Remove hppc from deletion policy

server/src/main/java/org/elasticsearch/index/engine/CombinedDeletionPolicy.java

@@ -8,8 +8,6 @@
 
 package org.elasticsearch.index.engine;
 
-import com.carrotsearch.hppc.ObjectIntHashMap;
-
 import org.apache.logging.log4j.Logger;
 import org.apache.lucene.index.IndexCommit;
 import org.apache.lucene.index.IndexDeletionPolicy;
@@ -21,6 +19,7 @@
 
 import java.io.IOException;
 import java.nio.file.Path;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -38,7 +37,7 @@ public class CombinedDeletionPolicy extends IndexDeletionPolicy {
     private final TranslogDeletionPolicy translogDeletionPolicy;
     private final SoftDeletesPolicy softDeletesPolicy;
     private final LongSupplier globalCheckpointSupplier;
-    private final ObjectIntHashMap<IndexCommit> snapshottedCommits; // Number of snapshots held against each commit point.
+    private final Map<IndexCommit, Integer> snapshottedCommits; // Number of snapshots held against each commit point.
     private volatile IndexCommit safeCommit; // the most recent safe commit point - its max_seqno at most the persisted global checkpoint.
     private volatile long maxSeqNoOfNextSafeCommit;
     private volatile IndexCommit lastCommit; // the most recent commit point
@@ -54,7 +53,7 @@ public class CombinedDeletionPolicy extends IndexDeletionPolicy {
         this.translogDeletionPolicy = translogDeletionPolicy;
         this.softDeletesPolicy = softDeletesPolicy;
         this.globalCheckpointSupplier = globalCheckpointSupplier;
-        this.snapshottedCommits = new ObjectIntHashMap<>();
+        this.snapshottedCommits = new HashMap<>();
     }
 
     @Override
@@ -146,7 +145,7 @@ synchronized IndexCommit acquireIndexCommit(boolean acquiringSafeCommit) {
         assert safeCommit != null : "Safe commit is not initialized yet";
         assert lastCommit != null : "Last commit is not initialized yet";
         final IndexCommit snapshotting = acquiringSafeCommit ? safeCommit : lastCommit;
-        snapshottedCommits.addTo(snapshotting, 1); // increase refCount
+        snapshottedCommits.merge(snapshotting, 1, Integer::sum); // increase refCount
         return new SnapshotIndexCommit(snapshotting);
     }
 
@@ -164,13 +163,17 @@ synchronized boolean releaseCommit(final IndexCommit snapshotCommit) {
                 + "], releasing commit ["
                 + releasingCommit
                 + "]";
-        final int refCount = snapshottedCommits.addTo(releasingCommit, -1); // release refCount
-        assert refCount >= 0 : "Number of snapshots can not be negative [" + refCount + "]";
-        if (refCount == 0) {
-            snapshottedCommits.remove(releasingCommit);
-        }
+        // release refCount
+        final Integer refCount = snapshottedCommits.compute(releasingCommit, (key, count) -> {
+            if (count == 1) {
+                return null;
+            }
+            return count - 1;
+        });
+
+        assert refCount == null || refCount > 0 : "Number of snapshots can not be negative [" + refCount + "]";
         // The commit can be clean up only if no pending snapshot and it is neither the safe commit nor last commit.
-        return refCount == 0 && releasingCommit.equals(safeCommit) == false && releasingCommit.equals(lastCommit) == false;
+        return refCount == null && releasingCommit.equals(safeCommit) == false && releasingCommit.equals(lastCommit) == false;
     }
 
     /**