Preparser Cache

This is a fairly simple pre-parser modification which should speed up one of MyBB's slowest functions.
Basically, MyBB's MyCode parser is rather slow; this plugin speeds this component up by caching the result so that the parser does not have to be run on every single page request (this is assuming that SHA1 hashing + a single query with some string manipulation is faster than running the parser 20+ times).

This plugin is compatible with all supported DB engines (SQLite in MyBB 1.6.0 is bugged, so cannot be tested).

Compatibility with other plugins
Due to the fact that this modification changes the environment under which the parser is run, I cannot guarantee that this will work with all MyCode/HTML or parser related plugins, especially those that may display posts differently to different users (on the other hand, this actually may have the potential to remove some of the issues in some poorly coded modifications).  Custom MyCodes should still work, and there is a workaround for the vB Quote plugin.
This will not work with the HTML in Posts plugin.

About design
The design of this is much simpler than my mod for MyBB 1.2, and as such, is nowhere near as aggressive, however, it's something I (originally!) banged up together in about an hour, and gets most of the benefits anyway.  It differs from both my 1.2 mod, and Ryan Gordon's 1.4 mod in that it operates at a parser level instead of at the showthread/postbit level.

The plugin only does posts and signatures on showthread.php, but it can be quite easily modified for other places, as it operates on a parser level.  Again, this was something I wrote fairly quickly, and could use a number of improvements in some areas.
The cache is periodically cleaned via a cleanup task.

Note
Note that this plugin also provides a way to manually clear the cache, under the Recount & Rebuild section of the AdminCP, should you ever have the need to do so.

Known Issues

• Attachments embedded with the [attachment=id] code may not have their download count updated
• A very minor one - it's possible to cause this plugin to display removed attachments embedded in the post (will be a dead link though).  Standard MyBB behavior will simply ignore the [attachment=id] code.  This will do the same if the post is updated in any way.
• For MyBB 1.8, quote times will be forced to use absolute time (instead of relative).  For earlier versions, there is no change to the timestamp displayed, however the "Today" and "Yesterday" text will never get updated (until a cache clear), so this can be inaccurate if this occurs
  

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Simple Benchmark
Just a simple benchmark I performed to get an idea of the speed gains of this plugin.  I'm benchmarking this page, with and without the plugin.  I guess the page is somewhat a good candidate for this plugin, although I didn't exactly cherry pick it on purpose.

Times were recorded by just using the time metric at the bottom of the page.  Note that the plugin does a number of things after the timer has completed, so I've also made a comparison after modifying MyBB's timer to more accurately measure the time (if you don't perform this modification, the preparser mod should pretty much always make your showthread pages seem to run faster).
Pages were loaded 3 times.

Standard behaviour: 0.2359838s, 0.2380810s, 0.2462718s
Standard behaviour, after editing timer: 0.2320759s, 0.2335730s, 0.2380040s
With preparser (with timer edit): 0.1327140s, 0.1319780s, 0.1258268s
With preparser (without timer edit (inaccurate)): 0.1291881s, 0.1186280s, 0.1211529s

Initial load with preparser, timer edit: 0.2454121s (this is the page load which caches everything - it'll be slower than normal page loads, but subsequent requests will be much faster)

1.0 benchmarks:
Standard behaviour: 0.2242870s, 0.2201211s, 0.2377510s
Standard behaviour, after editing timer: 0.2399340s, 0.2398720s, 0.2158720s
With preparser (with timer edit): 0.1303909s, 0.1500199s, 0.1303349s
With preparser (without timer edit (inaccurate)): 0.1157429s, 0.1143448s, 0.1083250s

[ZiNgA BuRgA]

(05-15-2011 02:47 AM)sledgeab Wrote:  What can I do?

You could explain your problems.  That'd be a start.

[Sama34]

Hi, when activating HTML on a by forum basis Preparser works, but if I install HTML in Posts plugin it doesn't.
http://mods.mybb.com/view/html-in-posts

May there be a solution for this or it is a issue relating the other plugin?

[ZiNgA BuRgA]

Parsing plugins like that have a fair likelihood of not working properly.
I'm not sure about that one though - it seems intrinsicly that it should work.

How does it not work?

[Sama34]

When using this plugin to limit HTML usage and Preparser is activated this is what is show:
http://img29.imageshack.us/img29/3803/20...http://img29.imageshack.us/img29/3803/20110625

When preparser is deactivated this is what is show:
http://img109.imageshack.us/img109/463/2...http://img109.imageshack.us/img109/463/20110625

I suppose it doesn't parse HTML the right way or something..

[ZiNgA BuRgA]

Sorry for being late, but I've had a look at this.  It looks like the HTML in Posts plugin does rely on some external information for it to work, and the Preparser changes the environment in which it works, so by design, there's really no solution unfortunately.
Sorry about that.

[Sama34]

Well, don't worry, tanks for taking the time to check it out

[DamYan]

Your plugin is amazing! But I have a little problem with HTML Permissions developed by labrocca: http://www.mybbcentral.com/thread-1678.html

In some cases, my team use html on forum (WordBB bridge, news on forum and portal), so this plugin is very useful for us.

Can you help me to fix Preparser?

[ZiNgA BuRgA]

I'm unaware of how that plugin works so I cannot provide any suggestions.
If it works similar to the plugin mentioned a few posts above, there is unfortunately no solution.

Many parser related plugins will probably not work well with the Preparser due to a number of reasons.

[Renegader]

http://community.mybb.com/thread-100341.html

Please take a look at this, I spent hours and hours and finally found out you had to disable that

[ZiNgA BuRgA]

Really says nothing useful that I can do anything about.
No queries performed in this plugin are un-indexed.

I do not have any such problems with the plugin.