ARROW-5726: [Java] Implement a common interface for int vectors

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

@@ -0,0 +1,29 @@
+/*
+ * 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.arrow.vector;
+
+/**
+ * Interface for all int type vectors.
+ */
+public interface BaseIntVector extends ValueVector {
+
+  /**
+   * set the encoded value from a {@link org.apache.arrow.vector.dictionary.Dictionary}.
+   */
+  void setEncodedValue(int index, int value);
+}

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

@@ -35,7 +35,7 @@
  * integer values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class BigIntVector extends BaseFixedWidthVector {
+public class BigIntVector extends BaseFixedWidthVector implements BaseIntVector {
   public static final byte TYPE_WIDTH = 8;
   private final FieldReader reader;
 
@@ -339,6 +339,11 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((BigIntVector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     BigIntVector to;
 

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

@@ -35,7 +35,7 @@
  * integer values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class IntVector extends BaseFixedWidthVector {
+public class IntVector extends BaseFixedWidthVector implements BaseIntVector {
   public static final byte TYPE_WIDTH = 4;
   private final FieldReader reader;
 
@@ -343,6 +343,11 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((IntVector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     IntVector to;
 

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

@@ -20,6 +20,7 @@
 import static org.apache.arrow.vector.NullCheckingForGet.NULL_CHECKING_ENABLED;
 
 import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.complex.impl.SmallIntReaderImpl;
 import org.apache.arrow.vector.complex.reader.FieldReader;
 import org.apache.arrow.vector.holders.NullableSmallIntHolder;
@@ -35,7 +36,7 @@
  * short values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class SmallIntVector extends BaseFixedWidthVector {
+public class SmallIntVector extends BaseFixedWidthVector implements BaseIntVector {
   public static final byte TYPE_WIDTH = 2;
   private final FieldReader reader;
 
@@ -370,6 +371,12 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((SmallIntVector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    Preconditions.checkArgument(value <= Short.MAX_VALUE, "value is overflow: %s", value);
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     SmallIntVector to;
 

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

@@ -20,6 +20,7 @@
 import static org.apache.arrow.vector.NullCheckingForGet.NULL_CHECKING_ENABLED;
 
 import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.complex.impl.TinyIntReaderImpl;
 import org.apache.arrow.vector.complex.reader.FieldReader;
 import org.apache.arrow.vector.holders.NullableTinyIntHolder;
@@ -35,7 +36,7 @@
  * byte values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class TinyIntVector extends BaseFixedWidthVector {
+public class TinyIntVector extends BaseFixedWidthVector implements BaseIntVector {
   public static final byte TYPE_WIDTH = 1;
   private final FieldReader reader;
 
@@ -370,6 +371,12 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((TinyIntVector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    Preconditions.checkArgument(value <= Byte.MAX_VALUE, "value is overflow: %s", value);
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     TinyIntVector to;
 

java/vector/src/main/java/org/apache/arrow/vector/UInt1Vector.java

@@ -20,6 +20,7 @@
 import static org.apache.arrow.vector.NullCheckingForGet.NULL_CHECKING_ENABLED;
 
 import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.complex.impl.UInt1ReaderImpl;
 import org.apache.arrow.vector.complex.reader.FieldReader;
 import org.apache.arrow.vector.holders.NullableUInt1Holder;
@@ -35,7 +36,7 @@
  * integer values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class UInt1Vector extends BaseFixedWidthVector {
+public class UInt1Vector extends BaseFixedWidthVector implements BaseIntVector {
   private static final byte TYPE_WIDTH = 1;
   private final FieldReader reader;
 
@@ -150,7 +151,7 @@ public void copyFrom(int fromIndex, int thisIndex, UInt1Vector from) {
   }
 
   /**
-   * Identical to {@link #copyFrom()} but reallocates buffer if index is larger
+   * Identical to {@link #copyFrom(int, int, UInt1Vector)} but reallocates buffer if index is larger
    * than capacity.
    */
   public void copyFromSafe(int fromIndex, int thisIndex, UInt1Vector from) {
@@ -329,6 +330,14 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((UInt1Vector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    Preconditions.checkArgument(value <= 0xFF, "value is overflow: %s", value);
+    this.setSafe(index, value);
+  }
+
+
+
   private class TransferImpl implements TransferPair {
     UInt1Vector to;
 

java/vector/src/main/java/org/apache/arrow/vector/UInt2Vector.java

@@ -20,6 +20,7 @@
 import static org.apache.arrow.vector.NullCheckingForGet.NULL_CHECKING_ENABLED;
 
 import org.apache.arrow.memory.BufferAllocator;
+import org.apache.arrow.util.Preconditions;
 import org.apache.arrow.vector.complex.impl.UInt2ReaderImpl;
 import org.apache.arrow.vector.complex.reader.FieldReader;
 import org.apache.arrow.vector.holders.NullableUInt2Holder;
@@ -35,7 +36,7 @@
  * integer values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class UInt2Vector extends BaseFixedWidthVector {
+public class UInt2Vector extends BaseFixedWidthVector implements BaseIntVector {
   private static final byte TYPE_WIDTH = 2;
   private final FieldReader reader;
 
