Re: cleaner/better zlib sources?

Er, it's a little hard to see, but zlib spends the bulk of its time in inflate_fast(). This is the fast path, invoked as long as there's at least 6 bytes of input and 258 bytes of output space available.

The code in inflate.c just handles the last few bytes when near one limit or the other. Are you sure it's a performance problem?

There's equivalent inflate code in the PGP 5.0i distribution (src/lib/pgp/compress/pgpZInflate.c) that's in the public domain AFAICT (it says "Not copyrighted", and "You can do whatever you like with this source file, though I would prefer that if you modify it and redistribute it that you include comments to that effect with your name and the date."), and uses switch statements only for resuming after a pause.

It's presumably well tested, but it's got a strong nasty-old-MSDOS code smell about it, some truly bizarre indenting (don't look at lines 1118-1126 with a full stomach), and would require a lot of massaging to integrate with zlib.