On Thursday, 23 May 2019 at 18:37:17 UTC, H. S. Teoh wrote:
On Thu, May 23, 2019 at 06:20:23PM +0000, kdevel via
Digitalmars-d-learn wrote:
On Thursday, 23 May 2019 at 09:44:15 UTC, Cym13 wrote:
[...]
> To go fast, read/write bigger chunks.
Or use rawWrite instead of write (reduces the runtime to about
1.6 s). When using write time is IMHO spent in unicode
processing and/or locking. Or write more characters at a time.
The code below takes 60 ms to complete.
If you're on Linux, writing a bunch of zeroes just to create a
large file is a waste of time. Just use the kernel's sparse
file feature:
https://www.systutorials.com/136652/handling-sparse-files-on-linux/
The blocks won't actually get allocated until you write
something to them, so this beats any write-based method of
creating a file filled with zeroes -- probably by several
orders of magnitude. :-P
T
Yes using sparse files is good, but only for this case. If you
need write something else than null it is not so usable. But
AFAIK not all FS support this anyway
