[llm] Add a generic text only LLM runner

Pull Request resolved: #11342

Introducing `text_llm_runner`. This can be used to run all text only decoder only LLM models supported by ExecuTorch.

* Metadata is being read out from the .pte file and being used to construct the runner object.
* examples/models/llama/runner.h[.cpp] only contains a simple wrapper around `text_llm_runner.h[.cpp]`.


In next PRs I will move examples/models/phi-3-mini/runner to use the generic runner.

Will look into QNN and MediaTek runners as well.
ghstack-source-id: 288166246
@exported-using-ghexport

Differential Revision: [D75910889](https://our.internmc.facebook.com/intern/diff/D75910889/)

Author: larryliu0820

examples/demo-apps/apple_ios/LLaMA/LLaMARunner/LLaMARunner/Exported/LLaMARunner.mm

@@ -31,7 +31,7 @@ - (instancetype)initWithModelPath:(NSString*)modelPath
   self = [super init];
   if (self) {
     [ExecuTorchLog.sharedLog addSink:self];
-    _runner = example::Runner::create(
+    _runner = example::create_llama_runner(
         modelPath.UTF8String, tokenizerPath.UTF8String);
   }
   return self;

examples/models/llama/main.cpp

@@ -81,8 +81,13 @@ int32_t main(int32_t argc, char** argv) {
   }
 #endif
   // create llama runner
-  std::unique_ptr<example::Runner> runner =
-      example::Runner::create(model_path, tokenizer_path, data_path);
+  std::unique_ptr<::executorch::extension::llm::TextLLMRunner> runner =
+      example::create_llama_runner(model_path, tokenizer_path, data_path);
+
+  if (runner == nullptr) {
+    ET_LOG(Error, "Failed to create llama runner");
+    return 1;
+  }
 
   if (warmup) {
     runner->warmup(prompt, /*max_new_tokens=*/seq_len);

examples/models/llama/runner/runner.cpp

@@ -11,8 +11,7 @@
 // The module takes in a string as input and emits a string as output.
 
 #include <executorch/examples/models/llama/runner/runner.h>
-
-#include <executorch/extension/llm/runner/util.h>
+#include <executorch/extension/module/module.h>
 
 #include <executorch/examples/models/llama/tokenizer/llama_tiktoken.h>
 #include <pytorch/tokenizers/hf_tokenizer.h>
@@ -26,41 +25,14 @@ using ::executorch::runtime::Result;
 
 namespace llm = ::executorch::extension::llm;
 
-namespace {
-static constexpr auto kEnableDynamicShape = "enable_dynamic_shape";
-static constexpr auto kBosId = "get_bos_id";
-static constexpr auto kEosIds = "get_eos_ids";
-static constexpr auto kMaxSeqLen = "get_max_seq_len";
-static constexpr auto kMaxContextLen = "get_max_context_len";
-static constexpr auto kVocabSize = "get_vocab_size";
-static constexpr auto kUseKVCache = "use_kv_cache";
-static constexpr auto kUseSDPAWithKVCache = "use_sdpa_with_kv_cache";
-
-std::unique_ptr<::tokenizers::Tokenizer> load_tokenizer(
-    const std::string& tokenizer_path) {
-  auto json_tokenizer = std::make_unique<tokenizers::HFTokenizer>();
-  if (json_tokenizer->load(tokenizer_path) == ::tokenizers::Error::Ok) {
-    ET_LOG(Info, "Loaded json tokenizer");
-    return json_tokenizer;
-  }
-
-  auto tiktoken_tokenizer = get_tiktoken_for_llama();
-  if (tiktoken_tokenizer->load(tokenizer_path) == ::tokenizers::Error::Ok) {
-    ET_LOG(Info, "Loaded TikToken tokenizer");
-    return tiktoken_tokenizer;
-  }
-
-  auto bpe_tokenizer = std::make_unique<::tokenizers::Llama2cTokenizer>();
-  if (bpe_tokenizer->load(tokenizer_path) == ::tokenizers::Error::Ok) {
-    ET_LOG(Info, "Loaded BPE tokenizer");
-    return bpe_tokenizer;
-  }
-
-  return nullptr;
+std::unique_ptr<::tokenizers::Tokenizer> load_llama_tokenizer(
+    const std::string& tokenizer_path,
+    Version version) {
+  auto special_tokens = get_special_tokens(version);
+  return llm::load_tokenizer(tokenizer_path, std::move(special_tokens));
 }
-} // namespace
 
