Offset operations

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The DataHub C++ SDK provides offset operations to initialize, retrieve, and reset subscription offsets.

Initialization

Parameters

Parameter name

Parameter type

Parameter description

projectName

String

The project name.

topicName

String

The topic name.

subId

string

shardIds

Code example

 void InitSubscriptionOffsetSession()
 {
    const std::string projectName = "";
    const std::string topicName = "";
    const std::string subId = "";
    std::vector<std::string> shardIds;
    try 
    {
        const OpenSubscriptionOffsetSessionResult& offsetSessionResult =
        client.InitSubscriptionOffsetSession(projectName, topicName, subId, shardIds);
        std::cout << offsetSessionResult.GetOffsets().size() << std::endl;

    } 
   catch(const DatahubException& e)
   {
      std::cerr << "Init offset fail: " << e.GetRequestId() << ", ErrorCode: " << e.GetErrorCode() << ", ErrorMessage: " << e.GetErrorMessage() << std::endl;
   }
}

Get offset

Parameters

Parameter name

Parameter type

Parameter description

projectName

String

The project name.

topicName

String

The topic name.

subId

string

shardIds

Code example

//Get offset
void GetSubscriptionOffset() 
{
    const std::string projectName = "";
    const std::string topicName = "";
    const std::string subId = "";
    std::vector<std::string> shardIds;
    try 
    {
        const GetSubscriptionOffsetResult& getSubscriptionOffsetResult =
        client.GetSubscriptionOffset(projectName, topicName, subId, shardIds;
        std::cout << getSubscriptionOffsetResult.GetOffsets().size() << std::endl;        std::cout << getSubscriptionOffsetResult.GetOffsets().size() << std::endl;
        std::cout << getSubscriptionResult.GetComment() << std::endl;

    }  
   catch(const DatahubException& e)
   {
      std::cerr << "Get offset fail: " << e.GetRequestId() << ", ErrorCode: " << e.GetErrorCode() << ", ErrorMessage: " << e.GetErrorMessage() << std::endl;
   }
}

Reset offset

Parameters

Parameter name

Parameter type

Parameter description

resetTimestamp

int64_t

resetSequence

int64_t

resetBatchIndex

int64_t

projectName

String

The project name.

topicName

String

The topic name.

subId

string

resetSubscriptionOffsets

Code example

void ResetSubscriptionOffset() 
{
    try 
    {
        int64_t resetTimestamp = 0l;
        int64_t resetSequence = 0l;
        uint32_t resetBatchIndex = 0u;
        const std::string projectName = "";
        const std::string topicName = "";
        const std::string subId = "";
        std::map<std::string, SubscriptionOffset> resetSubscriptionOffsets;
        for (auto iter = offsets.begin(); iter != offsets.end(); ++iter)
        {
            SubscriptionOffset offset(resetTimestamp, resetSequence, resetBatchIndex);
            resetSubscriptionOffsets.insert(
            std::pair<std::string, SubscriptionOffset>(iter->first, offset));
        }

    client.ResetSubscriptionOffset(projectName, topicName, subId, resetSubscriptionOffsets);    }  
   catch(const DatahubException& e)
   {
      std::cerr << "Reset offset fail: " << e.GetRequestId() << ", ErrorCode: " << e.GetErrorCode() << ", ErrorMessage: " << e.GetErrorMessage() << std::endl;
   }
}