MC viewer is terribly slow in inefficient when jumping to the end of big files

[birdie]

Try to view a big enough (>10MB) file in Midnight Commander internal viewer and hit "End" button - the bigger is file, the longer it will take to scroll to the end of the file.

Jumping to the end of 50MB text file takes 5 (five!) seconds on my 2600MHz AMD 64 CPU. It is unacceptable.

It doesn't matter if you have "Wrap" or "UnWrap?" setting.

An example file is attached.

[birdie]

Sample file (use 7z to unpack it)

[ossi]

now try this with something *big* (say, /proc/kcore) and see your system choke.

[birdie]

Are you scoffing at me or what?

MC 4.5.x and Far File Manager scroll to the end of any files instantly.

[mike.dld]

That's because MC scans all the file from top to bottom to display current line number in the status bar. The question is, do we really need this in viewer (FAR, for example, displays just a position percentage).

[birdie]

Replying to mike.dld:

That's because MC scans all the file from top to bottom to display current line number in the status bar. The question is, do we really need this in viewer (FAR, for example, displays just a position percentage).

What really matters is an ability to view files of any size.

[gotar]

+1
Line number is irrevelant if I can't even view it.

[marrtins]

Hi to all mc developers! I work on quite large log-files on daily basis and this is getting *really* annoying. Pleasure to work on old servers with old mc. Please make this *feature* go away or at least configurable. Thank you very much!

[birdie]

Replying to marrtins:

Hi to all mc developers! I work on quite large log-files on daily basis and this is getting *really* annoying. Pleasure to work on old servers with old mc. Please make this *feature* go away or at least configurable. Thank you very much!

Use older MC releases, until this bug is fixed.

[gotar]

This is seriuos defect, please don't colorize stats by changing it to enhancement.

[angel_il]

please publish results testing 4.6.х VS 4.7.0 (current master)
test case:
view file ~3Gb (open in viewer and go to EOF)

[birdie]

200MB text file:

MC 4.7.0-pre4: 40 seconds
MC 4.6.2-fc11: 11 seconds

However both results are unacceptable.

[birdie]

3GB file is 15 times bigger than 200MB, so jumping to the end of file will take 10 (ten) minutes in MC 4.7.

[angel_il]

ok, you right, i'm not... i try make viewer faster...

[birdie]

Out of curiosity I've just compiled MC 3.2.1 (the oldest version I could found on the net).

It jumps to the end of any file instantly. :)

[angel_il]

Replying to birdie:

Out of curiosity I've just compiled MC 3.2.1 (the oldest version I could found on the net).

It jumps to the end of any file instantly. :)

That's because MC scans all the file from top to bottom... (c)

[slavazanko]

(In #1417) > I am searching for simple word in internal viewer in 24 Mb text file.

Internal mc viewer needs 22 seconds when positioned at start of the
file to reach end of the file and tell me the word is not found.

Well... as fact, this is trouble described in #1585. You may check it:

1) echo "FIND_ME" >>big_file.txt
2) open big_file.txt in viewer
3) press 'End' key. Viewer after some pause will positioning at end of file.
4) press 'Home' key. Viewer will return at start of file.
5) Press F7 and enter search string "FIND_ME"

Search will much faster in this test case. Slowdown in mcview_ccache_* functions... IMHO :)

Illiya: I reassign ticket to you. After fix #1585 need to recheck test cases again.

[angel_il]

OK... birdie, build 608e7b497032b4d0be155f56dcb19878872e3513 and try it...
before 608e7b497032b4d0be155f56dcb19878872e3513 mcview jumps to the EOF instantly.

git reset --hard 608e7b497032b4d0be155f56dcb19878872e3513
./autogen.sh
./configure
make

[ossi]

the correct command is

git checkout 608e7b497032b4d0be155f56dcb19878872e3513

with reset --hard you will mess up the state of your local master branch. which is no biggie when you know how to recover ...

[angel_il]

branch: 1585_slow_viewer

first step to make viewer faster

[angel_il]

changeset: e9a91a93e4e50aaa9d093da74e508421170896a1

[angel_il]

initial: f36016f253f9bd71b77e8498279ac84a32a2cb81

[himikof]

Strange behaviour testcase

[himikof]

I have made a patch that fixes previously reported test case and removes unneeded eol_width parameter. Moving up-down seems to be working.

[himikof]

Patch for mcview_bol/mcview_eol

[himikof]

Fixes a few issues in left/right movement in hex viewer

[angel_il]

inital commit: dff373afb554e7087fe8bb3b751241f51681b80f

[angel_il]

changeset: d2668b188a3529f07e50506605e86f32ee3c7805

[angel_il]

Merged to master: [4c6b5fc569c80aab1e33be4eb7b66b9c7d787ab9].

[birdie]

I haven't tested the patch yet, but I still say thank you very much!