Examples with Collectors.partitioningBy java.util.stream.Collectors.partitioningBy used on opensource projects

Example 1 with Collectors.partitioningBy

use of java.util.stream.Collectors.partitioningBy in project hazelcast by hazelcast.

the class MasterJobContext method getErrorFromResponses.

/**
 * <ul>
 * <li>Returns {@code null} if there is no failure
 * <li>Returns a {@link CancellationException} if the job is cancelled
 *     forcefully.
 * <li>Returns a {@link JobTerminateRequestedException} if the current
 *     execution is stopped due to a requested termination, except for
 *     CANCEL_GRACEFUL, in which case CancellationException is returned.
 * <li>If there is at least one user failure, such as an exception in user
 *     code (restartable or not), then returns that failure.
 * <li>Otherwise, the failure is because a job participant has left the
 *     cluster. In that case, it returns {@code TopologyChangeException} so
 *     that the job will be restarted
 * </ul>
 */
private Throwable getErrorFromResponses(String opName, Collection<Map.Entry<MemberInfo, Object>> responses) {
    if (isCancelled()) {
        logger.fine(mc.jobIdString() + " to be cancelled after " + opName);
        return new CancellationException();
    }
    Map<Boolean, List<Entry<Address, Object>>> grouped = responses.stream().map(en -> entry(en.getKey().getAddress(), en.getValue())).collect(partitioningBy(e1 -> e1.getValue() instanceof Throwable));
    int successfulMembersCount = grouped.getOrDefault(false, emptyList()).size();
    if (successfulMembersCount == mc.executionPlanMap().size()) {
        logger.fine(opName + " of " + mc.jobIdString() + " was successful");
        return null;
    }
    List<Entry<Address, Object>> failures = grouped.getOrDefault(true, emptyList());
    if (!failures.isEmpty()) {
        logger.fine(opName + " of " + mc.jobIdString() + " has failures: " + failures);
    }
    // other exceptions, ignore this and handle the other exception.
    if (failures.stream().allMatch(entry -> entry.getValue() instanceof TerminatedWithSnapshotException)) {
        assert opName.equals("Execution") : "opName is '" + opName + "', expected 'Execution'";
        logger.fine(opName + " of " + mc.jobIdString() + " terminated after a terminal snapshot");
        TerminationMode mode = requestedTerminationMode;
        assert mode != null && mode.isWithTerminalSnapshot() : "mode=" + mode;
        return mode == CANCEL_GRACEFUL ? new CancellationException() : new JobTerminateRequestedException(mode);
    }
    // If all exceptions are of certain type, treat it as TopologyChangedException
    Map<Boolean, List<Entry<Address, Object>>> splitFailures = failures.stream().collect(Collectors.partitioningBy(e -> e.getValue() instanceof CancellationException || e.getValue() instanceof TerminatedWithSnapshotException || isTopologyException((Throwable) e.getValue())));
    List<Entry<Address, Object>> topologyFailures = splitFailures.getOrDefault(true, emptyList());
    List<Entry<Address, Object>> otherFailures = splitFailures.getOrDefault(false, emptyList());
    if (!otherFailures.isEmpty()) {
        return (Throwable) otherFailures.get(0).getValue();
    } else {
        return new TopologyChangedException("Causes from members: " + topologyFailures);
    }
}