ARROW-5902: [Java] Implement hash table and equals & hashCode API for dictionary encoding

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }

java/vector/src/main/codegen/templates/UnionVector.java

@@ -17,6 +17,7 @@
 
 import io.netty.buffer.ArrowBuf;
 import org.apache.arrow.memory.ReferenceManager;
+import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.pojo.FieldType;
 
 <@pp.dropOutputFile />
@@ -491,32 +492,35 @@ public Iterator<ValueVector> iterator() {
  return vectors.iterator();
  }
 
-
- public Object getObject(int index) {
+ private ValueVector getVector(int index) {
  int type = typeBuffer.getByte(index * TYPE_WIDTH);
  switch (MinorType.values()[type]) {
- case NULL:
- return null;
+case NULL:
+return null;
  <#list vv.types as type>
  <#list type.minor as minor>
  <#assign name = minor.class?cap_first />
  <#assign fields = minor.fields!type.fields />
  <#assign uncappedName = name?uncap_first/>
  <#if !minor.typeParams?? >
- case ${name?upper_case}:
-return get${name}Vector().getObject(index);
+case ${name?upper_case}:
+ return get${name}Vector();
  </#if>
  </#list>
  </#list>
- case STRUCT:
- return getStruct().getObject(index);
- case LIST:
- return getList().getObject(index);
- default:
- throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
+case STRUCT:
+return getStruct();
+case LIST:
+return getList();
+default:
+throw new UnsupportedOperationException("Cannot support type: " + MinorType.values()[type]);
  }
  }
 
+ public Object getObject(int index) {
+ return getVector(index).getObject(index);
+ }
+
  public byte[] get(int index) {
  return null;
  }
@@ -622,4 +626,27 @@ public void setType(int index, MinorType type) {
  private int getTypeBufferValueCapacity() {
  return typeBuffer.capacity() / TYPE_WIDTH;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return getVector(index).hashCode(index);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ UnionVector that = (UnionVector) to;
+ ValueVector leftVector = getVector(index);
+ ValueVector rightVector = that.getVector(toIndex);
+
+ if (leftVector.getClass() != rightVector.getClass()) {
+ return false;
+ }
+ return leftVector.equals(index, rightVector, toIndex);
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseFixedWidthVector.java

@@ -25,6 +25,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -837,4 +838,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseFixedWidthVector from
  handleSafe(thisIndex);
  copyFrom(fromIndex, thisIndex, from);
  }
+
+ @Override
+ public int hashCode(int index) {
+ int start = typeWidth * index;
+ int end = typeWidth * (index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseFixedWidthVector that = (BaseFixedWidthVector) to;
+
+ int leftStart = typeWidth * index;
+ int leftEnd = typeWidth * (index + 1);
+
+ int rightStart = typeWidth * toIndex;
+ int rightEnd = typeWidth * (toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/BaseVariableWidthVector.java

@@ -27,6 +27,7 @@
 import org.apache.arrow.memory.OutOfMemoryException;
 import org.apache.arrow.vector.ipc.message.ArrowFieldNode;
 import org.apache.arrow.vector.types.pojo.Field;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.OversizedAllocationException;
 import org.apache.arrow.vector.util.TransferPair;
@@ -1334,4 +1335,33 @@ public void copyFromSafe(int fromIndex, int thisIndex, BaseVariableWidthVector f
  }
  lastSet = thisIndex;
  }
+
+ @Override
+ public int hashCode(int index) {
+ final int start = getStartOffset(index);
+ final int end = getStartOffset(index + 1);
+ return ByteFunctionHelpers.hash(this.getDataBuffer(), start, end);
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ BaseVariableWidthVector that = (BaseVariableWidthVector) to;
+
+ final int leftStart = getStartOffset(index);
+ final int leftEnd = getStartOffset(index + 1);
+
+ final int rightStart = that.getStartOffset(toIndex);
+ final int rightEnd = that.getStartOffset(toIndex + 1);
+
+ int ret = ByteFunctionHelpers.equal(this.getDataBuffer(), leftStart, leftEnd,
+ that.getDataBuffer(), rightStart, rightEnd);
+ return ret == 1;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/ValueVector.java

@@ -237,4 +237,18 @@ public interface ValueVector extends Closeable, Iterable<ValueVector> {
  * @return true if element is null
  */
  boolean isNull(int index);
+
+ /**
+ * Returns hashCode of element in index.
+ */
+ int hashCode(int index);
+
+ /**
+ * Check whether the element in index equals to the element in targetIndex from the target vector.
+ * @param index index to compare in this vector
+ * @param target target vector
+ * @param targetIndex index to compare in target vector
+ * @return true if equals, otherwise false.
+ */
+ boolean equals(int index, ValueVector target, int targetIndex);
 }

java/vector/src/main/java/org/apache/arrow/vector/VarCharVector.java

@@ -270,7 +270,6 @@ public void setSafe(int index, Text text) {
  setSafe(index, text.getBytes(), 0, text.getLength());
  }
 
