// NewChecksumReader creates a new ChecksumReader for the given block.
func NewChecksumReader(block *hdfs.LocatedBlockProto) *ChecksumReader {
locs := block.GetLocs()
datanodes := make([]string, len(locs))
for i, loc := range locs {
dn := loc.GetId()
datanodes[i] = fmt.Sprintf("%s:%d", dn.GetIpAddr(), dn.GetXferPort())
}
return &ChecksumReader{
block: block,
datanodes: newDatanodeFailover(datanodes),
}
}
// NewBlockReader returns a new BlockReader, given the block information and
// security token from the namenode. It will connect (lazily) to one of the
// provided datanode locations based on which datanodes have seen failures.
func NewBlockReader(block *hdfs.LocatedBlockProto, offset int64, clientName string) *BlockReader {
locs := block.GetLocs()
datanodes := make([]string, len(locs))
for i, loc := range locs {
datanodes[i] = getDatanodeAddress(loc)
}
return &BlockReader{
clientName: clientName,
block: block,
datanodes: newDatanodeFailover(datanodes),
offset: offset,
}
}