Add the underlying operating system error (usually "No such file" or
"Out of space" respectively, but highly informative when it is not)
to these error messages.
* Don't preallocate sdust_buf or minizer list. kalloc should be fast enough -
benchmarks needed to confirm.
* Fixed a memory leak caused by divergence estimate (post v2.5)
* Reset the kalloc buffer after mapping a long query. This reduces peak memory
when large chunks of memory are allocated, at the cost of performance, though.
In human/mouse, the GTr..yAG pattern occurs to 91/92% of all GT-AG introns.
Modeling r..y clearly leads to higher accuracy. However, in SIRV, this
percentage is reduced to ~60%. The default "--splice --splice-flank=yes"
leads to lower accuracy. If someone benchmark minimap2 on SIRV, this would be
bad, but minimap2 is developed for practical applications, not for benchmarks.
I will live with that.
[PMID:18688272] shows that the base following GT tends to be A or G (i.e. R) in
both human and yeast, and that the base preceeding AG tends to be C or T (i.e.
Y). In the new model, we pay no cost to GTr..yAG, but we pay half of the cost
if there is no r or y. This improves the junction accuracy when mapping to
human and mouse and decreases the accuacy when mapping to SIRV. My guess is
that SIRV does not honor this trend. Need to investigate in future.
Also in this commit, --cost-non-gt-ag is aliased to -C. The default is changed
to 9 instead of 5. I also added --splice-flank to enable the above model. This
may become the default once I confirm my hypothesis on SIRV.
