diff --git a/protocol/src/main/java/com/zfoo/protocol/collection/ArrayUtils.java b/protocol/src/main/java/com/zfoo/protocol/collection/ArrayUtils.java
index b0284b3c..ad80c00b 100644
--- a/protocol/src/main/java/com/zfoo/protocol/collection/ArrayUtils.java
+++ b/protocol/src/main/java/com/zfoo/protocol/collection/ArrayUtils.java
@@ -35,6 +35,7 @@ public abstract class ArrayUtils {
     public static final double[] EMPTY_DOUBLE_ARRAY = new double[0];
     public static final char[] EMPTY_CHAR_ARRAY = new char[0];
 
+    public static final Object EMPTY_OBJECT = new Object();
 
     /**
      * length
diff --git a/protocol/src/main/java/com/zfoo/protocol/collection/HashByteSet.java b/protocol/src/main/java/com/zfoo/protocol/collection/HashByteSet.java
new file mode 100644
index 00000000..9a751434
--- /dev/null
+++ b/protocol/src/main/java/com/zfoo/protocol/collection/HashByteSet.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed 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 com.zfoo.protocol.collection;
+
+import io.netty.util.collection.ByteObjectHashMap;
+
+import java.util.AbstractSet;
+import java.util.Iterator;
+
+/**
+ * @author godotg
+ * @version 3.0
+ */
+public class HashByteSet extends AbstractSet<Byte> {
+
+    private final ByteObjectHashMap<Object> map;
+
+    public HashByteSet() {
+        map = new ByteObjectHashMap<>();
+    }
+
+    public HashByteSet(int initialCapacity) {
+        map = new ByteObjectHashMap<>(initialCapacity);
+    }
+
+    @Override
+    public Iterator<Byte> iterator() {
+        return map.keySet().iterator();
+    }
+
+    @Override
+    public int size() {
+        return map.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return map.containsKey(o);
+    }
+
+    @Override
+    public boolean add(Byte e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    public boolean add(byte e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return map.remove(o) == ArrayUtils.EMPTY_OBJECT;
+    }
+
+    @Override
+    public void clear() {
+        map.clear();
+    }
+
+}
diff --git a/protocol/src/main/java/com/zfoo/protocol/collection/HashIntSet.java b/protocol/src/main/java/com/zfoo/protocol/collection/HashIntSet.java
new file mode 100644
index 00000000..37fc4990
--- /dev/null
+++ b/protocol/src/main/java/com/zfoo/protocol/collection/HashIntSet.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed 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 com.zfoo.protocol.collection;
+
+import io.netty.util.collection.IntObjectHashMap;
+
+import java.util.AbstractSet;
+import java.util.Iterator;
+
+/**
+ * @author godotg
+ * @version 3.0
+ */
+public class HashIntSet extends AbstractSet<Integer> {
+
+    private final IntObjectHashMap<Object> map;
+
+    public HashIntSet() {
+        map = new IntObjectHashMap<>();
+    }
+
+    public HashIntSet(int initialCapacity) {
+        map = new IntObjectHashMap<>(initialCapacity);
+    }
+
+    @Override
+    public Iterator<Integer> iterator() {
+        return map.keySet().iterator();
+    }
+
+    @Override
+    public int size() {
+        return map.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return map.containsKey(o);
+    }
+
+    @Override
+    public boolean add(Integer e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    public boolean add(int e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return map.remove(o) == ArrayUtils.EMPTY_OBJECT;
+    }
+
+    @Override
+    public void clear() {
+        map.clear();
+    }
+
+}
diff --git a/protocol/src/main/java/com/zfoo/protocol/collection/HashLongSet.java b/protocol/src/main/java/com/zfoo/protocol/collection/HashLongSet.java
new file mode 100644
index 00000000..81593b1b
--- /dev/null
+++ b/protocol/src/main/java/com/zfoo/protocol/collection/HashLongSet.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed 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 com.zfoo.protocol.collection;
+
+import io.netty.util.collection.LongObjectHashMap;
+
+import java.util.AbstractSet;
+import java.util.Iterator;
+
+/**
+ * @author godotg
+ * @version 3.0
+ */
+public class HashLongSet extends AbstractSet<Long> {
+
+    private final LongObjectHashMap<Object> map;
+
+    public HashLongSet() {
+        map = new LongObjectHashMap<>();
+    }
+
+    public HashLongSet(int initialCapacity) {
+        map = new LongObjectHashMap<>(initialCapacity);
+    }
+
+    @Override
+    public Iterator<Long> iterator() {
+        return map.keySet().iterator();
+    }
+
+    @Override
+    public int size() {
+        return map.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return map.containsKey(o);
+    }
+
+    @Override
+    public boolean add(Long e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    public boolean add(long e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return map.remove(o) == ArrayUtils.EMPTY_OBJECT;
+    }
+
+    @Override
+    public void clear() {
+        map.clear();
+    }
+
+}
diff --git a/protocol/src/main/java/com/zfoo/protocol/collection/HashShortSet.java b/protocol/src/main/java/com/zfoo/protocol/collection/HashShortSet.java
new file mode 100644
index 00000000..2e493ece
--- /dev/null
+++ b/protocol/src/main/java/com/zfoo/protocol/collection/HashShortSet.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2020 The zfoo Authors
+ * Licensed 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 com.zfoo.protocol.collection;
+
+import io.netty.util.collection.ShortObjectHashMap;
+
+import java.util.AbstractSet;
+import java.util.Iterator;
+
+/**
+ * @author godotg
+ * @version 3.0
+ */
+public class HashShortSet extends AbstractSet<Short> {
+
+    private final ShortObjectHashMap<Object> map;
+
+    public HashShortSet() {
+        map = new ShortObjectHashMap<>();
+    }
+
+    public HashShortSet(int initialCapacity) {
+        map = new ShortObjectHashMap<>(initialCapacity);
+    }
+
+    @Override
+    public Iterator<Short> iterator() {
+        return map.keySet().iterator();
+    }
+
+    @Override
+    public int size() {
+        return map.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return map.containsKey(o);
+    }
+
+    @Override
+    public boolean add(Short e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    public boolean add(short e) {
+        return map.put(e, ArrayUtils.EMPTY_OBJECT) == null;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return map.remove(o) == ArrayUtils.EMPTY_OBJECT;
+    }
+
+    @Override
+    public void clear() {
+        map.clear();
+    }
+
+}