In <[EMAIL PROTECTED]>,
[EMAIL PROTECTED] wrote:
> options.size = 6442450944
> options.ranges = ["4096,1024","30000,314572800"]
> fd = open("testfile", "w")
> fd.seek(options.size-1)
> fd.write("a")
> for drange in options.ranges:
> off = int(drange.split(",")[0])
> len = int(drange.split(",")[1])
> print "off =", off, " len =", len
> fd.seek(off)
> for x in range(len):
> fd.write("a")
>
> fd.close()
>
> This piece of code takes very long time and in fact I had to kill it as
> the linux system started doing lot of swapping. Am I doing something
> wrong here? Is there a better way to create/modify sparse files?
`range(len)` creates a list of size `len` *in memory* so you are trying to
build a list with 314,572,800 numbers. That seems to eat up all your RAM
and causes the swapping.
You can use `xrange(len)` instead which uses a constant amount of memory.
But be prepared to wait some time because now you are writing 314,572,800
characters *one by one* into the file. It would be faster to write larger
strings in each step.
Ciao,
Marc 'BlackJack' Rintsch
--
http://mail.python.org/mailman/listinfo/python-list
