llama : save and restore kv cache for single seq id

README.md

@@ -10,6 +10,7 @@ Inference of Meta's [LLaMA](https://arxiv.org/abs/2302.13971) model (and others)
 
 ### Recent API changes
 
+- [2024 Apr 4] State and session file functions reorganized under `llama_state_*` https://github.com/ggerganov/llama.cpp/pull/6341
 - [2024 Mar 26] Logits and embeddings API updated for compactness https://github.com/ggerganov/llama.cpp/pull/6122
 - [2024 Mar 13] Add `llama_synchronize()` + `llama_context_params.n_ubatch` https://github.com/ggerganov/llama.cpp/pull/6017
 - [2024 Mar 8] `llama_kv_cache_seq_rm()` returns a `bool` instead of `void`, and new `llama_n_seq_max()` returns the upper limit of acceptable `seq_id` in batches (relevant when dealing with multiple sequences) https://github.com/ggerganov/llama.cpp/pull/5328

examples/main/main.cpp

@@ -235,7 +235,7 @@ int main(int argc, char ** argv) {
  // The file exists and is not empty
  session_tokens.resize(n_ctx);
  size_t n_token_count_out = 0;
- if (!llama_load_session_file(ctx, path_session.c_str(), session_tokens.data(), session_tokens.capacity(), &n_token_count_out)) {
+ if (!llama_state_load_file(ctx, path_session.c_str(), session_tokens.data(), session_tokens.capacity(), &n_token_count_out)) {
  LOG_TEE("%s: error: failed to load session file '%s'\n", __func__, path_session.c_str());
  return 1;
  }
@@ -693,7 +693,7 @@ int main(int argc, char ** argv) {
  // optionally save the session on first sample (for faster prompt loading next time)
  if (!path_session.empty() && need_to_save_session && !params.prompt_cache_ro) {
  need_to_save_session = false;
- llama_save_session_file(ctx, path_session.c_str(), session_tokens.data(), session_tokens.size());
+ llama_state_save_file(ctx, path_session.c_str(), session_tokens.data(), session_tokens.size());
 
  LOG("saved session to %s\n", path_session.c_str());
  }
@@ -935,7 +935,7 @@ int main(int argc, char ** argv) {
 
  if (!path_session.empty() && params.prompt_cache_all && !params.prompt_cache_ro) {
  LOG_TEE("\n%s: saving final output to session file '%s'\n", __func__, path_session.c_str());
- llama_save_session_file(ctx, path_session.c_str(), session_tokens.data(), session_tokens.size());
+ llama_state_save_file(ctx, path_session.c_str(), session_tokens.data(), session_tokens.size());
  }
 
  llama_print_timings(ctx);

examples/save-load-state/save-load-state.cpp

@@ -24,6 +24,7 @@ int main(int argc, char ** argv) {
 
  std::string result0;
  std::string result1;
+ std::string result2;
 
  // init
  llama_model * model;
@@ -44,8 +45,8 @@ int main(int argc, char ** argv) {
 
  // save state (rng, logits, embedding and kv_cache) to file
  {
- std::vector<uint8_t> state_mem(llama_get_state_size(ctx));
- const size_t written = llama_copy_state_data(ctx, state_mem.data());
+ std::vector<uint8_t> state_mem(llama_state_get_size(ctx));
+ const size_t written = llama_state_get_data(ctx, state_mem.data());
 
  FILE *fp_write = fopen("dump_state.bin", "wb");
  fwrite(state_mem.data(), 1, written, fp_write);
@@ -97,13 +98,13 @@ int main(int argc, char ** argv) {
 
  // load state (rng, logits, embedding and kv_cache) from file
  {
- std::vector<uint8_t> state_mem(llama_get_state_size(ctx2));
+ std::vector<uint8_t> state_mem(llama_state_get_size(ctx2));
 
  FILE * fp_read = fopen("dump_state.bin", "rb");
  const size_t read = fread(state_mem.data(), 1, state_mem.size(), fp_read);
  fclose(fp_read);
 
- if (read != llama_set_state_data(ctx2, state_mem.data())) {
+ if (read != llama_state_set_data(ctx2, state_mem.data())) {
  fprintf(stderr, "\n%s : failed to read state\n", __func__);
  llama_free(ctx2);
  llama_free_model(model);
@@ -141,16 +142,104 @@ int main(int argc, char ** argv) {
  n_past += 1;
  }
 
- printf("\n");
+ printf("\n\n");
 
  llama_free(ctx2);
- llama_free_model(model);
 
  if (result0 != result1) {
  fprintf(stderr, "\n%s : error : the 2 generations are different\n", __func__);
  return 1;
  }
 
