diegomez17 commented on code in PR #16939:
URL: https://github.com/apache/beam/pull/16939#discussion_r872577450
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sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/bigtable/BigtableServiceImpl.java:
##########
@@ -210,6 +212,224 @@ public Row getCurrentRow() throws NoSuchElementException {
}
}
+ @VisibleForTesting
+ static class BigtableSegmentReaderImpl implements Reader {
+ private BigtableSession session;
+
+ @Nullable private ReadRowsRequest nextRequest;
+ private final Queue<Row> buffer;
+ private final long refillSegmentWaterMark;
+ private final long maxSegmentByteSize;
+ private Future<UpstreamResults> future;
+ private Row currentRow;
+ private static ServiceCallMetric serviceCallMetric;
+
+ private static class UpstreamResults {
+ private final List<Row> rows;
+ private final @Nullable ReadRowsRequest nextRequest;
+
+ UpstreamResults(List<Row> rows, @Nullable ReadRowsRequest nextRequest) {
+ this.rows = rows;
+ this.nextRequest = nextRequest;
+ }
+ }
+
+ public static BigtableSegmentReaderImpl create(BigtableSession session,
BigtableSource source) {
+ RowSet set;
+ if (source.getRanges().isEmpty()) {
+ set =
RowSet.newBuilder().addRowRanges(RowRange.getDefaultInstance()).build();
+ } else {
+ RowRange[] rowRanges = new RowRange[source.getRanges().size()];
+ for (int i = 0; i < source.getRanges().size(); i++) {
+ rowRanges[i] =
+ RowRange.newBuilder()
+ .setStartKeyClosed(
+
ByteString.copyFrom(source.getRanges().get(i).getStartKey().getValue()))
+ .setEndKeyOpen(
+
ByteString.copyFrom(source.getRanges().get(i).getEndKey().getValue()))
+ .build();
+ }
+ set =
+ RowSet.newBuilder()
+
.addAllRowRanges(Arrays.stream(rowRanges).collect(Collectors.toList()))
+ .build();
+ }
+
+ RowFilter filter =
+ MoreObjects.firstNonNull(source.getRowFilter(),
RowFilter.getDefaultInstance());
+ ReadRowsRequest request =
+ ReadRowsRequest.newBuilder()
+ .setTableName(
+
session.getOptions().getInstanceName().toTableNameStr(source.getTableId().get()))
+ .setRows(set)
+ .setFilter(filter)
+ .setRowsLimit(source.getMaxBufferElementCount())
+ .build();
+
+ serviceCallMetric = populateReaderCallMetric(session,
source.getTableId().get());
+
+ long maxSegmentByteSize =
+ (long)(Runtime.getRuntime().totalMemory()
+ * DEFAULT_BYTE_LIMIT_PERCENTAGE);
+
+ return new BigtableSegmentReaderImpl(session, request,
maxSegmentByteSize);
+ }
+
+ @VisibleForTesting
+ BigtableSegmentReaderImpl(BigtableSession session, ReadRowsRequest
request, long maxSegmentByteSize) {
+ this.session = session;
+ this.nextRequest = request;
+ this.maxSegmentByteSize = maxSegmentByteSize;
+ this.buffer = new ArrayDeque<>();
+ // Asynchronously refill buffer when there is 10% of the elements are
left
+ this.refillSegmentWaterMark = request.getRowsLimit() / 10;
+ }
+
+ @Override
+ public boolean start() throws IOException {
+ future = fetchNextSegment();
+ return advance();
+ }
+
+ @Override
+ public boolean advance() throws IOException {
+ System.out.println("HI");
+ if (buffer.size() < refillSegmentWaterMark && future == null ) {
+ future = fetchNextSegment();
+ }
+ if (buffer.isEmpty() && future != null) {
+ waitReadRowsFuture();
+ }
+ currentRow = buffer.poll();
+ return currentRow != null;
+ }
+
+ private Future<UpstreamResults> fetchNextSegment() {