@@ -308,6 +309,12 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((UInt2Vector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    Preconditions.checkArgument(value <= Character.MAX_VALUE, "value is overflow: %s", value);
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     UInt2Vector to;
 

java/vector/src/main/java/org/apache/arrow/vector/UInt4Vector.java

@@ -35,7 +35,7 @@
  * integer values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class UInt4Vector extends BaseFixedWidthVector {
+public class UInt4Vector extends BaseFixedWidthVector implements BaseIntVector {
   private static final byte TYPE_WIDTH = 4;
   private final FieldReader reader;
 
@@ -301,6 +301,11 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((UInt4Vector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     UInt4Vector to;
 

java/vector/src/main/java/org/apache/arrow/vector/UInt8Vector.java

@@ -37,7 +37,7 @@
  * integer values which could be null. A validity buffer (bit vector) is
  * maintained to track which elements in the vector are null.
  */
-public class UInt8Vector extends BaseFixedWidthVector {
+public class UInt8Vector extends BaseFixedWidthVector implements BaseIntVector {
   private static final byte TYPE_WIDTH = 8;
   private final FieldReader reader;
 
@@ -302,6 +302,11 @@ public TransferPair makeTransferPair(ValueVector to) {
     return new TransferImpl((UInt8Vector) to);
   }
 
+  @Override
+  public void setEncodedValue(int index, int value) {
+    this.setSafe(index, value);
+  }
+
   private class TransferImpl implements TransferPair {
     UInt8Vector to;
 

java/vector/src/main/java/org/apache/arrow/vector/dictionary/DictionaryEncoder.java

@@ -17,12 +17,10 @@
 
 package org.apache.arrow.vector.dictionary;
 
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.apache.arrow.vector.BaseIntVector;
 import org.apache.arrow.vector.FieldVector;
 import org.apache.arrow.vector.ValueVector;
 import org.apache.arrow.vector.types.Types.MinorType;
@@ -61,43 +59,27 @@ public static ValueVector encode(ValueVector vector, Dictionary dictionary) {
     Field indexField = new Field(valueField.getName(), indexFieldType, null);
 
     // vector to hold our indices (dictionary encoded values)
-    FieldVector indices = indexField.createVector(vector.getAllocator());
-
-    // use reflection to pull out the set method
-    // TODO implement a common interface for int vectors
-    Method setter = null;
-    for (Class<?> c : Arrays.asList(int.class, long.class)) {
-      try {
-        setter = indices.getClass().getMethod("setSafe", int.class, c);
-        break;
-      } catch (NoSuchMethodException e) {
-        // ignore
-      }
+    FieldVector createdVector = indexField.createVector(vector.getAllocator());
+    if (! (createdVector instanceof BaseIntVector)) {
+      throw new IllegalArgumentException("Dictionary encoding does not have a valid int type:" +
+          createdVector.getClass());
     }
-    if (setter == null) {
-      throw new IllegalArgumentException("Dictionary encoding does not have a valid int type:" + indices.getClass());
-    }
-
-    int count = vector.getValueCount();
 
+    BaseIntVector indices = (BaseIntVector) createdVector;
     indices.allocateNew();
 
-    try {
-      for (int i = 0; i < count; i++) {
-        Object value = vector.getObject(i);
-        if (value != null) { // if it's null leave it null
-          // note: this may fail if value was not included in the dictionary
-          Object encoded = lookUps.get(value);
-          if (encoded == null) {
-            throw new IllegalArgumentException("Dictionary encoding not defined for value:" + value);
-          }
-          setter.invoke(indices, i, encoded);
+    int count = vector.getValueCount();
+
+    for (int i = 0; i < count; i++) {
+      Object value = vector.getObject(i);
+      if (value != null) { // if it's null leave it null
+        // note: this may fail if value was not included in the dictionary
+        Integer encoded = lookUps.get(value);
+        if (encoded == null) {
+          throw new IllegalArgumentException("Dictionary encoding not defined for value:" + value);
         }
+        indices.setEncodedValue(i, encoded);
       }
-    } catch (IllegalAccessException e) {
-      throw new RuntimeException("IllegalAccessException invoking vector mutator set():", e);
-    } catch (InvocationTargetException e) {
-      throw new RuntimeException("InvocationTargetException invoking vector mutator set():", e.getCause());
     }
 
     indices.setValueCount(count);