Use BitSet instead of LinkedHashSet to improve the performance of SlotRange construction.

Pull request: spring-projects#2525

Author: daihuabin

src/main/java/org/springframework/data/redis/connection/ClusterSlotHashUtil.java

@@ -28,7 +28,7 @@
  */
 public final class ClusterSlotHashUtil {
 
-	private static final int SLOT_COUNT = 16384;
+	public static final int SLOT_COUNT = 16384;
 
 	private static final byte SUBKEY_START = '{';
 	private static final byte SUBKEY_END = '}';

src/main/java/org/springframework/data/redis/connection/RedisClusterNode.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.redis.connection;
 
+import java.util.Arrays;
+import java.util.BitSet;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashSet;
@@ -166,11 +168,12 @@ public static RedisClusterNodeBuilder newRedisClusterNode() {
 
 	/**
 	 * @author Christoph Strobl
+	 * @author daihuabin
 	 * @since 1.7
 	 */
 	public static class SlotRange {
 
-		private final Set<Integer> range;
+		private final BitSet range;
 
 		/**
 		 * @param lowerBound must not be {@literal null}.
@@ -181,43 +184,67 @@ public SlotRange(Integer lowerBound, Integer upperBound) {
 			Assert.notNull(lowerBound, "LowerBound must not be null");
 			Assert.notNull(upperBound, "UpperBound must not be null");
 
-			this.range = new LinkedHashSet<>();
+			this.range = new BitSet(upperBound + 1);
 			for (int i = lowerBound; i <= upperBound; i++) {
-				this.range.add(i);
+				this.range.set(i);
 			}
 		}
 
 		public SlotRange(Collection<Integer> range) {
-			this.range = CollectionUtils.isEmpty(range) ? Collections.emptySet() : new LinkedHashSet<>(range);
+			if (CollectionUtils.isEmpty(range)) {
+				this.range = new BitSet(0);
+			} else {
+				this.range = new BitSet(ClusterSlotHashUtil.SLOT_COUNT);
+				for (Integer pos : range) {
+					this.range.set(pos);
+				}
+			}
+		}
+
+		public SlotRange(BitSet range) {
+			this.range = (BitSet) range.clone();
 		}
 
 		@Override
 		public String toString() {
-			return range.toString();
+			return Arrays.toString(this.getSlotsArray());
 		}
 
 		/**
 		 * @param slot
 		 * @return true when slot is part of the range.
 		 */
 		public boolean contains(int slot) {
-			return range.contains(slot);
+			return range.get(slot);
 		}
 
 		/**
 		 * @return
 		 */
 		public Set<Integer> getSlots() {
-			return Collections.unmodifiableSet(range);
+			if (range.isEmpty()) {
+				return Collections.emptySet();
+			}
+			LinkedHashSet<Integer> slots = new LinkedHashSet<>(Math.max(2 * range.cardinality(), 11));
+			for (int i = 0; i < range.length(); i++) {
+				if (range.get(i)) {
+					slots.add(i);
+				}
+			}
+			return Collections.unmodifiableSet(slots);
 		}
 
 		public int[] getSlotsArray() {
-
-			int[] slots = new int[range.size()];
+			if (range.isEmpty()) {
+				return new int[0];
+			}
+			int[] slots = new int[range.cardinality()];
 			int pos = 0;
 
-			for (Integer value : range) {
-				slots[pos++] = value.intValue();
+			for (int i = 0; i < ClusterSlotHashUtil.SLOT_COUNT; i++) {
+				if (this.range.get(i)) {
+					slots[pos++] = i;
+				}
 			}
 
 			return slots;

src/main/java/org/springframework/data/redis/connection/convert/Converters.java

@@ -30,6 +30,7 @@
 import org.springframework.data.geo.Metric;
 import org.springframework.data.geo.Metrics;
 import org.springframework.data.redis.RedisSystemException;
+import org.springframework.data.redis.connection.ClusterSlotHashUtil;
 import org.springframework.data.redis.connection.DataType;
 import org.springframework.data.redis.connection.RedisClusterNode;
 import org.springframework.data.redis.connection.RedisClusterNode.Flag;
@@ -57,6 +58,7 @@
  * @author Thomas Darimont
  * @author Mark Paluch
  * @author Christoph Strobl
+ * @author daihuabin
  */
 public abstract class Converters {
 
@@ -606,7 +608,7 @@ private LinkState parseLinkState(String[] args) {
 
 		private SlotRange parseSlotRange(String[] args) {
 
-			Set<Integer> slots = new LinkedHashSet<>();
+			BitSet slots = new BitSet(ClusterSlotHashUtil.SLOT_COUNT);
 
 			for (int i = SLOTS_INDEX; i < args.length; i++) {
 
@@ -623,11 +625,11 @@ private SlotRange parseSlotRange(String[] args) {
 						int from = Integer.valueOf(slotRange[0]);
 						int to = Integer.valueOf(slotRange[1]);
 						for (int slot = from; slot <= to; slot++) {
-							slots.add(slot);
+							slots.set(slot);
 						}
 					}
 				} else {
-					slots.add(Integer.valueOf(raw));
+					slots.set(Integer.valueOf(raw));
 				}
 			}