feat(core): add NP/PP box iterator support

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Core
 
+- Added NP/PP box index
+  iterator [support](https://github.com/tarantool/tarantool/commit/96df090fe71a7152ddee105eca454efc0c096c28)
 - Added
   [LINEARIZABLE](https://github.com/tarantool/tarantool/blob/e643f88a5e0c6d9ef2789b2033088fd04e7d39ae/src/box/txn.h#L228)
   isolation level.

tarantool-core/src/main/java/io/tarantool/core/protocol/BoxIterator.java

@@ -5,19 +5,149 @@
 
 package io.tarantool.core.protocol;
 
+/** Tarantool iterator types for data selection. Used in {@code box.select} requests. */
 public enum BoxIterator {
+
+  /**
+   * Matches keys equal to the provided search key (ASC order).
+   *
+   * <p>Binary value: {@code 0}
+   *
+   * @since Supported in all versions.
+   */
   EQ(0),
+
+  /**
+   * Matches keys equal to the provided search key (DESC order).
+   *
+   * <p>Binary value: {@code 1}
+   *
+   * @since Supported in all versions.
+   */
   REQ(1),
+
+  /**
+   * Iterates over all tuples in the index. The search key is ignored.
+   *
+   * <p>Binary value: {@code 2}
+   *
+   * @since Supported in all versions.
+   */
   ALL(2),
+
+  /**
+   * Matches keys strictly less than the provided search key ({@code key < x}).
+   *
+   * <p>Binary value: {@code 3}
+   *
+   * @since Supported in all versions.
+   */
   LT(3),
+
+  /**
+   * Matches keys less than or equal to the provided search key ({@code key <= x}).
+   *
+   * <p>Binary value: {@code 4}
+   *
+   * @since Supported in all versions.
+   */
   LE(4),
+
+  /**
+   * Matches keys greater than or equal to the provided search key ({@code key >= x}).
+   *
+   * <p>Binary value: {@code 5}
+   *
+   * @since Supported in all versions.
+   */
   GE(5),
+
+  /**
+   * Matches keys strictly greater than the provided search key ({@code key > x}).
+   *
+   * <p>Binary value: {@code 6}
+   *
+   * @since Supported in all versions.
+   */
   GT(6),
+
+  /**
+   * Matches keys where all bits from the search key are set (<b>Bitset index only</b>).
+   *
+   * <p>Binary value: {@code 7}
+   *
+   * @since Supported in all versions.
+   */
   BITS_ALL_SET(7),
+
+  /**
+   * Matches keys where at least one bit from the search key is set (<b>Bitset index only</b>).
+   *
+   * <p>Binary value: {@code 8}
+   *
+   * @since Supported in all versions.
+   */
   BITS_ANY_SET(8),
+
+  /**
+   * Matches keys where all bits from the search key are not set (<b>Bitset index only</b>).
+   *
+   * <p>Binary value: {@code 9}
+   *
+   * @since Supported in all versions.
+   */
   BITS_ALL_NOT_SET(9),
+
+  /**
+   * Matches keys that overlap with the provided search key (<b>RTREE index only</b>).
+   *
+   * <p>Binary value: {@code 10}
+   *
+   * @since Supported in all versions.
+   */
   OVERLAPS(10),
-  NEIGHBOR(11);
+
+  /**
+   * Iterates over tuples as they move away from the specified point {@code x} (<b>RTREE neighbor
+   * search</b>).
+   *
+   * <p>Binary value: {@code 11}
+   *
+   * @since Supported in all versions.
+   */
+  NEIGHBOR(11),
+
+  /**
+   * Next Prefix iterator.
+   *
+   * <p>Binary value: {@code 12}
+   *
+   * <p>Performs a prefix-based search on the last part of the key (if it is a string, ASC order).
+   * It skips all keys sharing the same prefix as the search key and starts the sequential scan from
+   * the first key whose prefix is strictly greater than the search key.
+   *
+   * <p>Degrades to {@link #GT} if the last part of the key is not a string. <b>Works only in {@code
+   * memtx} tree indexes</b>.
+   *
+   * @since Tarantool 3.2.0
+   */
+  NP(12),
+
+  /**
+   * Previous Prefix iterator.
+   *
+   * <p>Binary value: {@code 13}
+   *
+   * <p>Performs a prefix-based search on the last part of the key (if it is a string, DESC order).
+   * It looks for the last key whose prefix is strictly less than the search key, and then proceeds
+   * with a sequential reverse-order scan.
+   *
+   * <p>Degrades to {@link #LT} if the last part of the key is not a string. <b>Works only in {@code
+   * memtx} tree indexes</b>.
+   *
+   * @since Tarantool 3.2.0
+   */
+  PP(13);
 
