HarmonyOS 关于libohweb.so的接口OH_ArkWebHttpBodyStream_Read不返回读取实际长度的问题

接口的描述如下:

/**
 @brief Read the http body to the buffer.

 The buffer must be larger than the bufLen. We will be reading data from a worker thread to the buffer,\n
 so should not use the buffer in other threads before the callback to avoid concurrency issues.\n

 @param httpBodyStream The ArkWeb_HttpBodyStream.
 @param buffer The buffer to receive data.
 @param bufLen The size of bytes to read.

 @syscap SystemCapability.Web.Webview.Core
 @since 12/void OH_ArkWebHttpBodyStream_Read(const ArkWeb_HttpBodyStream httpBodyStream, uint8_t* buffer, int bufLen);

该接口并未返回实际读取的长度.

可能引发问题:

1.当包体过大,声明的函数内or 语句块的临时变量过大会引发 omm 问题

2.如果采用一下方式来规避 1 的问题,就发生了多次拷贝而影响性能问题

例如回调函数返回的数据长度超出 10MB

//在OH_ArkWebHttpBodyStream_Read 接口未发生变更的情况下,就会是以下的形态
void ReadCallback(const ArkWeb_HttpBodyStream  *httpBodyStream, uint8_t* buffer, int bytesRead)
{
  OH_LOG_INFO(LOG_APP, "read http body back.");
  bool isEof = OH_ArkWebHttpBodyStream_IsEof(httpBodyStream);
  int pos = 0;
  char* p = (char*)calloc(1,bytesRead);
  while((!isEof) && (pos != bytesRead)){
    uint8_t tmp[1024] = {0};
    memset(tmp,0,sizeof(tmp));
    OH_ArkWebHttpBodyStream_Read(httpBodyStream, tmp, sizeof(tmp));
    int lastPos = pos;
    pos += sizeof(tmp);
    if(pos > bytesRead){
      pos = bytesRead;
    }
    memcpy(p+lastPos,tmp,pos - lastPos);
  }
}

//如果接口OH_ArkWebHttpBodyStream_Read返回实际读取的长度,函数将是以下形态
void ReadCallback(const ArkWeb_HttpBodyStream  *httpBodyStream, uint8_t* buffer, int bytesRead)
{
  OH_LOG_INFO(LOG_APP, "read http body back.");
  bool isEof = OH_ArkWebHttpBodyStream_IsEof(httpBodyStream);
  int pos = 0;
  char* p = (char*)calloc(1,bytesRead);
  while((!isEof) && (pos != bytesRead)){
    int readSize = OH_ArkWebHttpBodyStream_Read(httpBodyStream, p+pos, bytesRead-pos);
    if(readSize < 0){
      //获取上次读取的错误接口
      break;
    }
    pos += readSize;
  }
}

1.降低拷贝次数

2.降低发生 omm 的可能