Lines 832-866 of _ckpt_process handle updating the final "live" checkpoint based on the current system state. This includes truncating the file, calculating checkpoint sizes, and calling _ckpt_update. This logic can be extracted into a helper function. The helper should be called while holding block->live_lock, and should encapsulate the logic at the live_update label through the end of the live checkpoint handling.

Files to change

• src/block/block_ckpt.c — extract live checkpoint update logic

Tasks

• [ ] Create __ckpt_update_live(session, block, ckptbase, ci, ckpt_size) that encapsulates lines 832-866 (criterion: function handles live checkpoint updates)
• [ ] Add spinlock assertion at the top of the function (criterion: WT_ASSERT_SPINLOCK_OWNED(session, &block->live_lock))
• [ ] Handle checkpoint size calculation and bounds checking (criterion: function correctly sets ckpt->size and ci->ckpt_size)
• [ ] Refactor __ckpt_process to call the helper (criterion: live_update section is replaced by a single function call)
• [ ] Measure complexity before and after: lizard src/block/block_ckpt.c 2>/dev/null || python3 -m lizard src/block/block_ckpt.c 2>/dev/null (criterion: CCN for __ckpt_process dropped by ≥3)
• [ ] Run existing block manager unit tests (criterion: ctest --test-dir build -R block passes)

Definition of Done

• [ ] New static function __ckpt_update_live handles live checkpoint update logic (lines 832-866)
• [ ] Function is called while block->live_lock is held (documented in function comment)
• [ ] Function handles: file truncation, checkpoint size calculation, and calling __ckpt_update for the ADD checkpoint
• [ ] __ckpt_process calls this helper instead of inline logic
• [ ] Cyclomatic complexity of __ckpt_process is reduced by at least 3-4 points (measured with lizard src/block/block_ckpt.c 2>/dev/null || python3 -m lizard src/block/block_ckpt.c 2>/dev/null)
• [ ] All existing tests pass (run ctest --test-dir build -R block -j$(nproc))
• [ ] Code formatted with cd dist && ./s_clang_format