[Bugfix] Fix None value handling in trace span creation for cancelled requests

[br4mm]

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• The purpose of the PR, such as "Fix some issue (link existing issues this PR will resolve)".
• The test plan, such as providing test command.
• The test results, such as pasting the results comparison before and after, or e2e results
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Purpose

When a request is cancelled, some metrics fields (first_token_time, finished_time, time_in_queue) can be None. The current code in create_trace_span method attempts to perform arithmetic operations on these None values, causing a TypeError and potentially crashing the application.

• Added null checks before calculating timing metrics (ttft and e2e_time)
• Only set span attributes when the calculated values are available
• Ensures graceful degradation where the span is still created with available data

Test Plan

Test Result

(Optional) Documentation Update

[github-actions]

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[gemini-code-assist]

Summary of Changes

Hello @br4mm, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request fixes a bug where the application could crash when processing cancelled requests due to None values in metrics fields. It introduces null checks and conditional attribute setting to ensure graceful degradation and prevent TypeErrors.

Highlights

• Bugfix: Addresses a TypeError that occurs when attempting arithmetic operations on None values for metrics fields in cancelled requests.
• Null Checks: Implements null checks before calculating timing metrics (ttft and e2e_time) to prevent errors.
• Span Attributes: Ensures that span attributes are only set when the calculated timing values are available, avoiding potential issues with None values.

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[gemini-code-assist]

Code Review

This pull request effectively addresses a potential TypeError in the trace span creation logic. It adds checks for None values in timing metrics, ensuring that calculations are only performed when the necessary data is available. The use of conditional checks improves the robustness of the code.

[miri-bar]

@br4mm any chance you can rebase this PR to resolve the ci failures?