-std::unique_ptr<Runner> Runner::create(
+std::unique_ptr<llm::TextLLMRunner> create_llama_runner(
     const std::string& model_path,
     const std::string& tokenizer_path,
     std::optional<const std::string> data_path,
@@ -71,309 +43,19 @@ std::unique_ptr<Runner> Runner::create(
       model_path.c_str(),
       tokenizer_path.c_str());
 
-  // Create the Module
-  std::unique_ptr<Module> module;
-  if (data_path.has_value()) {
-    module = std::make_unique<Module>(
-        model_path, data_path.value(), Module::LoadMode::File);
-  } else {
-    module = std::make_unique<Module>(model_path, Module::LoadMode::File);
-  }
-
-  // Initialize metadata with default values
-  std::unordered_map<std::string, int64_t> metadata({
-      {kEnableDynamicShape, false},
-      {kMaxSeqLen, 128},
-      {kMaxContextLen, 128},
-      {kUseKVCache, true},
-      {kUseSDPAWithKVCache, false},
-  });
-
   // Create and load tokenizer
   std::unique_ptr<::tokenizers::Tokenizer> tokenizer =
-      load_tokenizer(tokenizer_path);
+      load_llama_tokenizer(tokenizer_path, Version::Default);
 
-  // Fallback to BPE tokenizer if tiktoken fails
   if (tokenizer == nullptr) {
     ET_LOG(
         Info,
         "Failed to load %s as a Tiktoken, Sentencepiece or Llama2.c tokenizer, make sure the artifact is one of these types",
         tokenizer_path.c_str());
     return nullptr;
   }
-
-  ET_LOG(Info, "Reading metadata from model");
-
-  // Set tokenizer-related metadata
-  metadata[kBosId] = tokenizer->bos_tok();
-  auto eos_ids = std::make_unique<std::unordered_set<uint64_t>>(
-      std::unordered_set<uint64_t>{tokenizer->eos_tok()});
-  metadata[kVocabSize] = tokenizer->vocab_size();
-
-  // Read metadata from the model
-  auto method_names_result = module->method_names();
-  if (method_names_result.error() != Error::Ok) {
-    ET_LOG(Error, "Failed reading method names");
-    return nullptr;
-  }
-  const auto method_names = method_names_result.get();
-
-  for (auto& pair : metadata) {
-    const auto& method_name = pair.first;
-    auto& value = pair.second;
-
-    if (method_names.count(method_name)) {
-      auto get_result = module->get(method_name);
-      value = get_result.get().toScalar().to<decltype(metadata)::mapped_type>();
-    } else {
-      ET_LOG(
-          Info,
-          "Method %s not found, using the default value %" PRId64,
-          method_name.c_str(),
-          value);
-    }
-    ET_LOG(Info, "Metadata: %s = %" PRId64, method_name.c_str(), value);
-  }
-
-  // Get EOS IDs if available
-  if (method_names.count(kEosIds)) {
-    eos_ids->clear();
-    auto execute_result = module->execute(kEosIds);
-    if (execute_result.error() != Error::Ok) {
-      ET_LOG(Error, "Failed to execute %s", kEosIds);
-      return nullptr;
-    }
-    for (const auto& eos_id : execute_result.get()) {
-      auto value = eos_id.toScalar().to<int64_t>();
-      eos_ids->emplace(value);
-      ET_LOG(Info, "eos_id = %" PRId64, value);
-    }
-  }
-
-  // Create text_decoder_runner. Use a shared_ptr so that it can be shared with
-  // TextPrefiller and TextTokenGenerator
-  auto text_decoder_runner = std::make_unique<llm::TextDecoderRunner>(
-      module.get(), metadata.at(kUseKVCache));
-
-  // Create text_prefiller
-  auto text_prefiller = std::make_unique<llm::TextPrefiller>(
-      text_decoder_runner.get(),
-      metadata.at(kUseKVCache),
-      metadata.at(kEnableDynamicShape),
-      metadata.at(kMaxSeqLen));
-
-  // Create text_token_generator with stats
-  auto stats = std::make_unique<llm::Stats>();
-  auto text_token_generator = std::make_unique<llm::TextTokenGenerator>(
