private static List scanRpc()

in core/src/main/java/org/apache/accumulo/core/clientImpl/ThriftScanner.java [848:983]
112 lines of code
21 McCabe index (conditional complexity)

  private static List<KeyValue> scanRpc(ScanAddress addr, ScanState scanState,
      ClientContext context, long busyTimeout) throws AccumuloSecurityException,
      NotServingTabletException, TException, NoSuchScanIDException, TooManyFilesException,
      TSampleNotPresentException, ScanServerBusyException {

    Timer timer = null;

    final TInfo tinfo = TraceUtil.traceInfo();

    final HostAndPort parsedLocation = HostAndPort.fromString(addr.serverAddress);
    TabletScanClientService.Client client =
        ThriftUtil.getClient(ThriftClientTypes.TABLET_SCAN, parsedLocation, context);

    String old = Thread.currentThread().getName();
    try {
      ScanResult sr;

      if (scanState.prevLoc != null && !scanState.prevLoc.equals(addr)) {
        scanState.scanID = null;
      }

      scanState.prevLoc = addr;

      if (scanState.scanID == null) {
        Thread.currentThread().setName("Starting scan tserver=" + addr.serverAddress + " tableId="
            + addr.getExtent().tableId());

        if (log.isTraceEnabled()) {
          String msg = "Starting scan server=" + addr.serverAddress + " tablet=" + addr.getExtent()
              + " range=" + scanState.range + " ssil=" + scanState.serverSideIteratorList + " ssio="
              + scanState.serverSideIteratorOptions + " context=" + scanState.classLoaderContext;
          log.trace("tid={} {}", Thread.currentThread().getId(), msg);
          timer = Timer.startNew();
        }

        TabletType ttype = TabletType.type(addr.getExtent());
        boolean waitForWrites = !serversWaitedForWrites.get(ttype).contains(addr.serverAddress);

        InitialScan is = client.startScan(tinfo, scanState.context.rpcCreds(),
            addr.getExtent().toThrift(), scanState.range.toThrift(),
            scanState.columns.stream().map(Column::toThrift).collect(Collectors.toList()),
            scanState.size, scanState.serverSideIteratorList, scanState.serverSideIteratorOptions,
            scanState.authorizations.getAuthorizationsBB(), waitForWrites, scanState.isolated,
            scanState.readaheadThreshold,
            SamplerConfigurationImpl.toThrift(scanState.samplerConfig), scanState.batchTimeOut,
            scanState.classLoaderContext, scanState.executionHints, busyTimeout);
        if (waitForWrites) {
          serversWaitedForWrites.get(ttype).add(addr.serverAddress);
        }

        sr = is.result;

        if (sr.more) {
          scanState.scanID = is.scanID;
        } else {
          client.closeScan(tinfo, is.scanID);
        }

      } else {
        String msg =
            "Continuing scan tserver=" + addr.serverAddress + " scanid=" + scanState.scanID;
        Thread.currentThread().setName(msg);

        if (log.isTraceEnabled()) {
          log.trace("tid={} {}", Thread.currentThread().getId(), msg);
          timer = Timer.startNew();
        }

        sr = client.continueScan(tinfo, scanState.scanID, busyTimeout);
        if (!sr.more) {
          client.closeScan(tinfo, scanState.scanID);
          scanState.scanID = null;
        }
      }

      if (sr.more) {
        if (timer != null) {
          log.trace("tid={} Finished scan in {} #results={} scanid={}",
              Thread.currentThread().getId(),
              String.format("%.3f secs", timer.elapsed(MILLISECONDS) / 1000.0), sr.results.size(),
              scanState.scanID);
        }
      } else {
        if (addr.getExtent().endRow() == null) {
          scanState.finished = true;

          if (timer != null) {
            log.trace("tid={} Completely finished scan in {} #results={}",
                Thread.currentThread().getId(),
                String.format("%.3f secs", timer.elapsed(MILLISECONDS) / 1000.0),
                sr.results.size());
          }

        } else if (scanState.range.getEndKey() == null || !scanState.range
            .afterEndKey(new Key(addr.getExtent().endRow()).followingKey(PartialKey.ROW))) {
          scanState.startRow = addr.getExtent().endRow();
          scanState.skipStartRow = true;

          if (timer != null) {
            log.trace("tid={} Finished scanning tablet in {} #results={}",
                Thread.currentThread().getId(),
                String.format("%.3f secs", timer.elapsed(MILLISECONDS) / 1000.0),
                sr.results.size());
          }
        } else {
          scanState.finished = true;
          if (timer != null) {
            log.trace("tid={} Completely finished in {} #results={}",
                Thread.currentThread().getId(),
                String.format("%.3f secs", timer.elapsed(MILLISECONDS) / 1000.0),
                sr.results.size());
          }
        }
      }

      Key.decompress(sr.results);

      if (!sr.results.isEmpty() && !scanState.finished) {
        scanState.range = new Range(new Key(sr.results.get(sr.results.size() - 1).key), false,
            scanState.range.getEndKey(), scanState.range.isEndKeyInclusive());
      }

      List<KeyValue> results = new ArrayList<>(sr.results.size());
      for (TKeyValue tkv : sr.results) {
        results.add(new KeyValue(new Key(tkv.key), tkv.value));
      }

      return results;

    } catch (ThriftSecurityException e) {
      throw new AccumuloSecurityException(e.user, e.code, e);
    } finally {
      ThriftUtil.returnClient(client, context);
      Thread.currentThread().setName(old);
    }
  }