private List getPartitionsParallel()

in aws-glue-datacatalog-client-common/src/main/java/com/amazonaws/glue/catalog/metastore/DefaultAWSGlueMetastore.java [261:306]
40 lines of code
8 McCabe index (conditional complexity)

    private List<Partition> getPartitionsParallel(
            final String databaseName,
            final String tableName,
            final String expression,
            final long max) throws TException {
        // Prepare the segments
        List<Segment> segments = Lists.newArrayList();
        for (int i = 0; i < numPartitionSegments; i++) {
            segments.add(new Segment()
                    .withSegmentNumber(i)
                    .withTotalSegments(numPartitionSegments));
        }
        // Submit Glue API calls in parallel using the thread pool.
        // We could convert this into a parallelStream after upgrading to JDK 8 compiler base.
        List<Future<List<Partition>>> futures = Lists.newArrayList();
        for (final Segment segment : segments) {
            futures.add(this.executorService.submit(new Callable<List<Partition>>() {
                @Override
                public List<Partition> call() throws Exception {
                    return getCatalogPartitions(databaseName, tableName, expression, max, segment);
                }
            }));
        }

        // Get the results
        List<Partition> partitions = Lists.newArrayList();
        try {
            for (Future<List<Partition>> future : futures) {
                List<Partition> segmentPartitions = future.get();
                if (partitions.size() + segmentPartitions.size() >= max && max > 0) {
                    // Extract the required number of partitions from the segment and we're done.
                    long remaining = max - partitions.size();
                    partitions.addAll(segmentPartitions.subList(0, (int) remaining));
                    break;
                } else {
                    partitions.addAll(segmentPartitions);
                }
            }
        } catch (ExecutionException e) {
            Throwables.propagateIfInstanceOf(e.getCause(), AmazonServiceException.class);
            Throwables.propagate(e.getCause());
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
        return partitions;
    }