Add a choice of how to end streaming from callback: STOP or CANCEL

samples/cpp/text_generation/chat_sample.cpp

@@ -15,11 +15,11 @@ int main(int argc, char* argv[]) try {
 
     ov::genai::GenerationConfig config;
     config.max_new_tokens = 100;
-    std::function<bool(std::string)> streamer = [](std::string word) { 
+
+    auto streamer = [](std::string word) {
         std::cout << word << std::flush;
         // Return flag corresponds whether generation should be stopped.
-        // false means continue generation.
-        return false; 
+        return ov::genai::StreamerRunningStatus::RUNNING;
     };
 
     pipe.start_chat();

samples/cpp/text_generation/multinomial_causal_lm.cpp

@@ -21,7 +21,7 @@ int main(int argc, char* argv[]) try {
     config.top_k = 30;
     auto streamer = [](std::string subword) {
         std::cout << subword << std::flush;
-        return false;
+        return ov::genai::StreamerRunningStatus::RUNNING;
     };
 
     // Since the streamer is set, the results will

samples/cpp/text_generation/prompt_lookup_decoding_lm.cpp

@@ -29,7 +29,7 @@ int main(int argc, char* argv[]) try {
 
     auto streamer = [](std::string subword) {
         std::cout << subword << std::flush;
-        return false;
+        return ov::genai::StreamerRunningStatus::RUNNING;
     };
 
     // Since the streamer is set, the results will

samples/cpp/text_generation/speculative_decoding_lm.cpp

@@ -33,7 +33,7 @@ int main(int argc, char* argv[]) try {
 
     auto streamer = [](std::string subword) {
         std::cout << subword << std::flush;
-        return false;
+        return ov::genai::StreamerRunningStatus::RUNNING;
     };
 
     // Since the streamer is set, the results will

samples/python/text_generation/chat_sample.py

@@ -9,9 +9,7 @@
 def streamer(subword):
     print(subword, end='', flush=True)
     # Return flag corresponds whether generation should be stopped.
-    # False means continue generation.
-    return False
-
+    return openvino_genai.StreamerRunningStatus.RUNNING
 
 def main():
     parser = argparse.ArgumentParser()

samples/python/text_generation/multinomial_causal_lm.py

@@ -59,9 +59,9 @@ def get_stop_flag(self):
         Checks whether the generation process should be stopped.
 
         Returns:
-            bool: Always returns False in this implementation.
+            openvino_genai.StreamerRunningStatus: Always returns RUNNING in this implementation.
         """
-        return False
+        return openvino_genai.StreamerRunningStatus.RUNNING
 
     def put_word(self, word: str):
         """

samples/python/text_generation/prompt_lookup_decoding_lm.py

@@ -5,11 +5,10 @@
 import argparse
 import openvino_genai
 
-def streamer(subword): 
-        print(subword, end='', flush=True) 
-        # Return flag corresponds whether generation should be stopped. 
-        # False means continue generation. 
-        return False
+def streamer(subword):
+    print(subword, end='', flush=True) 
+    # Return flag corresponds whether generation should be stopped. 
+    return openvino_genai.StreamerRunningStatus.RUNNING
 
 def main():
     parser = argparse.ArgumentParser()

samples/python/text_generation/speculative_decoding_lm.py

@@ -9,8 +9,7 @@
 def streamer(subword):
     print(subword, end='', flush=True)
     # Return flag corresponds whether generation should be stopped. 
-    # False means continue generation.
-    return False
+    return openvino_genai.StreamerRunningStatus.RUNNING
 
 def main():
     parser = argparse.ArgumentParser()

samples/python/visual_language_chat/visual_language_chat.py

@@ -23,7 +23,7 @@ def streamer(subword: str) -> bool:
     print(subword, end='', flush=True)
 
     # No value is returned as in this example we don't want to stop the generation in this method.
-    # "return None" will be treated the same as "return False".
+    # "return None" will be treated the same as "return ov::genai::StreamerRunningStatus::RUNNING;".
 
