v;

 params_dft.cpuparams.n_threads = params_base.speculative.cpuparams.n_threads;
 params_dft.cpuparams_batch.n_threads = params_base.speculative.cpuparams_batch.n_threads;
 params_dft.tensor_buft_overrides = params_base.speculative.tensor_buft_overrides;

 llama_init_dft = common_init_from_params(params_dft);

 model_dft = llama_init_dft.model.get();

 if (model_dft == nullptr) {
 SRV_ERR("failed to load draft model, '%s'\n", params_base.speculative.model.path.c_str());
 return false;
 }

 vocab_dft_compatible = common_speculative_are_compatible(ctx, llama_init_dft.context.get());
 if (!vocab_dft_compatible) {
 SRV_INF("the draft model '%s' is not compatible with the target model '%s'. tokens will be translated between the draft and target models.\n", params_base.speculative.model.path.c_str(), params_base.model.path.c_str());
 }

 const int n_ctx_dft = llama_n_ctx(llama_init_dft.context.get());

 cparams_dft = common_context_params_to_llama(params_dft);
 cparams_dft.n_batch = n_ctx_dft;

 // the context is not needed - we will create one for each slot
 llama_init_dft.context.reset();
 }

 chat_templates = common_chat_templates_init(model, params_base.chat_template);
 try {
 common_chat_format_example(chat_templates.get(), params.use_jinja, params.default_template_kwargs);
 } catch (const std::exception & e) {
 SRV_WRN("%s: Chat template parsing error: %s\n", __func__, e.what());
 SRV_WRN("%s: The chat template that comes with this model is not yet supported, falling back to chatml. This may cause the model to output suboptimal responses\n", __func__);
 chat_templates = common_chat_templates_init(model, "chatml");
 }

 std::string & mmproj_path = params_base.mmproj.path;
 if (!mmproj_path.empty()) {
 mtmd_helper_log_set(common_log_default_callback, nullptr);

 mtmd_context_params mparams = mtmd_context_params_default();
 mparams.use_gpu = params_base.mmproj_use_gpu;
 mparams.print_timings = false;
 mparams.n_threads = params_base.cpuparams.n_threads;
 mparams.flash_attn_type = params_base.flash_attn_type;
 mparams.warmup = params_base.warmup;
 mparams.image_min_tokens = params_base.image_min_tokens;
 mparams.image_max_tokens = params_base.image_max_tokens;
 mctx = mtmd_init_from_file(mmproj_path.c_str(), model, mparams);
 if (mctx == nullptr) {
 SRV_ERR("failed to load multimodal model, '%s'\n", mmproj_path.c_str());
 return false;
 }
 SRV_INF("loaded multimodal model, '%s'\n", mmproj_path.c_str());

 if (params_base.ctx_shift) {
 params_base.ctx_shift = false;
 SRV_WRN("%s\n", "ctx_shift is not supported by multimodal, it will be disabled");
 }

 if (params_base.n_cache_reuse) {
 params_base.n_cache_reuse = 0;
 SRV_WRN("%s\n", "cache_reuse is not supported by multimodal, it will be disabled");
 }

 if (params_base.has_speculative()) {
 SRV_ERR("%s\n", "err: speculative decode is not supported by multimodal");
 return false;
 }
 }

 if (!llama_memory_can_shift(llama_get_memory(ctx))) {
 if (params_base.ctx_shift) {
 params_base.ctx_shift = false;
 SRV_WRN("%s\n", "ctx_shift is not supported by this context, it will be disabled");
 }

 if (params_base.n_cache_reuse) {
 params_base.n_cache_reuse = 0;
 SRV_WRN("%s\n", "cache_reuse is not supported by this context, it will be disabled");
 }
 }

 return true;
 }

 // initialize slots and server-related data
 void init() {
 // wiring up server queues
 queue_tasks.on_new_task([this](server_task && task) {
 process_single_task(std::move(task));
 });
 queue_tasks.on_update_slots([this]() {
 update_slots();
 });

 // Necessary similarity of prompt for slot selection
 slot_prompt_similarity = params_base.slot_prompt_similarity;

 // setup slots
 SRV_INF("initializing slots, n_slots = %d\n", params_base.n_parallel);

 const int n_ctx_train = llama_model_n_ctx_train(model);

 int n_ctx_slot = llama_n_ctx_seq(ctx);
 if (n_ctx_slot > n_ctx_train) {
 SRV_WRN("the slot context (%d) exceeds the training context of the model (%d) - capping\n", n_ctx_slot, n_ctx_train);
 n_ctx_slot = n_ctx_train;
 }

 for (int i = 0; i < params_base.n_parallel; i++) {
 server_slot slot;

 slot.id = i;
 slot.ctx = ctx;
 slot.n_ctx = n_ctx_slot;
 slot.mctx = mctx;
 slot.prompt.tokens.has_mtmd = mctx != nullptr;

 if (model_dft) {
 slot.batch_spec = llama_batch_init(params_base.speculative.n_max + 1, 0, 1);

 // TODO: rework speculative decoding [TAG_SERVER_SPEC_REWORK]
 slot.ctx_dft = llama_init_from_model(model_dft, cparams_dft);
 if (slot.ctx_dft == nullptr) {
 SRV_ERR("%s", "failed to create draft context\n");
 return;
 }

 slot.spec = common_speculative_init(slot.ctx, slot.ctx_dft);
 if (slot.spec == nullptr) {
 SRV_ERR("%s", "failed to create speculator\n");
 return;
 }
 for (auto & pair : params_base.speculative.replacements) {
 common_speculative_add_replacement_tgt_dft(slot.spec, pair.first.c_str(), pair.second.c_str());
 }
 }

 SLT_INF(slot, "new slot, n_ctx = %d\n", slot.n_ctx);

 slot.callback_on_release = [this](int) {
 queue_tasks.pop_deferred_task();
 };

 slot.reset();

 slots.push_back(std::move(slot));
 }

 {
 const char * LLAMA_SERVER_SLOTS_DEBUG = getenv("LLAMA_SERVER_SLOTS_DEBUG");
 slots_debug = LLAMA_SERVER_SLOTS_DEBUG ? atoi(LLAMA_SERVER_SLOTS_DEBUG) : 0;

 if (slots_debug) {
 SRV_WRN("slots debug = %d\n", slots_debug);
 }
 }

 // the update_slots() logic will always submit a maximum of n_batch or n_parallel tokens
 // note that n_batch can be > n_ctx (e.g. for non-causal attention models such as BERT where the KV cache is not used)
 {
 const int32_t n_batch = llama_n_batch(ctx);
 batch = llama_batch_init(std::max(n_batch, params_base.n_parallel), 0, 1);
 }

 metrics.init();

 if (params_base.cache_ram_mib != 0) {
 if (params_base.cache_ram_mib < 0) {
 SRV_WRN("prompt cache is enabled, size limit: %s\n", "no limit");
 } else {
 SRV_WRN("prompt cache is enabled, size limit: %d MiB\n", params_base.cache_ram_mib);
 }
 SRV_WRN("%s", "use `--cache-ram 0` to disable the prompt cache\n");

 prompt_cache = std::make_unique<server_prompt_cache>(params_base.cache_ram_mib, n_ctx);
 } else {
 SRV_WRN("%s", "prompt cache is disabled - use `--cache-ram N` to enable it\n");
 }
 SRV_WRN("%s", "for more info see https://github.com/ggml-org/llama.cpp/pull/16391\n");

 if (!params_base.model_alias.empty()) {
 // user explicitly specified model name
 model_name = params_base.model_alias;
 } else if (!params_base.model.name.empty()) {
 // use model name in registry format (for models in cache)
 model_name = params_base.model.name;
 } else {
 // fallback: derive model name from file name
 auto model_path = std::filesystem::path(params_base.model.path);
 model_name = model_path.filename().string();
 }

 // thinking is enabled if:
 // 1. It's not explicitly disabled (reasoning_budget == 0)
 // 2. The chat template supports it
 const bool enable_thinking = params_base.use_jinja && params_base.reasoning_budget != 0 && common_chat_templates_support_enable_thinking(chat_templates.get());
 SRV_INF("thinking = %d\n", enable_thinking);

 oai_parser_opt = {
 /* use_jinja */ params_base.use_jinja,
 /* prefill_assistant */ params_base.prefill_assistant,
 /* reasoning_format */ params_base.reasoning_format,
 /* chat_template_kwargs */ params_base.default_template_kwargs,
 /* common_chat_templates */ chat_templates.get(),
 /* allow_image */ mctx ? mtmd_support_vision(mctx) : false,
 /* allow_audio */ mctx ? mtmd_support_audio (mctx) : false,
 /* enable_thinking */ enable_thinking,
 /* media_path */ params_base.media_path,
 };

 // print sample chat example to make it clear which template is used
 LOG_INF("%s: chat template, chat_template: %s, example_format: '%s'\n", __func__,
 common_chat_templates_source(chat_templates.get()),
 common_chat_format_example(chat_templates.get(), params_base.use_jinja, params_base.default_template_kwargs).c_str());
 }

 server_slot * get_slot_by_id(int id) {
 for (server_slot & slot : slots) {
 if (slot.id == id) {
 return &slot;
 }
 }

 return nullptr;
 }

 server_slot * get_available_slot(const server_task & task) {
 server_slot * ret = nullptr;

 bool update_cache = false;

 // find the slot that has at least n% prompt similarity
 if (ret == nullptr && slot_prompt_similarity != 0.0f) {
 float sim_best = 0;

 for (server_slot & slot : slots) {
 // skip the slot if it is not available
 if (slot.is_processing()) {
 continue;
 }

 const auto & tokens = slot.prompt.tokens;

 // skip the slot if it does not contains cached tokens
 if (tokens.empty()) {
 continue;
 }

 // fraction of the Longest Common Prefix length with respect to the input prompt length
 const float sim_cur = float(tokens.get_common_prefix(task.tokens)) / task.tokens.size();

 // select the current slot if the criteria match
 if (sim_cur > sim_best && sim_cur > slot_prompt_similarity) {
 sim_best = sim_cur;

 ret = &slot;
 }
 }

 if (ret != nullptr) {
 const float f_keep = (sim_best*task.tokens.size()) / ret->prompt.tokens.size();

 SLT_INF(*ret, "selected slot by LCP similarity, sim_best = %.3f (> %.3f thold), f_keep = %.3f\n",
 sim_best, slot_prompt_similarity, f_keep);

 // if we are about to lose a large portion of the existing context - save it in the prompt cache
 if (f_keep < 0.5f) {
 update_cache = true;
 }
 }
 }

 // find the slot that has been least recently used
 if (ret == nullptr) {
 int64_t t_last = -1;

 for (server_slot & slot : slots) {
 // skip the slot if it is not available
 if (slot.is_processing()) {
 continue;
 }

 // select the current slot if the criteria match
 if (!ret || slot.t_last_used <= t_last) {
 t_last = slot.t_last_used;
 ret = &slot;
 }
 }

 if (ret != nullptr) {
 SLT_INF(*ret, "selected slot by LRU, t_last = %" PRId64 "\n", t_last);

 update_cache = true;
 }
 }

 if (ret) {
 const auto & tokens = ret->prompt.tokens;

 update_cache = update_cache && prompt_cache;

 // cache prompts only for completion tasks
 update_cache = update_cache && task.type == SERVER_TASK_TYPE_COMPLETION;

 // don't update the cache if the slot's context is empty
 update_cache = update_cache && tokens.size() > 0;

 // TODO: mtmd does not support prompt cache
 update_cache = update_cache && (ret->mctx == nullptr);

 if (update_cache) {
 SRV_WRN("%s", "updating prompt cache\n");

 const int64_t t_start = ggml_time_us();

 ret->prompt_save(*prompt_cache);

 if (!ret->prompt_load(*prompt_cache, task.tokens)) {
 clear_slot(*ret);
 }

 prompt_cache->update();

 SRV_WRN("prompt cache update took %.2f ms\n", (ggml_time_us() - t_start) / 1000.0);
 }
 }

 return ret;
 }

 void clear_slot(server_slot & slot) const {
 GGML_ASSERT(!slot.is_processing());

 SLT_WRN(slot, "clearing slot with %zu tokens\n", slot.prompt.tokens.size());

 llama_memory_seq_rm(llama_get_memory(ctx), slot.id, -1, -1);
 slot.prompt.tokens.clear();
 }

 // return true if at least one slot has been cleared
 // TODO: improve logic
 // - smarter decision which slot to clear (LRU or longest prompt?)
 // - move slot to level 2 cache instead of removing?
 // - instead of purging, try to store and resume later?
 bool try_clear_idle_slots() {
 bool res = false;

 if (!params_base.kv_unified) {
 return res;
 }

 for (auto & slot : slots) {
 if (slot.is_processing()) {
 continue;
 }

 if (slot.prompt.n_tokens() > 0) {
 SRV_WRN("purging slot %d with %zu tokens\n", slot.id, slot.prompt.tokens.size());

 clear_slot(slot);

 res = true;

 // clear slots one by one
 break;
 }
 }

 return res;
 }

 bool launch_slot_with_task(server_slot & slot, server_task && task) {
 slot.reset();

 if (!are_lora_equal(task.params.lora, slot.lora)) {
 // if lora has changed, check to see if the cache should be cleared
 if (lora_should_clear_cache(slot.lora, task.params.lora)) {
 SLT_INF(slot, "clearing cache for lora change. %zu loras -> %zu loras\n", slot.lora.size(), task.params.lora.size());
 slot.prompt.tokens.clear();
 } else {
 SLT_INF(slot, "keeping cache for alora. %zu target loras\n", task.params.lora.size());
 }
 slot.lora = task.params.lora;
 }

