Class MockBufferModel

src/host/ui/buffer_model.h:92–131

Deterministic, IPC-free BufferModel: holds a fixed vector supplied at construction (typically via make_default_mock_model()), so chrome development and tests never depend on randomness or live IPC. Storage is vector > rather than vector so each BufferRecord has a stable heap address: erase() must not move surviving records, because each oid::Sta

// moving that record on erase would dangle every other Stage's span. This
// makes MockBufferModel move-only, which is fine: nothing copies it.
class MockBufferModel : public BufferModel {
  public:
    explicit MockBufferModel(std::vector<std::unique_ptr<BufferRecord>> records)
        : storage_(std::move(records)) {}

    std::size_t size() const override {
        return storage_.size();
    }

    const BufferRecord& at(std::size_t i) const override {
        return *storage_.at(i);
    }

    const std::string& variable_name_of(std::size_t i) const override {
        return storage_.at(i)->variable_name;
    }

    // MockBufferModel's records never re-plot, so every slot's revision is
    // permanently 0: StageManager's sync() will never see it change and so
    // will never call Stage::buffer_update() for a mock buffer.
    std::uint64_t revision_of(std::size_t /*i*/) const override {
        return 0;
    }

    // Bounds-guarded erase: no-op if `i >= size()`. Erasing storage_[i]
    // (a unique_ptr) never touches the addresses of surviving BufferRecords,
    // so any Stage still holding a span into a surviving record's bytes
    // stays valid. Callers that also own per-index Stage state must drop
    // the Stage referencing the erased record *before* calling this, since
    // the Stage's span becomes dangling once the record is destroyed.
    void erase(std::size_t i) {
        if (i >= storage_.size()) {
            return;
        }
        storage_.erase(storage_.begin() + static_cast<std::ptrdiff_t>(i));
    }

  private:
    std::vector<std::unique_ptr<BufferRecord>> storage_;
};

// Human-readable type+channel label used by the buffer-list panel, e.g.
// "uint8x3", "float32x1".