Implement streamer for text-generation and add context arg to `Pi…

…peline.engine_forward` (#1140)

* Update with engine_forward and context

* Style

* Fix test engine_forward patching

* postprocessing_kwargs -> context

src/deepsparse/pipeline.py

@@ -19,6 +19,7 @@
 import os
 from abc import ABC, abstractmethod
 from concurrent.futures import ThreadPoolExecutor
+from functools import partial
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple, Type, Union
 
@@ -228,9 +229,9 @@ def __call__(self, *args, **kwargs) -> BaseModel:
             # batch size of the inputs may be `> self._batch_size` at this point
             engine_inputs: List[numpy.ndarray] = self.process_inputs(pipeline_inputs)
             if isinstance(engine_inputs, tuple):
-                engine_inputs, postprocess_kwargs = engine_inputs
+                engine_inputs, context = engine_inputs
             else:
-                postprocess_kwargs = {}
+                context = {}
 
             timer.stop(InferenceStages.PRE_PROCESS)
             self.log(
@@ -247,7 +248,10 @@ def __call__(self, *args, **kwargs) -> BaseModel:
             )
 
             # submit split batches to engine threadpool
-            batch_outputs = list(self.executor.map(self.engine_forward, batches))
+            engine_forward_with_context = partial(self.engine_forward, context=context)
+            batch_outputs = list(
+                self.executor.map(engine_forward_with_context, batches)
+            )
 
             # join together the batches of size `self._batch_size`
             engine_outputs = self.join_engine_outputs(batch_outputs, orig_batch_size)
@@ -270,9 +274,7 @@ def __call__(self, *args, **kwargs) -> BaseModel:
 
             # ------ POSTPROCESSING ------
             timer.start(InferenceStages.POST_PROCESS)
-            pipeline_outputs = self.process_engine_outputs(
-                engine_outputs, **postprocess_kwargs
-            )
+            pipeline_outputs = self.process_engine_outputs(engine_outputs, **context)
             if not isinstance(pipeline_outputs, self.output_schema):
                 raise ValueError(
                     f"Outputs of {self.__class__} must be instances of "
@@ -486,10 +488,13 @@ def split_engine_inputs(
         """
         return split_engine_inputs(items, batch_size)
 
-    def engine_forward(self, engine_inputs: List[numpy.ndarray]) -> List[numpy.ndarray]:
+    def engine_forward(
+        self, engine_inputs: List[numpy.ndarray], context: Dict = {}
+    ) -> List[numpy.ndarray]:
         """
         :param engine_inputs: list of numpy inputs to Pipeline engine forward
             pass
+        :param context: optional dictionary to be used during engine execution
         :return: result of forward pass to Pipeline engine
         """
         return self.engine(engine_inputs)

src/deepsparse/transformers/pipelines/text_generation.py

@@ -16,10 +16,11 @@
 import os
 import warnings
 from dataclasses import dataclass
-from typing import Generator, List, Optional, Tuple, Type, Union
+from typing import Dict, Generator, List, Optional, Tuple, Type, Union
 
 import numpy
 from pydantic import BaseModel, Field
+from transformers import TextStreamer
 
 from deepsparse import Pipeline
 from deepsparse.cpu import cpu_avx512_compatible
@@ -46,6 +47,9 @@ class _TextGenerationTimings:
 
 
 class TextGenerationInput(BaseModel):
+    class Config:
+        arbitrary_types_allowed = True
+
     sequences: Union[str, List[str]] = Field(
         description="The input sequences to generate the text from.",
     )
@@ -71,6 +75,13 @@ class TextGenerationInput(BaseModel):
         "to have consistent length so one "
         "can compute metric in a batched fashion. ",
     )
+    streamer: Optional[TextStreamer] = Field(
+        default=None,
+        description="Streamer object that will be used to stream the "
+        "generated sequences. Generated tokens are passed through "
+        "`streamer.put(token_ids)` and the streamer is responsible "
+        "for any further processing.",
+    )
 
 
 class TextGenerationOutput(BaseModel):
@@ -290,7 +301,9 @@ def process_inputs(self, inputs: TextGenerationInput) -> List[numpy.ndarray]:
             self.engine.session_id = inputs.session_id
             self.multitoken_engine.session_id = inputs.session_id
 
-        postprocessing_kwargs = dict(return_logits=inputs.return_logits)
+        postprocessing_kwargs = dict(
+            return_logits=inputs.return_logits, streamer=inputs.streamer
+        )
         return engine_input, postprocessing_kwargs
 
     def process_engine_outputs(
@@ -311,7 +324,7 @@ def process_engine_outputs(
         return TextGenerationOutput(sequences=sequences, logits=logits)
 
     def engine_forward(
-        self, engine_inputs: List[numpy.ndarray], **kwargs
+        self, engine_inputs: List[numpy.ndarray], context: Dict
     ) -> Tuple[numpy.ndarray, numpy.ndarray]:
         """
         Run the forward pass on the engine.
@@ -327,6 +340,8 @@ def engine_forward(
         # main thread. That is why `engine_` is prepended to each of the timer phase
         # names in this context
         with self.timer_manager.new_timer_context(total_inference=False) as timer:
+            streamer = context.get("streamer")
+
             if not self.multitoken_engine.kv_cache_enabled:
                 tokens, prompt_logits = self.multitoken_engine(engine_inputs)
                 return numpy.array([tokens]), prompt_logits
@@ -336,6 +351,9 @@ def engine_forward(
                 with timer.time(_TextGenerationTimings.PROMPT_PREFILL):
                     tokens, prompt_logits = self.prompt_inference(engine_inputs)
 
+            if streamer is not None:
+                streamer.put(numpy.array(tokens))
+
             # create the generated output
             max_tokens = (
                 self.max_generated_tokens
@@ -354,12 +372,18 @@ def engine_forward(
                     generated_tokens.append(token)
                     generated_logits.append(logits)
 
+                    if streamer is not None:
+                        streamer.put(numpy.array([token]))
+
                     if (
                         token == self.tokenizer.eos_token_id
                         and not self.force_max_tokens
                     ):
                         break
 
+            if streamer is not None:
+                streamer.end()
+
         return numpy.array([generated_tokens]), numpy.concatenate(
             generated_logits, axis=1
         )

tests/deepsparse/pipelines/test_pipeline.py

@@ -132,7 +132,7 @@ def test_pipeline_call_is_async(engine_mock):
     executor = ThreadPoolExecutor(max_workers=1)
     pipeline = Pipeline.create("token_classification", batch_size=1, executor=executor)
 
-    def sleep_then_engine_forward(xs):
+    def sleep_then_engine_forward(xs, context):
         # each call to engine_forward also sleeps
         time.sleep(20 / 1000)
         return pipeline.engine(xs)