 // if using alora, make sure it's only a single one requested and active
 size_t alora_invocation_start = task.tokens.size();
 if (lora_all_alora(slot.lora)) {
 const auto & enabled_ids = lora_get_enabled_ids(slot.lora);
 // TODO: This will error out if a user requests two aloras, but only
 // provides the activation string for one. We could, instead search
 // for all requested alora activation strings and then either keep
 // only the last one, or reject if multiple are found.
 if (enabled_ids.size() != 1) {
 send_error(task, "Cannot run multiple aLoRAs in a single request", ERROR_TYPE_INVALID_REQUEST);
 return false;
 }
 const auto & lora = slot.lora[enabled_ids[0]].ptr;

 // get the pointer and count for the invocation tokens
 const uint64_t n_invocation_tokens = llama_adapter_get_alora_n_invocation_tokens(lora);
 const llama_token * invocation_tokens = llama_adapter_get_alora_invocation_tokens (lora);

 // scan backwards through the prompt tokens to find the last
 // occurrence of the invocation sequence
 int match_idx = static_cast<int>(n_invocation_tokens) - 1;
 for (int i = task.tokens.size() - 1; i >= 0; --i) {
 // the token in this position matches the next token to find in
 // the invocation sequence
 if (task.tokens[i] == invocation_tokens[match_idx]) {
 // if it's a full match, we've found the start
 if (match_idx == 0) {
 alora_invocation_start = i;
 break;
 }
 // otherwise, check the next token in the sequence
 --match_idx;
 } else {
 // no match in this position, so start looking over again
 match_idx = static_cast<int>(n_invocation_tokens) - 1;
 }
 }

 // if the activation string is not found, disable the alora
 if (alora_invocation_start == task.tokens.size()) {
 SLT_DBG(slot, "alora %zu requested, but not found. deactivating\n", enabled_ids[0]);
 slot.lora[enabled_ids[0]].scale = 0.0f;
 } else {
 SLT_DBG(slot, "alora %zu activated starting at %zu\n", enabled_ids[0], alora_invocation_start);
 slot.alora_invocation_start = alora_invocation_start;
 }
 }

 if (!task.tokens.validate(ctx)) {
 send_error(task, "Prompt contains invalid tokens", ERROR_TYPE_INVALID_REQUEST);
 return false;
 }

 SLT_DBG(slot, "launching slot : %s\n", safe_json_to_str(slot.to_json()).c_str());

 // initialize samplers
 {
 if (slot.smpl != nullptr) {
 common_sampler_free(slot.smpl);
 }

 slot.smpl = common_sampler_init(model, task.params.sampling);
 if (slot.smpl == nullptr) {
 // for now, the only error that may happen here is invalid grammar
 send_error(task, "Failed to parse grammar", ERROR_TYPE_INVALID_REQUEST);
 return false;
 }

 SLT_INF(slot, "sampler chain: %s\n", common_sampler_print(slot.smpl).c_str());
 }

 // initialize draft batch
 // TODO: rework speculative decoding [TAG_SERVER_SPEC_REWORK]
 if (slot.ctx_dft) {
 llama_batch_free(slot.batch_spec);

 slot.batch_spec = llama_batch_init(task.params.speculative.n_max + 1, 0, 1);
 }

 slot.task = std::make_unique<const server_task>(std::move(task));

 slot.state = SLOT_STATE_STARTED;

 SLT_INF(slot, "%s", "processing task\n");

 return true;
 }

 bool process_token(completion_token_output & result, server_slot & slot) {
 // remember which tokens were sampled - used for repetition penalties during sampling
 const std::string token_str = result.text_to_send;
 slot.sampled = result.tok;

 slot.generated_text += token_str;
 if (slot.task->params.return_tokens) {
 slot.generated_tokens.push_back(result.tok);
 }
 slot.has_next_token = true;

 // check if there is incomplete UTF-8 character at the end
 bool incomplete = validate_utf8(slot.generated_text) < slot.generated_text.size();

 // search stop word and delete it
 if (!incomplete) {
 size_t pos = std::min(slot.n_sent_text, slot.generated_text.size());

 const std::string str_test = slot.generated_text.substr(pos);
 bool send_text = true;

 size_t stop_pos = slot.find_stopping_strings(str_test, token_str.size(), true);
 if (stop_pos != std::string::npos) {
 slot.generated_text.erase(
 slot.generated_text.begin() + pos + stop_pos,
 slot.generated_text.end());
 pos = std::min(slot.n_sent_text, slot.generated_text.size());
 } else if (slot.has_next_token && !llama_vocab_is_eog(vocab, result.tok) ) {
 stop_pos = slot.find_stopping_strings(str_test, token_str.size(), false);
 send_text = stop_pos == std::string::npos;
 }

 // check if there is any token to predict
 if (send_text) {
 // no send the stop word in the response
 result.text_to_send = slot.generated_text.substr(pos, std::string::npos);
 slot.n_sent_text += result.text_to_send.size();
 // add the token to slot queue and cache
 } else {
 result.text_to_send = "";
 }

 slot.add_token(result);
 if (slot.task->params.stream) {
 send_partial_response(slot, result, false);
 }
 }

 if (incomplete) {
 slot.has_next_token = true;
 }

 // if context shifting is disabled, make sure that we don't run out of context
 if (!params_base.ctx_shift && slot.prompt.n_tokens() + 1 >= slot.n_ctx) {
 slot.truncated = true;
 slot.stop = STOP_TYPE_LIMIT;
 slot.has_next_token = false;

 SLT_DBG(slot, "stopped due to running out of context capacity, prompt.n_tokens() = %d, task.n_tokens = %d, n_decoded = %d, n_ctx = %d\n",
 slot.prompt.n_tokens(), slot.task->n_tokens(), slot.n_decoded, slot.n_ctx);
 }

 // check the limits
 if (slot.n_decoded > 0 && slot.has_next_token && !slot.has_budget(params_base)) {
 slot.stop = STOP_TYPE_LIMIT;
 slot.has_next_token = false;

 SLT_DBG(slot, "stopped by limit, n_decoded = %d, n_predict = %d\n", slot.n_decoded, slot.task->params.n_predict);
 }

 if (slot.has_new_line) {
 // require that each new line has a whitespace prefix (i.e. indentation) of at least slot.params.n_indent
 if (slot.task->params.n_indent > 0) {
 // check the current indentation
 // TODO: improve by not doing it more than once for each new line
 if (slot.last_nl_pos > 0) {
 size_t pos = slot.last_nl_pos;

 int n_indent = 0;
 while (pos < slot.generated_text.size() && (slot.generated_text[pos] == ' ' || slot.generated_text[pos] == '\t')) {
 n_indent++;
 pos++;
 }

 if (pos < slot.generated_text.size() && n_indent < slot.task->params.n_indent) {
 slot.stop = STOP_TYPE_LIMIT;
 slot.has_next_token = false;

 // cut the last line
 slot.generated_text.erase(pos, std::string::npos);

 SLT_DBG(slot, "stopped by indentation limit, n_decoded = %d, n_indent = %d\n", slot.n_decoded, n_indent);
 }
 }

 // find the next new line
 {
 const size_t pos = slot.generated_text.find('\n', slot.last_nl_pos);

 if (pos != std::string::npos) {
 slot.last_nl_pos = pos + 1;
 }
 }
 }
 }

 // check if there is a new line in the generated text
 if (result.text_to_send.find('\n') != std::string::npos) {
 slot.has_new_line = true;

 // if we have seen a new line, we stop after a certain time limit, but only upon another new line
 if (slot.task->params.t_max_predict_ms > 0 && (ggml_time_us() - slot.t_start_generation > 1000.0f*slot.task->params.t_max_predict_ms)) {
 slot.stop = STOP_TYPE_LIMIT;
 slot.has_next_token = false;

 SLT_DBG(slot, "stopped by time limit, n_decoded = %d, t_max_predict_ms = %d ms\n", slot.n_decoded, (int) slot.task->params.t_max_predict_ms);
 }
 }

 if (llama_vocab_is_eog(vocab, result.tok)) {
 slot.stop = STOP_TYPE_EOS;
 slot.has_next_token = false;

 SLT_DBG(slot, "%s", "stopped by EOS\n");
 }

 SLT_DBG(slot, "n_decoded = %d, n_remaining = %d, next token: %5d '%s'\n", slot.n_decoded, slot.n_remaining, result.tok, token_str.c_str());

 return slot.has_next_token; // continue
 }

 void populate_token_probs(const server_slot & slot, completion_token_output & result, bool post_sampling, bool special, int idx) const {
 size_t n_probs = slot.task->params.sampling.n_probs;
 size_t n_vocab = llama_vocab_n_tokens(vocab);

 if (post_sampling) {
 const auto * cur_p = common_sampler_get_candidates(slot.smpl, true);
 const size_t max_probs = cur_p->size;

 // set probability for sampled token
 for (size_t i = 0; i < max_probs; i++) {
 if (cur_p->data[i].id == result.tok) {
 result.prob = cur_p->data[i].p;
 break;
 }
 }

 // set probability for top n_probs tokens
 result.probs.reserve(max_probs);
 for (size_t i = 0; i < std::min(max_probs, n_probs); i++) {
 result.probs.push_back({
 cur_p->data[i].id,
 common_token_to_piece(ctx, cur_p->data[i].id, special),
 cur_p->data[i].p
 });
 }
 } else {
 // TODO: optimize this with min-p optimization
 std::vector<llama_token_data> cur = get_token_probabilities(ctx, idx);

 // set probability for sampled token
 for (size_t i = 0; i < n_vocab; i++) {
 // set probability for sampled token
 if (cur[i].id == result.tok) {
 result.prob = cur[i].p;
 break;
 }
 }

 // set probability for top n_probs tokens
 result.probs.reserve(n_probs);
 for (size_t i = 0; i < std::min(n_vocab, n_probs); i++) {
 result.probs.push_back({
 cur[i].id,
 common_token_to_piece(ctx, cur[i].id, special),
 cur[i].p
 });
 }
 }
 }

 void send_error(const server_task & task, const std::string & error, const enum error_type type = ERROR_TYPE_SERVER) {
 send_error(task.id, error, type);
 }

 void send_error(const server_slot & slot, const std::string & error, const enum error_type type = ERROR_TYPE_SERVER) {
 send_error(slot.task->id, error, type, slot.task->n_tokens(), slot.n_ctx);
 }

 void send_error(const int id_task, const std::string & error, const enum error_type type = ERROR_TYPE_SERVER, const int32_t n_prompt_tokens = 0, const int32_t n_ctx = 0) {
 SRV_ERR("task id = %d, error: %s\n", id_task, error.c_str());

 if (type == ERROR_TYPE_EXCEED_CONTEXT_SIZE) {
 GGML_ASSERT(n_ctx > 0 && n_prompt_tokens > 0);
 }

 auto res = std::make_unique<server_task_result_error>();
 res->id = id_task;
 res->err_type = type;
 res->err_msg = error;
 res->n_prompt_tokens = n_prompt_tokens;
 res->n_ctx = n_ctx;

 queue_results.send(std::move(res));
 }

 // if multimodal is enabled, send an error and return false
 bool check_no_mtmd(const int id_task) {
 if (mctx) {
 send_error(id_task, "This feature is not supported by multimodal", ERROR_TYPE_NOT_SUPPORTED);
 return false;
 }
 return true;
 }

 void send_partial_response(server_slot & slot, const completion_token_output & tkn, bool is_progress) {
 auto res = std::make_unique<server_task_result_cmpl_partial>();

 res->id = slot.task->id;
 res->index = slot.task->index;

 if (is_progress) {
 res->is_progress = true;
 res->progress.total = slot.task->n_tokens();
 res->progress.cache = slot.n_prompt_tokens_cache;
 res->progress.processed = slot.prompt.tokens.size();
 res->progress.time_ms = (ggml_time_us() - slot.t_start_process_prompt) / 1000;
 } else {
 res->content = tkn.text_to_send;
 res->tokens = { tkn.tok };

 slot.update_chat_msg(res->oaicompat_msg_diffs);
 }

 res->n_decoded = slot.n_decoded;
 res->n_prompt_tokens = slot.task->n_tokens();
 res->post_sampling_probs = slot.task->params.post_sampling_probs;

 res->verbose = slot.task->params.verbose;
 res->res_type = slot.task->params.res_type;
 res->oaicompat_model = slot.task->params.oaicompat_model;
 res->oaicompat_cmpl_id = slot.task->params.oaicompat_cmpl_id;

 // populate res.probs_output
 if (slot.task->params.sampling.n_probs > 0) {
 res->prob_output = tkn; // copy the token probs
 }

