fix: Remove duplicate byte array allocation for CometDictionary (#224)

apache · Mar 21, 2024 · 9e59732 · 9e59732
1 parent eb6c704
commit 9e59732
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Showing 2 changed files with 17 additions and 10 deletions.
diff --git a/common/src/main/java/org/apache/comet/vector/CometDictionary.java b/common/src/main/java/org/apache/comet/vector/CometDictionary.java
@@ -156,10 +156,9 @@ private void initialize() {
         binaries = new ByteArrayWrapper[numValues];
         for (int i = 0; i < numValues; i++) {
           // Need copying here since we re-use byte array for decimal
-          byte[] bytes = values.getBinaryDecimal(i);
-          byte[] copy = new byte[DECIMAL_BYTE_WIDTH];
-          System.arraycopy(bytes, 0, copy, 0, DECIMAL_BYTE_WIDTH);
-          binaries[i] = new ByteArrayWrapper(copy);
+          byte[] bytes = new byte[DECIMAL_BYTE_WIDTH];
+          bytes = values.copyBinaryDecimal(i, bytes);
+          binaries[i] = new ByteArrayWrapper(bytes);
         }
         break;
       default:

diff --git a/common/src/main/java/org/apache/comet/vector/CometVector.java b/common/src/main/java/org/apache/comet/vector/CometVector.java
@@ -98,22 +98,30 @@ public Decimal getDecimal(int i, int precision, int scale) {
     }
   }
 
-  /** Reads a 16-byte byte array which are encoded big-endian for decimal128. */
+  /**
+   * Reads a 16-byte byte array which are encoded big-endian for decimal128 into internal byte
+   * array.
+   */
   byte[] getBinaryDecimal(int i) {
+    return copyBinaryDecimal(i, DECIMAL_BYTES);
+  }
+
+  /** Reads a 16-byte byte array which are encoded big-endian for decimal128. */
+  public byte[] copyBinaryDecimal(int i, byte[] dest) {
     long valueBufferAddress = getValueVector().getDataBuffer().memoryAddress();
     Platform.copyMemory(
         null,
         valueBufferAddress + (long) i * DECIMAL_BYTE_WIDTH,
-        DECIMAL_BYTES,
+        dest,
         Platform.BYTE_ARRAY_OFFSET,
         DECIMAL_BYTE_WIDTH);
     // Decimal is stored little-endian in Arrow, so we need to reverse the bytes here
     for (int j = 0, k = DECIMAL_BYTE_WIDTH - 1; j < DECIMAL_BYTE_WIDTH / 2; j++, k--) {
-      byte tmp = DECIMAL_BYTES[j];
-      DECIMAL_BYTES[j] = DECIMAL_BYTES[k];
-      DECIMAL_BYTES[k] = tmp;
+      byte tmp = dest[j];
+      dest[j] = dest[k];
+      dest[k] = tmp;
     }
-    return DECIMAL_BYTES;
+    return dest;
   }
 
   @Override