ACE_Message_Block *messageBlock = new ACE_Message_Block(1024); // create a message block with initial size 1024 char *data = "This is some data to add to the message block."; size_t dataLen = strlen(data); memcpy(messageBlock->wr_ptr(), data, dataLen); // copy data to the message block messageBlock->wr_ptr(dataLen); // update the wr_ptr to reflect the new size
ACE_Message_Block *messageBlock = new ACE_Message_Block(1024); // create a message block with initial size 1024 char *data = "Original data in the message block."; size_t dataLen = strlen(data); memcpy(messageBlock->wr_ptr(), data, dataLen); // copy original data to the message block messageBlock->wr_ptr(dataLen); // update the wr_ptr to reflect the new size char *newData = "New data to overwrite the old data."; size_t newDataLen = strlen(newData); memcpy(messageBlock->wr_ptr(), newData, newDataLen); // copy new data, which overwrites the original data messageBlock->wr_ptr(newDataLen); // update the wr_ptr to reflect the new sizeIn this example, we create a message block with an initial size of 1024 bytes. We then copy some original data into the message block using the memcpy function and update the 'wr_ptr' attribute to reflect the new size. We then overwrite the original data with some new data using the memcpy function and update the 'wr_ptr' attribute to reflect the new size. In conclusion, ACE_Message_Block is a core element of the ACE package library. Its 'wr_ptr' attribute enables developers to manipulate message block contents efficiently.