docs: add modular refactoring implementation plan

2026-08-16 02:49:35 +09:00
parent 1e5758f3e4
commit 2ab2e0c641
28 changed files with 2876 additions and 1 deletions
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+# Step 16: Generic SparseAssembler
+
+## 담당 역할과 필수 스킬
+
+- 담당 역할: `implementation-agent`
+- 필수 스킬: `harness`, `fesa-cpp-msvc-tdd`
+- 이 Step만 `RED -> observed failure -> minimal GREEN -> focused/full VERIFY`로 수행한다.
+
+## 읽어야 할 파일
+
+- `/AGENTS.md`
+- `/docs/CODINGSTYLE.md`
+- `/docs/ARCHITECTURE.md`
+- `/docs/ADR.md`
+- `/docs/cpp-object-oriented-modular-refactoring/implementation-plan.md`
+- Step 14 runtime Element contribution contract
+- Step 15 DofManager and invariant contract
+- `/include/fesa/assembly/sparse_assembler.h`, `/src/fesa/assembly/sparse_assembler.cpp`
+- `/include/fesa/assembly/parallel_for.h`, `/src/fesa/assembly/parallel_for.cpp`
+- `/tests/unit/assembly/sparse_assembler_test.cpp`
+- `/tests/unit/elements/euler_beam_3d_test.cpp`
+- `/tests/unit/elements/mitc4_shell_test.cpp`
+- `/phases/cpp-object-oriented-modular-refactoring/index.json`
+- `/phases/cpp-object-oriented-modular-refactoring/step16.md`
+
+## 작업
+
+Requirement `R-PIPELINE-001`의 assembly portion을 구현한다.
+
+1. `sparse_assembler_test.cpp`에 `C-ASSEMBLY-001`을 먼저 추가한다. A fake runtime Element
+   emits a known 2x2/3x3 local contribution with nonconsecutive full DOFs; tests verify exact CSR
+   structure/values and repeated serial/TBB byte identity.
+2. Current assembler's concrete storage branch fails to assemble the fake, providing RED.
+3. Candidate API:
+
+```cpp
+Result<SparseMatrix> SparseAssembler::Assemble(
+    const ElementView& elements,
+    const DofManager& dof_manager,
+    ParallelFor& parallel_for) const;
+```
+
+4. Each stable element index owns one local COO buffer created from
+   `Element::ComputeStiffness()` and DofManager scatter. Worker threads never mutate global CSR.
+5. Concatenate and reduce in the existing stable tuple ordering. Do not replace exact fixed
+   reduction with atomics, unordered containers or nondeterministic task completion order.
+6. Remove B33/MITC4 concrete branches from SparseAssembler after both current elements flow through
+   the interface.
+
+## Acceptance Criteria
+
+```powershell
+cmake --build .harness/build --config Debug --target fesa_unit_tests
+ctest --test-dir .harness/build -C Debug -R "SparseAssembly" --output-on-failure
+$typeBranches = @(rg -n "EulerBeam3D|Mitc4Shell" src/fesa/assembly/sparse_assembler.cpp)
+if ($typeBranches.Count -ne 0) { $typeBranches; throw "Concrete element branch remains" }
+& "C:/Program Files/LLVM/bin/clang-format.exe" --dry-run --Werror `
+  include/fesa/assembly/sparse_assembler.h `
+  src/fesa/assembly/sparse_assembler.cpp `
+  tests/unit/assembly/sparse_assembler_test.cpp
+cmake --build .harness/build --config Debug
+ctest --test-dir .harness/build -C Debug --show-only=json-v1
+ctest --test-dir .harness/build -C Debug --output-on-failure
+```
+
+## 검증 및 상태 갱신
+
+- RED fake contribution, exact CSR/repeated determinism, branch scan and full CTest를 summary에 기록한다.
+- Any ordering/numeric regression is `error`; do not relax equality.
+- 성공 시 현재 Step만 `completed`로 갱신한다.
+- timestamp, retry, commit, advancement는 Executor 소유다.
+
+## 금지사항
+
+- Worker가 global CSR storage를 직접 수정하게 하지 마라.
+- Floating-point reduction order or TBB policy를 변경하지 마라.
+- Load assembly를 이 interface에 합치지 마라. 이유: separate responsibility.
+- 직접 commit하거나 hook script를 수동 실행하지 마라.