|
| 1 | +from __future__ import annotations |
| 2 | + |
| 3 | +from collections.abc import AsyncIterator |
| 4 | +from dataclasses import dataclass, field |
| 5 | + |
| 6 | +from openai import AsyncStream |
| 7 | +from openai.types.chat import ChatCompletionChunk |
| 8 | +from openai.types.completion_usage import CompletionUsage |
| 9 | +from openai.types.responses import ( |
| 10 | + Response, |
| 11 | + ResponseCompletedEvent, |
| 12 | + ResponseContentPartAddedEvent, |
| 13 | + ResponseContentPartDoneEvent, |
| 14 | + ResponseCreatedEvent, |
| 15 | + ResponseFunctionCallArgumentsDeltaEvent, |
| 16 | + ResponseFunctionToolCall, |
| 17 | + ResponseOutputItem, |
| 18 | + ResponseOutputItemAddedEvent, |
| 19 | + ResponseOutputItemDoneEvent, |
| 20 | + ResponseOutputMessage, |
| 21 | + ResponseOutputRefusal, |
| 22 | + ResponseOutputText, |
| 23 | + ResponseRefusalDeltaEvent, |
| 24 | + ResponseTextDeltaEvent, |
| 25 | + ResponseUsage, |
| 26 | +) |
| 27 | +from openai.types.responses.response_usage import InputTokensDetails, OutputTokensDetails |
| 28 | + |
| 29 | +from ..items import TResponseStreamEvent |
| 30 | +from .fake_id import FAKE_RESPONSES_ID |
| 31 | + |
| 32 | + |
| 33 | +@dataclass |
| 34 | +class StreamingState: |
| 35 | + started: bool = False |
| 36 | + text_content_index_and_output: tuple[int, ResponseOutputText] | None = None |
| 37 | + refusal_content_index_and_output: tuple[int, ResponseOutputRefusal] | None = None |
| 38 | + function_calls: dict[int, ResponseFunctionToolCall] = field(default_factory=dict) |
| 39 | + |
| 40 | + |
| 41 | +class ChatCmplStreamHandler: |
| 42 | + @classmethod |
| 43 | + async def handle_stream( |
| 44 | + cls, |
| 45 | + response: Response, |
| 46 | + stream: AsyncStream[ChatCompletionChunk], |
| 47 | + ) -> AsyncIterator[TResponseStreamEvent]: |
| 48 | + usage: CompletionUsage | None = None |
| 49 | + state = StreamingState() |
| 50 | + |
| 51 | + async for chunk in stream: |
| 52 | + if not state.started: |
| 53 | + state.started = True |
| 54 | + yield ResponseCreatedEvent( |
| 55 | + response=response, |
| 56 | + type="response.created", |
| 57 | + ) |
| 58 | + |
| 59 | + usage = chunk.usage |
| 60 | + |
| 61 | + if not chunk.choices or not chunk.choices[0].delta: |
| 62 | + continue |
| 63 | + |
| 64 | + delta = chunk.choices[0].delta |
| 65 | + |
| 66 | + # Handle text |
| 67 | + if delta.content: |
| 68 | + if not state.text_content_index_and_output: |
| 69 | + # Initialize a content tracker for streaming text |
| 70 | + state.text_content_index_and_output = ( |
| 71 | + 0 if not state.refusal_content_index_and_output else 1, |
| 72 | + ResponseOutputText( |
| 73 | + text="", |
| 74 | + type="output_text", |
| 75 | + annotations=[], |
| 76 | + ), |
| 77 | + ) |
| 78 | + # Start a new assistant message stream |
| 79 | + assistant_item = ResponseOutputMessage( |
| 80 | + id=FAKE_RESPONSES_ID, |
| 81 | + content=[], |
| 82 | + role="assistant", |
| 83 | + type="message", |
| 84 | + status="in_progress", |
| 85 | + ) |
| 86 | + # Notify consumers of the start of a new output message + first content part |
| 87 | + yield ResponseOutputItemAddedEvent( |
| 88 | + item=assistant_item, |
| 89 | + output_index=0, |
| 90 | + type="response.output_item.added", |
| 91 | + ) |
| 92 | + yield ResponseContentPartAddedEvent( |
| 93 | + content_index=state.text_content_index_and_output[0], |
| 94 | + item_id=FAKE_RESPONSES_ID, |
| 95 | + output_index=0, |
| 96 | + part=ResponseOutputText( |
| 97 | + text="", |
| 98 | + type="output_text", |
| 99 | + annotations=[], |
| 100 | + ), |
| 101 | + type="response.content_part.added", |
| 102 | + ) |
| 103 | + # Emit the delta for this segment of content |
| 104 | + yield ResponseTextDeltaEvent( |
| 105 | + content_index=state.text_content_index_and_output[0], |
