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@codeflash-ai codeflash-ai bot commented Oct 31, 2025

📄 6% (0.06x) speedup for ChatCompletionStreamState.get_final_completion in src/openai/lib/streaming/chat/_completions.py

⏱️ Runtime : 1.52 milliseconds 1.44 milliseconds (best of 55 runs)

📝 Explanation and details

The optimized code achieves a 5% speedup through several key optimizations that reduce redundant computations and improve memory efficiency:

Primary Optimizations:

  1. Pre-compute Type Resolution: The original code calls solve_response_format_t(response_format) twice - once for each cast(Any, ParsedChoice/ParsedChatCompletion) operation. The optimized version computes this once and reuses the result, eliminating the duplicate expensive type resolution.

  2. Eliminate Redundant Dictionary Creation: Instead of creating nested dictionary literals inside the construct_type_unchecked calls, the optimized version pre-builds dictionaries (msg_dict_with_parsed, choice_dict, chat_completion_dict) as separate variables. This reduces the overhead of dictionary construction during the expensive type construction calls.

  3. More Efficient Input Tools Conversion: Changed from [t for t in input_tools] list comprehension to direct list(input_tools) call, which is slightly faster for simple conversion.

  4. Reduced Attribute Access: Stores tool_call.type in a local variable tc_type to avoid repeated attribute lookups in the conditional checks.

Performance Impact:
The line profiler shows the most significant improvements in the construct_type_unchecked calls (lines with 35.5% and 32.4% of total time), where the pre-computed types and pre-built dictionaries reduce the overhead of these expensive operations. The type resolution optimization is particularly effective since solve_response_format_t() involves complex type introspection that was being duplicated.

These optimizations are most beneficial for workloads with multiple choices in chat completions, where the loop-based improvements compound, and when using complex response formats that make type resolution expensive.

Correctness verification report:

Test Status
⚙️ Existing Unit Tests 8 Passed
🌀 Generated Regression Tests 2 Passed
⏪ Replay Tests 🔘 None Found
🔎 Concolic Coverage Tests 🔘 None Found
📊 Tests Coverage 100.0%
⚙️ Existing Unit Tests and Runtime
Test File::Test Function Original ⏱️ Optimized ⏱️ Speedup
lib/chat/test_completions_streaming.py::test_chat_completion_state_helper 1.52ms 1.44ms 5.64%✅
🌀 Generated Regression Tests and Runtime
import pytest
from openai.lib.streaming.chat._completions import ChatCompletionStreamState

# --- Minimal stubs for types and helpers to allow tests to run standalone ---

class DummyParsedChatCompletion:
    def __init__(self, id, choices):
        self.id = id
        self.choices = choices

    def to_dict(self):
        return {"id": self.id, "choices": [c.to_dict() for c in self.choices]}

class DummyParsedChoice:
    def __init__(self, message, finish_reason="stop"):
        self.message = message
        self.finish_reason = finish_reason

    def to_dict(self):
        return {"message": self.message.to_dict(), "finish_reason": self.finish_reason}

class DummyParsedMessage:
    def __init__(self, content, tool_calls=None, refusal=False):
        self.content = content
        self.tool_calls = tool_calls or []
        self.refusal = refusal

    def to_dict(self):
        return {
            "content": self.content,
            "tool_calls": [tc.to_dict() for tc in self.tool_calls] if self.tool_calls else None,
            "refusal": self.refusal,
        }

class DummyToolCall:
    def __init__(self, type, id="tool1", function=None, custom=None):
        self.type = type
        self.id = id
        self.function = function
        self.custom = custom

    def to_dict(self):
        out = {"type": self.type, "id": self.id}
        if self.type == "function":
            out["function"] = self.function
        if self.type == "custom":
            out["custom"] = self.custom
        return out

class DummyFunction:
    def __init__(self, name, arguments):
        self.name = name
        self.arguments = arguments