-
  /*----------------------------------------------------------------*
  | |
  | vector transfer |

java/vector/src/main/java/org/apache/arrow/vector/ZeroVector.java

@@ -244,4 +244,14 @@ public int getNullCount() {
  public boolean isNull(int index) {
  return false;
  }
+
+ @Override
+ public int hashCode(int index) {
+ return 0;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ return false;
+ }
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/FixedSizeListVector.java

@@ -45,6 +45,7 @@
 import org.apache.arrow.vector.types.pojo.DictionaryEncoding;
 import org.apache.arrow.vector.types.pojo.Field;
 import org.apache.arrow.vector.types.pojo.FieldType;
+import org.apache.arrow.vector.util.ByteFunctionHelpers;
 import org.apache.arrow.vector.util.CallBack;
 import org.apache.arrow.vector.util.JsonStringArrayList;
 import org.apache.arrow.vector.util.OversizedAllocationException;
@@ -496,6 +497,37 @@ public TransferPair makeTransferPair(ValueVector target) {
  return new TransferImpl((FixedSizeListVector) target);
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = 0; i < listSize; i++) {
+ hash = ByteFunctionHelpers.comebineHash(hash, vector.hashCode(index * listSize + i));
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ FixedSizeListVector that = (FixedSizeListVector) to;
+
+ for (int i = 0; i < listSize; i++) {
+ if (!vector.equals(index * listSize + i, that, toIndex * listSize + i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  FixedSizeListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/ListVector.java

@@ -412,6 +412,49 @@ public ArrowBuf getOffsetBuffer() {
  return offsetBuffer;
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ }
+ int hash = 0;
+ final int start = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int end = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+ for (int i = start; i < end; i++) {
+ hash = 31 * vector.hashCode(i);
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+
+ ListVector that = (ListVector) to;
+ final int leftStart = offsetBuffer.getInt(index * OFFSET_WIDTH);
+ final int leftEnd = offsetBuffer.getInt((index + 1) * OFFSET_WIDTH);
+
+ final int rightStart = that.offsetBuffer.getInt(toIndex * OFFSET_WIDTH);
+ final int rightEnd = that.offsetBuffer.getInt((toIndex + 1) * OFFSET_WIDTH);
+
+ if ((leftEnd - leftStart) != (rightEnd - rightStart)) {
+ return false;
+ }
+
+ for (int i = 0; i < (leftEnd - leftStart); i++) {
+ if (!vector.equals(leftStart + i, that.vector, rightStart + i)) {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
  private class TransferImpl implements TransferPair {
 
  ListVector to;

java/vector/src/main/java/org/apache/arrow/vector/complex/NonNullableStructVector.java

@@ -286,6 +286,56 @@ public Object getObject(int index) {
  return vv;
  }
 
+ @Override
+ public int hashCode(int index) {
+ int hash = 0;
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null && index < v.getValueCount()) {
+ hash += 31 * hash + v.hashCode(index);
+ }
+ }
+ return hash;
+ }
+
+ @Override
+ public boolean equals(int index, ValueVector to, int toIndex) {
+ if (to == null) {
+ return false;
+ }
+ if (this.getClass() != to.getClass()) {
+ return false;
+ }
+ NonNullableStructVector that = (NonNullableStructVector) to;
+ List<ValueVector> leftChildrens = new ArrayList<>();
+ List<ValueVector> rightChildrens = new ArrayList<>();
+
+ for (String child : getChildFieldNames()) {
+ ValueVector v = getChild(child);
+ if (v != null) {
+ leftChildrens.add(v);
+ }
+ }
+
+ for (String child : that.getChildFieldNames()) {
+ ValueVector v = that.getChild(child);
+ if (v != null) {
+ rightChildrens.add(v);
+ }
+ }
+
+ if (leftChildrens.size() != rightChildrens.size()) {
+ return false;
+ }
+
+ for (int i = 0; i < leftChildrens.size(); i++) {
+ if (!leftChildrens.get(i).equals(index, rightChildrens.get(i), toIndex)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
  @Override
  public boolean isNull(int index) {
  return false;
@@ -372,4 +422,5 @@ public void initializeChildrenFromFields(List<Field> children) {
  public List<FieldVector> getChildrenFromFields() {
  return getChildren();
  }
+
 }

java/vector/src/main/java/org/apache/arrow/vector/complex/StructVector.java

@@ -479,6 +479,15 @@ public Object getObject(int index) {
  }
  }
 
+ @Override
+ public int hashCode(int index) {
+ if (isSet(index) == 0) {
+ return 0;
+ } else {
+ return super.hashCode(index);
+ }
+ }
+
  @Override
  public void get(int index, ComplexHolder holder) {
  holder.isSet = isSet(index);
@@ -546,4 +555,5 @@ public void setValueCount(int valueCount) {
  super.setValueCount(valueCount);
  this.valueCount = valueCount;
  }
+
 }