| 106 | + delta=delta.content, |
| 107 | + item_id=FAKE_RESPONSES_ID, |
| 108 | + output_index=0, |
| 109 | + type="response.output_text.delta", |
| 110 | + ) |
| 111 | + # Accumulate the text into the response part |
| 112 | + state.text_content_index_and_output[1].text += delta.content |
| 113 | + |
| 114 | + # Handle refusals (model declines to answer) |
| 115 | + if delta.refusal: |
| 116 | + if not state.refusal_content_index_and_output: |
| 117 | + # Initialize a content tracker for streaming refusal text |
| 118 | + state.refusal_content_index_and_output = ( |
| 119 | + 0 if not state.text_content_index_and_output else 1, |
| 120 | + ResponseOutputRefusal(refusal="", type="refusal"), |
| 121 | + ) |
| 122 | + # Start a new assistant message if one doesn't exist yet (in-progress) |
| 123 | + assistant_item = ResponseOutputMessage( |
| 124 | + id=FAKE_RESPONSES_ID, |
| 125 | + content=[], |
| 126 | + role="assistant", |
| 127 | + type="message", |
| 128 | + status="in_progress", |
| 129 | + ) |
| 130 | + # Notify downstream that assistant message + first content part are starting |
| 131 | + yield ResponseOutputItemAddedEvent( |
| 132 | + item=assistant_item, |
| 133 | + output_index=0, |
| 134 | + type="response.output_item.added", |
| 135 | + ) |
| 136 | + yield ResponseContentPartAddedEvent( |
| 137 | + content_index=state.refusal_content_index_and_output[0], |
| 138 | + item_id=FAKE_RESPONSES_ID, |
| 139 | + output_index=0, |
| 140 | + part=ResponseOutputText( |
| 141 | + text="", |
| 142 | + type="output_text", |
| 143 | + annotations=[], |
| 144 | + ), |
| 145 | + type="response.content_part.added", |
| 146 | + ) |
| 147 | + # Emit the delta for this segment of refusal |
| 148 | + yield ResponseRefusalDeltaEvent( |
| 149 | + content_index=state.refusal_content_index_and_output[0], |
| 150 | + delta=delta.refusal, |
| 151 | + item_id=FAKE_RESPONSES_ID, |
| 152 | + output_index=0, |
| 153 | + type="response.refusal.delta", |
| 154 | + ) |
| 155 | + # Accumulate the refusal string in the output part |
| 156 | + state.refusal_content_index_and_output[1].refusal += delta.refusal |
| 157 | + |
| 158 | + # Handle tool calls |
| 159 | + # Because we don't know the name of the function until the end of the stream, we'll |
| 160 | + # save everything and yield events at the end |
| 161 | + if delta.tool_calls: |
| 162 | + for tc_delta in delta.tool_calls: |
| 163 | + if tc_delta.index not in state.function_calls: |
| 164 | + state.function_calls[tc_delta.index] = ResponseFunctionToolCall( |
| 165 | + id=FAKE_RESPONSES_ID, |
| 166 | + arguments="", |
| 167 | + name="", |
| 168 | + type="function_call", |
| 169 | + call_id="", |
| 170 | + ) |
| 171 | + tc_function = tc_delta.function |
| 172 | + |
| 173 | + state.function_calls[tc_delta.index].arguments += ( |
| 174 | + tc_function.arguments if tc_function else "" |
| 175 | + ) or "" |
| 176 | + state.function_calls[tc_delta.index].name += ( |
| 177 | + tc_function.name if tc_function else "" |
| 178 | + ) or "" |
| 179 | + state.function_calls[tc_delta.index].call_id += tc_delta.id or "" |
| 180 | + |
| 181 | + function_call_starting_index = 0 |
| 182 | + if state.text_content_index_and_output: |
| 183 | + function_call_starting_index += 1 |
| 184 | + # Send end event for this content part |
| 185 | + yield ResponseContentPartDoneEvent( |
| 186 | + content_index=state.text_content_index_and_output[0], |
| 187 | + item_id=FAKE_RESPONSES_ID, |
| 188 | + output_index=0, |
| 189 | + part=state.text_content_index_and_output[1], |
| 190 | + type="response.content_part.done", |
| 191 | + ) |
| 192 | + |
| 193 | + if state.refusal_content_index_and_output: |
| 194 | + function_call_starting_index += 1 |
| 195 | + # Send end event for this content part |
| 196 | + yield ResponseContentPartDoneEvent( |
