Examples with BlockingRowQueue io.confluent.ksql.query.BlockingRowQueue used on opensource projects

Example 1 with BlockingRowQueue

use of io.confluent.ksql.query.BlockingRowQueue in project ksql by confluentinc.

the class EndToEndIntegrationTest method verifyAvailableRows.

private static List<GenericRow> verifyAvailableRows(final TransientQueryMetadata queryMetadata, final int expectedRows) {
    final BlockingRowQueue rowQueue = queryMetadata.getRowQueue();
    assertThatEventually(expectedRows + " rows were not available after 30 seconds", () -> rowQueue.size() >= expectedRows, is(true), 30, TimeUnit.SECONDS);
    final List<KeyValueMetadata<List<?>, GenericRow>> rows = new ArrayList<>();
    rowQueue.drainTo(rows);
    return rows.stream().map(kvm -> kvm.getKeyValue().value()).collect(Collectors.toList());
}

Example 2 with BlockingRowQueue

use of io.confluent.ksql.query.BlockingRowQueue in project ksql by confluentinc.

the class QueryStreamWriter method write.

// CHECKSTYLE_RULES.OFF: CyclomaticComplexity
@Override
public void write(final OutputStream out) {
    // CHECKSTYLE_RULES.ON: CyclomaticComplexity
    try {
        out.write("[".getBytes(StandardCharsets.UTF_8));
        write(out, buildHeader());
        final BlockingRowQueue rowQueue = queryMetadata.getRowQueue();
        while (!connectionClosed && queryMetadata.isRunning() && !limitReached && !complete) {
            final KeyValueMetadata<List<?>, GenericRow> row = rowQueue.poll(disconnectCheckInterval, TimeUnit.MILLISECONDS);
            if (row != null) {
                write(out, buildRow(row));
            } else {
                // If no new rows have been written, the user may have terminated the connection without
                // us knowing. Check by trying to write a single newline.
                out.write("\n".getBytes(StandardCharsets.UTF_8));
                out.flush();
            }
            drainAndThrowOnError(out);
        }
        if (connectionClosed) {
            return;
        }
        drain(out);
        if (limitReached) {
            objectMapper.writeValue(out, StreamedRow.finalMessage("Limit Reached"));
        } else if (complete) {
            objectMapper.writeValue(out, StreamedRow.finalMessage("Query Completed"));
        }
        out.write("]\n".getBytes(StandardCharsets.UTF_8));
        out.flush();
    } catch (final EOFException exception) {
        // The user has terminated the connection; we can stop writing
        log.warn("Query terminated due to exception:" + exception.toString());
    } catch (final InterruptedException exception) {
        // The most likely cause of this is the server shutting down. Should just try to close
        // gracefully, without writing any more to the connection stream.
        log.warn("Interrupted while writing to connection stream");
    } catch (final Exception exception) {
        log.error("Exception occurred while writing to connection stream: ", exception);
        outputException(out, exception);
    } finally {
        close();
    }
}