 // populate timings if this is final response or timings_per_token is enabled
 if (slot.stop != STOP_TYPE_NONE || slot.task->params.timings_per_token) {
 res->timings = slot.get_timings();
 }

 queue_results.send(std::move(res));
 }

 void send_final_response(server_slot & slot) {
 auto res = std::make_unique<server_task_result_cmpl_final>();

 res->id = slot.task->id;
 res->id_slot = slot.id;

 res->index = slot.task->index;
 res->content = slot.generated_text;
 res->tokens = std::move(slot.generated_tokens);
 res->timings = slot.get_timings();
 res->prompt = slot.task->tokens.detokenize(ctx, true);
 res->response_fields = std::move(slot.task->params.response_fields);

 res->truncated = slot.truncated;
 res->n_decoded = slot.n_decoded;
 res->n_prompt_tokens = slot.task->n_tokens();
 res->n_tokens_cached = slot.prompt.n_tokens();
 res->has_new_line = slot.has_new_line;
 res->stopping_word = slot.stopping_word;
 res->stop = slot.stop;
 res->post_sampling_probs = slot.task->params.post_sampling_probs;

 res->verbose = slot.task->params.verbose;
 res->stream = slot.task->params.stream;
 res->include_usage = slot.task->params.include_usage;
 res->res_type = slot.task->params.res_type;
 res->oaicompat_model = slot.task->params.oaicompat_model;
 res->oaicompat_cmpl_id = slot.task->params.oaicompat_cmpl_id;
 res->oaicompat_msg = slot.update_chat_msg(res->oaicompat_msg_diffs);

 // populate res.probs_output
 if (slot.task->params.sampling.n_probs > 0) {
 if (!slot.task->params.stream && slot.stop == STOP_TYPE_WORD) {
 const llama_tokens stop_word_toks = common_tokenize(ctx, slot.stopping_word, false);

 size_t safe_offset = std::min(slot.generated_token_probs.size(), stop_word_toks.size());
 res->probs_output = std::vector<completion_token_output>(
 slot.generated_token_probs.begin(),
 slot.generated_token_probs.end() - safe_offset);
 } else {
 res->probs_output = std::vector<completion_token_output>(
 slot.generated_token_probs.begin(),
 slot.generated_token_probs.end());
 }
 }

 res->generation_params = slot.task->params; // copy the parameters

 queue_results.send(std::move(res));
 }

 void send_embedding(const server_slot & slot, const llama_batch & batch) {
 auto res = std::make_unique<server_task_result_embd>();
 res->id = slot.task->id;
 res->index = slot.task->index;
 res->n_tokens = slot.task->n_tokens();
 res->res_type = slot.task->params.res_type;

 const int n_embd = llama_model_n_embd(model);

 std::vector<float> embd_res(n_embd, 0.0f);

 for (int i = 0; i < batch.n_tokens; ++i) {
 if (!batch.logits[i] || batch.seq_id[i][0] != slot.id) {
 continue;
 }

 const float * embd = nullptr;
 if (llama_pooling_type(slot.ctx) == LLAMA_POOLING_TYPE_NONE) {
 embd = llama_get_embeddings_ith(ctx, i);
 } else {
 embd = llama_get_embeddings_seq(ctx, batch.seq_id[i][0]);
 }

 if (embd == nullptr) {
 SLT_ERR(slot, "failed to get embeddings, token = %d, seq_id = %d\n", batch.token[i], batch.seq_id[i][0]);

 res->embedding.push_back(std::vector<float>(n_embd, 0.0f));
 continue;
 }

 // normalize only when there is pooling
 if (llama_pooling_type(slot.ctx) != LLAMA_POOLING_TYPE_NONE) {
 common_embd_normalize(embd, embd_res.data(), n_embd, slot.task->params.embd_normalize);
 res->embedding.push_back(embd_res);
 break;
 }

 res->embedding.emplace_back(embd, embd + n_embd);
 }

 SLT_DBG(slot, "%s", "sending embeddings\n");

 queue_results.send(std::move(res));
 }

 void send_rerank(const server_slot & slot, const llama_batch & batch) {
 auto res = std::make_unique<server_task_result_rerank>();
 res->id = slot.task->id;
 res->index = slot.task->index;
 res->n_tokens = slot.task->n_tokens();

 for (int i = 0; i < batch.n_tokens; ++i) {
 if (!batch.logits[i] || batch.seq_id[i][0] != slot.id) {
 continue;
 }

 const float * embd = llama_get_embeddings_seq(ctx, batch.seq_id[i][0]);
 if (embd == NULL) {
 embd = llama_get_embeddings_ith(ctx, i);
 }

 if (embd == NULL) {
 SLT_ERR(slot, "failed to get embeddings, token = %d, seq_id = %d\n", batch.token[i], batch.seq_id[i][0]);

 res->score = -1e6;
 continue;
 }

 res->score = embd[0];
 }

 SLT_DBG(slot, "sending rerank result, res.score = %f\n", res->score);

 queue_results.send(std::move(res));
 }

 //
 // Functions to process the task
 //

 void process_single_task(server_task && task) {
 switch (task.type) {
 case SERVER_TASK_TYPE_COMPLETION:
 case SERVER_TASK_TYPE_INFILL:
 case SERVER_TASK_TYPE_EMBEDDING:
 case SERVER_TASK_TYPE_RERANK:
 {
 const int id_slot = task.id_slot;

 server_slot * slot = id_slot != -1 ? get_slot_by_id(id_slot) : get_available_slot(task);

 if (slot == nullptr) {
 // if no slot is available, we defer this task for processing later
 SRV_DBG("no slot is available, defer task, id_task = %d\n", task.id);
 queue_tasks.defer(std::move(task));
 break;
 }

 if (slot->is_processing()) {
 // if requested slot is unavailable, we defer this task for processing later
 SRV_DBG("requested slot is unavailable, defer task, id_task = %d\n", task.id);
 queue_tasks.defer(std::move(task));
 break;
 }

 if (!launch_slot_with_task(*slot, std::move(task))) {
 SRV_ERR("failed to launch slot with task, id_task = %d\n", task.id);
 break;
 }
 } break;
 case SERVER_TASK_TYPE_CANCEL:
 {
 // release slot linked with the task id
 for (auto & slot : slots) {
 if (slot.task && slot.task->id == task.id_target) {
 slot.release();
 break;
 }
 }
 } break;
 case SERVER_TASK_TYPE_NEXT_RESPONSE:
 {
 // do nothing
 } break;
 case SERVER_TASK_TYPE_METRICS:
 {
 json slots_data = json::array();

 int n_idle_slots = 0;
 int n_processing_slots = 0;

 for (server_slot & slot : slots) {
 json slot_data = slot.to_json(slots_debug == 0);

 if (slot.is_processing()) {
 n_processing_slots++;
 } else {
 n_idle_slots++;
 }

 slots_data.push_back(slot_data);
 }
 SRV_DBG("n_idle_slots = %d, n_processing_slots = %d\n", n_idle_slots, n_processing_slots);

 auto res = std::make_unique<server_task_result_metrics>();
 res->id = task.id;
 res->slots_data = std::move(slots_data);
 res->n_idle_slots = n_idle_slots;
 res->n_processing_slots = n_processing_slots;
 res->n_tasks_deferred = queue_tasks.queue_tasks_deferred_size();
 res->t_start = metrics.t_start;

 res->n_prompt_tokens_processed_total = metrics.n_prompt_tokens_processed_total;
 res->t_prompt_processing_total = metrics.t_prompt_processing_total;
 res->n_tokens_predicted_total = metrics.n_tokens_predicted_total;
 res->t_tokens_generation_total = metrics.t_tokens_generation_total;

 res->n_tokens_max = metrics.n_tokens_max;

 res->n_prompt_tokens_processed = metrics.n_prompt_tokens_processed;
 res->t_prompt_processing = metrics.t_prompt_processing;
 res->n_tokens_predicted = metrics.n_tokens_predicted;
 res->t_tokens_generation = metrics.t_tokens_generation;

 res->n_decode_total = metrics.n_decode_total;
 res->n_busy_slots_total = metrics.n_busy_slots_total;

 if (task.metrics_reset_bucket) {
 metrics.reset_bucket();
 }
 queue_results.send(std::move(res));
 } break;
 case SERVER_TASK_TYPE_SLOT_SAVE:
 {
 if (!check_no_mtmd(task.id)) {
 break;
 }

 int id_slot = task.slot_action.slot_id;
 server_slot * slot = get_slot_by_id(id_slot);
 if (slot == nullptr) {
 send_error(task, "Invalid slot ID", ERROR_TYPE_INVALID_REQUEST);
 break;
 }
 if (slot->is_processing()) {
 // if requested slot is unavailable, we defer this task for processing later
 SRV_DBG("requested slot is unavailable, defer task, id_task = %d\n", task.id);
 queue_tasks.defer(std::move(task));
 break;
 }

 const size_t token_count = slot->prompt.tokens.size();
 const int64_t t_start = ggml_time_us();

 std::string filename = task.slot_action.filename;
 std::string filepath = task.slot_action.filepath;

 const llama_tokens & tokens = slot->prompt.tokens.get_text_tokens();
 const size_t nwrite = llama_state_seq_save_file(ctx, filepath.c_str(), slot->id, tokens.data(), token_count);

 const int64_t t_end = ggml_time_us();
 const double t_save_ms = (t_end - t_start) / 1000.0;

 auto res = std::make_unique<server_task_result_slot_save_load>();
 res->id = task.id;
 res->id_slot = id_slot;
 res->filename = filename;
 res->is_save = true;
 res->n_tokens = token_count;
 res->n_bytes = nwrite;
 res->t_ms = t_save_ms;
 queue_results.send(std::move(res));
 } break;
 case SERVER_TASK_TYPE_SLOT_RESTORE:
 {
 if (!check_no_mtmd(task.id)) break;
 int id_slot = task.slot_action.slot_id;
 server_slot * slot = get_slot_by_id(id_slot);
 if (slot == nullptr) {
 send_error(task, "Invalid slot ID", ERROR_TYPE_INVALID_REQUEST);
 break;
 }
 if (slot->is_processing()) {
 // if requested slot is unavailable, we defer this task for processing later
 SRV_DBG("requested slot is unavailable, defer task, id_task = %d\n", task.id);
 queue_tasks.defer(std::move(task));
 break;
 }

 const int64_t t_start = ggml_time_us();

 std::string filename = task.slot_action.filename;
 std::string filepath = task.slot_action.filepath;

 llama_tokens tokens;
 tokens.resize(slot->n_ctx);
 size_t token_count = 0;
 size_t nread = llama_state_seq_load_file(ctx, filepath.c_str(), slot->id, tokens.data(), tokens.size(), &token_count);
 if (nread == 0) {
 slot->prompt.tokens.clear(); // KV may already been invalidated?
 send_error(task, "Unable to restore slot, no available space in KV cache or invalid slot save file", ERROR_TYPE_INVALID_REQUEST);
 break;
 }
 tokens.resize(token_count);
 slot->prompt.tokens.clear();
 slot->prompt.tokens.insert(tokens);

 const int64_t t_end = ggml_time_us();
 const double t_restore_ms = (t_end - t_start) / 1000.0;

 auto res = std::make_unique<server_task_result_slot_save_load>();
 res->id = task.id;
 res->id_slot = id_slot;
 res->filename = filename;
 res->is_save = false;
 res->n_tokens = token_count;
 res->n_bytes = nread;
 res->t_ms = t_restore_ms;
 queue_results.send(std::move(res));
 } break;
 case SERVER_TASK_TYPE_SLOT_ERASE:
 {
 if (!check_no_mtmd(task.id)) {
 break;
 }
 int id_slot = task.slot_action.slot_id;
 server_slot * slot = get_slot_by_id(id_slot);
 if (slot == nullptr) {
 send_error(task, "Invalid slot ID", ERROR_TYPE_INVALID_REQUEST);
 break;
 }
 if (slot->is_processing()) {
 // if requested slot is unavailable, we defer this task for processing later
 SRV_DBG("requested slot is unavailable, defer task, id_task = %d\n", task.id);
 queue_tasks.defer(std::move(task));
 break;
 }

 // Erase token cache
 const size_t n_erased = slot->prompt.tokens.size();

 clear_slot(*slot);

 auto res = std::make_unique<server_task_result_slot_erase>();
 res->id = task.id;
 res->id_slot = id_slot;
 res->n_erased = n_erased;
 queue_results.send(std::move(res));
 } break;
 case SERVER_TASK_TYPE_SET_LORA:
 {
 params_base.lora_adapters = std::move(task.set_lora);
 auto res = std::make_unique<server_task_result_apply_lora>();
 res->id = task.id;
 queue_results.send(std::move(res));
 } break;

 }
 }

 void update_slots() {
 // check if all slots are idle
 {
 bool all_idle = true;

 for (auto & slot : slots) {
 if (slot.is_processing()) {
 all_idle = false;
 break;
 }
 }

 if (all_idle) {
 SRV_INF("%s", "all slots are idle\n");

 return;
 }
 }

 {
 SRV_DBG("%s", "posting NEXT_RESPONSE\n");

 server_task task(SERVER_TASK_TYPE_NEXT_RESPONSE);
 task.id = queue_tasks.get_new_id();
 queue_tasks.post(std::move(task));
 }

 // apply context-shift if needed
 // TODO: simplify and improve
 for (server_slot & slot : slots) {
 if (slot.state == SLOT_STATE_GENERATING && slot.prompt.n_tokens() + 1 >= slot.n_ctx) {
 if (!params_base.ctx_shift) {
 // this check is redundant (for good)
 // we should never get here, because generation should already stopped in process_token()
 send_error(slot, "context shift is disabled", ERROR_TYPE_SERVER);
 slot.release();
 continue;
 }

 if (mctx) {
 // we should never reach this because params_base.ctx_shift is automatically disabled if mmproj is loaded
 // we don't support ctx_shift because an image chunk may contains multiple tokens
 GGML_ABORT("not supported by multimodal");
 }

