Sample Application Code

Sample Application Code
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Using the application data manager to share information within your application is very easy and powerful. You only need to do the following:

Define your data structure and implement the writeObject and readObject functions for it.
Create and instance of your new data structure
Initialize the data structure by assigning it a GUID(Globally Unique Identifier) and assigning a host to be responsible for updating its value when needed.
Calculate the value of the data structure on the responsible host node.
Use the data structure's value in your application.

Once you have completed this simple tasks you will have a custom data type that is being synchronized across all cluster nodes behind the scenes. This can make the process of sharing the transformation matrix a simple task that can be implemented in 50 lines of code.

Example 6.1. Define Your Data Structure

  1 #include <vpr/IO/SerializableObject.h>
    struct MyType 
    { 
       int something; 
  5    float otherStuff;
       char stupid;
       bool drawBool;
    }; 
    
 10 template<class MyType> 
    vpr::ReturnStatus 
    vpr::SerializableObjectMixin<MyType>::writeObject(vpr::ObjectWriter* writer)  
    {
       writer->writeUint16(something); 
 15    writer->writeBool(drawBool); 
    }
       
    template<class MyType> 
    vpr::ReturnStatus
 20 vpr::SerializableObjectMixin<MyType>::readObject(vpr::ObjectReader* reader) 
    { 
       something = reader->readUint16();
       drawBool = reader->readBool(); 
    }

	Define the data type that you want to share across the cluster.
	Implement the function that will serialize the structure.
	Implement the function that will de-serialize the structure.

Example 6.2. Declare an Instance

cluster::UserData<vpr::SerializableObjectMixin<MyType> > mMyData;

Declare an instance of your data type called mMyData

Example 6.3. Initialize the Data Structure

vpr::GUID new_guid("d6be4359-e8cf-41fc-a72b-a5b4f3f29aa2"); 
        std::string hostname = "gfxn1"; 
        mMyData.init(new_guid, hostname);

	Create a new GUID to identify the new data.
	Store the hostname of the cluster node that will be responsible for updating the value of the data structure.
	Initialize the data structure to be shared across the cluster.

Example 6.4. Calculate the Value of the Data Structure

  1 if (mMyData.isLocal()) 
    {
       if(0 != mButton0->getData()) 
       { 
  5       mMyData->drawBool = true; 
       } 
       else
       {
          mMyData->drawBool = false; 
 10    } 
    }

	Determine if the data structure is local, the value is being updated by the local machine.
	Get the current state of Button0.
	Change the value of the shared data structure to match Button0.

Example 6.5. Use the Data Structure

if (mMyData->drawBool == true) 
{
   drawNetwork(); 
}

	Test if the value of the mMyData is true.
	If true then call a function that draws the representation of the cluster network.