[ENet-discuss] sending and receiving structs from eNet

[Amir Ramezani]

i've did that with boost::serialization, but when i want to serialize
strings it crashes
there are some other serialization functions are exist such as google
protobuf, etc, but i used boost.serialization for my project
and, std::string hold's refference to the pointer, how this is serialized?

۱۳۹۵-۰۲-۱۳ ۵:۰۰ −۰۷:۰۰ گرینویچ, Ruud van Gaal <ruud at racer.nl>:
> I haven't used Boost::serialization myself. What I made was a class around
> a buffer (char []) where I have functions like AddInt(n), AddString(s) and
> such, which store the binary data in the char[] buffer. For a string you
> need to first store the length and then the characters myself (alternatives
> are possible but this is relatively common).
>
> The first thing though is to understand that a pointer is always 4 bytes
> (in 32 bits) pointing to an address where the actual string is stored,
> which is why sending that pointer value is guaranteed to fail on the other
> PC, since memory addresses on that other PC are different. More a C++ thing
> than Enet...
>
> Ruud
>
> On Fri, Apr 29, 2016 at 8:36 PM, Amir Ramezani
> <amir.ramezani1370 at gmail.com>
> wrote:
>
>> can i use boost::serialization?
>> or what do you recommend?
>> and, how can i send strings between client and the server?
>> thanks
>>
>> ۱۳۹۵-۰۲-۱۰ ۱۱:۲۶ −۰۷:۰۰ گرینویچ, Nathan Pritchard <npr1tchard at hotmail.com
>> >:
>> > Quite a few things you need to consider, I'll cover (what I think are)
>> > the main two:
>> >
>> > 1) You're not sending the strings for 'username' or 'password', etc.
>> > You're sending pointers. Think about that, you're sending a (in the
>> > case
>> > of your 32-bit machine) 4-byte memory address to another client.
>> >
>> > 2) You need to read up Endianness and understand host and network byte
>> > ordering. Bytes ordering for numbers (ints, float, etc) are interpreted
>> > differently by different OSs.
>> >
>> > Consider writing a serialization/deserialization routine for handling
>> > these structs. If you want to be sending dynamically sized structures
>> > with data that needs to be interpreted, you can't just memcpy
>> unfortunately.
>> >
>> >
>> > On 29/04/2016 17:52, Amir Ramezani wrote:
>> >> hello all,
>> >> i want to send struct using eNet, the structure definition is like
>> >> this:
>> >> //the structure that represents the game data to be sent
>> >> typedef struct gamedata
>> >> {
>> >> const char *username;
>> >> const char *password;
>> >> int rank;
>> >> bool userpass_incorrect;
>> >> bool account_not_exist;
>> >> const char *mac_address;
>> >> const char *hdd_serial;
>> >> const char *ip_address;
>> >> int x;
>> >> int y;
>> >> int z;
>> >> int health;
>> >> bool is_banned;
>> >> bool notify;
>> >> const char *pm_user;
>> >> const char *chat_user;
>> >> const char *message;
>> >> const char *server_message;
>> >> const char *motd;
>> >> bool came_online;
>> >> bool went_offline;
>> >> }gamedata;
>> >>
>> >> now, when my server receive's this struct from client, it crashe's
>> >> size is the size of packet that had been received, and data is the
>> >> packet content variable
>> >> and gd is the structure that i want to process
>> >> i use memcpy to copy from data to struct:
>> >> memcpy(gd, data+size, sizeof(*data) +size);
>> >> but when i receive it, and want to process it, (dirring the
>> >> debugging), i just get a memory access problem
>> >> what am i doing wrong?
>> >> compiler: gcc 5.3.0
>> >> using gnu++14,
>> >> ide:code::blocks
>> >> debugger: gdb
>> >> operating system: windows7 ultimate 32 bit
>> >> thanks
>> >> _______________________________________________
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>> >> http://lists.cubik.org/mailman/listinfo/enet-discuss
>> >
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>>
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