Add one more thread on compression and decompression to account for the staggered nature of thread recruitment.
Make the initial buffer slightly smaller and make it progressively larger, thus recruiting threads sooner and more evenly.
This also speeds up decompression for the same reason.
Check the amount of memory being used by each thread on decompression to ensure we don't try to recruit too much ram.
Add the md5 value to the end of each archive.
This can then be used for integrity testing instead of crc32.
Keep crc in new archives to maintain compatibility with version 0.5 files.
Use md5 integrity testing on decompression when available in preference, and disable calculation of crc32.
Display the choice of integrity testing in verbose output and when -i is used.
Display the md5 and crc values when max verbosity, file info, or display hash is enabled.
Store a new flag in the magic header to show that the md5 value is stored at the end of the file.
Update the magic header information document.
Implement md5 hash checking on compression by doing the md5 hash check as each sb low buffer has been allocated to avoid going over the file again where possible.
This overlapping of compressing streams means that when files are large enough to be split into multiple blocks, all CPUs will be used more effectively throughout the compression, affording a nice speedup.
Move the writing of the chunk byte size and initial headers into the compthread to prevent any races occurring.
Fix a few dodgy callocs that may have been overflowing!
The previous commit reverts were done because the changes designed to speed it up actually slowed it down instead.
Choose sane defaults for memory usage since linux ludicriously overcommits.
Use sliding mmap for any compression windows greater than 2/3 ram.
Consolidate and simplify testing of allocatable ram.
Minor tweaks to output.
Round up the size of the high buffer in sliding mmap to one page.
Squeeze a little more out of 32 bit compression windows.
Remove -P option as failing to set permissions only issues a warning now, removing any requirement for -P.
Change default compression level back to 7 as 9 was not giving significantly better compression but was slowing things down.
Place the data from each stream into a buffer that then is handed over to one thread which is allowed to begin doing the backend compression while the main rzip stream continues operating.
Fork up to as many threads as CPUs and feed data to them in a ring fashion, parallelising the workload as much as possible.
This causes a big speed up on the compression side on SMP machines.
Thread compression is limited to a minimum of 10MB compressed per thread to minimise the compromise to compression of smaller windows.
Alter the progress output to match some of the changes in verbose modes.
Prevent failure when offset is not a multiple of page size.
Add chunk percentage complete to output.
Tweak output at various verbosities.
Update documentation to reflect improved performance of unlimited mode.
Update benchmark results.
More tidying.
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.