+ SettableFuture<UpstreamResults> f = SettableFuture.create();
+ // When the nextRequest is null, the last fill completed and the buffer
contains the last rows
+ if (nextRequest == null) {
+ f.set(new UpstreamResults(ImmutableList.of(), null));
+ return f;
+ }
+
+ // TODO(diegomez): Remove atomic ScanHandler for simpler
StreamObserver/Future implementation
+ AtomicReference<ScanHandler> atomicScanHandler = new AtomicReference<>();
+ ScanHandler handler =
+ session
+ .getDataClient()
+ .readFlatRows(
+ nextRequest,
+ new StreamObserver<FlatRow>() {
+ List<Row> rows = new ArrayList<>();
+ long currentByteSize = 0;
+ boolean byteLimitReached = false;
+
+ @Override
+ public void onNext(FlatRow flatRow) {
+ Row row = FlatRowConverter.convert(flatRow);
+ currentByteSize += row.getSerializedSize();
+ rows.add(row);
+
+ if (currentByteSize > maxSegmentByteSize) {
+ byteLimitReached = true;
+ atomicScanHandler.get().cancel();
+ return;
+ }
+ }
+
+ @Override
+ public void onError(Throwable e) {
+ f.setException(e);
+ }
+
+ @Override
+ public void onCompleted() {
+ ReadRowsRequest nextNextRequest = null;
+
+ // When requested rows < limit, the current request will
be the last
+ if (byteLimitReached || rows.size() ==
nextRequest.getRowsLimit()) {
+ nextNextRequest =
+ truncateRequest(nextRequest, rows.get(rows.size()
- 1).getKey());
+ }
+ f.set(new UpstreamResults(rows, nextNextRequest));
+ }
+ });
+ atomicScanHandler.set(handler);
+ return f;
+ }
+
+ private void waitReadRowsFuture() throws IOException {
+ try {
+ UpstreamResults r = future.get();
+ buffer.addAll(r.rows);
+ nextRequest = r.nextRequest;
+ future = null;
+ serviceCallMetric.call("ok");
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ throw new IOException(e);
+ } catch (ExecutionException e) {
+ throw new IOException(e.getCause());
+ }
+ catch (Exception e) {
+ if (e instanceof InterruptedException) {
+ Thread.currentThread().interrupt();
+ throw new IOException(e);
+ }
+ if (e.getCause() instanceof StatusRuntimeException) {
+ throw new IOException(e);
+ }
+ }
+ }
+
+ private ReadRowsRequest truncateRequest(ReadRowsRequest request,
ByteString lastKey) {
+ RowSet.Builder segment = RowSet.newBuilder();
+
+ for (RowRange rowRange : request.getRows().getRowRangesList()) {
+ int startCmp = StartPoint.extract(rowRange).compareTo(new
StartPoint(lastKey, true));
+ int endCmp = EndPoint.extract(rowRange).compareTo(new
EndPoint(lastKey, true));
+
+ if (startCmp > 0) {
+ // If the startKey is passed the split point than add the whole range
+ segment.addRowRanges(rowRange);
+ } else if (endCmp > 0) {
+ // Row is split, remove all read rowKeys and split RowSet at last
buffered Row
+ RowRange subRange =
rowRange.toBuilder().setStartKeyOpen(lastKey).build();
+ segment.addRowRanges(subRange);
+ }
+ }
+ if (segment.getRowRangesCount() == 0) {
+ return null;
+ }
+ ReadRowsRequest newRequest =
+ ReadRowsRequest.newBuilder()
+ .setTableName(request.getTableName())
+ .setRows(segment.build())
+ .setFilter(request.getFilter())
+ .setRowsLimit(request.getRowsLimit())
+ .build();
+
+ return newRequest;
+ }
+
+ @Override
+ public void close() throws IOException {
+ if (session == null) {
+ // Only possible when previously closed, so we know that results is
also null.
Review Comment:
Do not know, from previous implementation.
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