/**
   * Checks that gets work for implicit txs.
   *
   * @param cache Cache to test.
   * @throws Exception If failed.
   */
  private void checkExplicitTx(Ignite ignite, IgniteCache<String, String> cache) throws Exception {
    IgniteCache<String, String> asyncCache = cache.withAsync();

    Transaction tx = ignite.transactions().txStart();

    try {
      assertNull(cache.get("key1"));

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      asyncCache.get("key2");

      assertNull(asyncCache.future().get());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      assertTrue(cache.getAll(F.asSet("key3", "key4")).isEmpty());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      asyncCache.getAll(F.asSet("key5", "key6"));

      assertTrue(((Map) asyncCache.future().get()).isEmpty());

      tx.commit();
    } finally {
      tx.close();
    }

    tx = ignite.transactions().txStart();

    try {
      cache.put("key7", "key7");

      cache.remove("key7");

      assertNull(cache.get("key7"));

      tx.commit();
    } finally {
      tx.close();
    }

    checkEmpty(cache);
  }
  /**
   * Tests offset and limit clauses for query.
   *
   * @throws Exception If failed.
   */
  public void testOffsetLimit() throws Exception {
    IgniteCache<Integer, Integer> c =
        ignite(0).getOrCreateCache(cacheConfig("ints", true, Integer.class, Integer.class));

    try {
      List<Integer> res = new ArrayList<>();

      Random rnd = new GridRandom();

      for (int i = 0; i < 10; i++) {
        int val = rnd.nextInt(100);

        c.put(i, val);
        res.add(val);
      }

      Collections.sort(res);

      String qry = "select _val from Integer order by _val ";

      assertEqualsCollections(res, columnQuery(c, qry));
      assertEqualsCollections(res.subList(0, 0), columnQuery(c, qry + "limit ?", 0));
      assertEqualsCollections(res.subList(0, 3), columnQuery(c, qry + "limit ?", 3));
      assertEqualsCollections(res.subList(0, 9), columnQuery(c, qry + "limit ? offset ?", 9, 0));
      assertEqualsCollections(res.subList(3, 7), columnQuery(c, qry + "limit ? offset ?", 4, 3));
      assertEqualsCollections(res.subList(7, 9), columnQuery(c, qry + "limit ? offset ?", 2, 7));
      assertEqualsCollections(res.subList(8, 10), columnQuery(c, qry + "limit ? offset ?", 2, 8));
      assertEqualsCollections(res.subList(9, 10), columnQuery(c, qry + "limit ? offset ?", 1, 9));
      assertEqualsCollections(res.subList(10, 10), columnQuery(c, qry + "limit ? offset ?", 1, 10));
      assertEqualsCollections(
          res.subList(9, 10), columnQuery(c, qry + "limit ? offset abs(-(4 + ?))", 1, 5));
    } finally {
      c.destroy();
    }
  }
  /** @throws Exception If failed. */
  public void testGroupIndexOperations() throws Exception {
    IgniteCache<Integer, GroupIndexTestValue> c =
        ignite(0)
            .getOrCreateCache(cacheConfig("grp", false, Integer.class, GroupIndexTestValue.class));

    try {
      // Check group index usage.
      String qry = "select 1 from GroupIndexTestValue ";

      String plan = columnQuery(c, "explain " + qry + "where a = 1 and b > 0").get(0).toString();

      info("Plan: " + plan);

      assertTrue(plan.contains("grpIdx"));

      // Sorted list
      List<GroupIndexTestValue> list =
          F.asList(
              new GroupIndexTestValue(0, 0),
              new GroupIndexTestValue(0, 5),
              new GroupIndexTestValue(1, 1),
              new GroupIndexTestValue(1, 3),
              new GroupIndexTestValue(2, -1),
              new GroupIndexTestValue(2, 2));

      // Fill cache.
      for (int i = 0; i < list.size(); i++) c.put(i, list.get(i));

      // Check results.
      assertEquals(1, columnQuery(c, qry + "where a = 1 and b = 1").size());
      assertEquals(2, columnQuery(c, qry + "where a = 1 and b < 4").size());
      assertEquals(2, columnQuery(c, qry + "where a = 1 and b <= 3").size());
      assertEquals(1, columnQuery(c, qry + "where a = 1 and b < 3").size());
      assertEquals(2, columnQuery(c, qry + "where a = 1 and b > 0").size());
      assertEquals(1, columnQuery(c, qry + "where a = 1 and b > 1").size());
      assertEquals(2, columnQuery(c, qry + "where a = 1 and b >= 1").size());
      assertEquals(4, columnQuery(c, qry + "where a > 0 and b > 0").size());
      assertEquals(4, columnQuery(c, qry + "where a > 0 and b >= 1").size());
      assertEquals(3, columnQuery(c, qry + "where a > 0 and b > 1").size());
    } finally {
      c.destroy();
    }
  }
  /**
   * @param g Grid.
   * @throws Exception If failed.
   */
  private void checkNodes(Ignite g) throws Exception {
    IgniteCache<String, String> cache = g.cache("test");

    for (char c = 'a'; c <= 'z'; c++) {
      String key = Character.toString(c);

      cache.put(key, "val-" + key);

      String v1 = cache.get(key);
      String v2 = cache.get(key); // Get second time.

      info("v1: " + v1);
      info("v2: " + v2);

      assertNotNull(v1);
      assertNotNull(v2);

      if (affinity(cache).mapKeyToNode(key).isLocal()) assertSame(v1, v2);
      else assertEquals(v1, v2);
    }
  }
  /**
   * Checks that cache is empty.
   *
   * @param cache Cache to check.
   * @throws org.apache.ignite.internal.IgniteInterruptedCheckedException If interrupted while
   *     sleeping.
   */
  @SuppressWarnings({"ErrorNotRethrown", "TypeMayBeWeakened"})
  private void checkEmpty(IgniteCache<String, String> cache)
      throws IgniteInterruptedCheckedException {
    for (int i = 0; i < 3; i++) {
      try {
        assertTrue(!cache.iterator().hasNext());

        break;
      } catch (AssertionError e) {
        if (i == 2) throw e;

        info(">>> Cache is not empty, flushing evictions.");

        U.sleep(1000);
      }
    }
  }
  /**
   * Checks that gets work for implicit txs.
   *
   * @param cache Cache to test.
   * @throws Exception If failed.
   */
  private void checkImplicitTx(IgniteCache<String, String> cache) throws Exception {
    assertNull(cache.get("key1"));

    IgniteCache<String, String> asyncCache = cache.withAsync();

    asyncCache.get("key2");

    assertNull(asyncCache.future().get());

    assertTrue(cache.getAll(F.asSet("key3", "key4")).isEmpty());

    asyncCache.getAll(F.asSet("key5", "key6"));

    assertTrue(((Map) asyncCache.future().get()).isEmpty());

    cache.put("key7", "key7");
    cache.remove("key7", "key7");
    assertNull(cache.get("key7"));

    checkEmpty(cache);
  }
 /**
  * @param c Cache.
  * @param qry Query.
  * @param args Arguments.
  * @return Column as list.
  */
 private static <X> List<X> columnQuery(IgniteCache<?, ?> c, String qry, Object... args) {
   return column(0, c.query(new SqlFieldsQuery(qry).setArgs(args)).getAll());
 }