 // Shift context
 int n_keep = slot.task->params.n_keep < 0 ? slot.task->n_tokens() : slot.task->params.n_keep;

 if (add_bos_token) {
 n_keep += 1;
 }

 n_keep = std::min(slot.n_ctx - 4, n_keep);

 const int n_left = slot.prompt.n_tokens() - n_keep;
 const int n_discard = slot.task->params.n_discard ? slot.task->params.n_discard : (n_left / 2);

 SLT_WRN(slot, "slot context shift, n_keep = %d, n_left = %d, n_discard = %d\n", n_keep, n_left, n_discard);

 llama_memory_seq_rm (llama_get_memory(ctx), slot.id, n_keep , n_keep + n_discard);
 llama_memory_seq_add(llama_get_memory(ctx), slot.id, n_keep + n_discard, slot.prompt.n_tokens(), -n_discard);

 // add generated tokens to cache
 // ref: https://github.com/ggml-org/llama.cpp/pull/16818#discussion_r2473269481
 {
 GGML_ASSERT(!slot.prompt.tokens.has_mtmd);

 llama_tokens new_tokens = slot.prompt.tokens.get_text_tokens(); // copy
 for (size_t i = n_keep + n_discard; i < new_tokens.size(); i++) {
 new_tokens[i - n_discard] = new_tokens[i];
 }

 new_tokens.resize(slot.prompt.tokens.size() - n_discard);

 slot.prompt.tokens.clear();
 slot.prompt.tokens.insert(new_tokens);
 }

 slot.truncated = true;
 }
 }

 // start populating the batch for this iteration
 common_batch_clear(batch);

 // track if given slot can be batched with slots already in the batch
 server_slot * slot_batched = nullptr;

 auto accept_special_token = [&](server_slot & slot, llama_token token) {
 return params_base.special ||
 slot.task->params.sampling.preserved_tokens.find(token) != slot.task->params.sampling.preserved_tokens.end();
 };

 // first, add sampled tokens from any ongoing sequences
 for (auto & slot : slots) {
 if (slot.state != SLOT_STATE_GENERATING) {
 continue;
 }

 // check if we can batch this slot with the previous one
 if (!slot_batched) {
 slot_batched = &slot;
 } else if (!slot_batched->can_batch_with(slot)) {
 continue;
 }

 slot.i_batch = batch.n_tokens;

 common_batch_add(batch, slot.sampled, slot.prompt.tokens.pos_next(), { slot.id }, true);

 slot.prompt.tokens.push_back(slot.sampled);

 SLT_DBG(slot, "slot decode token, n_ctx = %d, n_tokens = %d, truncated = %d\n",
 slot.n_ctx, slot.prompt.n_tokens(), slot.truncated);
 }

 // process in chunks of params.n_batch
 int32_t n_batch = llama_n_batch(ctx);
 int32_t n_ubatch = llama_n_ubatch(ctx);

 float alora_scale = -1.0f;
 size_t alora_disabled_id = 0;

 // next, batch any pending prompts without exceeding n_batch
 if (params_base.cont_batching || batch.n_tokens == 0) {
 for (auto & slot : slots) {
 if (!slot.is_processing()) {
 continue;
 }

 // check if we can batch this slot with the previous one
 if (slot_batched && !slot_batched->can_batch_with(slot)) {
 continue;
 }

 // this slot still has a prompt to be processed
 if (slot.state == SLOT_STATE_PROCESSING_PROMPT || slot.state == SLOT_STATE_STARTED) {
 const auto & input_tokens = slot.task->tokens;

 // TODO: maybe move branch to outside of this loop in the future
 if (slot.state == SLOT_STATE_STARTED) {
 slot.t_start_process_prompt = ggml_time_us();
 slot.t_start_generation = 0;

 slot.state = SLOT_STATE_PROCESSING_PROMPT;

 SLT_INF(slot, "new prompt, n_ctx_slot = %d, n_keep = %d, task.n_tokens = %d\n",
 slot.n_ctx, slot.task->params.n_keep, slot.task->n_tokens());

 // print prompt tokens (for debugging)
 /*if (1) {
 // first 16 tokens (avoid flooding logs)
 for (int i = 0; i < std::min<int>(16, input_tokens.size()); i++) {
 SLT_DBG(slot, "prompt token %3d: %6d '%s'\n", i, input_tokens[i], common_token_to_piece(ctx, input_tokens[i]).c_str());
 }
 } else {
 // all
 for (int i = 0; i < (int) input_tokens.size(); i++) {
 SLT_DBG(slot, "prompt token %3d: %6d '%s'\n", i, input_tokens[i], common_token_to_piece(ctx, input_tokens[i]).c_str());
 }
 }*/

 // keep track how many tokens we can reuse from the previous state
 int n_past = 0;

 // empty prompt passed -> release the slot and send empty response
 if (input_tokens.empty()) {
 SLT_WRN(slot, "%s", "empty prompt - releasing slot\n");

 slot.print_timings();
 send_final_response(slot);
 slot.release();

 continue;
 }

 // TODO: support memory-less logits computation
 if (slot.need_logits() && !llama_get_memory(ctx)) {
 send_error(slot, "the current context does not logits computation. skipping", ERROR_TYPE_SERVER);
 slot.release();
 continue;
 }

 if (!slot.can_split()) {
 if (slot.task->n_tokens() > n_ubatch) {
 send_error(slot, "input is too large to process. increase the physical batch size", ERROR_TYPE_SERVER);
 slot.release();
 continue;
 }

 if (slot.task->n_tokens() > slot.n_ctx) {
 send_error(slot, "input is larger than the max context size. skipping", ERROR_TYPE_EXCEED_CONTEXT_SIZE);
 slot.release();
 continue;
 }
 } else {
 if (slot.task->n_tokens() >= slot.n_ctx) {
 send_error(slot, "the request exceeds the available context size, try increasing it", ERROR_TYPE_EXCEED_CONTEXT_SIZE);
 slot.release();
 continue;
 }

 if (slot.task->params.cache_prompt) {
 // reuse any previously computed tokens that are common with the new prompt
 n_past = slot.prompt.tokens.get_common_prefix(input_tokens);

 // if there is an alora invoked, don't cache after the invocation start
 if (slot.alora_invocation_start > 0) {
 SLT_DBG(slot, "only caching to alora invocation start (n_past = %d, alora_invocation_start = %d)\n", n_past, slot.alora_invocation_start);
 n_past = std::min(n_past, slot.alora_invocation_start - 1);
 }

 // reuse chunks from the cached prompt by shifting their KV cache in the new position
 if (params_base.n_cache_reuse > 0) {
 GGML_ASSERT(!slot.prompt.tokens.has_mtmd);

 size_t head_c = n_past; // cache
 size_t head_p = n_past; // current prompt

 if (mctx) {
 // we should never reach this
 GGML_ABORT("not supported by multimodal");
 }

 SLT_DBG(slot, "trying to reuse chunks with size > %d, n_past = %d\n", params_base.n_cache_reuse, n_past);

 while (head_c < slot.prompt.tokens.size() &&
 head_p < input_tokens.size()) {

 size_t n_match = 0;
 while (head_c + n_match < slot.prompt.tokens.size() &&
 head_p + n_match < input_tokens.size() &&
 slot.prompt.tokens[head_c + n_match] == input_tokens[head_p + n_match]) {

 n_match++;
 }

 if (n_match >= (size_t) params_base.n_cache_reuse) {
 SLT_INF(slot, "reusing chunk with size %zu, shifting KV cache [%zu, %zu) -> [%zu, %zu)\n", n_match, head_c, head_c + n_match, head_p, head_p + n_match);
 //for (size_t i = head_p; i < head_p + n_match; i++) {
 // SLT_DBG(slot, "cache token %3zu: %6d '%s'\n", i, prompt_tokens[i], common_token_to_piece(ctx, prompt_tokens[i]).c_str());
 //}

 const int64_t kv_shift = (int64_t) head_p - (int64_t) head_c;

 llama_memory_seq_rm (llama_get_memory(ctx), slot.id, head_p, head_c);
 llama_memory_seq_add(llama_get_memory(ctx), slot.id, head_c, head_c + n_match, kv_shift);

 for (size_t i = 0; i < n_match; i++) {
 slot.prompt.tokens.set_token(head_p + i, slot.prompt.tokens[head_c + i]);
 n_past++;
 }

 head_c += n_match;
 head_p += n_match;
 } else {
 head_c += 1;
 }
 }

 SLT_DBG(slot, "after context reuse, new n_past = %d\n", n_past);
 }
 } else {
 // if we don't cache the prompt, we have to remove all previous tokens
 n_past = 0;
 }

 // note: when n_swa == 0, the model does not use SWA, which is equivalent to a window of 1
 const auto n_swa = std::max(1, llama_model_n_swa(model));

 // the largest pos_min required for a checkpoint to be useful
 const auto pos_min_thold = std::max(0, n_past - n_swa);

 // note: disallow with mtmd contexts for now
 // https://github.com/ggml-org/llama.cpp/issues/17043
 if (!mctx && n_past > 0 && n_past < slot.prompt.n_tokens()) {
 const auto pos_min = llama_memory_seq_pos_min(llama_get_memory(ctx), slot.id);
 if (pos_min == -1) {
 SLT_ERR(slot, "n_past = %d, slot.prompt.tokens.size() = %d, seq_id = %d, pos_min = %d\n", n_past, (int) slot.prompt.tokens.size(), slot.id, pos_min);
 GGML_ABORT("pos_min == -1, but n_past > 0 - should not happen: https://github.com/ggml-org/llama.cpp/pull/13833#discussion_r2116181237");
 }

 // when the prompt prefix does not match, print the tokens around the mismatch
 // this is useful for debugging prompt caching
 if (slots_debug) {
 const int np0 = std::max<int>(n_past - 4, 0);
 const int np1 = std::min<int>(n_past + 6, std::min(slot.prompt.tokens.size(), slot.task->tokens.size()));

 std::stringstream ss0;
 std::stringstream ss1;

 std::stringstream st0;
 std::stringstream st1;

 ss0 << "old: ... ";
 ss1 << "new: ... ";

 for (int i = np0; i < np1; i++) {
 if (i == n_past) {
 ss0 << " | ";
 ss1 << " | ";
 }

 {
 const auto token = slot.prompt.tokens[i];
 const auto piece = token != LLAMA_TOKEN_NULL ? common_token_to_piece(ctx, token) : "[mtmd]";
 ss0 << piece;
 st0 << std::setw(8) << token;
 }

 {
 const auto token = slot.task->tokens[i];
 const auto piece = token != LLAMA_TOKEN_NULL ? common_token_to_piece(ctx, token) : "[mtmd]";
 ss1 << piece;
 st1 << std::setw(8) << token;
 }
 }

 SLT_WRN(slot, "%s\n", ss0.str().c_str());
 SLT_WRN(slot, "%s\n", ss1.str().c_str());

 SLT_WRN(slot, "%s\n", st0.str().c_str());
 SLT_WRN(slot, "%s\n", st1.str().c_str());
 }

 if (pos_min > pos_min_thold) {
 // TODO: support can be added in the future when corresponding vision models get released
 GGML_ASSERT(!slot.prompt.tokens.has_mtmd);

 SLT_WRN(slot, "n_past = %d, slot.prompt.tokens.size() = %d, seq_id = %d, pos_min = %d, n_swa = %d\n", n_past, (int) slot.prompt.tokens.size(), slot.id, pos_min, n_swa);

 // search for a context checkpoint
 const auto it = std::find_if(
 slot.prompt.checkpoints.rbegin(),
 slot.prompt.checkpoints.rend(),
 [&](const auto & cur) {
 // guarantee that a checkpoint will result in at least one token being processed [TAG_PROMPT_LOGITS]
 return cur.pos_min < pos_min_thold;
 }
 );

 bool do_reset = it == slot.prompt.checkpoints.rend();

 if (!do_reset) {
 // restore the context checkpoint
 const size_t checkpoint_size = it->data.size();
 const size_t n = llama_state_seq_set_data_ext(ctx, it->data.data(), checkpoint_size, slot.id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);

 if (n != checkpoint_size) {
 SLT_ERR(slot, "failed to restore context checkpoint (pos_min = %d, pos_max = %d, size = %.3f MiB)\n", it->pos_min, it->pos_max, (float) checkpoint_size / 1024 / 1024);
 do_reset = true;
 //printf("[DEBUG] `do_reset` was set to `true` after failing to restore a checkpoint");
 } else {
 n_past = std::min(n_past, std::max(it->pos_min + 1, it->pos_max));
 SLT_WRN(slot, "restored context checkpoint (pos_min = %d, pos_max = %d, size = %.3f MiB)\n", it->pos_min, it->pos_max, (float) checkpoint_size / 1024 / 1024);
 }
 }

 if (do_reset) {
 SLT_WRN(slot, "forcing full prompt re-processing due to lack of cache data (likely due to SWA or hybrid/recurrent memory, see %s)\n",
 "https://github.com/ggml-org/llama.cpp/pull/13194#issuecomment-2868343055");
 n_past = 0;
 }
 }
 }

 {
 // erase any checkpoints with pos_min > pos_min_thold
 for (auto it = slot.prompt.checkpoints.begin(); it != slot.prompt.checkpoints.end();) {
 const auto & cur = *it;
 if (cur.pos_min > pos_min_thold) {
 SLT_WRN(slot, "erased invalidated context checkpoint (pos_min = %d, pos_max = %d, n_swa = %d, size = %.3f MiB)\n", cur.pos_min, cur.pos_max, n_swa, (float) cur.data.size() / 1024 / 1024);
 it = slot.prompt.checkpoints.erase(it);
 } else {
 ++it;
 }
 }
 }
 }

