AI业务子系统

• 简介
• 目录
• 约束
• 使用
• 涉及仓
• AI引擎开发导航

简介

AI业务子系统是OpenHarmony提供原生的分布式AI能力的子系统。本次开源范围是提供了统一的AI引擎框架，实现算法能力快速插件化集成。框架中主要包含插件管理、模块管理和通信管理等模块，对AI算法能力进行生命周期管理和按需部署。后续，会逐步定义统一的AI能力接口，便于AI能力的分布式调用。同时，提供适配不同推理框架层级的统一推理接口。

图 1 AI引擎框架

目录

/foundation/ai/engine                        # AI子系统主目录
├── interfaces
│  └── kits                                  # AI子系统对外接口
└── services
│  ├── client                                # AI子系统Client模块
│  │  ├── client_executor                    # Client模块执行主体
│  │  └── communication_adapter              # Client模块通信适配层，支持拓展
│  ├── common                                # AI子系统公共工具、协议模块
│  │  ├── platform
│  │  ├── protocol
│  │  └── utils
│  └── server                                # AI子系统服务端模块
│  │  ├── communication_adapter              # Server模块通信适配层，支持拓展
│  │  ├── plugin
│  │     ├── asr
│  │        └── keyword_spotting             # ASR算法插件参考：唤醒词识别
│  │     └── cv
│  │        └── image_classification         # CV算法插件参考：图片分类
│  │  ├── plugin_manager
│  │  └── server_executor                    # Server模块执行主体

约束

语言限制：C/C++语言

操作系统限制：OpenHarmony操作系统

AI服务启动的约束与限制：SAMGR（System Ability Manager）启动且运行正常

使用

1. AI业务子系统编译

   轻量级AI引擎框架模块，代码所在路径：//foundation/ai/engine/services

   编译指令如下：

   设置编译路径

   hb set -root dir(项目代码根目录)

   设置编译产品（执行后用方向键和回车进行选择）：

   hb set -p

   执行编译：

   hb build -f（编译全仓）
   或者 hb build ai_engine（只编译ai_engine组件）

   注意：hb相关配置请参考编译构建子系统build_lite

2. 插件开发（以唤醒词识别为例）

   位置：//foundation/ai/engine/services/server/plugin/asr/keyword_spotting

   注意：插件需要实现server提供的IPlugin接口和IPluginCallback接口

   #include "plugin/i_plugin.h
   class KWSPlugin : public IPlugin {       # Keywords Spotting Plugin（KWSPlugin）继承IPlugin算法插件基类public:
       KWSPlugin();
       ~KWSPlugin();
   
       const long long GetVersion() const override;
       const char* GetName() const override;
       const char* GetInferMode() const override;
   
       int32_t Prepare(long long transactionId, const DataInfo &inputInfo, DataInfo &outputInfo) override;
       int32_t SetOption(int optionType, const DataInfo &inputInfo) override;
       int32_t GetOption(int optionType, const DataInfo &inputInfo, DataInfo &outputInfo) override;
       int32_t SyncProcess(IRequest *request, IResponse *&response) override;
       int32_t AsyncProcess(IRequest *request, IPluginCallback*callback) override;
       int32_t Release(bool isFullUnload, long long transactionId, const DataInfo &inputInfo) override;
       .
       .
       .
   };

   注意：SyncProcess和AsyncProcess接口只需要根据算法实际情况实现一个接口即可，另一个用空方法占位（这里KWS插件为同步算法，故异步接口为空实现）。

   #include "aie_log.h"
   #include "aie_retcode_inner.h"
   .
   .
   .
   
   const long long KWSPlugin::GetVersion() const
   {
       return ALGOTYPE_VERSION_KWS;
   }
   
   const char *KWSPlugin::GetName() const
   {
       return ALGORITHM_NAME_KWS.c_str();
   }
   
   const char *KWSPlugin::GetInferMode() const
   {
       return DEFAULT_INFER_MODE.c_str();
   }
   .
   .
   .
   int32_t KWSPlugin::AsyncProcess(IRequest *request, IPluginCallback *callback)
   {
       return RETCODE_SUCCESS;
   }

3. 插件SDK开发（以唤醒词识别kws_sdk为例）

   位置：//foundation/ai/engine/services/client/algorithm_sdk/asr/keyword_spotting

   唤醒词识别SDK：

   class KWSSdk {
   public:
       KWSSdk();
       virtual ~KWSSdk();
   
       /**
        * @brief Create a new session with KWS Plugin
        *
        * @return Returns KWS_RETCODE_SUCCESS(0) if the operation is successful,
        *         returns a non-zero value otherwise.
        */
       int32_t Create();
   
