After the line

[20:54:55] [Client thread/INFO]: [WayofTime.alchemicalWizardry.common.book.BookParser:parseTextFile:38]: I am in an island of files!

in the log of client Minecraft is hanging up for 2m10s and only then continues loading. And this is on my desktop PC with Intel(R) Core(TM) i7-3970X CPU @ 3.50GHz. Other people using this modpack have to wait even very much longer, up to 10m! Please make a fix removing this delay.

Hand-maded ModPack, BloodMagic-1.7.10-1.3.1-7, full modlist: http://pastebin.com/rS3bHY3s

BTW, it wil be cool if you add the link to this issue tracker on www.minecraftforum.net (may be to FAQ).

This is very odd, since I did add something to alleviate this burden already... Did it not make it into the version or something?

Version BloodMagic-1.7.10-1.3.0b-3 don't hangs up client loading for long, BloodMagic-1.7.10-1.3.1-7 do. I've rolled back to 1.3.0b-3 to not have this problem. Sec, I'll switch back to 1.3.1-7 to give you the log.

http://rghost.ru/7c96brxkp - here is the logs. That's strange that my office computer (Intel I5) have only 47 secs of that delay... Anyway, different computers, different delay.
lines appear so:
[16:31:01] [Client thread/INFO]: [WayofTime.alchemicalWizardry.common.book.BookParser:parseTextFile:38]: I am in an island of files!
[16:31:48] [Client thread/INFO]: Adding the following recipe to the Compression Handler: 1xtile.blockGold@0
[16:31:48] [Client thread/INFO]: Adding the following recipe to the Compression Handler: 1xtile.blockIron@0
[16:31:48] [Client thread/INFO]: Adding the following recipe to the Compression Handler: 1xtile.blockDiamond@0

A few hours later I can check again my home computer with Intel I7, which have 2m10s delay here.

When, if ever, do the following lines appear? "Adding the following recipe to the Compression Handler:"

Oh, really... so the delay isn't at the compression handler, but is actually in the book parser? Or is it still working away at the pre-handler? Hmmm... The issue might be in my book parser and not my compression registry if that is the case. I don't see why, though, since the parser only really manipulates strings.

Really strange - home computer, Intel I7, same delay about 2m10s (much longer than on I5!). If you not succeed to replay the delay, I can assist - may be we need some "debug" version which will be more verbose at log output when book parser & pre-handler is working?
(What it can do so long with a books? Maybe it cycles too much due to typo?)
(offtop: I've heard that processor cooler is increasing RPM at the delay so it is intensively loads the CPU)

Your book parser has some O(n²) or even O(n³) loops.
From what I can see, the calls to Minecraft's listFormattedStringToWidth method are pretty expensive and you're making a lot of them.
Maybe you should use an alternative beause in all the times you call this function you're never actually using the result - only how many lines it has.

I suggest using a profiler to see where the culprits are though.

Ok, so I will definitely disable that for now until I can get it running at a reasonable rate. Don't expect a -8 until next week, however - lots of IRL projects needa doin'!~

Fixed