This frees a byte value to use for 'end of key' (to correctly sort
short keys) while still having a weight assigned to the field sep.
(Unless -t is given, the field sep is in the field data.)
Do reverse sorts by writing the output file in reverse order (rather
than reversing the sort - apart from merges).
All key compares are now unweighted.
For 'sort -u' mark duplicates keys during the sort and don't write
to the output.
Use -S to mean a posix sort - where equal keys are sorted using the
raw record (rather than being kept in the original order).
For 'sort -f' (no keys) generate a key of the folded data (as for -n
-i and -d), simplifies the code and allows a 'posix' sort.
an array of 'RECHEADER *' and remove all the crappy stuff that backed up
by REC_DATA_OFFSET (etc).
Also change radix_sort() to return the number of elements, soon to be used
to drop duplicate keys (for sort -u).
- If we generate a key, it is always sortable using memcmp()
- If we are sorting the whole record, then a weight-table must be used
during compares.
- Major surgery to encoding of numbers to ensure unique keys for equal
numeric values. Reverse numerics are handled by inverting the sign.
- Case folding (-f) is handled when the sort keys are generated. No other
code has to care at all.
- Key uniqueness (-u) is done during merge for large datasets. It only
has to be done when writing the output file for small files.
Since the file is in key order this is simple!
Probably fixes all of: PR/27257 PR/25551 PR/22182 PR/31095 PR/30504
PR/36816 PR/37860 PR/39308
Also PR/18614 should no longer die, but a little more work needs to be
done on the merging for very large files.
Simplify logic for reading input records.
Do a merge sort whenever we have 16 partial sorted blocks.
The patient is breathing, but still carrying a lot of extra weight.
first key byte and writing to a temp file, then sorting the records from
each temp file that had the same first key byte (and repeating for upto
4 key bytes) was a nice idea, but completely doomed to failure.
Eg PR/9308 where a 70MB file has all but one record the same and short keys.
Not only does the code not work, it is rather guaranteed to be slow.
Instead always use a merge sort for fully sorted chunk of records (each
temporary file contains one lot of sorted records).
The -H option already did this, so just rip out all the code and variables
that can't be used when -H was specified.
Further cleanup to come ...
reference, when we want to find the record header put the larger value
into 'hdr_off' to avoid any confusion that the code might be changing
'depth'!
There is now no need to save the original value as 'odepth' in append.c.
All an a vague attempt to make this code slightly readable.
* get rid of union f_handle, replace by passing explicit int parameter
and (new) struct filelist
* add new typedefs gen_func_t and put_func_t and use where appropriate
'offset' members of struct recheader/trecheader are shorts - they are size_t
now
this makes sort pass all tests in TEST/stests again after my last change
other misc cosmetic changes