       /**
        * @brief Synchronously execute keyword spotting once
        *
        * @param audioInput pcm data.
        * @return Returns KWS_RETCODE_SUCCESS(0) if the operation is successful,
        *         returns a non-zero value otherwise.
        */
       int32_t SyncExecute(const Array<int16_t> &audioInput);
   
       /**
        * @brief Asynchronously execute keyword spotting once
        *
        * @param audioInput pcm data.
        * @return Returns KWS_RETCODE_SUCCESS(0) if the operation is successful,
        *         returns a non-zero value otherwise.
        */
       int32_t AsyncExecute(const Array<int16_t> &audioInput);
   
       /**
        * @brief Set callback
        *
        * @param callback Callback function that will be called during the process.
        * @return Returns KWS_RETCODE_SUCCESS(0) if the operation is successful,
        *         returns a non-zero value otherwise.
        */
       int32_t SetCallback(const std::shared_ptr<KWSCallback> &callback);
   
       /**
        * @brief Destroy the created session with KWS Plugin
        *
        * @return Returns KWS_RETCODE_SUCCESS(0) if the operation is successful,
        *         returns a non-zero value otherwise.
        */
       int32_t Destroy();

   注意：SDK调用AI引擎客户端接口顺序应遵循AieClientInit->AieClientPrepare->AieClientSyncProcess/AieClientAsyncProcess->AieClientRelease->AieClientDestroy，否则调用接口会返回错误码；同时应保证各个接口都有调用到，要不然会引起内存泄漏。

   int32_t KWSSdk::KWSSdkImpl::Create()
   {
       if (kwsHandle_ != INVALID_KWS_HANDLE) {
           HILOGE("[KWSSdkImpl]The SDK has been created");
           return KWS_RETCODE_FAILURE;
       }
       if (InitComponents() != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]Fail to init sdk components");
           return KWS_RETCODE_FAILURE;
       }
       int32_t retCode = AieClientInit(configInfo_, clientInfo_, algorithmInfo_, nullptr);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]AieClientInit failed. Error code[%d]", retCode);
           return KWS_RETCODE_FAILURE;
       }
       if (clientInfo_.clientId == INVALID_CLIENT_ID) {
           HILOGE("[KWSSdkImpl]Fail to allocate client id");
           return KWS_RETCODE_FAILURE;
       }
       DataInfo inputInfo = {
           .data = nullptr,
           .length = 0,
       };
       DataInfo outputInfo = {
           .data = nullptr,
           .length = 0,
       };
       retCode = AieClientPrepare(clientInfo_, algorithmInfo_, inputInfo, outputInfo, nullptr);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]AieclientPrepare failed. Error code[%d]", retCode);
           return KWS_RETCODE_FAILURE;
       }
       if (outputInfo.data == nullptr || outputInfo.length <= 0) {
           HILOGE("[KWSSdkImpl]The data or length of output info is invalid");
           return KWS_RETCODE_FAILURE;
       }
       MallocPointerGuard<unsigned char> pointerGuard(outputInfo.data);
       retCode = PluginHelper::UnSerializeHandle(outputInfo, kwsHandle_);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]Get handle from inputInfo failed");
           return KWS_RETCODE_FAILURE;
       }
       return KWS_RETCODE_SUCCESS;
   }
   
   int32_t KWSSdk::KWSSdkImpl::SyncExecute(const Array<uint16_t> &audioInput)
   {
       intptr_t newHandle = 0;
       Array<int32_t> kwsResult = {
           .data = nullptr,
           .size = 0
       };
       DataInfo inputInfo = {
           .data = nullptr,
           .length = 0
       };
       DataInfo outputInfo = {
           .data = nullptr,
           .length = 0
       };
       int32_t retCode = PluginHelper::SerializeInputData(kwsHandle_, audioInput, inputInfo);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]Fail to serialize input data");
           callback_->OnError(KWS_RETCODE_SERIALIZATION_ERROR);
           return RETCODE_FAILURE;
       }
       retCode = AieClientSyncProcess(clientInfo_, algorithmInfo_, inputInfo, outputInfo);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]AieClientSyncProcess failed. Error code[%d]", retCode);
           callback_->OnError(KWS_RETCODE_PLUGIN_EXECUTION_ERROR);
           return RETCODE_FAILURE;
       }
       if (outputInfo.data == nullptr || outputInfo.length <= 0) {
           HILOGE("[KWSSdkImpl] The data or length of outputInfo is invalid. Error code[%d]", retCode);
           callback_->OnError(KWS_RETCODE_NULL_PARAM);
           return RETCODE_FAILURE;
       }
       MallocPointerGuard<unsigned char> pointerGuard(outputInfo.data);
       retCode = PluginHelper::UnSerializeOutputData(outputInfo, newHandle, kwsResult);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]UnSerializeOutputData failed. Error code[%d]", retCode);
           callback_->OnError(KWS_RETCODE_UNSERIALIZATION_ERROR);
           return retCode;
       }
       if (kwsHandle_ != newHandle) {
           HILOGE("[KWSSdkImpl]The handle[%lld] of output data is not equal to the current handle[%lld]",
               (long long)newHandle, (long long)kwsHandle_);
           callback_->OnError(KWS_RETCODE_PLUGIN_SESSION_ERROR);
           return RETCODE_FAILURE;
       }
       callback_->OnResult(kwsResult);
       return RETCODE_SUCCESS;
   }
   