class DummyCustom:
    def __init__(self, name):
        self.name = name

# --- Exception stubs ---

class LengthFinishReasonError(Exception):
    pass

class ContentFilterFinishReasonError(Exception):
    pass

# --- The function under test, simplified for standalone testing ---
def get_final_completion(state):
    """
    Simulates the behavior of ChatCompletionStreamState.get_final_completion().
    Expects `state` to have a .current_completion_snapshot attribute,
    which is a DummyParsedChatCompletion.
    """
    # Simulate raising for length/content_filter finish_reason
    for choice in state.current_completion_snapshot.choices:
        if getattr(choice, "finish_reason", None) == "length":
            raise LengthFinishReasonError()
        if getattr(choice, "finish_reason", None) == "content_filter":
            raise ContentFilterFinishReasonError()
    # Simulate parsing tool_calls and content
    # (for this test, just return the snapshot as is)
    return state.current_completion_snapshot

# --- Helper for state simulation ---
class DummyState:
    def __init__(self, snapshot):
        self.current_completion_snapshot = snapshot

# --- Unit Tests ---

# 1. Basic Test Cases













#------------------------------------------------
import pytest
from openai.lib.streaming.chat._completions import ChatCompletionStreamState

# --- Function to test: get_final_completion ---
# Since the actual implementation is not provided, we create a minimal but correct
# implementation based on the docstring and context above. For testing purposes,
# we will simulate a simple version and mock the required classes and behaviors.

# --- Minimal stubs for required classes and helpers ---

class ParsedChatCompletion:
    def __init__(self, data):
        self.data = data
from openai.lib.streaming.chat._completions import ChatCompletionStreamState

# --- Pytest unit tests ---

# 1. Basic Test Cases






def test_no_snapshots():
    """Test when no snapshots are provided at all."""
    state = ChatCompletionStreamState()
    codeflash_output = state.get_final_completion(); result = codeflash_output

To edit these changes git checkout codeflash/optimize-ChatCompletionStreamState.get_final_completion-mhe47mvq and push.

Codeflash Static Badge

The optimized code achieves a 5% speedup through several key optimizations that reduce redundant computations and improve memory efficiency:

**Primary Optimizations:**

1. **Pre-compute Type Resolution:** The original code calls `solve_response_format_t(response_format)` twice - once for each `cast(Any, ParsedChoice/ParsedChatCompletion)` operation. The optimized version computes this once and reuses the result, eliminating the duplicate expensive type resolution.

2. **Eliminate Redundant Dictionary Creation:** Instead of creating nested dictionary literals inside the `construct_type_unchecked` calls, the optimized version pre-builds dictionaries (`msg_dict_with_parsed`, `choice_dict`, `chat_completion_dict`) as separate variables. This reduces the overhead of dictionary construction during the expensive type construction calls.

3. **More Efficient Input Tools Conversion:** Changed from `[t for t in input_tools]` list comprehension to direct `list(input_tools)` call, which is slightly faster for simple conversion.

4. **Reduced Attribute Access:** Stores `tool_call.type` in a local variable `tc_type` to avoid repeated attribute lookups in the conditional checks.

**Performance Impact:**
The line profiler shows the most significant improvements in the `construct_type_unchecked` calls (lines with 35.5% and 32.4% of total time), where the pre-computed types and pre-built dictionaries reduce the overhead of these expensive operations. The type resolution optimization is particularly effective since `solve_response_format_t()` involves complex type introspection that was being duplicated.

These optimizations are most beneficial for workloads with multiple choices in chat completions, where the loop-based improvements compound, and when using complex response formats that make type resolution expensive.
@codeflash-ai codeflash-ai bot requested a review from mashraf-222 October 31, 2025 00:28
@codeflash-ai codeflash-ai bot added ⚡️ codeflash Optimization PR opened by Codeflash AI 🎯 Quality: Medium Optimization Quality according to Codeflash labels Oct 31, 2025
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