Examples with AggregateResponse org.apache.hadoop.hbase.protobuf.generated.AggregateProtos.AggregateResponse used on opensource projects

Example 21 with AggregateResponse

use of org.apache.hadoop.hbase.protobuf.generated.AggregateProtos.AggregateResponse in project hbase by apache.

the class AggregationClient method getMedianArgs.

/**
   * It helps locate the region with median for a given column whose weight
   * is specified in an optional column.
   * From individual regions, it obtains sum of values and sum of weights.
   * @param table
   * @param ci
   * @param scan
   * @return pair whose first element is a map between start row of the region
   *  and (sum of values, sum of weights) for the region, the second element is
   *  (sum of values, sum of weights) for all the regions chosen
   * @throws Throwable
   */
private <R, S, P extends Message, Q extends Message, T extends Message> Pair<NavigableMap<byte[], List<S>>, List<S>> getMedianArgs(final Table table, final ColumnInterpreter<R, S, P, Q, T> ci, final Scan scan) throws Throwable {
    final AggregateRequest requestArg = validateArgAndGetPB(scan, ci, false);
    final NavigableMap<byte[], List<S>> map = new TreeMap<>(Bytes.BYTES_COMPARATOR);
    class StdCallback implements Batch.Callback<List<S>> {

        S sumVal = null, sumWeights = null;

        public synchronized Pair<NavigableMap<byte[], List<S>>, List<S>> getMedianParams() {
            List<S> l = new ArrayList<>(2);
            l.add(sumVal);
            l.add(sumWeights);
            Pair<NavigableMap<byte[], List<S>>, List<S>> p = new Pair<>(map, l);
            return p;
        }

        @Override
        public synchronized void update(byte[] region, byte[] row, List<S> result) {
            map.put(row, result);
            sumVal = ci.add(sumVal, result.get(0));
            sumWeights = ci.add(sumWeights, result.get(1));
        }
    }
    StdCallback stdCallback = new StdCallback();
    table.coprocessorService(AggregateService.class, scan.getStartRow(), scan.getStopRow(), new Batch.Call<AggregateService, List<S>>() {

        @Override
        public List<S> call(AggregateService instance) throws IOException {
            RpcController controller = new AggregationClientRpcController();
            CoprocessorRpcUtils.BlockingRpcCallback<AggregateResponse> rpcCallback = new CoprocessorRpcUtils.BlockingRpcCallback<>();
            instance.getMedian(controller, requestArg, rpcCallback);
            AggregateResponse response = rpcCallback.get();
            if (controller.failed()) {
                throw new IOException(controller.errorText());
            }
            List<S> list = new ArrayList<>();
            for (int i = 0; i < response.getFirstPartCount(); i++) {
                ByteString b = response.getFirstPart(i);
                T t = getParsedGenericInstance(ci.getClass(), 4, b);
                S s = ci.getPromotedValueFromProto(t);
                list.add(s);
            }
            return list;
        }
    }, stdCallback);
    return stdCallback.getMedianParams();
}