 // [TAG_PROMPT_LOGITS]
 if (n_past == slot.task->n_tokens() && n_past > 0) {
 SLT_WRN(slot, "need to evaluate at least 1 token for each active slot (n_past = %d, task.n_tokens() = %d)\n", n_past, slot.task->n_tokens());
 n_past--;
 SLT_WRN(slot, "n_past was set to %d\n", n_past);
 }

 slot.n_prompt_tokens_cache = n_past;
 slot.n_prompt_tokens_processed = 0;

 slot.prompt.tokens.keep_first(n_past);
 }

 if (!slot.can_split()) {
 // cannot fit the prompt in the current batch - will try next iter
 if (batch.n_tokens + slot.task->n_tokens() > n_batch) {
 continue;
 }
 }

 // truncate any tokens that are beyond n_past for this slot
 const llama_pos p0 = slot.prompt.tokens.pos_next();

 SLT_INF(slot, "n_tokens = %d, memory_seq_rm [%d, end)\n", slot.prompt.n_tokens(), p0);

 if (!llama_memory_seq_rm(llama_get_memory(ctx), slot.id, p0, -1)) {
 SLT_WRN(slot, "failed to truncate tokens with position >= %d - clearing the memory\n", p0);

 clear_slot(slot);

 // there is no common part left
 slot.n_prompt_tokens_cache = 0;
 }

 // check if we should process the image
 if (slot.prompt.n_tokens() < slot.task->n_tokens() && input_tokens[slot.prompt.n_tokens()] == LLAMA_TOKEN_NULL) {
 // process the image
 size_t n_tokens_out = 0;
 int32_t res = input_tokens.process_chunk(ctx, mctx, slot.prompt.n_tokens(), slot.prompt.tokens.pos_next(), slot.id, n_tokens_out);
 if (res != 0) {
 SLT_ERR(slot, "failed to process image, res = %d\n", res);
 send_error(slot, "failed to process image", ERROR_TYPE_SERVER);
 slot.release();
 continue;
 }

 slot.n_prompt_tokens_processed += n_tokens_out;

 // add the image chunk to cache
 {
 const auto & chunk = input_tokens.find_chunk(slot.prompt.n_tokens());
 slot.prompt.tokens.push_back(chunk.get()); // copy
 }
 }

 // If using an alora, there may be uncached tokens that come
 // before the invocation sequence. When this happens, the
 // tokens before the invocation sequence need to be
 // processed without the adapter in a separate batch, then
 // the adapter needs to be enabled for the remaining tokens.
 if (lora_all_alora(slot.lora) && slot.alora_invocation_start - 1 > slot.prompt.n_tokens()) {
 SLT_DBG(slot, "processing pre-alora tokens without the adapter (n_tokens = %d, alora_invocation_start = %d)\n", slot.prompt.n_tokens(), slot.alora_invocation_start);
 const auto & enabled_loras = lora_get_enabled_ids(slot.lora);
 GGML_ASSERT(enabled_loras.size() == 1);
 alora_scale = slot.lora[enabled_loras[0]].scale;
 slot.lora[enabled_loras[0]].scale = 0.0f;
 alora_disabled_id = enabled_loras[0];
 }

 bool do_checkpoint = params_base.n_ctx_checkpoints > 0;

 // make checkpoints only for completion tasks
 do_checkpoint = do_checkpoint && slot.task->type == SERVER_TASK_TYPE_COMPLETION;

 // make a checkpoint of the parts of the memory that cannot be rolled back.
 // checkpoints are created only if:
 // - the model uses SWA and we are not using `swa_full`
 // - the model architecture is marked as recurrent or hybrid
 //
 // TODO: try to make this conditional on the context or the memory module, instead of the model type
 do_checkpoint = do_checkpoint && (
 llama_model_is_recurrent(model) ||
 llama_model_is_hybrid(model) ||
 (llama_model_n_swa(model) > 0 && !params_base.swa_full)
 );

 // add prompt tokens for processing in the current batch
 while (slot.prompt.n_tokens() < slot.task->n_tokens() && batch.n_tokens < n_batch) {
 // get next token to process
 llama_token cur_tok = input_tokens[slot.prompt.n_tokens()];
 if (cur_tok == LLAMA_TOKEN_NULL) {
 break; // end of text chunk
 }

 // if this is an alora request with pre-invocation
 // tokens that are not cached, we need to stop filling
 // this batch at those pre-invocation tokens.
 if (alora_scale > 0 && slot.prompt.n_tokens() == slot.alora_invocation_start - 1) {
 SLT_DBG(slot, "stop prompt batch filling at (n_tokens = %d, alora_invocation_start = %d)\n", slot.prompt.n_tokens(), slot.alora_invocation_start);
 break;
 }

 // embedding requires all tokens in the batch to be output
 common_batch_add(batch,
 cur_tok,
 slot.prompt.tokens.pos_next(),
 { slot.id },
 slot.need_embd());
 slot.prompt.tokens.push_back(cur_tok);

 slot.n_prompt_tokens_processed++;

 // process the last few tokens of the prompt separately in order to allow for a checkpoint to be created.
 if (do_checkpoint && slot.task->n_tokens() - slot.prompt.n_tokens() == 64) {
 break;
 }
 }

 // SLT_INF(slot, "new slot.prompt.tokens: %s\n", slot.slot.prompt.tokens.str().c_str());

 SLT_INF(slot, "prompt processing progress, n_tokens = %d, batch.n_tokens = %d, progress = %f\n", slot.prompt.n_tokens(), batch.n_tokens, (float) slot.prompt.n_tokens() / slot.task->n_tokens());

 // entire prompt has been processed
 if (slot.prompt.n_tokens() == slot.task->n_tokens()) {
 slot.state = SLOT_STATE_DONE_PROMPT;

 GGML_ASSERT(batch.n_tokens > 0);

 common_sampler_reset(slot.smpl);

 // Process all prompt tokens through sampler system
 for (int i = 0; i < slot.task->n_tokens(); ++i) {
 llama_token id = input_tokens[i];
 if (id != LLAMA_TOKEN_NULL) {
 common_sampler_accept(slot.smpl, id, false);
 }
 }

 // extract the logits only for the last token
 batch.logits[batch.n_tokens - 1] = true;

 slot.n_decoded = 0;
 slot.i_batch = batch.n_tokens - 1;

 SLT_INF(slot, "prompt done, n_tokens = %d, batch.n_tokens = %d\n", slot.prompt.n_tokens(), batch.n_tokens);

 const auto pos_min = llama_memory_seq_pos_min(llama_get_memory(ctx), slot.id);
 const auto pos_max = llama_memory_seq_pos_max(llama_get_memory(ctx), slot.id);

 // no need for empty or small checkpoints
 do_checkpoint = do_checkpoint && (pos_min >= 0 && pos_max >= 64);

 // no need to create checkpoints that are too close together
 do_checkpoint = do_checkpoint && (slot.prompt.checkpoints.empty() || pos_max > slot.prompt.checkpoints.back().pos_max + 64);

 if (do_checkpoint) {
 while (slot.prompt.checkpoints.size() >= (size_t) params_base.n_ctx_checkpoints) {
 // make room for the new checkpoint, if needed
 const auto & cur = slot.prompt.checkpoints.front();

 SLT_WRN(slot, "erasing old context checkpoint (pos_min = %d, pos_max = %d, size = %.3f MiB)\n",
 cur.pos_min, cur.pos_max, (float) cur.data.size() / 1024 / 1024);

 slot.prompt.checkpoints.erase(slot.prompt.checkpoints.begin());
 }

 const size_t checkpoint_size = llama_state_seq_get_size_ext(ctx, slot.id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);

 auto & cur = slot.prompt.checkpoints.emplace_back(server_prompt_checkpoint{
 /*.pos_min = */ pos_min,
 /*.pos_max = */ pos_max,
 /*.data = */ std::vector<uint8_t>(checkpoint_size),
 });

 llama_state_seq_get_data_ext(ctx, cur.data.data(), checkpoint_size, slot.id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);

 SLT_WRN(slot, "created context checkpoint %d of %d (pos_min = %d, pos_max = %d, size = %.3f MiB)\n",
 (int) slot.prompt.checkpoints.size(), params_base.n_ctx_checkpoints, cur.pos_min, cur.pos_max, (float) cur.data.size() / 1024 / 1024);
 }
 }
 }

 if (!slot_batched) {
 slot_batched = &slot;
 }

 if (batch.n_tokens >= n_batch) {
 break;
 }
 }
 }

 if (batch.n_tokens == 0) {
 SRV_WRN("%s", "no tokens to decode\n");
 return;
 }

 SRV_DBG("decoding batch, n_tokens = %d\n", batch.n_tokens);

 if (slot_batched) {
 // apply lora, only need to do it once per batch
 common_set_adapter_lora(ctx, slot_batched->lora);

 // if the lora is temporarily disabled for an alora, re-enable it
 // for next time
 if (alora_scale > 0.0f) {
 SRV_DBG("re-enabling alora with scale %f\n", alora_scale);
 slot_batched->lora[alora_disabled_id].scale = alora_scale;
 }

 llama_set_embeddings(ctx, slot_batched->need_embd());
 }

 int32_t i_next = 0;

 // process the created batch of tokens
 for (int32_t i = 0; i < batch.n_tokens; i = i_next) {
 const int32_t n_tokens = std::min(n_batch, batch.n_tokens - i);

 llama_batch batch_view = {
 n_tokens,
 batch.token + i,
 nullptr,
 batch.pos + i,
 batch.n_seq_id + i,
 batch.seq_id + i,
 batch.logits + i,
 };

 const int ret = llama_decode(ctx, batch_view);

 metrics.on_decoded(slots);

 if (ret != 0) {
 {
 std::string err;

 if (n_batch == 1 && ret == 1) {
 // TODO: try to terminate only the largest active slot/sequence and continue with the rest
 // need to remove the tokens from the current batch too
 err = "Context size has been exceeded.";
 }

 if (ret == -1) {
 err = "Invalid input batch.";
 }

 if (ret < -1) {
 // TODO: update slot state based on llama_memory_seq_pos_min() and llama_memory_seq_pos_max()
 err = "Compute error.";
 }

 // TODO: handle ret == 2 (abort) when we start aborting

 if (!err.empty()) {
 SRV_ERR("%s i = %d, n_batch = %d, ret = %d\n", err.c_str(), i, n_batch, ret);

 for (auto & slot : slots) {
 if (slot.is_processing()) {
 send_error(slot, err);
 slot.release();

 // note: it's complicated to keep track of how much of the current batch has been
 // processed before the error occurred, so we simply clear the entire context
 clear_slot(slot);
 }
 }

 break;
 }
 }

 // retry with half the batch size to try to find a free slot in the KV cache
 if (!try_clear_idle_slots()) {
 n_batch /= 2;
 }

 SRV_WRN("failed to find free space in the KV cache, retrying with smaller batch size, i = %d, n_batch = %d, ret = %d\n", i, n_batch, ret);

 continue; // continue loop of n_batch
 }

 // move the head of the batch forward with the number of tokens we just processed
 i_next = i + n_tokens;

 // on successful decode, restore the original batch size
 n_batch = llama_n_batch(ctx);

 for (auto & slot : slots) {
 // optionally send prompt processing progress
 if (slot.state == SLOT_STATE_PROCESSING_PROMPT || slot.state == SLOT_STATE_DONE_PROMPT) {
 if (slot.task->params.stream && slot.task->params.return_progress) {
 send_partial_response(slot, {}, true);
 }
 }

 if (slot.i_batch < (int) i || slot.i_batch >= (int) (i + n_tokens)) {
 continue; // continue loop of slots
 }

 if (slot.state == SLOT_STATE_DONE_PROMPT) {
 if (slot.task->type == SERVER_TASK_TYPE_EMBEDDING) {
 // prompt evaluated for embedding
 send_embedding(slot, batch_view);
 slot.release();
 slot.i_batch = -1;
 continue; // continue loop of slots
 }

 if (slot.task->type == SERVER_TASK_TYPE_RERANK) {
 send_rerank(slot, batch_view);
 slot.release();
 slot.i_batch = -1;
 continue; // continue loop of slots
 }

 // prompt evaluated for next-token prediction
 slot.state = SLOT_STATE_GENERATING;
 } else if (slot.state != SLOT_STATE_GENERATING) {
 continue; // continue loop of slots
 }

 const int tok_idx = slot.i_batch - i;

 llama_token id = common_sampler_sample(slot.smpl, ctx, tok_idx);

 slot.i_batch = -1;

 common_sampler_accept(slot.smpl, id, true);

 slot.n_decoded += 1;

 const int64_t t_current = ggml_time_us();

 if (slot.n_decoded == 1) {
 slot.t_start_generation = t_current;
 slot.t_prompt_processing = (slot.t_start_generation - slot.t_start_process_prompt) / 1e3;
 metrics.on_prompt_eval(slot);
 }

 slot.t_token_generation = std::max<int64_t>(1, t_current - slot.t_start_generation) / 1e3;

 completion_token_output result;
 result.tok = id;
 result.text_to_send = common_token_to_piece(ctx, result.tok, accept_special_token(slot, result.tok));
 result.prob = 1.0f; // TODO: set it here instead of doing inside populate_token_probs

 if (slot.task->params.sampling.n_probs > 0) {
 populate_token_probs(slot, result, slot.task->params.post_sampling_probs, params_base.special, tok_idx);
 }

 if (!process_token(result, slot)) {
 // release slot because of stop condition
 slot.print_timings();
 send_final_response(slot);
 metrics.on_prediction(slot);
 slot.release();

 continue;
 }
 }

 // do speculative decoding
 // TODO: rework to have a single draft llama_context shared across all slots [TAG_SERVER_SPEC_REWORK]
 // perform the speculative drafting for all sequences at the same time in a single batch
 for (auto & slot : slots) {
 if (!slot.is_processing() || !slot.can_speculate()) {
 continue;
 }

 if (slot.state != SLOT_STATE_GENERATING) {
 continue;
 }

 if (mctx) {
 // we should never reach this, as speculative is automatically disabled if mmproj is loaded
 GGML_ABORT("not supported by multimodal");
 }

