January 27th, 2014, 02:05 AM
C++ Memory Mapped Files Trouble
I have a data buffer project in Windows 7 x64 embedded OS (using Visual Studio 2008), that would work simply like that:
One writer application will send data (no network protocols, just procedure call on the same machine) to my app like 20 packages per second, each data packages will be approximately 3 MB size and comes with a timestamp tag.
My application will store each data item for 100 minutes and then remove. (So I can calculate the total size from beginnig no need for dynamic allocation etc...)
Meanwhile there will be up to 5 reader applications which will query data from my app via Timestamp tag and retreive data (no updates or deletitions on data by reader apps).
So since the data in my buffer app can grow over 50GB I don't think that shared memory is going to work for my case.
I'm thinking about using Boost Memory Mapped Files or Windows API Memory Mapped Files.
So theoratically I will crate a fixed size File on harddisk (lets say 50GB) and then map some portion to RAM write the data to this portion, if the reader applications wants to use the data which is mapped currently on memory, then they will use directly, otherwise they will map some other potion of the file to their address spaces and use from there...
My problem is I haven't use Map File concept at all and I'm not a C++ developer so I'm not very familiar with the language fundementals. I've searched tutorials of boost and msdn for windows as well but there is not too much code example.
So I don't know how to map some portion of the data to memory and manage it, also how to search data in file or memory according to the timestamp tag. Yes there are codes for creating files and mapping the whole file to memory but none for dividing it into regions, aligning or padding the data which I need for my case.
Any help with some code portion or sample projects would help extremely...
Thank you very much for reading and further helps...
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