static ScanResponse doMetaScanResponse(
final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta,
final AtomicLong sequenceids,
final ScanRequest request) {
ScanResponse.Builder builder = ScanResponse.newBuilder();
int max = request.getNumberOfRows();
int count = 0;
Map<byte[], Pair<HRegionInfo, ServerName>> tail =
request.hasScan() ? meta.tailMap(request.getScan().getStartRow().toByteArray()) : meta;
ClientProtos.Result.Builder resultBuilder = ClientProtos.Result.newBuilder();
for (Map.Entry<byte[], Pair<HRegionInfo, ServerName>> e : tail.entrySet()) {
// Can be 0 on open of a scanner -- i.e. rpc to setup scannerid only.
if (max <= 0) break;
if (++count > max) break;
HRegionInfo hri = e.getValue().getFirst();
ByteString row = HBaseZeroCopyByteString.wrap(hri.getRegionName());
resultBuilder.clear();
resultBuilder.addCell(getRegionInfo(row, hri));
resultBuilder.addCell(getServer(row, e.getValue().getSecond()));
resultBuilder.addCell(getStartCode(row));
builder.addResults(resultBuilder.build());
// Set more to false if we are on the last region in table.
if (hri.getEndKey().length <= 0) builder.setMoreResults(false);
else builder.setMoreResults(true);
}
// If no scannerid, set one.
builder.setScannerId(
request.hasScannerId() ? request.getScannerId() : sequenceids.incrementAndGet());
return builder.build();
}
/**
* Create Results from the cells using the cells meta data.
*
* @param cellScanner
* @param response
* @return results
*/
public static Result[] getResults(CellScanner cellScanner, ScanResponse response)
throws IOException {
if (response == null) return null;
// If cellscanner, then the number of Results to return is the count of elements in the
// cellsPerResult list. Otherwise, it is how many results are embedded inside the response.
int noOfResults =
cellScanner != null ? response.getCellsPerResultCount() : response.getResultsCount();
Result[] results = new Result[noOfResults];
for (int i = 0; i < noOfResults; i++) {
if (cellScanner != null) {
// Cells are out in cellblocks. Group them up again as Results. How many to read at a
// time will be found in getCellsLength -- length here is how many Cells in the i'th Result
int noOfCells = response.getCellsPerResult(i);
boolean isPartial =
response.getPartialFlagPerResultCount() > i
? response.getPartialFlagPerResult(i)
: false;
List<Cell> cells = new ArrayList<Cell>(noOfCells);
for (int j = 0; j < noOfCells; j++) {
try {
if (cellScanner.advance() == false) {
// We are not able to retrieve the exact number of cells which ResultCellMeta says us.
// We have to scan for the same results again. Throwing DNRIOE as a client retry on
// the
// same scanner will result in OutOfOrderScannerNextException
String msg =
"Results sent from server="
+ noOfResults
+ ". But only got "
+ i
+ " results completely at client. Resetting the scanner to scan again.";
LOG.error(msg);
throw new DoNotRetryIOException(msg);
}
} catch (IOException ioe) {
// We are getting IOE while retrieving the cells for Results.
// We have to scan for the same results again. Throwing DNRIOE as a client retry on the
// same scanner will result in OutOfOrderScannerNextException
LOG.error(
"Exception while reading cells from result."
+ "Resetting the scanner to scan again.",
ioe);
throw new DoNotRetryIOException("Resetting the scanner.", ioe);
}
cells.add(cellScanner.current());
}
results[i] = Result.create(cells, null, response.getStale(), isPartial);
} else {
// Result is pure pb.
results[i] = ProtobufUtil.toResult(response.getResults(i));
}
}
return results;
}
