A.J.Mechelynck schrieb:
Robert M Robinson wrote:
First, thanks very much for creating VIM! I have been using it on
Linux systems for years, and now use it via cygwin at home as well. I
vastly prefer VIM to EMACS, especially at home. I learned vi on a
VAX/VMS system long ago (a friend of mine had ported it), when our
computer science department was loading so many people on the VAXen
that EDT was rendered unusably slow. I still like VIM largely because
I can do so much with so little effort in so little time.
That brings me to my question. I have noticed that when editing large
files (millions of lines), deleting a large number of lines (say,
hundreds of thousands to millions) takes an unbelieveably long time in
VIM--at least on my systems. This struck me as so odd, I looked you
up (for the first time in all my years of use) so I could ask why!
Seriously, going to line 1 million of a 2 million line file and typing
the command ":.,$d" takes _minutes_ on my system (Red Hat Linux on a
2GHz Athlon processor (i686), 512kb cache, 3 Gb memory), far longer
than searching the entire 2 million line file for a single word
(":g/MyQueryName/p"). Doing it this way fits way better into my usual
workflow than using "head -n 1000000", because of course I'm using a
regular expression search to determine that I
want to truncate my file at line 1000000 in the first place.
I looked in the archive, and couldn't see that this issue had been
raised before. Is there any chance it can get added to the list of
performance enhancement requests?
Thanks,
Max Robinson, PhD
I think this is just "part of how Vim behaves".
When you edit a file, Vim holds the whole file in memory (IIUC). When
you delete a million lines, Vim frees (i.e., releases to the OS) the
memory those lines were using. That takes some time.
Best regards,
Tony.
What about the numbered registers?
:h "1
After freeing the lines, they are copied to "1 .
And the content of "1 is shifted to "2 (before, of course)
And so on, until register "9.
To avoid the copies, the blackhole register can be used:
:.,$d _
If there are copies, registeres can be cleared by hand:
:let @1 = ""
:let @2 = ""
...
:let @9 = ""
This also takes time, but frees the memory.
--
Regards,
Andy
