GEODE-9519: Implement Radish ZSCAN command (#6831)

 - Change implementation to return integer cursor instead of BigInteger
 as there was no possible way for the returned value for cursor to be
 greater than Integer.MAX_VALUE
 - Move scan execution logic to AbstractScanExecutor to allow
 inheritance
 - Do not attempt to handle CURSOR values greater than Long.MAX_VALUE
for HSCAN and ZSCAN
 - Use scan count argument directly rather than looping in RedisSortedSet
 and RedisHash
 - Minor refactor of how scan empty results are returned
 - Add ZSCAN to list of supported commands
 - Add tests for ZSCAN

Authored-by: Donal Evans <doevans@vmware.com>

Author: Donal Evans

geode-apis-compatible-with-redis/src/acceptanceTest/java/org/apache/geode/redis/internal/executor/sortedset/ZScanNativeRedisIntegrationTest.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for additional information regarding
+ * copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the License. You may obtain a
+ * copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package org.apache.geode.redis.internal.executor.sortedset;
+
+import org.junit.ClassRule;
+
+import org.apache.geode.redis.NativeRedisClusterTestRule;
+
+public class ZScanNativeRedisIntegrationTest extends AbstractZScanIntegrationTest {
+
+  @ClassRule
+  public static NativeRedisClusterTestRule redis = new NativeRedisClusterTestRule();
+
+  @Override
+  public int getPort() {
+    return redis.getExposedPorts().get(0);
+  }
+
+  @Override
+  public void flushAll() {
+    redis.flushAll();
+  }
+}

geode-apis-compatible-with-redis/src/integrationTest/java/org/apache/geode/redis/internal/executor/hash/AbstractHScanIntegrationTest.java

@@ -26,6 +26,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
+import java.math.BigInteger;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
@@ -57,6 +58,7 @@ public abstract class AbstractHScanIntegrationTest implements RedisIntegrationTe
   public static final String HASH_KEY = "key";
   public static final int SLOT_FOR_KEY = CRC16.calculate(HASH_KEY) % RegionProvider.REDIS_SLOTS;
   public static final String ZERO_CURSOR = "0";
+  public static final BigInteger UNSIGNED_LONG_CAPACITY = new BigInteger("18446744073709551615");
 
   public static final String FIELD_ONE = "1";
   public static final String VALUE_ONE = "yellow";
@@ -240,6 +242,20 @@ public void givenNegativeCursor_returnsEntriesUsingAbsoluteValueOfCursor() {
     assertThat(new HashSet<>(allEntries)).isEqualTo(entryMap.entrySet());
   }
 
+  @Test
+  public void shouldReturnError_givenCursorGreaterThanUnsignedLongMaxValue() {
+    jedis.hset(HASH_KEY, FIELD_ONE, VALUE_ONE);
+
+    assertThatThrownBy(() -> jedis.sendCommand(HASH_KEY, Protocol.Command.HSCAN, HASH_KEY,
+        UNSIGNED_LONG_CAPACITY.add(new BigInteger("10")).toString()))
+            .hasMessageContaining(ERROR_CURSOR);
+  }
+
+  @Test
+  public void shouldNotError_givenCursorEqualToLongMaxValue() {
+    jedis.hset(HASH_KEY, FIELD_ONE, VALUE_ONE);
+    jedis.sendCommand(HASH_KEY, Protocol.Command.HSCAN, HASH_KEY, String.valueOf(Long.MAX_VALUE));
+  }
 
   @Test
   public void givenInvalidRegexSyntax_returnsEmptyArray() {

geode-apis-compatible-with-redis/src/integrationTest/java/org/apache/geode/redis/internal/executor/hash/HScanIntegrationTest.java

@@ -19,14 +19,14 @@
 import static org.apache.geode.redis.internal.RedisConstants.ERROR_CURSOR;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
-import java.math.BigInteger;
-
 import org.junit.ClassRule;
 import org.junit.Test;
+import redis.clients.jedis.Protocol;
 
 import org.apache.geode.redis.GeodeRedisServerRule;
 
 public class HScanIntegrationTest extends AbstractHScanIntegrationTest {
+  String GREATER_THAN_LONG_MAX = "9_223_372_036_854_775_808";
 
   @ClassRule
   public static GeodeRedisServerRule server = new GeodeRedisServerRule();
@@ -36,27 +36,15 @@ public int getPort() {
     return server.getPort();
   }
 
-
-  // Note: these tests will not pass native redis, so included here in concrete test class
-  @Test
-  public void givenCursorGreaterThanIntMaxValue_returnsCursorError() {
-    int largestCursorValue = Integer.MAX_VALUE;
-
-    BigInteger tooBigCursor =
-        new BigInteger(String.valueOf(largestCursorValue)).add(BigInteger.valueOf(1));
-
-    assertThatThrownBy(() -> jedis.hscan("a", tooBigCursor.toString()))
-        .hasMessageContaining(ERROR_CURSOR);
-  }
-
+  // Redis allows CURSOR values up to UNSIGNED_LONG_CAPACITY, but behaviour for CURSOR values
+  // greater than Integer.MAX_VALUE is undefined, so we choose to return an error if a value greater
+  // than Long.MAX_VALUE is passed
   @Test
-  public void givenCursorLessThanIntMinValue_returnsCursorError() {
-    int smallestCursorValue = Integer.MIN_VALUE;
-
-    BigInteger tooSmallCursor =
-        new BigInteger(String.valueOf(smallestCursorValue)).subtract(BigInteger.valueOf(1));
+  public void shouldReturnError_givenCursorGreaterThanLongMaxValue() {
+    jedis.hset(HASH_KEY, FIELD_ONE, VALUE_ONE);
 
-    assertThatThrownBy(() -> jedis.hscan("a", tooSmallCursor.toString()))
-        .hasMessageContaining(ERROR_CURSOR);
+    assertThatThrownBy(() -> jedis.sendCommand(HASH_KEY, Protocol.Command.HSCAN, HASH_KEY,
+        GREATER_THAN_LONG_MAX))
+            .hasMessageContaining(ERROR_CURSOR);
   }
 }

geode-apis-compatible-with-redis/src/integrationTest/java/org/apache/geode/redis/internal/executor/server/AbstractHitsMissesIntegrationTest.java

@@ -348,6 +348,11 @@ public void testZrevrank() {
     runCommandAndAssertHitsAndMisses(SORTED_SET_KEY, (k, m) -> jedis.zrevrank(k, m));
   }
 
+  @Test
+  public void testZscan() {
+    runCommandAndAssertHitsAndMisses(SORTED_SET_KEY, (k, v) -> jedis.zscan(k, v));
+  }
+
   @Test
   public void testZscore() {
     runCommandAndAssertHitsAndMisses(SORTED_SET_KEY, (k, v) -> jedis.zscore(k, v));