Revert to zero padding

[lpoli]

Currently with chunked upload zero padding has been removed. As per discussion in slack channels, For a blobber, it should get minimum of blockSize amount of data which is 64KB or multiple of blockSize.

Give there are n data-blobbers and blocksize is 64KB, the reading should be done as follow:

chunkSize  := n * blockSize
chunkNums := int(math.Ceil(float64(fileSize) / float64(chunkSize)))

resultantSize := chunkNums * chunkSize
numPaddings := resultantSize - fileSize

reader := io.MultiReader(originalFileReader, bytes.NewReader(make([]byte, numPaddings)))

[guruhubb]

Is this same as https://github.com/0chain/gosdk/issues/426?

[cnlangzi]

@guruhubb yes. it is same as https://github.com/0chain/gosdk/issues/426

[lpoli]

The requirement is to have minimum block size i.e. 64KB. We can apply this requirement with pricing i.e. minimum cost shall be cost of 64KB. So it should be like this: If writemarker has size S and write price is W then cost of writing S bytes = Ceil_Of(S / 64KB) * W

@dabasov Please let us know if you think otherwise

[dabasov]

related to https://github.com/0chain/0chain/issues/1816