 
 def read_image(path: str) -> Tensor:

src/README.md

@@ -172,8 +172,7 @@ int main(int argc, char* argv[]) {
     auto streamer = [](std::string word) {
         std::cout << word << std::flush;
         // Return flag corresponds whether generation should be stopped.
-        // false means continue generation.
-        return false;
+        return ov::genai::StreamerRunningStatus::RUNNING;
     };
     std::cout << pipe.generate("The Sun is yellow because", ov::genai::streamer(streamer), ov::genai::max_new_tokens(200));
 }

src/cpp/include/openvino/genai/generation_handle.hpp

@@ -15,8 +15,8 @@ enum class GenerationStatus {
     RUNNING = 0, // Default status for ongoing generation
     FINISHED = 1, // Status set when generation has been finished
     IGNORED = 2, // Status set when generation run into out-of-memory condition and could not be continued
-    DROPPED_BY_PIPELINE = 3, // Currently not used, TODO: implement abort functionality
-    DROPPED_BY_HANDLE = 4 // Status set when generation handle is dropped
+    CANCEL = 3, // Status set when generation handle is canceled
+    STOP = 4 // Status set when generation handle is stopped
 };
 
 struct EncodedGenerationResult {
@@ -70,10 +70,10 @@ using GenerationOutputs = std::unordered_map<uint64_t, GenerationOutput>;
 
 class GenerationStream;
 
-class OPENVINO_GENAI_EXPORTS GenerationHandleImpl {
+class OPENVINO_GENAI_EXPORTS 
+GenerationHandleImpl {
     std::shared_ptr<GenerationStream> m_generation_stream;
-    ov::genai::GenerationConfig m_sampling_params;
-
+    ov::genai::GenerationConfig m_sampling_params; 
 public:
     GenerationHandleImpl(std::shared_ptr<GenerationStream> generation_stream, const ov::genai::GenerationConfig& sampling_params) :
     m_generation_stream(std::move(generation_stream)),
@@ -88,10 +88,18 @@ class OPENVINO_GENAI_EXPORTS GenerationHandleImpl {
     GenerationStatus get_status();
 
     bool can_read();
-    bool is_dropped();
 
+    bool is_stopped();
+
+    bool is_canceled();
+
+    OPENVINO_DEPRECATED("Please, use `stop()` instead of `drop()`.")
     void drop();
 
+    void stop();
+
+    void cancel();
+
     GenerationOutputs back();
     // Reads result of a generation for single iteration
     GenerationOutputs read();

src/cpp/include/openvino/genai/llm_pipeline.hpp

@@ -18,8 +18,10 @@
 namespace ov {
 namespace genai {
 
-// Return flag corresponds whether generation should be stopped: false means continue generation, true means stop.
-using StreamerVariant = std::variant<std::function<bool(std::string)>, std::shared_ptr<StreamerBase>, std::monostate>;
+// Return flag corresponds whether generation should be stopped. It could be:
+// ov::genai::StreamerRunningStatus flag, RUNNING means continue generation, STOP means stop generation, CANCEL means stop generation and remove last propmt and answer from history
+// *DEPRECATED* bool flag, false means continue generation, true means stop. Please, use `ov::genai::StreamerRunningStatus` instead.
+using StreamerVariant = std::variant<std::function<bool(std::string)>, std::function<StreamerRunningStatus(std::string)>, std::shared_ptr<StreamerBase>, std::monostate>;
 using OptionalGenerationConfig = std::optional<GenerationConfig>;
 using EncodedInputs = std::variant<ov::Tensor, TokenizedInputs>;
 using StringInputs = std::variant<std::string, std::vector<std::string>>;

src/cpp/include/openvino/genai/streamer_base.hpp

@@ -4,16 +4,29 @@
 #pragma once
 
 #include "openvino/genai/tokenizer.hpp"
+#include "openvino/genai/generation_handle.hpp"
+#include <variant>
 
