實作商業邏輯

1. 確認 VSIDL 目錄含有必要的建構、protobuf 和 VSIDL 檔案。如要從現有範例開始，您可以在 /system/software_defined_vehicle/samples/vsidl/stable/catalog 下找到有效目錄資料夾的範例。

   目錄結構範例：

   my_catalog/
   ├── Android.bp          # Defines rust_protobuf modules for .proto files
   ├── types.proto         # Protobuf message / RPC service definitions
   └── architecture.vsidl  # VSIDL service bundle definitions
   

2. 編寫自訂程式碼，導入商業邏輯：

   • RPC 伺服器：實作 lib.rs 中的特徵。

   • 發布、訂閱和 RPC 用戶端：呼叫 service_bundle.rs 內產生的函式，與其他服務互動。

   Rust

   1. 執行下列指令，產生骨架實作：

      vsidlc -c /path/to/catalog -o /path/to/output --services
      

      使用 --services 標記執行 vsidlc，即可為每個服務套件產生樣板 Rust 實作項目。這會提供必要的架構，包括原始碼 (main.rs) 和建構設定檔 (Android.bp) (含所有依附元件)，讓您專注於實作核心業務邏輯時，能立即交換預設訊息。

   2. 針對每個服務套件，在下列位置找出 Rust 實作項目：

      /path/to/output/services/ServiceBundleName/src/main.rs。

   3. 根據預設，產生的實作會建立含有預設值的訊息，並在發布端和訂閱端或 RPC 用戶端和伺服器之間傳送。如要修改這項行為，請在 main.rs 中找出 TODO 註解，然後根據偏好調整。例如：

      async fn handle_tire_pressure_range_unique_publisher(
          publisher: sdv::mw::Publisher<TirePressureRange>,
      ) {
          loop {
              // TODO: Modify the frequency of publishing messages here.
              sleep(Duration::from_secs(1)).await;
              // TODO: Modify the message content here.
              let message = TirePressureRange::default();
              info!("Publishing on TirePressureRange#UNIQUE");
              publisher.publish(&message).unwrap();
          }
      }
      

   4. 為確保下次執行 vsidlc 時，系統不會覆寫您對產生檔案所做的修改，請將 services 資料夾移出 /path/to/output 資料夾。

   C++

   1. 建立新的標頭檔案 src/lib.hpp，其中包含服務套件的類別：

      #pragma once
      #include <sdv/service_bundle.h>
      #include <sdv/context.hpp>
      
      namespace com::sdv::oem::service_bundle {
      
      // Sample implementation of the service bundle interface.
      class ServiceBundleName : public android::sdv::service_bundle::ServiceBundle {
      public:
          ServiceBundleName(sdv_comms::ctx::Context context);
          ~ServiceBundleName();
          void onStart() override;
          void onStop() override;
      };
      }  // namespace com::sdv::oem::service_bundle
      

   2. 建立新的來源檔案 src/lib.cpp，並實作類別：

      #include "src/lib.hpp"
      #include <sdv/sb_macro.h>
      #include <iostream>
      using com::sdv::oem::service_bundle::ServiceBundleName;
      
      // Register the new service bundle.
      REGISTER_SERVICE_BUNDLE(ServiceBundleName);
      
      // Sample implementation of the service bundle interface.
      namespace com::sdv::oem::service_bundle {
      // Creates a new instance of the ServiceBundleName.
      // Called when service bundle is created by the system.
      // Context object is provided as a parameter that gives access to the
      // communication stack APIs.
      ServiceBundleName::ServiceBundleName([[maybe_unused]] sdv_comms::ctx::Context context) :
        ServiceBundle(context) {
          // Memory allocations and static data loading should be done as
          // part of this method.
          //
          // Loading of the dynamic resources (sockets, files, etc)
          // is strongly discouraged due to possible Suspend-to-RAM scenario.
          //
          // The dynamic data can be loaded in the onStart method.
      }
      
      // Called when the service bundle is started by the system.
      void ServiceBundleName::onStart() {
          // Dynamic resources(sockets, files, etc) should be allocated during this call.
      }
      
      // Called when the service bundle is stopped by the system in preparation
      // for shutdown or suspend to RAM/Disc.
      void ServiceBundleName::onStop() {
          // Stop phase requires the service bundle to delete the dynamic resources
          // (sockets, files, etc) that were previously allocated in the onStart method.
      }
      
      // Called when the service bundle is destroyed by the system.
      ServiceBundleName::~ServiceBundleName() {
          // Static resources deallocation needs to be implemented in the destructor.
      }
      }  // namespace com::sdv::oem::service_bundle
      

   3. 在新的或現有的 Android.bp 檔案中，建立服務套件程式庫 Soong 目標：

      // Service bundle library.
      cc_library_shared {
        name: "libservice_bundle",
        srcs: ["src/lib.cpp",],
        // Allows the library to be available inside APEX.
        apex_available: [
            "//apex_available:platform",
            "//apex_available:anyapex",
        ],
        shared_libs: [
          // Service Bundle lifecycle C++ API.
          "libsdv_lifecycle_client_cpp",
          // commstack library that provides context object reference
          "libsdv_comms_cpp",
        ],
      
        // Service bundle package is packed into /product apexes.
        product_specific: true,
      }
      

後續步驟

如要部署服務套裝組合，請參閱「建構及部署服務套裝組合」。