| 197 | + content_index=state.refusal_content_index_and_output[0], |
| 198 | + item_id=FAKE_RESPONSES_ID, |
| 199 | + output_index=0, |
| 200 | + part=state.refusal_content_index_and_output[1], |
| 201 | + type="response.content_part.done", |
| 202 | + ) |
| 203 | + |
| 204 | + # Actually send events for the function calls |
| 205 | + for function_call in state.function_calls.values(): |
| 206 | + # First, a ResponseOutputItemAdded for the function call |
| 207 | + yield ResponseOutputItemAddedEvent( |
| 208 | + item=ResponseFunctionToolCall( |
| 209 | + id=FAKE_RESPONSES_ID, |
| 210 | + call_id=function_call.call_id, |
| 211 | + arguments=function_call.arguments, |
| 212 | + name=function_call.name, |
| 213 | + type="function_call", |
| 214 | + ), |
| 215 | + output_index=function_call_starting_index, |
| 216 | + type="response.output_item.added", |
| 217 | + ) |
| 218 | + # Then, yield the args |
| 219 | + yield ResponseFunctionCallArgumentsDeltaEvent( |
| 220 | + delta=function_call.arguments, |
| 221 | + item_id=FAKE_RESPONSES_ID, |
| 222 | + output_index=function_call_starting_index, |
| 223 | + type="response.function_call_arguments.delta", |
| 224 | + ) |
| 225 | + # Finally, the ResponseOutputItemDone |
| 226 | + yield ResponseOutputItemDoneEvent( |
| 227 | + item=ResponseFunctionToolCall( |
| 228 | + id=FAKE_RESPONSES_ID, |
| 229 | + call_id=function_call.call_id, |
| 230 | + arguments=function_call.arguments, |
| 231 | + name=function_call.name, |
| 232 | + type="function_call", |
| 233 | + ), |
| 234 | + output_index=function_call_starting_index, |
| 235 | + type="response.output_item.done", |
| 236 | + ) |
| 237 | + |
| 238 | + # Finally, send the Response completed event |
| 239 | + outputs: list[ResponseOutputItem] = [] |
| 240 | + if state.text_content_index_and_output or state.refusal_content_index_and_output: |
| 241 | + assistant_msg = ResponseOutputMessage( |
| 242 | + id=FAKE_RESPONSES_ID, |
| 243 | + content=[], |
| 244 | + role="assistant", |
| 245 | + type="message", |
| 246 | + status="completed", |
| 247 | + ) |
| 248 | + if state.text_content_index_and_output: |
| 249 | + assistant_msg.content.append(state.text_content_index_and_output[1]) |
| 250 | + if state.refusal_content_index_and_output: |
| 251 | + assistant_msg.content.append(state.refusal_content_index_and_output[1]) |
| 252 | + outputs.append(assistant_msg) |
| 253 | + |
| 254 | + # send a ResponseOutputItemDone for the assistant message |
| 255 | + yield ResponseOutputItemDoneEvent( |
| 256 | + item=assistant_msg, |
| 257 | + output_index=0, |
| 258 | + type="response.output_item.done", |
| 259 | + ) |
| 260 | + |
| 261 | + for function_call in state.function_calls.values(): |
| 262 | + outputs.append(function_call) |
| 263 | + |
| 264 | + final_response = response.model_copy() |
| 265 | + final_response.output = outputs |
| 266 | + final_response.usage = ( |
| 267 | + ResponseUsage( |
| 268 | + input_tokens=usage.prompt_tokens, |
| 269 | + output_tokens=usage.completion_tokens, |
| 270 | + total_tokens=usage.total_tokens, |
| 271 | + output_tokens_details=OutputTokensDetails( |
| 272 | + reasoning_tokens=usage.completion_tokens_details.reasoning_tokens |
| 273 | + if usage.completion_tokens_details |
| 274 | + and usage.completion_tokens_details.reasoning_tokens |
| 275 | + else 0 |
| 276 | + ), |
| 277 | + input_tokens_details=InputTokensDetails( |
| 278 | + cached_tokens=usage.prompt_tokens_details.cached_tokens |
| 279 | + if usage.prompt_tokens_details and usage.prompt_tokens_details.cached_tokens |
| 280 | + else 0 |
| 281 | + ), |
| 282 | + ) |
| 283 | + if usage |
| 284 | + else None |
| 285 | + ) |
| 286 | + |
| 287 | + yield ResponseCompletedEvent( |
| 288 | + response=final_response, |
| 289 | + type="response.completed", |
| 290 | + ) |
0 commit comments