Real data sets for bitmap testing
See also https://github.com/RoaringBitmap/CRoaring/tree/master/benchmarks/realdata for uncompressed .txt versions.
Essentially, each file represents a set of integer values. You can create
bitmaps out of these files.
In many cases, the description of the data sets is provided in :
To be used with software published on http://roaringbitmap.org/
Files starting with the prefix "dimension" were prepared by Xavier Léauté from
a Druid dump.
There is one special file (bitsets_1925630_96.gz) which is a binary file. All other files are just zipped text files. This special file can be deserialized by first reading an int, that is the amout of rows to come (e.g. 1925630 rows)
A row is read by first reading an int, the amount of longs to come (e.g. 96 longs), and then reading those longs.
Used DataInputStream to write this.