view tests/test-dispatch.py.out @ 25899:c35ee1bbbbdc

highlight: exit early on textual and unknown files (issue3005)

When highlight extension encountered files that pygments didn't recognize, it
used to fall back to text lexer. Also, pygments uses TextLexer for .txt files.
This lexer is noop by design.

On bigger files, however, doing the noop highlighting resulted in noticeable
extra CPU work and memory usage: to show a 1 MB text file, hgweb required about
0.7s more (on top of ~3.8s, Q8400) and consumed about 100 MB of RAM more (on
top of ~150 MB).

Let's just exit the function when it's clear that nothing will be highlighted.

Due to how this pygmentize function works (it modifies the template in-place),
we can just return from it and everything else will work as if highlight
extension wasn't enabled.

running: init test1
result: None
running: add foo
result: 0
running: commit -m commit1 -d 2000-01-01 foo
result: None
running: commit -m commit2 -d 2000-01-02 foo
result: None
running: log -r 0
changeset:   0:0e4634943879
user:        test
date:        Sat Jan 01 00:00:00 2000 +0000
summary:     commit1

result: None
running: log -r tip
changeset:   1:45589e459b2e
tag:         tip
user:        test
date:        Sun Jan 02 00:00:00 2000 +0000
summary:     commit2

result: None