+ // make new context
+ auto* ctx3 = llama_new_context_with_model(model, llama_context_params_from_gpt_params(params));
+
+ printf("\nsingle seq run: %s", params.prompt.c_str());
+
+ // load state (rng, logits, embedding and kv_cache) from file
+ {
+ std::vector<uint8_t> state_mem(llama_state_get_size(ctx3));
+
+ FILE * fp_read = fopen("dump_state.bin", "rb");
+ const size_t read = fread(state_mem.data(), 1, state_mem.size(), fp_read);
+ fclose(fp_read);
+
+ if (read != llama_state_set_data(ctx3, state_mem.data())) {
+ fprintf(stderr, "\n%s : failed to read state\n", __func__);
+ llama_free(ctx3);
+ llama_free_model(model);
+ return 1;
+ }
+
+ fprintf(stderr, "%s : deserialized state from %zd out of a maximum of %zd bytes\n", __func__, read, state_mem.size());
+ }
+
+ // restore state (last tokens)
+ n_past = n_past_saved;
+
+ // save seq 0 and load into seq 1
+ {
+ // save kv of seq 0
+ std::vector<uint8_t> seq_store(llama_state_seq_get_size(ctx3, 0));
+ const size_t ncopy = llama_state_seq_get_data(ctx3, seq_store.data(), 0);
+ if (ncopy != seq_store.size()) {
+ fprintf(stderr, "\n%s : seq copy data length %zd does not match expected length %zd\n", __func__, ncopy, seq_store.size());
+ llama_free(ctx3);
+ llama_free_model(model);
+ return 1;
+ }
+ fprintf(stderr, "%s : seq 0 copied, %zd bytes\n", __func__, ncopy);
+
+ // erase whole kv
+ llama_kv_cache_clear(ctx3);
+ fprintf(stderr, "%s : kv cache cleared\n", __func__);
+
+ // restore kv into seq 1
+ const size_t nset = llama_state_seq_set_data(ctx3, seq_store.data(), 1);
+ if (nset != seq_store.size()) {
+ fprintf(stderr, "\n%s : seq set data length %zd does not match expected length %zd\n", __func__, nset, seq_store.size());
+ llama_free(ctx3);
+ llama_free_model(model);
+ return 1;
+ }
+ fprintf(stderr, "%s : seq 1 restored, %zd bytes\n", __func__, nset);
+ }
+
+ // third run with seq 1 instead of 0
+ for (auto i = 0; i < params.n_predict; i++) {
+ auto * logits = llama_get_logits(ctx3);
+ auto n_vocab = llama_n_vocab(model);
+ std::vector<llama_token_data> candidates;
+ candidates.reserve(n_vocab);
+ for (llama_token token_id = 0; token_id < n_vocab; token_id++) {
+ candidates.emplace_back(llama_token_data{token_id, logits[token_id], 0.0f});
+ }
+ llama_token_data_array candidates_p = { candidates.data(), candidates.size(), false };
+ auto next_token = llama_sample_token(ctx3, &candidates_p);
+ auto next_token_str = llama_token_to_piece(ctx3, next_token);
+
+ printf("%s", next_token_str.c_str());
+ result2 += next_token_str;
+
+ if (llama_decode(ctx3, llama_batch_get_one(&next_token, 1, n_past, 1))) {
+ fprintf(stderr, "\n%s : failed to evaluate\n", __func__);
+ llama_free(ctx3);
+ llama_free_model(model);
+ return 1;
+ }
+ n_past += 1;
+ }
+
+ printf("\n");
+
+ llama_free(ctx3);
+ llama_free_model(model);
+
+ if (result0 != result2) {
+ fprintf(stderr, "\n%s : error : the seq restore generation is different\n", __func__);
+ return 1;
+ }
+
  fprintf(stderr, "\n%s : success\n", __func__);
 
  return 0;

examples/server/README.md

@@ -57,6 +57,7 @@ page cache before using this. See https://github.com/ggerganov/llama.cpp/issues/
 - `-n N, --n-predict N`: Set the maximum tokens to predict. Default: `-1`
 - `--slots-endpoint-disable`: To disable slots state monitoring endpoint. Slots state may contain user data, prompts included.
 - `--metrics`: enable prometheus `/metrics` compatible endpoint. Default: disabled
+- `--slot-save-path PATH`: Specifies the path where the state of slots (the prompt cache) can be stored. If not provided, the slot management endpoints will be disabled.
 - `--chat-template JINJA_TEMPLATE`: Set custom jinja chat template. This parameter accepts a string, not a file name. Default: template taken from model's metadata. We only support [some pre-defined templates](https://github.com/ggerganov/llama.cpp/wiki/Templates-supported-by-llama_chat_apply_template)
 - `--log-disable`: Output logs to stdout only, not to `llama.log`. Default: enabled
 - `--log-format FORMAT`: Define the log output to FORMAT: json or text Default: `json`
@@ -517,6 +518,57 @@ Available metrics:
 - `llamacpp:requests_processing`: Number of requests processing.
 - `llamacpp:requests_deferred`: Number of requests deferred.
 
+- **POST** `/slots/{id_slot}?action=save`: Save the prompt cache of the specified slot to a file.
+
+ *Options:*
+
+ `filename`: Name of the file to save the slot's prompt cache. The file will be saved in the directory specified by the `--slot-save-path` server parameter.
+
+### Result JSON
+
+```json
+{
+ "id_slot": 0,
+ "filename": "slot_save_file.bin",
+ "n_saved": 1745,
+ "n_written": 14309796,
+ "timings": {
+ "save_ms": 49.865
+ }
+}
+```
+
+- **POST** `/slots/{id_slot}?action=restore`: Restore the prompt cache of the specified slot from a file.
+
+ *Options:*
+
+ `filename`: Name of the file to restore the slot's prompt cache from. The file should be located in the directory specified by the `--slot-save-path` server parameter.
+
+### Result JSON
+
+```json
+{
+ "id_slot": 0,
+ "filename": "slot_save_file.bin",
+ "n_restored": 1745,
+ "n_read": 14309796,
+ "timings": {
+ "restore_ms": 42.937
+ }
+}
+```
+
+- **POST** `/slots/{id_slot}?action=erase`: Erase the prompt cache of the specified slot.
+
+### Result JSON
+
+```json
+{
+ "id_slot": 0,
+ "n_erased": 1745
+}
+```
+
 ## More examples
 
 ### Change system prompt on runtime