I am using pyaccumulo. Here's the code snippet:
rowIds=['r2','r10']
hashFilter = KeyModifyIterator(priority=10)
iterator.append(hashFilter)
for entry in self.dbconn.batch_scan(table ,
scanranges=(Range(srow=row, erow=row) for row in
rowIDs),iterators=[hashFilter]):
print entry
Best regards,
Yamini Joshi
On Fri, Sep 30, 2016 at 12:31 PM, Dan Blum <[email protected]> wrote:
> What code are you using to test the iterator, where you see no output?
>
>
>
> *From:* Yamini Joshi [mailto:[email protected]]
> *Sent:* Friday, September 30, 2016 1:26 PM
> *To:* [email protected]
> *Subject:* Modify Keys within iterator
>
>
>
> 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
>