-      tokenizer.get(),
-      text_decoder_runner.get(),
-      metadata.at(kUseKVCache),
-      std::move(eos_ids),
-      stats.get());
-
-  // Create and return the Runner instance
-  return std::make_unique<Runner>(
-      std::move(metadata),
-      std::move(tokenizer),
-      std::move(module),
-      std::move(text_decoder_runner),
-      std::move(text_prefiller),
-      std::move(text_token_generator),
-      std::move(stats),
-      temperature);
-}
-
-Runner::Runner(
-    std::unordered_map<std::string, int64_t> metadata,
-    std::unique_ptr<::tokenizers::Tokenizer> tokenizer,
-    std::unique_ptr<::executorch::extension::Module> module,
-    std::unique_ptr<::executorch::extension::llm::TextDecoderRunner>
-        text_decoder_runner,
-    std::unique_ptr<::executorch::extension::llm::TextPrefiller> text_prefiller,
-    std::unique_ptr<::executorch::extension::llm::TextTokenGenerator>
-        text_token_generator,
-    std::unique_ptr<::executorch::extension::llm::Stats> stats,
-    float temperature)
-    : tokenizer_(std::move(tokenizer)),
-      metadata_(std::move(metadata)),
-      module_(std::move(module)),
-      text_decoder_runner_(std::move(text_decoder_runner)),
-      text_prefiller_(std::move(text_prefiller)),
-      text_token_generator_(std::move(text_token_generator)),
-      stats_(std::move(stats)),
-      temperature_(temperature) {
-  // Note: This constructor assumes that text_prefiller and text_token_generator
-  // already have references to the Module and TextDecoderRunner they need
-}
-
-bool Runner::is_loaded() const {
-  return text_prefiller_->is_loaded() && text_token_generator_->is_loaded();
-}
-
-Error Runner::load() {
-  if (is_loaded()) {
-    return Error::Ok;
-  }
-  ET_CHECK_OK_OR_RETURN_ERROR(text_prefiller_->load());
-  ET_CHECK_OK_OR_RETURN_ERROR(text_token_generator_->load());
-  return Error::Ok;
-}
-
-// Don't print with the same priority during warmup
-#define RUNNER_ET_LOG(warmup, format, ...) \
-  if (warmup) {                            \
-    ET_LOG(Debug, format, __VA_ARGS__);    \
-  } else {                                 \
-    ET_LOG(Info, format, __VA_ARGS__);     \
-  }
-
-Error Runner::generate(
-    const std::string& prompt,
-    const ::executorch::extension::llm::GenerationConfig& config,
-    std::function<void(const std::string&)> token_callback,
-    std::function<void(const llm::Stats&)> stats_callback) {
-  // Prepare the inputs.
-  // Use ones-initialized inputs.
-  ET_CHECK_MSG(!prompt.empty(), "Prompt cannot be null");
-  if (!is_loaded()) {
-    stats_->model_load_start_ms = llm::time_in_ms();
-    ET_CHECK_OK_OR_RETURN_ERROR(load());
-    stats_->model_load_end_ms = llm::time_in_ms();
-  }
-
-  if (config.warming) {
-    ET_LOG(Info, "Doing a warmup run...");
-  }
-
-  RUNNER_ET_LOG(
-      config.warming,
-      "RSS after loading model: %f MiB (0 if unsupported)",
-      llm::get_rss_bytes() / 1024.0 / 1024.0);
-
-  // Wrap the token_callback with print function
-  std::function<void(const std::string&)> wrapped_callback =
-      [token_callback, config](const std::string& piece) {
-        if (!config.warming) {
-          llm::safe_printf(piece.c_str());
-          fflush(stdout);
-        }
-        if (token_callback) {
-          token_callback(piece);
-        }
-      };
-  // First token time only measures the time it takes to encode the prompt and
-  // return a response token.
-
-  stats_->inference_start_ms = llm::time_in_ms();
-  shouldStop_ = false;
-
-  ::tokenizers::Result<std::vector<uint64_t>> encode_res = tokenizer_->encode(
-      prompt,
-      /* bos */ 0,
