Examples with AggregationFunction org.apache.rya.api.function.aggregation.AggregationFunction used on opensource projects

Example 1 with AggregationFunction

use of org.apache.rya.api.function.aggregation.AggregationFunction in project incubator-rya by apache.

the class AggregationResultUpdater method updateAggregateResults.

/**
 * Updates the results of an Aggregation node where its child has emitted a new Binding Set.
 *
 * @param tx - The transaction all Fluo queries will use. (not null)
 * @param childBindingSet - The Binding Set that was omitted by the Aggregation Node's child. (not null)
 * @param aggregationMetadata - The metadata of the Aggregation node whose results will be updated. (not null)
 * @throws Exception The update could not be successfully performed.
 */
public void updateAggregateResults(final TransactionBase tx, final VisibilityBindingSet childBindingSet, final AggregationMetadata aggregationMetadata) throws Exception {
    requireNonNull(tx);
    requireNonNull(childBindingSet);
    requireNonNull(aggregationMetadata);
    log.trace("Transaction ID: " + tx.getStartTimestamp() + "\n" + "Child Binding Set:\n" + childBindingSet + "\n");
    // The Row ID for the Aggregation State that needs to be updated is defined by the Group By variables.
    final String aggregationNodeId = aggregationMetadata.getNodeId();
    final VariableOrder groupByVars = aggregationMetadata.getGroupByVariableOrder();
    final Bytes rowId = makeRowKey(aggregationNodeId, groupByVars, childBindingSet);
    // Load the old state from the bytes if one was found; otherwise initialize the state.
    final Optional<Bytes> stateBytes = Optional.ofNullable(tx.get(rowId, FluoQueryColumns.AGGREGATION_BINDING_SET));
    final AggregationState state;
    if (stateBytes.isPresent()) {
        // Deserialize the old state
        final byte[] bytes = stateBytes.get().toArray();
        state = AGG_STATE_SERDE.deserialize(bytes);
    } else {
        // Initialize a new state.
        state = new AggregationState();
        // If we have group by bindings, their values need to be added to the state's binding set.
        final MapBindingSet bindingSet = state.getBindingSet();
        for (final String variable : aggregationMetadata.getGroupByVariableOrder()) {
            bindingSet.addBinding(childBindingSet.getBinding(variable));
        }
    }
    log.trace("Transaction ID: " + tx.getStartTimestamp() + "\n" + "Before Update: " + LogUtils.clean(state.getBindingSet().toString()) + "\n");
    // Update the visibilities of the result binding set based on the child's visibilities.
    final String oldVisibility = state.getVisibility();
    final String updateVisibilities = VisibilitySimplifier.unionAndSimplify(oldVisibility, childBindingSet.getVisibility());
    state.setVisibility(updateVisibilities);
    // Update the Aggregation State with each Aggregation function included within this group.
    for (final AggregationElement aggregation : aggregationMetadata.getAggregations()) {
        final AggregationType type = aggregation.getAggregationType();
        final AggregationFunction function = FUNCTIONS.get(type);
        if (function == null) {
            throw new RuntimeException("Unrecognized aggregation function: " + type);
        }
        function.update(aggregation, state, childBindingSet);
    }
    log.trace("Transaction ID: " + tx.getStartTimestamp() + "\n" + "After Update:" + LogUtils.clean(state.getBindingSet().toString()) + "\n");
    // Store the updated state. This will write on top of any old state that was present for the Group By values.
    tx.set(rowId, FluoQueryColumns.AGGREGATION_BINDING_SET, Bytes.of(AGG_STATE_SERDE.serialize(state)));
}