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From Ross Black <ross.w.bl...@gmail.com>
Subject Re: problem with keys returned from multiget_slice
Date Wed, 01 Feb 2012 12:10:52 GMT
I just solved it.
It was my mistake with using ByteBuffer.. the array() method returns the
entire array without considering the index offset into the array.
It works using
    String rowName =
Charset.forName(UTF_8).decode(entry.getKey()).toString();

Ross


On 1 February 2012 22:42, Ross Black <ross.w.black@gmail.com> wrote:

> Hi,
>
> I am trying to get multiget_slice working with the raw thrift client, but
> am having problems interpreting the returned keys.
> I assume I am doing something wrong but figure what.
>
> Here is the test program...
>
> import org.apache.cassandra.thrift.*;
> import org.apache.thrift.protocol.TBinaryProtocol;
> import org.apache.thrift.protocol.TProtocol;
> import org.apache.thrift.transport.TFramedTransport;
> import org.apache.thrift.transport.TSocket;
> import org.apache.thrift.transport.TTransport;
>
> import java.nio.ByteBuffer;
> import java.util.Arrays;
> import java.util.Collections;
> import java.util.List;
> import java.util.Map;
>
> public class TestMultiGet {
>
>     private static final String KEYSPACE = "junk";
>     private static final String COLUMN_FAMILY = "blah";
>
>     public static void main(String[] args) throws Exception {
>         TTransport transport = new TFramedTransport(new
> TSocket("localhost", 9160, 30 * 1000));
>         transport.open();
>         TProtocol protocol = new TBinaryProtocol(transport);
>         Cassandra.Client client = new Cassandra.Client(protocol);
>
>         ByteBuffer rowKey = ByteBuffer.wrap("row111".getBytes());
>         ByteBuffer colKey = ByteBuffer.wrap("BBB".getBytes());
>         ByteBuffer value = ByteBuffer.wrap("datadata".getBytes());
>         long timestamp = System.currentTimeMillis();
>         ColumnParent columnParent = new ColumnParent(COLUMN_FAMILY);
>         Column column = new
> Column().setName(colKey).setValue(value).setTimestamp(timestamp);
>
>         client.set_keyspace(KEYSPACE);
>         client.insert(rowKey, columnParent, column, ConsistencyLevel.ONE);
>
>         SlicePredicate predicate = new
> SlicePredicate().setColumn_names(Collections.singletonList(colKey));
>         Map<ByteBuffer, List<ColumnOrSuperColumn>> sliceMap =
> client.multiget_slice(Collections.singletonList(rowKey), columnParent,
> predicate, ConsistencyLevel.QUORUM);
>         for (Map.Entry<ByteBuffer, List<ColumnOrSuperColumn>> entry :
> sliceMap.entrySet()) {
>             byte[] key = entry.getKey().array();
>             System.err.println("Row bytes = " + Arrays.toString(key));
>             System.err.println("Row = ###\n" + new String(key) + "###");
>
>             List<ColumnOrSuperColumn> columns = entry.getValue();
>             for (ColumnOrSuperColumn col : columns) {
>                 byte[] name = col.getColumn().getName();
>                 System.err.println("Column = " + new String(name));
>             }
>         }
>     }
> }
>
>
> And here is the output I get when I run it...
> Row bytes = [-128, 1, 0, 2, 0, 0, 0, 14, 109, 117, 108, 116, 105, 103,
> 101, 116, 95, 115, 108, 105, 99, 101, 0, 0, 0, 3, 13, 0, 0, 11, 15, 0, 0,
> 0, 1, 0, 0, 0, 6, 114, 111, 119, 49, 49, 49, 12, 0, 0, 0, 1, 12, 0, 1, 11,
> 0, 1, 0, 0, 0, 3, 66, 66, 66, 11, 0, 2, 0, 0, 0, 8, 100, 97, 116, 97, 100,
> 97, 116, 97, 10, 0, 3, 0, 0, 1, 53, 56, -84, 0, 87, 0, 0, 0]
> Row = ###@row111@BBB@datadata@###
> Column = BBB
>
> where the @ represents unprintable chars.
>
> I assumed that the keys in the returned Map would be the same as the keys
> passed in, but they instead seem to contain the entire result.
> I have tried this with 0.8.x and 1.0.7 with the same result.
>
> Should the returned keys be the same as the requested keys, or do they
> need to be interpreted as some other data structure?
> What do I need to do to fix this?
>
>
> Thanks,
> Ross
>
>

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