-      /* eos */ 0);
-
-  ET_CHECK_TK_OK_OR_RETURN_ERROR(
-      encode_res.error(), "Failed to encode prompt %s", prompt.c_str());
-
-  // encode the (string) prompt into tokens sequence
-  std::vector<uint64_t> prompt_tokens = encode_res.get();
-  int num_prompt_tokens = prompt_tokens.size();
-
-  ET_CHECK_MSG(num_prompt_tokens >= 1, "Expected at least 1 prompt token");
-  ET_CHECK_MSG(
-      num_prompt_tokens < metadata_.at(kMaxContextLen),
-      "num_prompt_tokens %d >= max_seq_len_ %" PRId64
-      ", Max seq length exceeded - please increase max seq len value in your export script",
-      num_prompt_tokens,
-      metadata_.at(kMaxContextLen));
-
-  // Determine max_new_tokens using the GenerationConfig's resolve method
-  int max_new_tokens = config.resolve_max_new_tokens(
-      metadata_.at(kMaxContextLen), num_prompt_tokens);
-
-  ET_LOG(Info, "Max new tokens resolved: %d", max_new_tokens);
-
-  // Prefill first
-  // Here feed all tokens to the model and get the next predicted token
-  // after the prompt. After that we will enter generate loop.
-
-  // print prompts
-  if (config.echo) {
-    wrapped_callback(prompt);
-  }
-  int64_t pos = 0;
-  auto prefill_res = text_prefiller_->prefill(prompt_tokens, pos);
-  ET_CHECK_OK_OR_RETURN_ERROR(prefill_res.error());
-  uint64_t cur_token = prefill_res.get();
-  stats_->first_token_ms = llm::time_in_ms();
-  stats_->prompt_eval_end_ms = llm::time_in_ms();
-
-  // print the first token from prefill. No prev_token so use cur_token for it.
-  wrapped_callback(
-      ET_UNWRAP_TOKENIZER(tokenizer_->decode(cur_token, cur_token)));
-  RUNNER_ET_LOG(
-      config.warming,
-      "RSS after prompt prefill: %f MiB (0 if unsupported)",
-      llm::get_rss_bytes() / 1024.0 / 1024.0);
-
-  // start the main loop
-  prompt_tokens.push_back(cur_token);
-
-  // Generate max_new_tokens - 1 because prefill already generated 1 token.
-  int64_t num_generated_tokens = ET_UNWRAP(text_token_generator_->generate(
-      prompt_tokens,
-      num_prompt_tokens,
-      max_new_tokens - 1,
-      temperature_ == -1.0f ? config.temperature : temperature_,
-      wrapped_callback));
-
-  stats_->inference_end_ms = llm::time_in_ms();
-  if (!config.warming) {
-    printf("\n");
-  }
-  RUNNER_ET_LOG(
-      config.warming,
-      "RSS after finishing text generation: %f MiB (0 if unsupported)",
-      llm::get_rss_bytes() / 1024.0 / 1024.0);
-
-  if (num_generated_tokens == max_new_tokens) {
-    RUNNER_ET_LOG(config.warming, "Max new tokens %i reached!", max_new_tokens);
-  }
-
-  stats_->num_prompt_tokens = num_prompt_tokens;
-  stats_->num_generated_tokens = num_generated_tokens;
-
-  if (config.warming) {
-    ET_LOG(Info, "Warmup run finished!");
-  } else {
-    // Do not print report during warmup
-    ::executorch::llm::print_report(*stats_);
-  }
-  if (stats_callback) {
-    stats_callback(*stats_);
-  }
-
-  return Error::Ok;
-}
-
-Error Runner::warmup(const std::string& prompt, int32_t max_new_tokens) {
-  // Create a GenerationConfig for warmup
-  llm::GenerationConfig config{
-      .echo = false, .max_new_tokens = max_new_tokens, .warming = true};
-
-  // Call generate with the warmup config
-  Error err = generate(prompt, config);
-
-  // Reset stats after warmup, not resetting the std::unique_ptr!
-  stats_->reset();
-  return err;
+  return llm::create_text_llm_runner(
+      model_path, std::move(tokenizer), data_path);
 }
 
-void Runner::stop() {
-  if (is_loaded()) {
-    text_token_generator_->stop();
-  } else {
-    ET_LOG(Error, "Token generator is not loaded, cannot stop");
-  }
-}
 } // namespace example