鸿蒙系统的分布式能力如何在应用中实现？

graph TD
    A[应用层] --> B[分布式数据管理]
    A --> C[分布式任务调度]
    A --> D[分布式设备虚拟化]
    B --> E[数据同步]
    C --> F[能力调用]
    D --> G[硬件虚拟化]
    E --> H[安全通道]
    F --> H
    G --> H
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// 初始化设备管理
import deviceManager from '@ohos.distributedHardware.deviceManager';

// 发现音箱设备
const deviceFilters = {
  deviceTypes: ['speaker'],
  authForm: 'PIN_CODE' // 认证方式
};

deviceManager.createDeviceManager('com.example.music', (err, manager) => {
  manager.on('deviceOnline', (device) => {
    if (device.type === 'speaker') {
      this.connectToSpeaker(device);
    }
  });
  manager.startDeviceDiscovery(filters);
});

// 建立安全连接
private async connectToSpeaker(device: DeviceInfo) {
  try {
    const authInfo = await deviceManager.authenticateDevice(device);
    const connection = await deviceManager.createDistributedChannel({
      deviceId: device.deviceId,
      sessionType: 'AUDIO_STREAM'
    });
    this.audioChannel = connection;
  } catch (error) {
    logger.error('连接失败: ' + error.code);
  }
}
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// Native层音频管道建立（C++）
OH_AudioStreamBuilder* builder;
OH_AudioStreamBuilder_Create(&builder, AUDIO_OUTPUT);
OH_AudioStreamBuilder_SetDistributedParams(builder, {
  .codec = AUDIO_CODEC_AAC,
  .bitrate = 192000,
  .latencyMode = LOW_LATENCY
});

OH_AudioRenderer* renderer;
OH_AudioStreamBuilder_GenerateRenderer(builder, &renderer);

// 启动分布式音频流
OH_AudioRenderer_Start(renderer);
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// 手机端控制指令发送
class MusicController {
  static sendControl(command: PlayCommand) {
    this.audioChannel?.sendData({
      type: 'CONTROL',
      data: {
        action: command.action,
        timestamp: performance.now() // 精确同步
      }
    }, { priority: 'HIGH' });
  }
}

// 音箱端接收处理
audioChannel.on('data', (payload) => {
  if (payload.type === 'CONTROL') {
    switch(payload.data.action) {
      case 'PLAY':
        audioPlayer.playAt(payload.data.timestamp);
        break;
      case 'PAUSE':
        audioPlayer.pause();
        break;
    }
  }
});
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// 平板端发起算力请求
import distributedMissionManager from '@ohos.distributedMissionManager';

const missionOptions = {
  deviceId: 'desktop_device_id',
  abilityName: 'com.example.document.ComputeService',
  parameters: {
    filePath: this.currentDoc.path,
    operation: 'IMAGE_RENDER'
  }
};

distributedMissionManager.startMission(missionOptions)
  .then((missionId) => {
    this.monitorProgress(missionId);
  });

// 监控任务状态
private monitorProgress(missionId: string) {
  const progressWatcher = distributedMissionManager.on(
    'missionProgress', 
    { missionId },
    (progress) => {
      this.updateUI(progress);
    }
  );
}
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// 大文件分片处理
const CHUNK_SIZE = 1024 * 1024; // 1MB

async function transferLargeFile(file: File) {
  for (let i = 0; i < file.size; i += CHUNK_SIZE) {
    const chunk = file.slice(i, i + CHUNK_SIZE);
    await distributedFile.transfer({
      data: chunk,
      sequence: i / CHUNK_SIZE,
      isLast: i + CHUNK_SIZE >= file.size
    });
  }
}

// 接收端重组
let chunks = [];
distributedFile.on('data', (chunk) => {
  chunks[chunk.sequence] = chunk.data;
  if (chunk.isLast) {
    const file = new Blob(chunks);
    this.processComplete(file);
  }
});
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// 安全通道配置示例
const secureChannel = await deviceManager.createSecureChannel({
  deviceId: targetDevice,
  cryptoConfig: {
    cipher: 'SM4_128_GCM',
    keyExchange: 'ECDH_P256',
    authTagLength: 16
  },
  qos: {
    priority: 'HIGH',
    timeout: 5000
  }
});
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// 网络质量检测
networkMonitor.on('change', (quality) => {
  switch(quality.level) {
    case 'POOR':
      this.adjustBitrate(0.5);
      break;
    case 'GOOD':
      this.enableHD();
      break;
  }
});

// 断线重连机制
connection.on('close', () => {
  const retry = new ExponentialBackoffRetry({
    initialDelay: 1000,
    maxDelay: 10000
  });
  retry.execute(this.reconnect);
});
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graph LR
    A[控制指令] -->|最高优先级| B[专用通道]
    C[音频数据] -->|中等优先级| D[QoS标记]
    E[文件传输] -->|后台优先级| F[带宽限制]
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# 查看跨设备调用日志
hdc shell hilog | grep -E 'Distributed|SoftBus'

# 性能分析工具
hdc shell dumpsys distributed_client -profile
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// 使用前检查目标设备能力
capability.check({
  required: ['AUDIO_OUTPUT', 'HIGH_PERF_COMPUTE'],
  callback: (result) => {
    if (!result.supported) {
      this.showFallbackUI();
    }
  }
});
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try {
  await distributedService.execute();
} catch (error) {
  if (error.code === 'SERVICE_UNAVAILABLE') {
    localExecutor.process() // 本地降级处理
  }
}
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// 跨设备迁移动画
animateTo({
  duration: 300,
  curve: 'easeOut',
  onFinish: () => {
    this.transferToOtherDevice();
  }
}, () => {
  this.highlightTargetDevice();
})
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// 使用Jitter Buffer调节
OH_AudioStream_SetParam(stream, {
  jitter_buffer: {
    min: 50ms,
    max: 200ms,
    adaptive: true
  }
});
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distributedFile.resumeTransfer({
  fileId: '123',
  startOffset: lastReceivedByte
});
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