 namespace ov {
 namespace genai {
 
+enum class StreamerRunningStatus {
+    RUNNING = 0, // Continue to run of inference
+    STOP = 1, // Stop generation, keep history as is, KV cache includes last request and generated tokens
+    CANCEL = 2 // Stop generate, drop last prompt and all generated tokens from history, KV cache include history but last step
+};
+
+using CallbackTypeVariant = std::variant<bool, StreamerRunningStatus, std::monostate>;
+
 /**
  * @brief base class for streamers. In order to use inherit from from this class and implement put, and methods
  *
  * @param m_tokenizer tokenizer
  */
 class OPENVINO_GENAI_EXPORTS StreamerBase {
+protected:
+    StreamerRunningStatus m_streaming_finish_status = StreamerRunningStatus::RUNNING;
+
 public:
     /// @brief put is called every time new token is decoded,
     /// @return bool flag to indicate whether generation should be stopped, if return true generation stops
@@ -22,6 +35,12 @@ class OPENVINO_GENAI_EXPORTS StreamerBase {
     /// @brief end is called at the end of generation. It can be used to flush cache if your own streamer has one
     virtual void end() = 0;
 
+    /// @brief get_streaming_status() is called by the pipline to take more detailed about streaming status. m_streaming_finish_status, which contains streaming status info, could be set in put().
+    /// @return ov::genai::StreamerRunningStatus to determine the streaming status of generation, whether generation is running, stopped or cancelled
+    virtual StreamerRunningStatus get_streaming_status() {
+        return m_streaming_finish_status;
+    }
+
     virtual ~StreamerBase();
 };
 

src/cpp/src/continuous_batching_adapter.hpp

@@ -97,7 +97,7 @@ class ContinuousBatchingAdapter final : public LLMPipelineImplBase {
         std::vector<std::string> plain_replies;
         std::vector<float> plain_scores;
         for (GenerationResult& res : generated) {
-            OPENVINO_ASSERT(res.m_status == GenerationStatus::FINISHED || res.m_status == GenerationStatus::DROPPED_BY_HANDLE, "Got unfinished GenerationStatus");
+            OPENVINO_ASSERT(res.m_status == GenerationStatus::FINISHED || res.m_status == GenerationStatus::STOP || res.m_status == GenerationStatus::CANCEL, "Got unfinished GenerationStatus");
             std::move(res.m_generation_ids.begin(), res.m_generation_ids.end(), std::back_inserter(plain_replies));
             std::move(res.m_scores.begin(), res.m_scores.end(), std::back_inserter(plain_scores));
         }
@@ -189,7 +189,7 @@ class ContinuousBatchingAdapter final : public LLMPipelineImplBase {
         std::vector<std::vector<int64_t>> plain_tokens;
         std::vector<float> plain_scores;
         for (EncodedGenerationResult& res : generated) {
-            OPENVINO_ASSERT(res.m_status == GenerationStatus::FINISHED || res.m_status == GenerationStatus::DROPPED_BY_HANDLE, "Got unfinished GenerationStatus");
+            OPENVINO_ASSERT(res.m_status == GenerationStatus::FINISHED || res.m_status == GenerationStatus::STOP || res.m_status == GenerationStatus::CANCEL, "Got unfinished GenerationStatus");
             std::move(res.m_generation_ids.begin(), res.m_generation_ids.end(), std::back_inserter(plain_tokens));
             std::move(res.m_scores.begin(), res.m_scores.end(), std::back_inserter(plain_scores));
         }

src/cpp/src/continuous_batching_impl.cpp

@@ -420,17 +420,7 @@ ContinuousBatchingPipeline::ContinuousBatchingImpl::generate(const std::vector<o
     }
     set_adapters(sampling_params[0].adapters);
 
-    const std::shared_ptr<StreamerBase>& streamer_ptr = std::visit(overloaded{
-        [](std::monostate) -> std::shared_ptr<StreamerBase> {
-            return nullptr;
-        },
-        [](const std::shared_ptr<StreamerBase>& streamer) {
-            return streamer;
-        },
-        [this](const std::function<bool(std::string)>& streamer) -> std::shared_ptr<StreamerBase> {
-            return std::make_unique<TextCallbackStreamer>(m_tokenizer, streamer);
-        }
-    }, streamer);
+    const std::shared_ptr<StreamerBase>& streamer_ptr = ov::genai::utils::create_streamer(streamer, m_tokenizer);
 