   int32_t KWSSdk::KWSSdkImpl::Destroy()
   {
       if (kwsHandle_ == INVALID_KWS_HANDLE) {
           return KWS_RETCODE_SUCCESS;
       }
       DataInfo inputInfo = {
           .data = nullptr,
           .length = 0
       };
       int32_t retCode = PluginHelper::SerializeHandle(kwsHandle_, inputInfo);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]SerializeHandle failed. Error code[%d]", retCode);
           return KWS_RETCODE_FAILURE;
       }
       retCode = AieClientRelease(clientInfo_, algorithmInfo_, inputInfo);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]AieClientRelease failed. Error code[%d]", retCode);
           return KWS_RETCODE_FAILURE;
       }
       retCode = AieClientDestroy(clientInfo_);
       if (retCode != RETCODE_SUCCESS) {
           HILOGE("[KWSSdkImpl]AieClientDestroy failed. Error code[%d]", retCode);
           return KWS_RETCODE_FAILURE;
       }
       mfccProcessor_ = nullptr;
       pcmIterator_ = nullptr;
       callback_ = nullptr;
       kwsHandle_ = INVALID_KWS_HANDLE;
       return KWS_RETCODE_SUCCESS;
   }

4. sample开发（参考唤醒词识别demo）

   位置：//applications/sample/camera/ai/asr/keyword_spotting

   调用Create

   bool KwsManager::PreparedInference()
   {
       if (capturer_ == nullptr) {
           printf("[KwsManager] only load plugin after AudioCapturer ready\n");
           return false;
       }
       if (plugin_ != nullptr) {
           printf("[KwsManager] stop created InferencePlugin at first\n");
           StopInference();
       }
       plugin_ = std::make_shared<KWSSdk>();
       if (plugin_ == nullptr) {
           printf("[KwsManager] fail to create inferencePlugin\n");
           return false;
       }
       if (plugin_->Create() != SUCCESS) {
           printf("[KwsManager] KWSSdk fail to create.\n");
           return false;
       }
       std::shared_ptr<KWSCallback> callback = std::make_shared<MyKwsCallback>();
       if (callback == nullptr) {
           printf("[KwsManager] new Callback failed.\n");
           return false;
       }
       plugin_->SetCallback(callback);
       return true;
   }

   调用SyncExecute

   void KwsManager::ConsumeSamples()
   {
       uintptr_t sampleAddr = 0;
       size_t sampleSize = 0;
       int32_t retCode = SUCCESS;
       while (status_ == RUNNING) {
           {
               std::lock_guard<std::mutex> lock(mutex_);
               if (cache_ == nullptr) {
                   printf("[KwsManager] cache_ is nullptr.\n");
                   break;
               }
               sampleSize = cache_->GetCapturedBuffer(sampleAddr);
           }
           if (sampleSize == 0 || sampleAddr == 0) {
               continue;
           }
           Array<int16_t> input = {
               .data = (int16_t *)(sampleAddr),
               .size = sampleSize >> 1
           };
           {
               std::lock_guard<std::mutex> lock(mutex_);
               if (plugin_ == nullptr) {
                   printf("[KwsManager] cache_ is nullptr.\n");
                   break;
               }
               if ((retCode = plugin_->SyncExecute(input)) != SUCCESS) {
                   printf("[KwsManager] SyncExecute KWS failed with retCode = [%d]\n", retCode);
                   continue;
               }
           }
       }
   }

   调用Destroy

   void KwsManager::StopInference()
   {
       printf("[KwsManager] StopInference\n");
       if (plugin_ != nullptr) {
           int ret = plugin_->Destroy();
           if (ret != SUCCESS) {
               printf("[KwsManager] plugin_ destroy failed.\n");
           }
           plugin_ = nullptr;
       }
   }

涉及仓

AI子系统

ai_engine

依赖仓：

build_lite

distributedschedule_samgr_lite

startup_init_lite

AI引擎开发导航

• 《AI插件开发指南》