freeQueue = new LinkedBlockingQueue<>();
+ // current num of Buffers in queue
+ AtomicInteger totalCount;
+
+ public ByteBufferAllocator(int cap, int count) {
+ this.capacity = cap;
+ this.maxCount = count;
+ this.totalCount = new AtomicInteger(0);
+ }
+
+ public ByteBuffer get() throws InterruptedException {
+ ByteBuffer buffer = null;
+ while (buffer == null) {
+ if (freeQueue.size() > 0) {
+ buffer = freeQueue.poll();
+ } else if (totalCount.get() < maxCount) {
+ buffer = ByteBuffer.allocate(capacity);
+ totalCount.incrementAndGet();
+ } else {
+ buffer = freeQueue.poll(1, TimeUnit.SECONDS);
+ }
+ }
+ return buffer;
+ }
+
+ public void release(ByteBuffer buffer) {
+ if (freeQueue.size() < maxCount) {
+ buffer.clear();
+ freeQueue.add(buffer);
+ }
+ }
+}
diff --git a/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/buffer/KVByteBuffer.java b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/buffer/KVByteBuffer.java
new file mode 100644
index 000000000..524a0f58f
--- /dev/null
+++ b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/buffer/KVByteBuffer.java
@@ -0,0 +1,98 @@
+/*
+ * 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.hugegraph.store.buffer;
+
+import java.nio.ByteBuffer;
+
+public class KVByteBuffer {
+
+ ByteBuffer buffer;
+
+ public KVByteBuffer(int capacity) {
+ buffer = ByteBuffer.allocate(capacity);
+ }
+
+ public KVByteBuffer(byte[] buffer) {
+ this.buffer = ByteBuffer.wrap(buffer);
+ }
+
+ public KVByteBuffer(ByteBuffer buffer) {
+ this.buffer = buffer;
+ }
+
+ public void clear() {
+ this.buffer.clear();
+ }
+
+ public KVByteBuffer flip() {
+ buffer.flip();
+ return this;
+ }
+
+ public ByteBuffer getBuffer() {
+ return buffer;
+ }
+
+ public ByteBuffer copyBuffer() {
+ byte[] buf = new byte[buffer.position()];
+ System.arraycopy(buffer.array(), 0, buf, 0, buffer.position());
+ return ByteBuffer.wrap(buf);
+ }
+
+ public void put(byte data) {
+ buffer.put(data);
+ }
+
+ public void put(byte[] data) {
+ if (data != null) {
+ buffer.putInt(data.length);
+ buffer.put(data);
+ }
+ }
+
+ public byte[] getBytes() {
+ int len = buffer.getInt();
+ byte[] data = new byte[len];
+ buffer.get(data);
+ return data;
+ }
+
+ public byte get() {
+ return buffer.get();
+ }
+
+ public void putInt(int data) {
+ buffer.putInt(data);
+ }
+
+ public int getInt() {
+ return buffer.getInt();
+ }
+
+ public byte[] array() {
+ return this.buffer.array();
+ }
+
+ public int position() {
+ return this.buffer.position();
+ }
+
+ public final boolean hasRemaining() {
+ return this.buffer.hasRemaining();
+ }
+}
diff --git a/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/Bits.java b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/Bits.java
new file mode 100644
index 000000000..2b78a22b8
--- /dev/null
+++ b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/Bits.java
@@ -0,0 +1,66 @@
+/*
+ * 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.hugegraph.store.term;
+
+import java.nio.ByteBuffer;
+
+public class Bits {
+
+ /**
+ * 大头字节序写入short
+ */
+ public static void putShort(byte[] buf, int offSet, int x) {
+ buf[offSet] = (byte) (x >> 8);
+ buf[offSet + 1] = (byte) (x);
+ }
+
+ public static void putInt(byte[] buf, int offSet, int x) {
+ buf[offSet] = (byte) (x >> 24);
+ buf[offSet + 1] = (byte) (x >> 16);
+ buf[offSet + 2] = (byte) (x >> 8);
+ buf[offSet + 3] = (byte) (x);
+ }
+
+ /**
+ * 大头字节序读取short
+ */
+ public static int getShort(byte[] buf, int offSet) {
+ int x = buf[offSet] & 0xff;
+ x = (x << 8) + (buf[offSet + 1] & 0xff);
+ return x;
+ }
+
+ public static int getInt(byte[] buf, int offSet) {
+ int x = (buf[offSet] << 24)
+ + ((buf[offSet + 1] & 0xff) << 16)
+ + ((buf[offSet + 2] & 0xff) << 8)
+ + (buf[offSet + 3] & 0xff);
+ return x;
+ }
+
+ public static void put(byte[] buf, int offSet, byte[] srcBuf) {
+ System.arraycopy(srcBuf, 0, buf, offSet, srcBuf.length);
+ }
+
+ public static int toInt(byte[] bytes) {
+ ByteBuffer buffer = ByteBuffer.allocate(Integer.BYTES);
+ buffer.put(bytes);
+ buffer.flip();//need flip
+ return buffer.getInt();
+ }
+}
diff --git a/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/HgPair.java b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/HgPair.java
new file mode 100644
index 000000000..84aa00b9a
--- /dev/null
+++ b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/HgPair.java
@@ -0,0 +1,142 @@
+/*
+ * 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.hugegraph.store.term;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+/**
+ * Copy from javafx.util:Pair
+ * TODO: refer license later, ?% match, maybe refer to avafx.util:Pair
+ *
+ * created on 2021/10/15
+ */
+public class HgPair implements Serializable {
+
+ /**
+ * Key of this Pair.
