Hello Everyone!
I am trying to write an iterator to modify keys within a table (at scan).
My use case is to select a few records that match a certain criterion and
then modify them within the iterator(using the following class) for some
other succeeding iterator/combiner. The problem is that this iterator does
return any records/keys. I added some primitive prints and found that the
keys (this.key) is changed but the output of iterator is nothing. I'd
appreciate if someone could give me any insight. I'm sure I'm making a
teeny tiny mistake somewhere.
Schema:
row colF
colQ ts Val
I/P: r_1 f f_1
v1
r_1 fx f_1
v1
O/P: f_1 r
r_1 v1
f_1 fx
fx v1
public class KeyModifyIterator implements SortedKeyValueIterator<Key,Value>
{
private SortedKeyValueIterator<Key,Value> source;
private Key key;
private Value value;
@Override
public void init(SortedKeyValueIterator<Key,Value> source,
Map<String,String> options, IteratorEnvironment env) throws IOException {
this.source = source;
}
@Override
public boolean hasTop() {
return key != null;
}
@Override
public void next() throws IOException {
if (source.hasTop()) {
ByteSequence currentRow = source.getTopKey().getRowData();
ByteSequence currentColf =
source.getTopKey().getColumnFamilyData();
ByteSequence currentColq =
source.getTopKey().getColumnQualifierData();
long ts = source.getTopKey().getTimestamp();
String v = source.getTopValue().toString();
System.out.println("Key = " + currentRow.toString() + " Cf = "
+ currentColf.toString() + " Cq = " + currentColq.toString() + " val = " +
v.toString());
if (currentColf.toString().equals("fx")){
System.out.println("Updating fx" );
this.key = new Key(currentColq.toArray(),
currentColf.toArray(), currentColf.toArray(), new byte[0], ts);
this.value = new Value (v.getBytes(UTF_8));
}
else{
System.out.println("Updating other" );
this.key = new Key(currentColq.toArray(),
"r".getBytes(UTF_8), currentRow.toArray(), new byte[0], ts);
this.value = new Value (v.getBytes(UTF_8));
System.out.println(this.key.toString());
}
source.next();
} else {
this.key = null;
this.value = null;
}
}
@Override
public void seek(Range range, Collection<ByteSequence> columnFamilies,
boolean inclusive) throws IOException {
source.seek(range, columnFamilies, inclusive);
next();
}
@Override
public Key getTopKey() {
return key;
}
@Override
public Value getTopValue() {
return value;
}
@Override
public SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment
env) {
return null;
}
}
Best regards,
Yamini Joshi
