Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>You could make a wrapper over <code>mq_send()</code> having char buffer allocated.</p> <p>Every message you send will be serialized into this buffer and then you will pass it to <code>mq_send</code> with appropriate length - sizeof(int) + sizeof(long) + strlen(pRecvData).</p> <p>The receiver will read this data and deserialize it into sFileStruct.</p> <p>IMHO using std::string instead of char* would be better.</p> <p>Sample code (not tested):</p> <pre><code>class MQWrapper { std::string m_strBuffer; public: int Send( const sFileStruct&amp; sfs ) { m_strBuffer.clear(); m_strBuffer.append( static_cast&lt;const char*&gt; &amp; sfs.uiCommand, sizeof(sfs.uiCommand) ); m_strBuffer.append( static_cast&lt;const char*&gt; &amp; sfs.ulNoOfBytes, sizeof(sfs.ulNoOfBytes) ); m_strBuffer.append( sfs.pRecvData ); // only if it's zero-terminated string!!! return mq_send(m_qSendDesc, m_strBuffer.c_str(), m_strBuffer.length(), inPriority); } char m_receiveBUffer[ BUFFER_SIZE ]; int Receive( sFileStruct&amp; sfs ) { int res = mq_receive( m_qSendDesc, receiveBUffer, BUFFER, outPriority ); if( res &lt; 0 ) return res; if( res &lt; sizeof(int) + sizeof(long) ) return -1000; // malformed message sfs.uiCommand = * ( static_cast&lt;unsigned int*&gt; (m_receiveBUffer[0]) ); sfs.ulNoOfBytes = * ( static_cast&lt;long*&gt; (m_receiveBUffer[ sizeof(int) ] ) ); // I don't really use this style in my work and not sure how to use it // str::string would be much easier int stringLen = res - sizeof(int) - sizeof(long); sfs.pRecvData = new char [ stringLen + 1 ]; // you have to delete [] it later if( stringLen &gt; 0 ) strcpy( sfs.pRecvData, receiveBUffer + sizeof(int) + sizeof(long), stringLen ); ss.pRecvData[ stringLen ] = '\0'; // null terminator return 0; } }; </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POPassing messages between processes using message queues
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USDmitry Yudakov
    1. USDmitry Yudakov
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. POPassing messages between processes using message queues
      singulars
      1. PTQuestion
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTAcceptedByOriginator
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThanks for suggestion. I am trying to use this. Is it possible to provide how to parse the above packed info on receiver side.
      singulars
      1. PO
      1. USvenkysmarty
    2. CO@user519882 I posted some example for Receive function as well. To be honest I'm not feeling really comfortable not using stl stuff like std::string, but still it could give you a hint of how to solve your problem.
      singulars
      1. PO
      1. USDmitry Yudakov
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload