[SPARK-10095] [SQL] use public API of BigInteger

In UnsafeRow, we use the private field of BigInteger for better performance, but it actually didn't contribute much (3% in one benchmark) to end-to-end runtime, and make it not portable (may fail on other JVM implementations).

So we should use the public API instead.

cc rxin

Author: Davies Liu <davies@databricks.com>

Closes #8286 from davies/portable_decimal.

1 files changed, 0 insertions, 18 deletions

diff --git a/unsafe/src/main/java/org/apache/spark/unsafe/Platform.java b/unsafe/src/main/java/org/apache/spark/unsafe/Platform.java
index 18343efdc3..1c16da9829 100644
--- a/unsafe/src/main/java/org/apache/spark/unsafe/Platform.java
+++ b/unsafe/src/main/java/org/apache/spark/unsafe/Platform.java
@@ -18,7 +18,6 @@
 package org.apache.spark.unsafe;
 
 import java.lang.reflect.Field;
-import java.math.BigInteger;
 
 import sun.misc.Unsafe;
 
@@ -34,10 +33,6 @@ public final class Platform {
 
   public static final int DOUBLE_ARRAY_OFFSET;
 
-  // Support for resetting final fields while deserializing
-  public static final long BIG_INTEGER_SIGNUM_OFFSET;
-  public static final long BIG_INTEGER_MAG_OFFSET;
-
   public static int getInt(Object object, long offset) {
     return _UNSAFE.getInt(object, offset);
   }
@@ -150,24 +145,11 @@ public final class Platform {
       INT_ARRAY_OFFSET = _UNSAFE.arrayBaseOffset(int[].class);
       LONG_ARRAY_OFFSET = _UNSAFE.arrayBaseOffset(long[].class);
       DOUBLE_ARRAY_OFFSET = _UNSAFE.arrayBaseOffset(double[].class);
-
-      long signumOffset = 0;
-      long magOffset = 0;
-      try {
-        signumOffset = _UNSAFE.objectFieldOffset(BigInteger.class.getDeclaredField("signum"));
-        magOffset = _UNSAFE.objectFieldOffset(BigInteger.class.getDeclaredField("mag"));
-      } catch (Exception ex) {
-        // should not happen
-      }
-      BIG_INTEGER_SIGNUM_OFFSET = signumOffset;
-      BIG_INTEGER_MAG_OFFSET = magOffset;
     } else {
       BYTE_ARRAY_OFFSET = 0;
       INT_ARRAY_OFFSET = 0;
       LONG_ARRAY_OFFSET = 0;
       DOUBLE_ARRAY_OFFSET = 0;
-      BIG_INTEGER_SIGNUM_OFFSET = 0;
-      BIG_INTEGER_MAG_OFFSET = 0;
     }
   }
 }