Logprobs fixes for streaming chat/completions.

This also brings the two chat/completions code paths back into
alignment.

Author: zewt

endpoints/OAI/utils/chat_completion.py

@@ -47,12 +47,12 @@ def _create_response(generations: List[dict], model_name: Optional[str]):
 
         logprob_response = None
 
-        tokens = unwrap(generation.get("tokens"), [])
         token_probs = unwrap(generation.get("token_probs"), [])
-        logprobs = unwrap(generation.get("logprobs"), [])
         if token_probs:
+            tokens = unwrap(generation.get("tokens"), [])
+            logprobs = unwrap(generation.get("logprobs"), [])
             collected_token_probs = []
-            for output_token, token_logprob, top_logprobs in zip(
+            for generated_token, generated_token_logprob, top_logprobs in zip(
                 tokens, token_probs, logprobs, strict=True
             ):
                 completion_logprobs = [
@@ -62,8 +62,8 @@ def _create_response(generations: List[dict], model_name: Optional[str]):
 
                 collected_token_probs.append(
                     ChatCompletionLogprobChoice(
-                        token=output_token,
-                        logprob=token_logprob,
+                        token=generated_token,
+                        logprob=generated_token_logprob,
                         top_logprobs=completion_logprobs,
                     )
                 )
@@ -112,22 +112,30 @@ def _create_stream_chunk(
             role="assistant", content=unwrap(generation.get("text"), "")
         )
 
+        logprob_response = None
+
         token_probs = unwrap(generation.get("token_probs"), {})
         if token_probs:
-            logprobs = unwrap(generation.get("logprobs"), {})
-            top_logprobs = [
-                ChatCompletionLogprob(token=token, logprob=logprob)
-                for token, logprob in logprobs.items()
-            ]
-
-            generated_token = next(iter(token_probs))
-            token_prob_response = ChatCompletionLogprob(
-                token=generated_token,
-                logprob=token_probs[generated_token],
-                top_logprobs=top_logprobs,
-            )
+            tokens = unwrap(generation.get("tokens"), [])
+            logprobs = unwrap(generation.get("logprobs"), [])
+            collected_token_probs = []
+            for generated_token, generated_token_logprob, top_logprobs in zip(
+                tokens, token_probs, logprobs, strict=True
+            ):
+                completion_logprobs = [
+                    ChatCompletionLogprob(token=token, logprob=token_logprob)
+                    for token, token_logprob in top_logprobs.items()
+                ]
+
+                collected_token_probs.append(
+                    ChatCompletionLogprobChoice(
+                        token=generated_token,
+                        logprob=generated_token_logprob,
+                        top_logprobs=completion_logprobs,
+                    )
+                )
 
-            logprob_response = ChatCompletionLogprobs(content=[token_prob_response])
+            logprob_response = ChatCompletionLogprobs(content=collected_token_probs)
 
         choice = ChatCompletionStreamChoice(
             index=index,