public void visit()

in src/main/java/org/apache/accumulo/testing/randomwalk/conditional/Transfer.java [66:137]
57 lines of code
9 McCabe index (conditional complexity)

  public void visit(State state, RandWalkEnv env, Properties props) throws Exception {
    String table = state.getString("tableName");
    Random rand = state.getRandom();
    AccumuloClient client = env.getAccumuloClient();

    int numAccts = state.getInteger("numAccts");
    // note: non integer exponents are slow

    ZipfDistribution zdiBanks = new ZipfDistribution(state.getInteger("numBanks"), 1);
    String bank = Utils.getBank(zdiBanks.inverseCumulativeProbability(rand.nextDouble()));
    ZipfDistribution zdiAccts = new ZipfDistribution(numAccts, 1);
    String acct1 = Utils.getAccount(zdiAccts.inverseCumulativeProbability(rand.nextDouble()));
    String acct2 = Utils.getAccount(zdiAccts.inverseCumulativeProbability(rand.nextDouble()));
    while (acct2.equals(acct1)) {
      // intentionally not using zipf distribution to pick on retry
      acct2 = Utils.getAccount(rand.nextInt(numAccts));
    }

    // TODO document how data should be read when using ConditionalWriter
    try (Scanner scanner = new IsolatedScanner(client.createScanner(table, Authorizations.EMPTY))) {

      scanner.setRange(new Range(bank));
      scanner.fetchColumnFamily(new Text(acct1));
      scanner.fetchColumnFamily(new Text(acct2));

      Account a1 = new Account();
      Account a2 = new Account();
      Account a;

      for (Entry<Key,Value> entry : scanner) {
        String cf = entry.getKey().getColumnFamilyData().toString();
        String cq = entry.getKey().getColumnQualifierData().toString();

        if (cf.equals(acct1))
          a = a1;
        else if (cf.equals(acct2))
          a = a2;
        else
          throw new Exception("Unexpected column fam: " + cf);

        if (cq.equals("bal"))
          a.setBal(entry.getValue().toString());
        else if (cq.equals("seq"))
          a.setSeq(entry.getValue().toString());
        else
          throw new Exception("Unexpected column qual: " + cq);
      }

      int amt = rand.nextInt(50);

      log.debug(
          "transfer req " + bank + " " + amt + " " + acct1 + " " + a1 + " " + acct2 + " " + a2);

      if (a1.bal >= amt) {
        ConditionalMutation cm = new ConditionalMutation(bank,
            new Condition(acct1, "seq").setValue(Utils.getSeq(a1.seq)),
            new Condition(acct2, "seq").setValue(Utils.getSeq(a2.seq)));
        cm.put(acct1, "bal", (a1.bal - amt) + "");
        cm.put(acct2, "bal", (a2.bal + amt) + "");
        cm.put(acct1, "seq", Utils.getSeq(a1.seq + 1));
        cm.put(acct2, "seq", Utils.getSeq(a2.seq + 1));

        ConditionalWriter cw = (ConditionalWriter) state.get("cw");
        Status status = cw.write(cm).getStatus();
        while (status == Status.UNKNOWN) {
          log.debug("retrying transfer " + status);
          status = cw.write(cm).getStatus();
        }
        log.debug("transfer result " + bank + " " + status + " " + a1 + " " + a2);
      }
    }
  }