+ */
+ private K key;
+ /**
+ * Value of this Pair.
+ */
+ private V value;
+
+ public HgPair() {
+
+ }
+
+ /**
+ * Creates a new pair
+ *
+ * @param key The key for this pair
+ * @param value The value to use for this pair
+ */
+ public HgPair(K key, V value) {
+ this.key = key;
+ this.value = value;
+ }
+
+ /**
+ * Gets the key for this pair.
+ *
+ * @return key for this pair
+ */
+ public K getKey() {
+ return key;
+ }
+
+ public void setKey(K key) {
+ this.key = key;
+ }
+
+ /**
+ * Gets the value for this pair.
+ *
+ * @return value for this pair
+ */
+ public V getValue() {
+ return value;
+ }
+
+ public void setValue(V value) {
+ this.value = value;
+ }
+
+ /**
+ * String representation of this
+ * Pair.
+ *
+ * The default name/value delimiter '=' is always used.
+ *
+ * @return String representation of this Pair
+ */
+ @Override
+ public String toString() {
+ return key + "=" + value;
+ }
+
+ /**
+ * Generate a hash code for this Pair.
+ *
+ * The hash code is calculated using both the name and
+ * the value of the Pair.
+ *
+ * @return hash code for this Pair
+ */
+ @Override
+ public int hashCode() {
+ // name's hashCode is multiplied by an arbitrary prime number (13)
+ // in order to make sure there is a difference in the hashCode between
+ // these two parameters:
+ // name: a value: aa
+ // name: aa value: a
+ return key.hashCode() * 13 + (value == null ? 0 : value.hashCode());
+ }
+
+ /**
+ * Test this Pair for equality with another
+ * Object.
+ *
+ * If the Object to be tested is not a
+ * Pair or is null, then this method
+ * returns false.
+ *
+ * Two Pairs are considered equal if and only if
+ * both the names and values are equal.
+ *
+ * @param o the Object to test for
+ * equality with this Pair
+ * @return true if the given Object is
+ * equal to this Pair else false
+ */
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) {
+ return true;
+ }
+ if (o instanceof HgPair) {
+ HgPair pair = (HgPair) o;
+ if (!Objects.equals(key, pair.key)) {
+ return false;
+ }
+ return Objects.equals(value, pair.value);
+ }
+ return false;
+ }
+}
diff --git a/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/HgTriple.java b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/HgTriple.java
new file mode 100644
index 000000000..5206b2444
--- /dev/null
+++ b/hugegraph-store/hg-store-common/src/main/java/org/apache/hugegraph/store/term/HgTriple.java
@@ -0,0 +1,79 @@
+/*
+ * 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.hugegraph.store.term;
+
+import java.util.Objects;
+
+/**
+ * created on 2021/10/19
+ */
+public class HgTriple {
+
+ private final X x;
+ private final Y y;
+ private final Z z;
+ private int hash = -1;
+
+ public HgTriple(X x, Y y, Z z) {
+ this.x = x;
+ this.y = y;
+ this.z = z;
+ }
+
+ public X getX() {
+ return x;
+ }
+
+ public Y getY() {
+ return y;
+ }
+
+ public Z getZ() {
+ return z;
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) {
+ return true;
+ }
+ if (o == null || getClass() != o.getClass()) {
+ return false;
+ }
+ HgTriple hgTriple = (HgTriple) o;
+ return Objects.equals(x, hgTriple.x) && Objects.equals(y, hgTriple.y) &&
+ Objects.equals(z, hgTriple.z);
+ }
+
+ @Override
+ public int hashCode() {
+ if (hash == -1) {
+ hash = Objects.hash(x, y, z);
+ }
+ return this.hash;
+ }
+
+ @Override
+ public String toString() {
+ return "HgTriple{" +
+ "x=" + x +
+ ", y=" + y +
+ ", z=" + z +
+ '}';
+ }
+}