 // determine the max draft that fits the current slot state
 int n_draft_max = slot.task->params.speculative.n_max;

 // note: slot.prompt is not yet expanded with the `id` token sampled above
 // also, need to leave space for 1 extra token to allow context shifts
 n_draft_max = std::min(n_draft_max, slot.n_ctx - slot.prompt.n_tokens() - 2);

 if (slot.n_remaining > 0) {
 n_draft_max = std::min(n_draft_max, slot.n_remaining - 1);
 }

 SLT_DBG(slot, "max possible draft: %d\n", n_draft_max);

 if (n_draft_max < slot.task->params.speculative.n_min) {
 SLT_DBG(slot, "the max possible draft is too small: %d < %d - skipping speculative decoding\n", n_draft_max, slot.task->params.speculative.n_min);

 continue;
 }

 llama_token id = slot.sampled;

 struct common_speculative_params params_spec;
 params_spec.n_draft = n_draft_max;
 params_spec.n_reuse = llama_n_ctx(slot.ctx_dft) - slot.task->params.speculative.n_max;
 params_spec.p_min = slot.task->params.speculative.p_min;

 const llama_tokens & cached_text_tokens = slot.prompt.tokens.get_text_tokens();
 llama_tokens draft = common_speculative_gen_draft(slot.spec, params_spec, cached_text_tokens, id);

 // ignore small drafts
 if (slot.task->params.speculative.n_min > (int) draft.size()) {
 SLT_DBG(slot, "ignoring small draft: %d < %d\n", (int) draft.size(), slot.task->params.speculative.n_min);

 continue;
 }

 // keep track of total number of drafted tokens tested
 slot.n_draft_total += draft.size();

 // construct the speculation batch
 common_batch_clear(slot.batch_spec);
 common_batch_add (slot.batch_spec, id, slot.prompt.tokens.pos_next(), { slot.id }, true);

 for (size_t i = 0; i < draft.size(); ++i) {
 common_batch_add(slot.batch_spec, draft[i], slot.prompt.tokens.pos_next() + 1 + i, { slot.id }, true);
 }

 SLT_DBG(slot, "decoding speculative batch, size = %d\n", slot.batch_spec.n_tokens);

 llama_decode(ctx, slot.batch_spec);

 // the accepted tokens from the speculation
 const auto ids = common_sampler_sample_and_accept_n(slot.smpl, ctx, draft);

 slot.n_decoded += ids.size();

 // update how many tokens out of those tested were accepted
 slot.n_draft_accepted += ids.size() - 1;

 slot.prompt.tokens.push_back(id);
 slot.prompt.tokens.insert({ids.begin(), ids.end() - 1});

 llama_memory_seq_rm(llama_get_memory(ctx), slot.id, slot.prompt.n_tokens(), -1);

 for (size_t i = 0; i < ids.size(); ++i) {
 completion_token_output result;

 result.tok = ids[i];
 result.text_to_send = common_token_to_piece(ctx, result.tok, accept_special_token(slot, result.tok));
 result.prob = 1.0f; // set later

 // TODO: set result.probs

 if (!process_token(result, slot)) {
 slot.print_timings();
 send_final_response(slot);
 metrics.on_prediction(slot);
 slot.release();

 break;
 }
 }

 SLT_DBG(slot, "accepted %d/%d draft tokens, new n_tokens = %d\n", (int) ids.size() - 1, (int) draft.size(), slot.prompt.n_tokens());
 }
 }

 SRV_DBG("%s", "run slots completed\n");
 }

 json model_meta() const {
 return json {
 {"vocab_type", llama_vocab_type (vocab)},
 {"n_vocab", llama_vocab_n_tokens (vocab)},
 {"n_ctx_train", llama_model_n_ctx_train(model)},
 {"n_embd", llama_model_n_embd (model)},
 {"n_params", llama_model_n_params (model)},
 {"size", llama_model_size (model)},
 };
 }

 int get_slot_n_ctx() {
 return slots.back().n_ctx;
 }
};

//
// server_context (public API)
//

server_context::server_context() : impl(new server_context_impl()) {}
server_context::~server_context() = default;

void server_context::init() {
 impl->init();
}

bool server_context::load_model(const common_params & params) {
 return impl->load_model(params);
}

void server_context::start_loop() {
 impl->queue_tasks.start_loop();
}

void server_context::terminate() {
 impl->queue_tasks.terminate();
}

llama_context * server_context::get_llama_context() const {
 return impl->ctx;
}

std::pair<server_queue &, server_response &> server_context::get_queues() {
 return { impl->queue_tasks, impl->queue_results };
}



// generator-like API for HTTP response generation
struct server_res_generator : server_http_res {
 server_response_reader rd;
 server_res_generator(server_context_impl & ctx_server)
 : rd({ctx_server.queue_tasks, ctx_server.queue_results}, HTTP_POLLING_SECONDS) {}
 void ok(const json & response_data) {
 status = 200;
 data = safe_json_to_str(response_data);
 }
 void error(const json & error_data) {
 status = json_value(error_data, "code", 500);
 data = safe_json_to_str({{ "error", error_data }});
 }
};



//
// server_routes
//

static std::unique_ptr<server_res_generator> handle_completions_impl(
 server_context_impl & ctx_server,
 server_task_type type,
 const json & data,
 const std::vector<raw_buffer> & files,
 const std::function<bool()> & should_stop,
 task_response_type res_type) {
 GGML_ASSERT(type == SERVER_TASK_TYPE_COMPLETION || type == SERVER_TASK_TYPE_INFILL);

 auto res = std::make_unique<server_res_generator>(ctx_server);
 auto completion_id = gen_chatcmplid();
 auto & rd = res->rd;

 try {
 std::vector<server_task> tasks;

 const auto & prompt = data.at("prompt");
 // TODO: this log can become very long, put it behind a flag or think about a more compact format
 //SRV_DBG("Prompt: %s\n", prompt.is_string() ? prompt.get<std::string>().c_str() : prompt.dump(2).c_str());

 // process prompt
 std::vector<server_tokens> inputs;

 if (res_type != TASK_RESPONSE_TYPE_NONE && ctx_server.mctx != nullptr) {
 // This is the case used by OAI compatible chat path with MTMD. TODO It can be moved to the path below.
 inputs.push_back(process_mtmd_prompt(ctx_server.mctx, prompt.get<std::string>(), files));
 } else {
 // Everything else, including multimodal completions.
 inputs = tokenize_input_prompts(ctx_server.vocab, ctx_server.mctx, prompt, true, true);
 }
 tasks.reserve(inputs.size());
 for (size_t i = 0; i < inputs.size(); i++) {
 server_task task = server_task(type);

 task.id = ctx_server.queue_tasks.get_new_id();
 task.index = i;

 task.tokens = std::move(inputs[i]);
 task.params = server_task::params_from_json_cmpl(
 ctx_server.ctx,
 ctx_server.params_base,
 data);
 task.id_slot = json_value(data, "id_slot", -1);

 // OAI-compat
 task.params.res_type = res_type;
 task.params.oaicompat_cmpl_id = completion_id;
 task.params.oaicompat_model = ctx_server.model_name;

 tasks.push_back(std::move(task));
 }

 rd.post_tasks(std::move(tasks));
 } catch (const std::exception & e) {
 res->error(format_error_response(e.what(), ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 bool stream = json_value(data, "stream", false);

 if (!stream) {
 // non-stream, wait for the results
 auto all_results = rd.wait_for_all(should_stop);
 if (all_results.is_terminated) {
 return res; // connection is closed
 } else if (all_results.error) {
 res->error(all_results.error->to_json());
 return res;
 } else {
 json arr = json::array();
 for (auto & res : all_results.results) {
 GGML_ASSERT(dynamic_cast<server_task_result_cmpl_final*>(res.get()) != nullptr);
 arr.push_back(res->to_json());
 }
 // if single request, return single object instead of array
 res->ok(arr.size() == 1 ? arr[0] : arr);
 }

 } else {
 // in streaming mode, the first error must be treated as non-stream response
 // this is to match the OAI API behavior
 // ref: https://github.com/ggml-org/llama.cpp/pull/16486#discussion_r2419657309
 server_task_result_ptr first_result = rd.next(should_stop);
 if (first_result == nullptr) {
 return res; // connection is closed
 } else if (first_result->is_error()) {
 res->error(first_result->to_json());
 return res;
 } else {
 GGML_ASSERT(
 dynamic_cast<server_task_result_cmpl_partial*>(first_result.get()) != nullptr
 || dynamic_cast<server_task_result_cmpl_final*>(first_result.get()) != nullptr
 );
 }

 // next responses are streamed
 if (res_type == TASK_RESPONSE_TYPE_ANTHROPIC) {
 res->data = format_anthropic_sse(first_result->to_json());
 } else {
 res->data = format_oai_sse(first_result->to_json()); // to be sent immediately
 }
 res->status = 200;
 res->content_type = "text/event-stream";
 res->next = [res_this = res.get(), res_type, &should_stop](std::string & output) -> bool {
 if (should_stop()) {
 SRV_DBG("%s", "stopping streaming due to should_stop condition\n");
 return false; // should_stop condition met
 }

 if (!res_this->data.empty()) {
 // flush the first chunk
 output = std::move(res_this->data);
 res_this->data.clear();
 return true;
 }

 server_response_reader & rd = res_this->rd;

 // check if there is more data
 if (!rd.has_next()) {
 if (res_type == TASK_RESPONSE_TYPE_ANTHROPIC) {
 // Anthropic doesn't send [DONE], message_stop was already sent
 output = "";
 } else if (res_type != TASK_RESPONSE_TYPE_NONE) {
 output = "data: [DONE]\n\n";
 } else {
 output = "";
 }
 SRV_DBG("%s", "all results received, terminating stream\n");
 return false; // no more data, terminate
 }

 // receive subsequent results
 auto result = rd.next(should_stop);
 if (result == nullptr) {
 SRV_DBG("%s", "stopping streaming due to should_stop condition\n");
 return false; // should_stop condition met
 }

 // send the results
 json res_json = result->to_json();
 if (result->is_error()) {
 if (res_type == TASK_RESPONSE_TYPE_ANTHROPIC) {
 output = format_anthropic_sse({
 {"event", "error"},
 {"data", res_json},
 });
 } else {
 output = format_oai_sse(json {{ "error", res_json }});
 }
 SRV_DBG("%s", "error received during streaming, terminating stream\n");
 return false; // terminate on error
 } else {
 GGML_ASSERT(
 dynamic_cast<server_task_result_cmpl_partial*>(result.get()) != nullptr
 || dynamic_cast<server_task_result_cmpl_final*>(result.get()) != nullptr
 );
 if (res_type == TASK_RESPONSE_TYPE_ANTHROPIC) {
 output = format_anthropic_sse(res_json);
 } else {
 output = format_oai_sse(res_json);
 }
 }

 // has next data, continue
 return true;
 };
 }

 return res;
}

void server_routes::init_routes() {
 this->get_health = [this](const server_http_req &) {
 // error and loading states are handled by middleware
 auto res = std::make_unique<server_res_generator>(ctx_server);
 res->ok({{"status", "ok"}});
 return res;
 };

 this->get_metrics = [this](const server_http_req &) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 if (!params.endpoint_metrics) {
 res->error(format_error_response("This server does not support metrics endpoint. Start it with `--metrics`", ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }

 // request slots data using task queue
 // TODO: use server_response_reader
 int task_id = ctx_server.queue_tasks.get_new_id();
 {
 server_task task(SERVER_TASK_TYPE_METRICS);
 task.id = task_id;
 ctx_server.queue_results.add_waiting_task_id(task_id);
 ctx_server.queue_tasks.post(std::move(task), true); // high-priority task
 }

 // get the result
 server_task_result_ptr result = ctx_server.queue_results.recv(task_id);
 ctx_server.queue_results.remove_waiting_task_id(task_id);

 if (result->is_error()) {
 res->error(result->to_json());
 return res;
 }

 // TODO: get rid of this dynamic_cast
 auto res_task = dynamic_cast<server_task_result_metrics*>(result.get());
 GGML_ASSERT(res_task != nullptr);

