Description
Extracting actual data from a RowResult can be an ugly process when you don't know what you're looking for (to be able to query the Map).
For example, if i want to get all columns in a family, or I pass a large number of columns each of which may or may not exist in the specified row, I need to go through the entire list of column/Cells. Currently this is done with something like:
RowResult result = HTable.getRow(rowkey,columns)
Set<Map.Entry<byte [], Cell>> cols = result.entrySet();
From here I know how many entries are in the Set (cols.size()), but if I want to go through them, this requires another step change the Set into an Array or an Iterator.
Iterator<Map.Entry<byte [], Cell>> iterator = cols.iterator();
or
Map.Entry<byte [], Cell> [] entries = cols.toArray(new RowResult.Entry[0])
So going from what is returned from HBase, into something usable by the client, requires at least two additional lines and data structure conversions. The Map -> Set<Map.Entry> is very likely to be fast. I'm unsure about the speed of the Iterator or toArray. I would guess that the change to Iterator is fairly efficient (not requiring a copy of the memory), whereas toArray likely does.