This code is essentially replacement for eestream.CalcPieceSize. To call
eestream.CalcPieceSize we need eestream.RedundancyStrategy which is not
trivial to get as it requires infectious.FEC. For example infectious.FEC
creation is visible on GE loop observer CPU profile because we were
doing this for each segment in DB.
New method was added to storj.Redundancy and here we are just wiring it
with metabase Segment.
BenchmarkSegmentPieceSize
BenchmarkSegmentPieceSize/eestream.CalcPieceSize
BenchmarkSegmentPieceSize/eestream.CalcPieceSize-8 5822 189189 ns/op 9776 B/op 8 allocs/op
BenchmarkSegmentPieceSize/segment.PieceSize
BenchmarkSegmentPieceSize/segment.PieceSize-8 94721329 11.49 ns/op 0 B/op 0 allocs/op
Change-Id: I5a8b4237aedd1424c54ed0af448061a236b00295
16b7901fde