def hcompress(self, hashroot):
hfiles = self.keys(hashroot + "<STR_LIT>")<EOL>all = {}<EOL>for f in hfiles:<EOL><INDENT>all.update(self[f])<EOL>self.uncache(f)<EOL><DEDENT>self[hashroot + '<STR_LIT>'] = all<EOL>for f in hfiles:<EOL><INDENT>p = self.root / f<EOL>if p.basename() == '<STR_LIT>':<EOL><INDENT>continue<EOL><DEDENT>p.remove()<EOL><DEDENT>
Compress category 'hashroot', so hset is fast again

        hget will fail if fast_only is True for compressed items (that were
        hset before hcompress).