Slug #434
Emacs UI: very slow when input file is big (with long lines)
Description
Emacs has become very slow as I edit a large (3Mbyte) file.cocoa5.
The file contains several quite long lines (up to about 500000 chars).
The slow down is sufficient to be quite bothersome.
I suspect the problem is due to repeated parsing of the file for correct indentation etc. Maybe this should turn itself off if the buffer becomes too large (perhaps with a visible warning to the user, and a key-binding to force a single run of the parser -- similar to what ediff does for large regions?).
Related issues
History
#1
Updated by John Abbott over 10 years ago
Updated by - Category set to EmacsUI
The problems of serious slow down occur only when the cursor is towards the end of the file -- response is normal when the cursor is near the start of the file.
The scroll wheel of my mouse is "unusable" when the cursor is towards the end of the file, and the scrolling would make the final part of a long line come into view. Behaviour: cursor switches to "egg timer" shape (several times) then, after several seconds' delay, suddenly the visible portion jumps by many lines.
[not sure if this really is the fault of cocoa5-mode]
#2
Updated by John Abbott over 10 years ago
I created a 3Mbyte file with short lines (100 copies of the code in radical.cpkg). There was some slow down, but quite bearable.
I added a long line (Fact(205000), about 1Mbyte), and suddenly the problem of slow responses returned, and at one point emacs complained of stack overflow in regexp matcher.
I fear that this might be hard to fix, unless we can use the idea of turning off automatic syntax highlighting in large buffers...
#3
Updated by Anna Maria Bigatti over 10 years ago
Updated by - Target version set to CoCoA-5.1.0 Easter14
#4
Updated by John Abbott about 10 years ago
- Target version changed from CoCoA-5.1.0 Easter14 to CoCoA-5.?.?
#5
Updated by John Abbott about 8 years ago
- Related to Slug #875: Interpreter is too slow reading a big polynomial added