This is done by taking each stream of data on read in into separate buffers for up to as many threads as CPUs.
As each thread's data becomes available, feed it into runzip once it is requests more of the stream.
Provided there are enough chunks in the originally compressed data, this provides a massive speedup potentially proportional to the number of CPUs. The slower the backend compression, the better the speed up (i.e. zpaq is the best sped up).
Fix the output of zpaq compress and decompress from trampling on itself and racing and consuming a lot of CPU time printing to the console.
When limiting cwindow to 6 on 32 bits, ensure that control.window is also set.
When testing for the maximum size of testmalloc, the multiple used was out by one, so increase it.
Minor output tweaks.
Modify the sliding mmap window to have a 64k smaller buffer which matches the size of the search size, and change the larger lower buffer to make it slide with the main hash search progress. This makes for a MUCH faster unlimited mode, making it actually usable.
Limit windows to 2GB again on 32 bit, but do it when determining the largest size possible in rzip.c.
Implement a linux-kernel like unlikely() wrapper for inbuilt expect, and modify most fatal warnings to be unlikely, and a few places where it's also suitable.
Minor cleanups.
Make stdout write directly to stdout on decompression without the need for temporary files since there is no need to seek backwards.
Make file testing not actually write the file during test.
More tidying up.
Fix the longstanding limit on 32 bits that allowed us to allocate only 2GB of ram by moving the big malloc calls to mmap equivalents which allow us to mmap up to 2^44 bytes of anonymous space.
Use progressively smaller preallocation to try and defragment ram prior to real mmap call to increase success rate of allocating ram when it's a significant proportion of total ram.
Don't fail if preallocation is unsuccessful.
Add more detailed error reporting.
Minor cleanups.
This will increase speed of compression and generate a smaller file, but not be backward compatible.
Tweak the way memory is allocated to optimise chances of success and minimise slowdown for the machine.
fsync to empty dirty data before allocating large ram to increase chance of mem allocation and decrease disk thrash of write vs read.
Add lots more information to verbose mode.
Lots of code tidying and minor tweaks.
Premalloc ram to improve early detection of being unable to allocate that much ram.
Make sure to always make chunk size a multiple of page size for mmap to work.
Begin changes to make variable byte width offsets in rzip chunks.
Decrease header entries to only 2 byte wide as per original rzip.
Random other tidying.
