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File based FIFO (first in first out)

Posted on 1998-07-15
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Last Modified: 2010-04-04
How can i realize a fast file-based fifo, it means i read the oldest data i wrote in and delete it after reading, new data is written in on the other side of the file structure, new data-- data--data--oldest data
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Question by:q064828
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ZifNab earned 200 total points
ID: 1357930
Look at freeware QDB of

http://home.sprynet.com/sprynet/rrm/index.html

It's purpose is of using db without DBE.

Actually it is just a file of records, but with most capabilities of DB! Look at it! I think you can use this!

Zif.


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by:ZifNab
ID: 1357931
hi q064828,

forgot to mention something. Because it acts like a DB... you can easely add and remove the records fifo. Besides, the beauty of this is that the components are already written. And they are very well written and they are freeware too! What else do you want? Your projects jumps already to the last fase!

Zif.
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by:BlackMan
ID: 1357932
If you don't want to go for a DB solution, you can also use the round-robin method, where you allocate a file with f.ex. 100 records and then has 2 pointers, PointerToNextRecordToRead and PointerToNextRecordToWrite (or perhaps with shorter names :-)
When PTNRTW reaches End-Of-File, you just continue at the beginnign of the file.
Just make sure that there is enough room for all records, so that you are not overwriting records you haven't read yet.
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by:ZifNab
ID: 1357933
Hi Blackman, the beauty of QDB is that is ISN'T a DB it's in fact just a file with the capabilities of a DB. Zif. Look for yourself.
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by:BlackMan
ID: 1357934
Ok, Zif, I might take a look at it sometime (I think IU've allready downloaded it..)
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