     OPENVINO_ASSERT(streamer_ptr == nullptr || input_ids.size() == 1 && sampling_params[0].num_return_sequences == 1 &&
         (sampling_params[0].is_greedy_decoding() || sampling_params[0].is_multinomial()),
@@ -466,7 +456,7 @@ ContinuousBatchingPipeline::ContinuousBatchingImpl::generate(const std::vector<o
                     std::unordered_map<uint64_t, GenerationOutput> token = generation->read();
                     for (const auto& gen_token : token.begin()->second.generated_ids) {
                         if (streamer_ptr->put(gen_token)) {
-                            generation->drop();
+                            streamer_ptr->get_streaming_status() == ov::genai::StreamerRunningStatus::CANCEL ? generation->cancel() : generation->stop();
                             break;
                         }
                     }
@@ -525,6 +515,7 @@ ContinuousBatchingPipeline::ContinuousBatchingImpl::generate(const std::vector<o
         result.m_request_id = request_id;
         result.m_generation_ids.resize(num_outputs);
         result.m_scores.resize(num_outputs);
+        result.m_status = request->get_generation_stream()->get_status();
 
         for (size_t i = 0; i < num_outputs; ++i) {
             const auto & sequence = sequences[i];
@@ -559,7 +550,7 @@ void ContinuousBatchingPipeline::ContinuousBatchingImpl::_free_non_running_reque
     std::vector<SequenceGroup::Ptr>::iterator requests_iterator = m_requests.begin();
     while (requests_iterator != m_requests.end()) {
         const auto& request = *requests_iterator;
-        if (request->has_finished() || request->handle_dropped()) {
+        if(request->has_finished() || request->handle_stopped() || request->handle_canceled()) {
             for (const auto& sequence: request->get_sequences()) {
                 if (m_scheduler->has_block_table(sequence->get_id())) {
                     m_scheduler->free_sequence(sequence->get_id());
@@ -577,7 +568,7 @@ void ContinuousBatchingPipeline::ContinuousBatchingImpl::_notify_requests_droppe
     // Notify the last time by pushing empty output
     // This causes read() to unblock by adding anything to the queue
     for (SequenceGroup::Ptr& request : m_requests) {
-        if (request->handle_dropped())
+        if (request->handle_stopped() || request->handle_canceled())
             request->push_empty_outputs();
     }
 }

src/cpp/src/generation_handle.cpp

@@ -9,32 +9,44 @@
 using namespace ov::genai;
 
 GenerationHandleImpl::~GenerationHandleImpl() {
-    drop();
+    stop();
 }
 
 GenerationStatus GenerationHandleImpl::get_status() {
     return m_generation_stream->get_status();
 }
 
 bool GenerationHandleImpl::can_read() {
-    return !is_dropped() && m_generation_stream->can_read();
+    return !is_canceled() && !is_stopped() && m_generation_stream->can_read();
 }
 
-bool GenerationHandleImpl::is_dropped() {
-    return get_status() == GenerationStatus::DROPPED_BY_HANDLE;
+bool GenerationHandleImpl::is_stopped() {
+    return get_status() == GenerationStatus::STOP;
+}
+
+bool GenerationHandleImpl::is_canceled() {
+    return get_status() == GenerationStatus::CANCEL;
 }
 
 void GenerationHandleImpl::drop() {
-    m_generation_stream->drop();
+    m_generation_stream->stop();
+}
+
+void GenerationHandleImpl::stop() {
+    m_generation_stream->stop();
+}
+
+void GenerationHandleImpl::cancel() {
+    m_generation_stream->cancel();
 }
 
