mimicking a file in memory

Grant Edwards grante at visi.com
Tue Nov 20 23:06:34 CET 2007


On 2007-11-20, Jarek Zgoda <jzgoda at o2.usun.pl> wrote:

>> Here is my dilemma: I don't want to copy the files into a
>> local directory for mutagen's sake, only to have to remove
>> them afterward. Instead, I'd like to load the files into
>> memory and still be able to hand the built-in "file" function
>> a filename to access the file in memory.
>>
>> Any ideas on how to do this?

By "memory" I presume you mean virtual memory?  RAM with
disk-blocks as backing store? On any real OS, tempfiles are
just RAM with disk-blocks as backing store. 

Sound similar? The only difference is the API used to access
the bytes.  You want a file-I/O API, so you can either use the
extensively tested and and highly optimized filesystem code in
the OS to make disk-backed-RAM look like a file, or you can try
to write Python code that does the same thing.

Which do you think is going to work faster/better?

[The kernel is generally better at knowing what needs to be in
RAM than you are -- let it do its job.]

IOW: just use a temp file.  Life will be simple. The bytes
probably won't ever hit the platters (if they do, then that
means they would have the other way too).

-- 
Grant Edwards                   grante             Yow! It's a hole all the
                                  at               way to downtown Burbank!
                               visi.com            



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