This is sorta an optimisation, and sorta a bug fix. In one
test case I have available, it can speed a page build up from 3
minutes to 3 seconds.
The root of the problem is that $links{$page} contains arrays of
links, rather than hashes of links. And when a link is found,
it is just pushed onto the array, without checking for dups.
Now, the array is emptied before scanning a page, so there
should not be a lot of opportunity for lots of duplicate links
to pile up in it. But, in some cases, they can, and if there
are hundreds of duplicate links in the array, then scanning it
for matching links, as match_link and some other code does,
becomes much more expensive than it needs to be.
Perhaps the real right fix would be to change the data structure
to a hash. But, the list of links is never accessed like that,
you always want to iterate through it.
I also looked at deduping the list in saveindex, but that does
a lot of unnecessary work, and doesn't completly solve the problem.
So, finally, I decided to add an add_link function that handles deduping,
and make ikiwiki-transition remove the old dup links.
* pagespec_match_list: New API function, matches pages in a list
and throws an error if the pagespec is bad.
* inline, brokenlinks, calendar, linkmap, map, orphans, pagecount,
pagestate, postsparkline: Display a handy error message if the pagespec
is erronious.
* Add IkiWiki::ErrorReason objects, and modify pagespecs to return
them in cases where they fail to match due to a configuration or syntax
error.
* inline: Display a handy error message if the inline cannot display any
pages due to such an error.
This is perhaps somewhat incomplete, as other users of pagespecs do not
display the error, and will eventually need similar modifications to inline.
I should probably factor out a pagespec_match_all function and make it throw
ErrorReasons.
This means that the underlay needs to have a wmd/wmd/wmd.js,
which is a trifle weird, but it isolates all the wmd stuff in a
single wmd subdirectory of the built wiki. The wmd/images creating
a toplevel images directory was particularly bad.
Falls back to looking for shortcuts.mdwn for backwards compatabiity; there
probably exist wikis that have changed the pageext but still use
shortcuts.mdwn.