 std::unordered_map<uint64_t, GenerationOutput> GenerationHandleImpl::back() {
-    OPENVINO_ASSERT(!is_dropped(), "GenerationHandle cannot be used after it is dropped.");
+    OPENVINO_ASSERT(!is_stopped(), "GenerationHandle cannot be used after it is stopped.");
     return m_generation_stream->back();
 }
 
 std::unordered_map<uint64_t, GenerationOutput> GenerationHandleImpl::read() {
-    OPENVINO_ASSERT(!is_dropped(), "GenerationHandle cannot be used after it is dropped.");
+    OPENVINO_ASSERT(!is_stopped(), "GenerationHandle cannot be used after it is stopped.");
     return m_generation_stream->read();
 }
 
@@ -57,7 +69,7 @@ void add_partial_result(std::unordered_map<uint64_t, GenerationOutput>& partial_
 }
 
 std::vector<GenerationOutput> GenerationHandleImpl::read_all() {
-    OPENVINO_ASSERT(!is_dropped(), "GenerationHandle cannot be used after it is dropped.");
+    OPENVINO_ASSERT(!is_stopped(), "GenerationHandle cannot be used after it is stopped.");
     std::vector<GenerationOutput> results;
     std::unordered_map<uint64_t, GenerationOutput> partial_results;
     // We iterate until generation is running or there are tokens we haven't read yet

src/cpp/src/generation_stream.hpp

@@ -51,9 +51,14 @@ class GenerationStream {
         return m_status;
     }
 
-    void drop() {
+    void stop() {
         std::lock_guard<std::mutex> lock(m_mutex);
-        m_status = GenerationStatus::DROPPED_BY_HANDLE;
+        m_status = GenerationStatus::STOP;
+    }
+
+    void cancel() {
+        std::lock_guard<std::mutex> lock(m_mutex);
+        m_status = GenerationStatus::CANCEL;
     }
 };
 }

src/cpp/src/icontinuous_batching.cpp

@@ -89,7 +89,7 @@ ContinuousBatchingPipeline::IContinuousBatchingPipeline::generate(
             const auto decode_start = std::chrono::steady_clock::now();
             generated.push_back(m_tokenizer.decode(res.m_generation_ids.at(idx)));
             raw_counters.detokenization_durations.emplace_back(std::chrono::steady_clock::now() - decode_start);
-            if (m_is_chat_conversation && 0 == idx) {
+            if (m_is_chat_conversation && 0 == idx && res.m_status != ov::genai::GenerationStatus::CANCEL) {
                 m_history.push_back({{"role", "assistant"}, {"content", generated.back()}});
             }
         }
@@ -110,6 +110,10 @@ ContinuousBatchingPipeline::IContinuousBatchingPipeline::generate(
         });
     }
 
+    // if streaming was canceled, prompt/answer of current step shouldn't be presented in history, so let's remove prompt from history
+    if (m_is_chat_conversation && !encoded.empty() && encoded[0].m_status == ov::genai::GenerationStatus::CANCEL)
+        m_history.pop_back();
+
     return decoded;
 }
 }

src/cpp/src/llm_pipeline.cpp

@@ -47,7 +47,9 @@ std::pair<ov::AnyMap, ov::genai::static_llm::ModelConfigDesc> split_model_descr(
 std::pair<std::string, Any> streamer(StreamerVariant func) {
     if (auto streamer_obj = std::get_if<std::shared_ptr<StreamerBase>>(&func)) {
         return {utils::STREAMER_ARG_NAME, Any::make<std::shared_ptr<StreamerBase>>(*streamer_obj)};
-    } else  {
+    } else if (auto streamer_obj = std::get_if<std::function<StreamerRunningStatus(std::string)>>(&func)) {
+        return {utils::STREAMER_ARG_NAME, Any::make<std::function<StreamerRunningStatus(std::string)>>(*streamer_obj)};
+    } else {
         auto callback = std::get<std::function<bool(std::string)>>(func);
         return {utils::STREAMER_ARG_NAME, Any::make<std::function<bool(std::string)>>(callback)};
     }