   private final int code;
 

tarantool-core/src/test/java/io/tarantool/core/integration/IProtoClientTest.java

@@ -891,6 +891,74 @@ public void testSelect(
     assertEquals(expected, decodeTuple(client, data));
   }
 
+  public static Stream<Arguments> dataForTestIterator3() {
+    final String prepared =
+        "box.space.space_a:insert({'a', 'a'});"
+            + "box.space.space_a:insert({'aa', 'aa'});"
+            + "box.space.space_a:insert({'ab', 'ab'});"
+            + "box.space.space_a:insert({'b', 'b'});"
+            + "box.space.space_a:insert({'ba', 'ba'});"
+            + "box.space.space_a:insert({'bb', 'bb'});"
+            + "box.space.space_a:insert({'c', 'c'});"
+            + "box.space.space_a:insert({'ca', 'ca'});"
+            + "box.space.space_a:insert({'cb', 'cb'});";
+
+    return Stream.of(
+        Arguments.of(
+            BoxIterator.NP.toString(),
+            prepared,
+            ValueFactory.newArray(ValueFactory.newString("b")),
+            ValueFactory.newArray(
+                ValueFactory.newArray(ValueFactory.newString("c"), ValueFactory.newString("c")),
+                ValueFactory.newArray(ValueFactory.newString("ca"), ValueFactory.newString("ca")),
+                ValueFactory.newArray(ValueFactory.newString("cb"), ValueFactory.newString("cb"))),
+            spaceAId,
+            BoxIterator.NP),
+        Arguments.of(
+            BoxIterator.PP.toString(),
+            prepared,
+            ValueFactory.newArray(ValueFactory.newString("b")),
+            ValueFactory.newArray(
+                ValueFactory.newArray(ValueFactory.newString("ab"), ValueFactory.newString("ab")),
+                ValueFactory.newArray(ValueFactory.newString("aa"), ValueFactory.newString("aa")),
+                ValueFactory.newArray(ValueFactory.newString("a"), ValueFactory.newString("a"))),
+            spaceAId,
+            BoxIterator.PP));
+  }
+
+  @EnabledIfEnvironmentVariable(named = "TARANTOOL_VERSION", matches = "3.*")
+  @ParameterizedTest(name = "{0}")
+  @MethodSource("dataForTestIterator3")
+  void testIterator3(
+      String label,
+      String toPrepare,
+      ArrayValue key,
+      ArrayValue expected,
+      Integer space,
+      BoxIterator iterator)
+      throws Exception {
+    testIteratorCommon(toPrepare, key, expected, space, 0, Integer.MAX_VALUE, 0, iterator);
+  }
+
+  void testIteratorCommon(
+      String toPrepare,
+      ArrayValue key,
+      ArrayValue expected,
+      Integer space,
+      Integer index,
+      Integer limit,
+      Integer offset,
+      BoxIterator iterator)
+      throws Exception {
+    TarantoolContainerClientHelper.executeCommand(tt, toPrepare);
+    IProtoClient client = createClientAndConnect(address, true);
+    client.authorize(API_USER, CREDS.get(API_USER)).join();
+    IProtoMessage message = client.select(space, index, key, limit, offset, iterator).get();
+    checkMessageHeader(message, IPROTO_OK, 4);
+    ArrayValue data = message.getBodyArrayValue(IPROTO_DATA);
+    Assertions.assertEquals(expected, decodeTuple(client, data));
+  }
+
   @ParameterizedTest
   @MethodSource("dataForTestSelect")
   public void testRawSelect(