Interface for reading variable length files with header and footer.
- by John S
I could use some hints or tips for a decent interface for reading file of special characteristics.
The files in question has a header (~120 bytes), a body (1 byte - 3gb) and a footer (4 bytes).
The header contains information about the body and the footer is only a simple CRC32-value of the body.
I use Java so my idea was to extend the "InputStream" class and add a constructor such as "public MyInStream( InputStream in)" where I immediately read the header and the direct the overridden read()'s the body.
Problem is, I can't give the user of the class the CRC32-value until the whole body has been read.
Because the file can be 3gb large, putting it all in memory is a be an idea.
Reading it all in to a temporary file is going to be a performance hit if there are many small files.
I don't know how large the file is because the InputStream doesn't have to be a file, it could be a socket.
Looking at it again, maybe extending InputStream is a bad idea.
Thank you for reading the confused thoughts of a tired programmer. :)
