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Thread: Packet getting fragmented when sending over QTcpSocket

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  1. 25th July 2009, 19:41 #1
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    The fact that it comes in parts is meaningless and has nothing to do with freezing anything. If you know what you expect then you can wait until your expectations are filled. Doing this by ignoring the data is probably not the best idea but it is possible. A better way is to read the pending data (thus freeing the incoming buffer), scanning that data for end of message (which is easy in your case) and either processing the data or waiting until more comes in. Remember that you can also get more than one message in a single go, you need to handle situations like that as well.
    Your biological and technological distinctiveness will be added to our own. Resistance is futile.

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  3. 25th July 2009, 20:13 #2
    Kill3rReaper
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    Ehhhh, I thought there was some other way to do it
    Anyway, thank you for answer!
    Czesc
    Last edited by Kill3rReaper; 25th July 2009 at 22:24.
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  4. 25th July 2009, 23:01 #3
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    Quote Originally Posted by Kill3rReaper View Post
    Ehhhh, I thought there was some other way to do it
    Sure there is. Use QXmlStreamReader.
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  5. 5th August 2009, 00:53 #4
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    Ehhh... I just was writing new class for XML packets, when I try to write something XML to <body> </body> section... Code between these tags is interpretting by my algorism... When I was using QDomElement, I did't have got that problem What I can do?
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  6. 5th August 2009, 08:13 #5
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    and what is the problem exactly?
    I would like to be a "Guru"

    Useful hints (try them before asking):
    1. Use Qt Assistant
    2. Search the forum

    If you haven't found solution yet then create new topic with smart question.
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  7. 5th August 2009, 17:22 #6
    Kill3rReaper
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    My english sux very much...
    For example:
    Qt Code: 
    1. <message from='test@jab.com/Jabber' type='chat' xml:lang='pl' to='test@jabbim.pl'><active xmlns='http://jabber.org/protocol/chatstates'/><body>Hey!</body></message>
    To copy to clipboard, switch view to plain text mode 
    If I change body section to: "Hej <someth" my application freezes.
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  8. 5th August 2009, 18:54 #7
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    Quote Originally Posted by Kill3rReaper View Post
    My english sux very much...
    If I change body section to: "Hej <someth" my application freezes.
    I have not used the XML parser in Qt before, but other XML parsers would interpret the '<' symbol in the body as the opening to a tag. The parser would then read until it finds a closing '<' tag. Try converting the '<' to "&lt;" and see if your program still hangs.

    You can do the string conversion manually or for '<' and '>' with QString's replace string functions. There might be a method in one of the XML classes to quote characters that are meaningful to XML for you.
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  9. 5th August 2009, 23:08 #8
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    Well, he can't change the packet cause that's the way the server sends it.

    My solution would be if you see the opening "body" tag, treat everything that follows as text untill you reach closing "body" tag. But that's not perfect cause someone could be chatting about HTML and send </body> and that would screw the parser up.
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  10. 5th August 2009, 23:11 #9
    Kill3rReaper
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    Default Re: Packet getting fragmented when sending over QTcpSocket

    Quote Originally Posted by wrdieter View Post
    I have not used the XML parser in Qt before, but other XML parsers would interpret the '<' symbol in the body as the opening to a tag. The parser would then read until it finds a closing '<' tag. Try converting the '<' to "&lt;" and see if your program still hangs.

    You can do the string conversion manually or for '<' and '>' with QString's replace string functions. There might be a method in one of the XML classes to quote characters that are meaningful to XML for you.
    It's good idea
    I thought about use QDomElement class to solve this problem, but your solution sounds good
    P.S: I know that the XML parser interprets '<' symbol as the opening tag, but I could not cope with this ;/
    Last edited by Kill3rReaper; 5th August 2009 at 23:59.
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