 // metrics definition: https://prometheus.io/docs/practices/naming/#metric-names
 json all_metrics_def = json {
 {"counter", {{
 {"name", "prompt_tokens_total"},
 {"help", "Number of prompt tokens processed."},
 {"value", (uint64_t) res_task->n_prompt_tokens_processed_total}
 }, {
 {"name", "prompt_seconds_total"},
 {"help", "Prompt process time"},
 {"value", (uint64_t) res_task->t_prompt_processing_total / 1.e3}
 }, {
 {"name", "tokens_predicted_total"},
 {"help", "Number of generation tokens processed."},
 {"value", (uint64_t) res_task->n_tokens_predicted_total}
 }, {
 {"name", "tokens_predicted_seconds_total"},
 {"help", "Predict process time"},
 {"value", (uint64_t) res_task->t_tokens_generation_total / 1.e3}
 }, {
 {"name", "n_decode_total"},
 {"help", "Total number of llama_decode() calls"},
 {"value", res_task->n_decode_total}
 }, {
 {"name", "n_tokens_max"},
 {"help", "Largest observed n_tokens."},
 {"value", res_task->n_tokens_max}
 }, {
 {"name", "n_busy_slots_per_decode"},
 {"help", "Average number of busy slots per llama_decode() call"},
 {"value", (float) res_task->n_busy_slots_total / std::max((float) res_task->n_decode_total, 1.f)}
 }}},
 {"gauge", {{
 {"name", "prompt_tokens_seconds"},
 {"help", "Average prompt throughput in tokens/s."},
 {"value", res_task->n_prompt_tokens_processed ? 1.e3 / res_task->t_prompt_processing * res_task->n_prompt_tokens_processed : 0.}
 },{
 {"name", "predicted_tokens_seconds"},
 {"help", "Average generation throughput in tokens/s."},
 {"value", res_task->n_tokens_predicted ? 1.e3 / res_task->t_tokens_generation * res_task->n_tokens_predicted : 0.}
 },{
 {"name", "requests_processing"},
 {"help", "Number of requests processing."},
 {"value", (uint64_t) res_task->n_processing_slots}
 },{
 {"name", "requests_deferred"},
 {"help", "Number of requests deferred."},
 {"value", (uint64_t) res_task->n_tasks_deferred}
 }}}
 };

 std::stringstream prometheus;

 for (const auto & el : all_metrics_def.items()) {
 const auto & type = el.key();
 const auto & metrics_def = el.value();

 for (const auto & metric_def : metrics_def) {
 const std::string name = metric_def.at("name");
 const std::string help = metric_def.at("help");

 auto value = json_value(metric_def, "value", 0.);
 prometheus << "# HELP llamacpp:" << name << " " << help << "\n"
 << "# TYPE llamacpp:" << name << " " << type << "\n"
 << "llamacpp:" << name << " " << value << "\n";
 }
 }

 res->headers["Process-Start-Time-Unix"] = std::to_string(res_task->t_start);
 res->content_type = "text/plain; version=0.0.4";
 res->status = 200;
 res->data = prometheus.str();
 return res;
 };

 this->get_slots = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 if (!params.endpoint_slots) {
 res->error(format_error_response("This server does not support slots endpoint. Start it with `--slots`", ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }

 // request slots data using task queue
 int task_id = ctx_server.queue_tasks.get_new_id();
 {
 server_task task(SERVER_TASK_TYPE_METRICS);
 task.id = task_id;
 ctx_server.queue_results.add_waiting_task_id(task_id);
 ctx_server.queue_tasks.post(std::move(task), true); // high-priority task
 }

 // get the result
 server_task_result_ptr result = ctx_server.queue_results.recv(task_id);
 ctx_server.queue_results.remove_waiting_task_id(task_id);

 if (result->is_error()) {
 res->error(result->to_json());
 return res;
 }

 // TODO: get rid of this dynamic_cast
 auto res_task = dynamic_cast<server_task_result_metrics*>(result.get());
 GGML_ASSERT(res_task != nullptr);

 // optionally return "fail_on_no_slot" error
 if (!req.get_param("fail_on_no_slot").empty()) {
 if (res_task->n_idle_slots == 0) {
 res->error(format_error_response("no slot available", ERROR_TYPE_UNAVAILABLE));
 return res;
 }
 }

 res->ok(res_task->slots_data);
 return res;
 };

 this->post_slots = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 if (params.slot_save_path.empty()) {
 res->error(format_error_response("This server does not support slots action. Start it with `--slot-save-path`", ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }

 std::string id_slot_str = req.get_param("id_slot");
 int id_slot;

 try {
 id_slot = std::stoi(id_slot_str);
 } catch (const std::exception &) {
 res->error(format_error_response("Invalid slot ID", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 std::string action = req.get_param("action");

 if (action == "save") {
 return handle_slots_save(req, id_slot);
 } else if (action == "restore") {
 return handle_slots_restore(req, id_slot);
 } else if (action == "erase") {
 return handle_slots_erase(req, id_slot);
 } else {
 res->error(format_error_response("Invalid action", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 };

 this->get_props = [this](const server_http_req &) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 json default_generation_settings_for_props;

 {
 task_params params;

 params.sampling = ctx_server.params_base.sampling;

 default_generation_settings_for_props = json {
 {"params", params.to_json(true)},
 {"n_ctx", ctx_server.get_slot_n_ctx()},
 };
 }

 // this endpoint is publicly available, please only return what is safe to be exposed
 json data = {
 { "default_generation_settings", default_generation_settings_for_props },
 { "total_slots", ctx_server.params_base.n_parallel },
 { "model_alias", ctx_server.model_name },
 { "model_path", ctx_server.params_base.model.path },
 { "modalities", json {
 {"vision", ctx_server.oai_parser_opt.allow_image},
 {"audio", ctx_server.oai_parser_opt.allow_audio},
 } },
 { "endpoint_slots", params.endpoint_slots },
 { "endpoint_props", params.endpoint_props },
 { "endpoint_metrics", params.endpoint_metrics },
 { "webui", params.webui },
 { "chat_template", common_chat_templates_source(ctx_server.chat_templates.get()) },
 { "bos_token", common_token_to_piece(ctx_server.ctx, llama_vocab_bos(ctx_server.vocab), /* special= */ true)},
 { "eos_token", common_token_to_piece(ctx_server.ctx, llama_vocab_eos(ctx_server.vocab), /* special= */ true)},
 { "build_info", build_info },
 };
 if (ctx_server.params_base.use_jinja) {
 if (auto tool_use_src = common_chat_templates_source(ctx_server.chat_templates.get(), "tool_use")) {
 data["chat_template_tool_use"] = tool_use_src;
 }
 }

 res->ok(data);
 return res;
 };

 this->post_props = [this](const server_http_req &) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 if (!params.endpoint_props) {
 res->error(format_error_response("This server does not support changing global properties. Start it with `--props`", ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }
 // update any props here

 res->ok({{ "success", true }});
 return res;
 };

 this->get_api_show = [this](const server_http_req &) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 bool has_mtmd = ctx_server.mctx != nullptr;
 json data = {
 {
 "template", common_chat_templates_source(ctx_server.chat_templates.get()),
 },
 {
 "model_info", {
 { "llama.context_length", ctx_server.get_slot_n_ctx() },
 }
 },
 {"modelfile", ""},
 {"parameters", ""},
 {"template", common_chat_templates_source(ctx_server.chat_templates.get())},
 {"details", {
 {"parent_model", ""},
 {"format", "gguf"},
 {"family", ""},
 {"families", {""}},
 {"parameter_size", ""},
 {"quantization_level", ""}
 }},
 {"model_info", ""},
 {"capabilities", has_mtmd ? json({"completion","multimodal"}) : json({"completion"})}
 };

 res->ok(data);
 return res;
 };

 this->post_infill = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 // check model compatibility
 std::string err;
 if (llama_vocab_fim_pre(ctx_server.vocab) == LLAMA_TOKEN_NULL) {
 err += "prefix token is missing. ";
 }
 if (llama_vocab_fim_suf(ctx_server.vocab) == LLAMA_TOKEN_NULL) {
 err += "suffix token is missing. ";
 }
 if (llama_vocab_fim_mid(ctx_server.vocab) == LLAMA_TOKEN_NULL) {
 err += "middle token is missing. ";
 }
 if (!err.empty()) {
 res->error(format_error_response(string_format("Infill is not supported by this model: %s", err.c_str()), ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }

 // validate input
 json data = json::parse(req.body);
 if (data.contains("prompt") && !data.at("prompt").is_string()) {
 // prompt is optional
 res->error(format_error_response("\"prompt\" must be a string", ERROR_TYPE_INVALID_REQUEST));
 }

 if (!data.contains("input_prefix")) {
 res->error(format_error_response("\"input_prefix\" is required", ERROR_TYPE_INVALID_REQUEST));
 }

 if (!data.contains("input_suffix")) {
 res->error(format_error_response("\"input_suffix\" is required", ERROR_TYPE_INVALID_REQUEST));
 }

 if (data.contains("input_extra") && !data.at("input_extra").is_array()) {
 // input_extra is optional
 res->error(format_error_response("\"input_extra\" must be an array of {\"filename\": string, \"text\": string}", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 json input_extra = json_value(data, "input_extra", json::array());
 for (const auto & chunk : input_extra) {
 // { "text": string, "filename": string }
 if (!chunk.contains("text") || !chunk.at("text").is_string()) {
 res->error(format_error_response("extra_context chunk must contain a \"text\" field with a string value", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 // filename is optional
 if (chunk.contains("filename") && !chunk.at("filename").is_string()) {
 res->error(format_error_response("extra_context chunk's \"filename\" field must be a string", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 }
 data["input_extra"] = input_extra; // default to empty array if it's not exist

 std::string prompt = json_value(data, "prompt", std::string());
 std::vector<server_tokens> tokenized_prompts = tokenize_input_prompts(ctx_server.vocab, ctx_server.mctx, prompt, false, true);
 SRV_DBG("creating infill tasks, n_prompts = %d\n", (int) tokenized_prompts.size());
 data["prompt"] = format_prompt_infill(
 ctx_server.vocab,
 data.at("input_prefix"),
 data.at("input_suffix"),
 data.at("input_extra"),
 ctx_server.params_base.n_batch,
 ctx_server.params_base.n_predict,
 ctx_server.get_slot_n_ctx(),
 ctx_server.params_base.spm_infill,
 tokenized_prompts[0].get_text_tokens() // TODO: this could maybe be multimodal.
 );

 std::vector<raw_buffer> files; // dummy
 return handle_completions_impl(
 ctx_server,
 SERVER_TASK_TYPE_INFILL,
 data,
 files,
 req.should_stop,
 TASK_RESPONSE_TYPE_NONE); // infill is not OAI compatible
 };

 this->post_completions = [this](const server_http_req & req) {
 std::vector<raw_buffer> files; // dummy
 const json body = json::parse(req.body);
 return handle_completions_impl(
 ctx_server,
 SERVER_TASK_TYPE_COMPLETION,
 body,
 files,
 req.should_stop,
 TASK_RESPONSE_TYPE_NONE);
 };

 this->post_completions_oai = [this](const server_http_req & req) {
 std::vector<raw_buffer> files; // dummy
 const json body = json::parse(req.body);
 return handle_completions_impl(
 ctx_server,
 SERVER_TASK_TYPE_COMPLETION,
 body,
 files,
 req.should_stop,
 TASK_RESPONSE_TYPE_OAI_CMPL);
 };

 this->post_chat_completions = [this](const server_http_req & req) {
 std::vector<raw_buffer> files;
 json body = json::parse(req.body);
 json body_parsed = oaicompat_chat_params_parse(
 body,
 ctx_server.oai_parser_opt,
 files);
 return handle_completions_impl(
 ctx_server,
 SERVER_TASK_TYPE_COMPLETION,
 body_parsed,
 files,
 req.should_stop,
 TASK_RESPONSE_TYPE_OAI_CHAT);
 };

 this->post_anthropic_messages = [this](const server_http_req & req) {
 std::vector<raw_buffer> files;
 json body = convert_anthropic_to_oai(json::parse(req.body));
 json body_parsed = oaicompat_chat_params_parse(
 body,
 ctx_server.oai_parser_opt,
 files);
 return handle_completions_impl(
 ctx_server,
 SERVER_TASK_TYPE_COMPLETION,
 body_parsed,
 files,
 req.should_stop,
 TASK_RESPONSE_TYPE_ANTHROPIC);
 };

 this->post_anthropic_count_tokens = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 std::vector<raw_buffer> files;
 json body = convert_anthropic_to_oai(json::parse(req.body));
 json body_parsed = oaicompat_chat_params_parse(
 body,
 ctx_server.oai_parser_opt,
 files);

 json prompt = body_parsed.at("prompt");
 llama_tokens tokens = tokenize_mixed(ctx_server.vocab, prompt, true, true);

 res->ok({{"input_tokens", static_cast<int>(tokens.size())}});
 return res;
 };

 // same with handle_chat_completions, but without inference part
 this->post_apply_template = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 std::vector<raw_buffer> files; // dummy, unused
 json body = json::parse(req.body);
 json data = oaicompat_chat_params_parse(
 body,
 ctx_server.oai_parser_opt,
 files);
 res->ok({{ "prompt", std::move(data.at("prompt")) }});
 return res;
 };

 this->get_models = [this](const server_http_req &) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 json model_meta = nullptr;
 if (is_ready()) {
 model_meta = ctx_server.model_meta();
 }
 bool has_mtmd = ctx_server.mctx != nullptr;
 json models = {
 {"models", {
 {
 {"name", ctx_server.model_name},
 {"model", ctx_server.model_name},
 {"modified_at", ""},
 {"size", ""},
 {"digest", ""}, // dummy value, llama.cpp does not support managing model file's hash
 {"type", "model"},
 {"description", ""},
 {"tags", {""}},
 {"capabilities", has_mtmd ? json({"completion","multimodal"}) : json({"completion"})},
 {"parameters", ""},
 {"details", {
 {"parent_model", ""},
 {"format", "gguf"},
 {"family", ""},
 {"families", {""}},
 {"parameter_size", ""},
 {"quantization_level", ""}
 }}
 }
 }},
 {"object", "list"},
 {"data", {
 {
 {"id", ctx_server.model_name},
 {"object", "model"},
 {"created", std::time(0)},
 {"owned_by", "llamacpp"},
 {"meta", model_meta},
 },
 }}
 };

 res->ok(models);
 return res;
 };

 this->post_tokenize = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 const json body = json::parse(req.body);
 json tokens_response = json::array();
 if (body.count("content") != 0) {
 const bool add_special = json_value(body, "add_special", false);
 const bool parse_special = json_value(body, "parse_special", true);
 const bool with_pieces = json_value(body, "with_pieces", false);

 llama_tokens tokens = tokenize_mixed(ctx_server.vocab, body.at("content"), add_special, parse_special);

 if (with_pieces) {
 for (const auto& token : tokens) {
 std::string piece = common_token_to_piece(ctx_server.ctx, token);
 json piece_json;

 // Check if the piece is valid UTF-8
 if (is_valid_utf8(piece)) {
 piece_json = piece;
 } else {
 // If not valid UTF-8, store as array of byte values
 piece_json = json::array();
 for (unsigned char c : piece) {
 piece_json.push_back(static_cast<int>(c));
 }
 }

 tokens_response.push_back({
 {"id", token},
 {"piece", piece_json}
 });
 }
 } else {
 tokens_response = tokens;
 }
 }

 res->ok(json{{"tokens", std::move(tokens_response)}});
 return res;
 };

 this->post_detokenize = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 const json body = json::parse(req.body);

 std::string content;
 if (body.count("tokens") != 0) {
 const llama_tokens tokens = body.at("tokens");
 content = tokens_to_str(ctx_server.ctx, tokens);
 }

 res->ok(json{{"content", std::move(content)}});
 return res;
 };

 this->post_embeddings = [this](const server_http_req & req) {
 return handle_embeddings_impl(req, TASK_RESPONSE_TYPE_NONE);
 };

 this->post_embeddings_oai = [this](const server_http_req & req) {
 return handle_embeddings_impl(req, TASK_RESPONSE_TYPE_OAI_EMBD);
 };

 this->post_rerank = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 if (!ctx_server.params_base.embedding || ctx_server.params_base.pooling_type != LLAMA_POOLING_TYPE_RANK) {
 res->error(format_error_response("This server does not support reranking. Start it with `--reranking`", ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }

 const json body = json::parse(req.body);

 // if true, use TEI API format, otherwise use Jina API format
 // Jina: https://jina.ai/reranker/
 // TEI: https://huggingface.github.io/text-embeddings-inference/#/Text%20Embeddings%20Inference/rerank
 bool is_tei_format = body.contains("texts");

 json query;
 if (body.count("query") == 1) {
 query = body.at("query");
 if (!query.is_string()) {
 res->error(format_error_response("\"query\" must be a string", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 } else {
 res->error(format_error_response("\"query\" must be provided", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 std::vector<std::string> documents = json_value(body, "documents",
 json_value(body, "texts", std::vector<std::string>()));
 if (documents.empty()) {
 res->error(format_error_response("\"documents\" must be a non-empty string array", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 int top_n = json_value(body, "top_n", (int)documents.size());

 // create and queue the task
 json responses = json::array();
 server_response_reader rd({ctx_server.queue_tasks, ctx_server.queue_results}, HTTP_POLLING_SECONDS);
 {
 std::vector<server_task> tasks;
 tasks.reserve(documents.size());
 for (size_t i = 0; i < documents.size(); i++) {
 auto tmp = format_prompt_rerank(ctx_server.model, ctx_server.vocab, ctx_server.mctx, query, documents[i]);
 server_task task = server_task(SERVER_TASK_TYPE_RERANK);
 task.id = ctx_server.queue_tasks.get_new_id();
 task.index = i;
 task.tokens = std::move(tmp);
 tasks.push_back(std::move(task));
 }
 rd.post_tasks(std::move(tasks));
 }

 // wait for the results
 auto all_results = rd.wait_for_all(req.should_stop);

 // collect results
 if (all_results.is_terminated) {
 return res; // connection is closed
 } else if (all_results.error) {
 res->error(all_results.error->to_json());
 return res;
 } else {
 for (auto & res : all_results.results) {
 GGML_ASSERT(dynamic_cast<server_task_result_rerank*>(res.get()) != nullptr);
 responses.push_back(res->to_json());
 }
 }

 // write JSON response
 json root = format_response_rerank(
 body,
 ctx_server.model_name,
 responses,
 is_tei_format,
 documents,
 top_n);

 res->ok(root);
 return res;
 };

 this->get_lora_adapters = [this](const server_http_req &) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 json result = json::array();
 const auto & loras = ctx_server.params_base.lora_adapters;
 for (size_t i = 0; i < loras.size(); ++i) {
 auto & lora = loras[i];
 json entry = {
 {"id", i},
 {"path", lora.path},
 {"scale", lora.scale},
 {"task_name", lora.task_name},
 {"prompt_prefix", lora.prompt_prefix},
 };
 std::string alora_invocation_string = "";
 const uint64_t n_alora_tokens = llama_adapter_get_alora_n_invocation_tokens(lora.ptr);
 std::vector<llama_token> alora_invocation_tokens;
 if (n_alora_tokens) {
 const llama_token * alora_tokens = llama_adapter_get_alora_invocation_tokens(lora.ptr);
 for (uint64_t i = 0; i < n_alora_tokens; ++i) {
 alora_invocation_string += common_token_to_piece(ctx_server.ctx, alora_tokens[i]);
 alora_invocation_tokens.push_back(alora_tokens[i]);
 }
 entry["alora_invocation_string"] = alora_invocation_string;
 entry["alora_invocation_tokens"] = alora_invocation_tokens;
 }
 result.push_back(std::move(entry));
 }
 res->ok(result);
 return res;
 };

 this->post_lora_adapters = [this](const server_http_req & req) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 const json body = json::parse(req.body);
 if (!body.is_array()) {
 res->error(format_error_response("Request body must be an array", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 int task_id = ctx_server.queue_tasks.get_new_id();
 {
 server_task task(SERVER_TASK_TYPE_SET_LORA);
 task.id = task_id;
 task.set_lora = parse_lora_request(ctx_server.params_base.lora_adapters, body);
 ctx_server.queue_results.add_waiting_task_id(task_id);
 ctx_server.queue_tasks.post(std::move(task));
 }

 // get the result
 server_task_result_ptr result = ctx_server.queue_results.recv(task_id);
 ctx_server.queue_results.remove_waiting_task_id(task_id);

 if (result->is_error()) {
 res->error(result->to_json());
 return res;
 }

 GGML_ASSERT(dynamic_cast<server_task_result_apply_lora*>(result.get()) != nullptr);
 res->ok(result->to_json());
 return res;
 };
}

std::unique_ptr<server_res_generator> server_routes::handle_slots_save(const server_http_req & req, int id_slot) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 const json request_data = json::parse(req.body);
 std::string filename = request_data.at("filename");
 if (!fs_validate_filename(filename)) {
 res->error(format_error_response("Invalid filename", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 std::string filepath = params.slot_save_path + filename;

 int task_id = ctx_server.queue_tasks.get_new_id();
 {
 server_task task(SERVER_TASK_TYPE_SLOT_SAVE);
 task.id = task_id;
 task.slot_action.slot_id = id_slot;
 task.slot_action.filename = filename;
 task.slot_action.filepath = filepath;

 // TODO: use server_response_reader
 ctx_server.queue_results.add_waiting_task_id(task_id);
 ctx_server.queue_tasks.post(std::move(task));
 }

 server_task_result_ptr result = ctx_server.queue_results.recv(task_id);
 ctx_server.queue_results.remove_waiting_task_id(task_id);

 if (result->is_error()) {
 res->error(result->to_json());
 return res;
 }

 res->ok(result->to_json());
 return res;
}

std::unique_ptr<server_res_generator> server_routes::handle_slots_restore(const server_http_req & req, int id_slot) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 const json request_data = json::parse(req.body);
 std::string filename = request_data.at("filename");
 if (!fs_validate_filename(filename)) {
 res->error(format_error_response("Invalid filename", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 std::string filepath = params.slot_save_path + filename;

 int task_id = ctx_server.queue_tasks.get_new_id();
 {
 server_task task(SERVER_TASK_TYPE_SLOT_RESTORE);
 task.id = task_id;
 task.slot_action.slot_id = id_slot;
 task.slot_action.filename = filename;
 task.slot_action.filepath = filepath;

 // TODO: use server_response_reader
 ctx_server.queue_results.add_waiting_task_id(task_id);
 ctx_server.queue_tasks.post(std::move(task));
 }

 server_task_result_ptr result = ctx_server.queue_results.recv(task_id);
 ctx_server.queue_results.remove_waiting_task_id(task_id);

 if (result->is_error()) {
 res->error(result->to_json());
 return res;
 }

 GGML_ASSERT(dynamic_cast<server_task_result_slot_save_load*>(result.get()) != nullptr);
 res->ok(result->to_json());
 return res;
}

std::unique_ptr<server_res_generator> server_routes::handle_slots_erase(const server_http_req &, int id_slot) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 int task_id = ctx_server.queue_tasks.get_new_id();
 {
 server_task task(SERVER_TASK_TYPE_SLOT_ERASE);
 task.id = task_id;
 task.slot_action.slot_id = id_slot;

 // TODO: use server_response_reader
 ctx_server.queue_results.add_waiting_task_id(task_id);
 ctx_server.queue_tasks.post(std::move(task));
 }

 server_task_result_ptr result = ctx_server.queue_results.recv(task_id);
 ctx_server.queue_results.remove_waiting_task_id(task_id);

 if (result->is_error()) {
 res->error(result->to_json());
 return res;
 }

 GGML_ASSERT(dynamic_cast<server_task_result_slot_erase*>(result.get()) != nullptr);
 res->ok(result->to_json());
 return res;
}

std::unique_ptr<server_res_generator> server_routes::handle_embeddings_impl(const server_http_req & req, task_response_type res_type) {
 auto res = std::make_unique<server_res_generator>(ctx_server);
 if (!ctx_server.params_base.embedding) {
 res->error(format_error_response("This server does not support embeddings. Start it with `--embeddings`", ERROR_TYPE_NOT_SUPPORTED));
 return res;
 }

 if (res_type != TASK_RESPONSE_TYPE_NONE && llama_pooling_type(ctx_server.ctx) == LLAMA_POOLING_TYPE_NONE) {
 res->error(format_error_response("Pooling type 'none' is not OAI compatible. Please use a different pooling type", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 const json body = json::parse(req.body);

 // for the shape of input/content, see tokenize_input_prompts()
 json prompt;
 if (body.count("input") != 0) {
 prompt = body.at("input");
 } else if (body.contains("content")) {
 res_type = TASK_RESPONSE_TYPE_NONE; // "content" field is not OAI compatible
 prompt = body.at("content");
 } else {
 res->error(format_error_response("\"input\" or \"content\" must be provided", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }

 bool use_base64 = false;
 if (body.count("encoding_format") != 0) {
 const std::string& format = body.at("encoding_format");
 if (format == "base64") {
 use_base64 = true;
 } else if (format != "float") {
 res->error(format_error_response("The format to return the embeddings in. Can be either float or base64", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 }

 auto tokenized_prompts = tokenize_input_prompts(ctx_server.vocab, ctx_server.mctx, prompt, true, true);
 for (const auto & tokens : tokenized_prompts) {
 // this check is necessary for models that do not add BOS token to the input
 if (tokens.empty()) {
 res->error(format_error_response("Input content cannot be empty", ERROR_TYPE_INVALID_REQUEST));
 return res;
 }
 }

 int embd_normalize = 2; // default to Euclidean/L2 norm
 if (body.count("embd_normalize") != 0) {
 embd_normalize = body.at("embd_normalize");
 if (llama_pooling_type(ctx_server.ctx) == LLAMA_POOLING_TYPE_NONE) {
 SRV_DBG("embd_normalize is not supported by pooling type %d, ignoring it\n", llama_pooling_type(ctx_server.ctx));
 }
 }

 // create and queue the task
 json responses = json::array();
 server_response_reader rd({ctx_server.queue_tasks, ctx_server.queue_results}, HTTP_POLLING_SECONDS);
 {
 std::vector<server_task> tasks;
 for (size_t i = 0; i < tokenized_prompts.size(); i++) {
 server_task task = server_task(SERVER_TASK_TYPE_EMBEDDING);

 task.id = ctx_server.queue_tasks.get_new_id();
 task.index = i;
 task.tokens = std::move(tokenized_prompts[i]);

 // OAI-compat
 task.params.res_type = res_type;
 task.params.embd_normalize = embd_normalize;

 tasks.push_back(std::move(task));
 }
 rd.post_tasks(std::move(tasks));
 }

 // wait for the results
 auto all_results = rd.wait_for_all(req.should_stop);

 // collect results
 if (all_results.is_terminated) {
 return res; // connection is closed
 } else if (all_results.error) {
 res->error(all_results.error->to_json());
 return res;
 } else {
 for (auto & res : all_results.results) {
 GGML_ASSERT(dynamic_cast<server_task_result_embd*>(res.get()) != nullptr);
 responses.push_back(res->to_json());
 }
 }

 // write JSON response
 json root = res_type == TASK_RESPONSE_TYPE_OAI_EMBD
 ? format_embeddings_response_oaicompat(body, ctx_server.model_name, responses, use_base64)
 : json(responses);
 res->ok(root);
 return res;
}