support more optioin about usage in stream mode (#985)

Co-authored-by: Ying Sheng <sqy1415@gmail.com>

python/sglang/srt/openai_api/protocol.py

@@ -78,6 +78,10 @@ class UsageInfo(BaseModel):
     completion_tokens: Optional[int] = 0
 
 
+class StreamOptions(BaseModel):
+    include_usage: Optional[bool] = False
+
+
 class FileRequest(BaseModel):
     # https://platform.openai.com/docs/api-reference/files/create
     file: bytes  # The File object (not file name) to be uploaded
@@ -149,6 +153,7 @@ class CompletionRequest(BaseModel):
     seed: Optional[int] = None
     stop: Optional[Union[str, List[str]]] = Field(default_factory=list)
     stream: Optional[bool] = False
+    stream_options: Optional[StreamOptions] = None
     suffix: Optional[str] = None
     temperature: Optional[float] = 1.0
     top_p: Optional[float] = 1.0
@@ -188,7 +193,7 @@ class CompletionStreamResponse(BaseModel):
     created: int = Field(default_factory=lambda: int(time.time()))
     model: str
     choices: List[CompletionResponseStreamChoice]
-    usage: UsageInfo
+    usage: Optional[UsageInfo] = None
 
 
 class ChatCompletionMessageGenericParam(BaseModel):
@@ -247,6 +252,7 @@ class ChatCompletionRequest(BaseModel):
     seed: Optional[int] = None
     stop: Optional[Union[str, List[str]]] = Field(default_factory=list)
     stream: Optional[bool] = False
+    stream_options: Optional[StreamOptions] = None
     temperature: Optional[float] = 0.7
     top_p: Optional[float] = 1.0
     user: Optional[str] = None
@@ -294,6 +300,7 @@ class ChatCompletionStreamResponse(BaseModel):
     created: int = Field(default_factory=lambda: int(time.time()))
     model: str
     choices: List[ChatCompletionResponseStreamChoice]
+    usage: Optional[UsageInfo] = None
 
 
 class EmbeddingRequest(BaseModel):
@@ -310,3 +317,4 @@ class EmbeddingResponse(BaseModel):
     index: str
     embedding: List[float] = None
     object: str = "embedding"
+    usage: Optional[UsageInfo] = None