synchronized void cleanupLeaseForClosedShard()

in src/main/java/com/amazonaws/services/dynamodbv2/streamsadapter/DynamoDBStreamsShardSyncer.java [707:748]
38 lines of code
11 McCabe index (conditional complexity)

    synchronized void cleanupLeaseForClosedShard(String closedShardId,
        Set<String> childShardIds,
        Map<String, KinesisClientLease> trackedLeases,
        ILeaseManager<KinesisClientLease> leaseManager)
        throws DependencyException, InvalidStateException, ProvisionedThroughputException {
        KinesisClientLease leaseForClosedShard = trackedLeases.get(closedShardId);
        List<KinesisClientLease> childShardLeases = new ArrayList<>();

        for (String childShardId : childShardIds) {
            KinesisClientLease childLease = trackedLeases.get(childShardId);
            if (childLease != null) {
                childShardLeases.add(childLease);
            }
        }

        if ((leaseForClosedShard != null)
            && (leaseForClosedShard.getCheckpoint().equals(ExtendedSequenceNumber.SHARD_END))
            && (childShardLeases.size() == childShardIds.size())) {
            boolean okayToDelete = true;
            for (KinesisClientLease lease : childShardLeases) {
                if (!lease.getCheckpoint().equals(ExtendedSequenceNumber.SHARD_END)) {
                    okayToDelete = false; // if any child is still being processed, don't delete lease for parent
                    break;
                }
            }

            try {
                if (Instant.now().isBefore(getShardCreationTime(closedShardId).plus(MIN_LEASE_RETENTION))) {
                    okayToDelete = false; // if parent was created within lease retention period, don't delete lease for parent
                }
            } catch (RuntimeException e) {
                LOG.info("Could not extract creation time from ShardId [" + closedShardId +"]");
                LOG.debug(e);
            }

            if (okayToDelete) {
                LOG.info("Deleting lease for shard " + leaseForClosedShard.getLeaseKey()
                    + " as it is eligible for cleanup - its child shard is check-pointed at SHARD_END.");
                leaseManager.deleteLease(leaseForClosedShard);
            }
        }
    }