Invokes the fast cover algorithm with reasonable default parameters. Versions of zstd <= 1.3.5 used the cover algorithm.

Slower, higher quality generator.

The new builder, named fastcover, is about 10x faster than the previous default generator, cover, while suffering only negligible accuracy losses (<1%). It's effectively an approximative version of cover, which throws away accuracy for the benefit of speed and memory. This is zstd's default. Slower but higher quality generator remains accessible using Cover.