[4/N][Refactor] Refactor AscendAttentionMetadataBuilder for better extensibility and make the builder class of torchair extend from it

[shen-shanshan]

What this PR does / why we need it?

Refactor AscendAttentionMetadataBuilder for better extensibility and make the builder class of torchair extend from it.

Extract _assemble_build_info() and _assemble_attn_metadata() method from build() in AscendAttentionMetadataBuilder for better extensibility.

Workflow of build() method:

• Prepare build info: the common logic of preparing build info.
• _assemble_build_info(): the custom logic that can be overwritten in torchair_attention.py.
• _assemble_attn_metadata(): the custom logic that can be overwritten in torchair_attention.py.

After this refactor, we can remove the build() method in AscendAttentionTorchairMetadataBuilder, and just need to overwrite these two methods: _assemble_build_info() and _assemble_attn_metadata().

Note

Do not merge this PR before #2017.

Does this PR introduce any user-facing change?

How was this patch tested?

• vLLM version: v0.10.2
• vLLM main: vllm-project/vllm@0af3ce1

[gemini-code-assist]

Code Review

This pull request refactors the build method in AscendAttentionMetadataBuilder by extracting _prepare_build_info and _assemble_build_info. This is a good change that improves modularity and extensibility, as demonstrated by the new AscendAttentionTorchairMetadataBuilder. The implementation is solid, but I've found one area in the new torchair_attention.py file with some confusing code that could be clarified.

[github-actions]

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[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[codecov]

Codecov Report

❌ Patch coverage is 70.27027% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.64%. Comparing base (2693196) to head (ea15107).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
vllm_ascend/torchair/torchair_attention.py	25.00%	9 Missing ⚠️
vllm_ascend/attention/attention_v1.py	92.00%	2 Missing ⚠️

❌ Your patch check has failed because the patch coverage (70.27%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2375      +/-   ##
==========================================
+ Coverage   72.61%   72.64%   +0.03%     
==========================================
  Files         154      154              
  Lines       21319    21333      +14     
==========================================
+ Hits        15480    15497      +17     
+ Misses       5839     5836       -3     

Flag	Coverage Δ
unittests	72.64% <70.27%> (+0.03%)	⬆️

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[shen-shanshan]

@wangxiyuan This PR has been peer reviewed in the meeting before, and the CI has all passed finally.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[shen-shanshan]

test:

pytest -sv tests/e2e/multicard/test_torchair_graph_mode.py::test_e2e_qwen2_with_torchair

output:

Generated text: 'Hello, my name is Alex and I am a'
Generated text: 'The president of the United States is a very important person.'
Generated text: 'The capital of France is Paris. It is the'
Generated text: 'The future of AI is in the hands of the'
PASSED

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.