From ebeb6977d6731388477bbf010b14d6321fe9f7bc Mon Sep 17 00:00:00 2001
From: Davies Liu <davies@databricks.com>
Date: Fri, 14 Aug 2015 11:02:40 -0700
Subject: [PATCH 1/3] fix serialization of UTF8String across different JVM

---
 .../apache/spark/unsafe/types/UTF8String.java | 25 +++++++++++++++----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java b/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
index 667c00900f2c5..71d4c5cb67344 100644
--- a/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
+++ b/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
@@ -18,8 +18,7 @@
 package org.apache.spark.unsafe.types;
 
 import javax.annotation.Nonnull;
-import java.io.Serializable;
-import java.io.UnsupportedEncodingException;
+import java.io.*;
 import java.nio.ByteOrder;
 import java.util.Arrays;
 import java.util.Map;
@@ -41,9 +40,9 @@
 public final class UTF8String implements Comparable<UTF8String>, Serializable {
 
   @Nonnull
-  private final Object base;
-  private final long offset;
-  private final int numBytes;
+  private Object base;
+  private long offset;
+  private int numBytes;
 
   public Object getBaseObject() { return base; }
   public long getBaseOffset() { return offset; }
@@ -978,4 +977,20 @@ public UTF8String soundex() {
     }
     return UTF8String.fromBytes(sx);
   }
+
+  private static final long serialVersionUID = 42L;
+
+  private void writeObject(ObjectOutputStream out) throws IOException {
+    byte[] bytes = getBytes();
+    out.writeInt(bytes.length);
+    out.write(bytes);
+  }
+
+  private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
+    offset = BYTE_ARRAY_OFFSET;
+    numBytes = in.readInt();
+    base = new byte[numBytes];
+    in.readFully((byte[]) base);
+  }
+
 }

From 4ba1ac0c76377d53c80b7996b54d79ddb2244550 Mon Sep 17 00:00:00 2001
From: Davies Liu <davies@databricks.com>
Date: Fri, 14 Aug 2015 11:34:19 -0700
Subject: [PATCH 2/3] change to use Externalizable

---
 .../apache/spark/unsafe/types/UTF8String.java  | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java b/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
index 71d4c5cb67344..12ad6a7c3746e 100644
--- a/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
+++ b/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
@@ -37,8 +37,9 @@
  * <p>
  * Note: This is not designed for general use cases, should not be used outside SQL.
  */
-public final class UTF8String implements Comparable<UTF8String>, Serializable {
+public final class UTF8String implements Comparable<UTF8String>, Externalizable {
 
+  // These are only updated by readExternal()
   @Nonnull
   private Object base;
   private long offset;
@@ -126,6 +127,11 @@ protected UTF8String(Object base, long offset, int numBytes) {
     this.numBytes = numBytes;
   }
 
+  // for serialization
+  public UTF8String() {
+    this(null, 0, 0);
+  }
+
   /**
    * Writes the content of this string into a memory address, identified by an object and an offset.
    * The target memory address must already been allocated, and have enough space to hold all the
@@ -978,15 +984,17 @@ public UTF8String soundex() {
     return UTF8String.fromBytes(sx);
   }
 
-  private static final long serialVersionUID = 42L;
-
-  private void writeObject(ObjectOutputStream out) throws IOException {
+  public void writeExternal(ObjectOutput out) throws IOException {
     byte[] bytes = getBytes();
     out.writeInt(bytes.length);
     out.write(bytes);
   }
 
-  private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
+  static {
+
+  }
+
+  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
     offset = BYTE_ARRAY_OFFSET;
     numBytes = in.readInt();
     base = new byte[numBytes];

From e677bc3a81f6f5c5e883017f879f3e58711cf9dc Mon Sep 17 00:00:00 2001
From: Davies Liu <davies@databricks.com>
Date: Fri, 14 Aug 2015 12:33:40 -0700
Subject: [PATCH 3/3] Update UTF8String.java

---
 .../main/java/org/apache/spark/unsafe/types/UTF8String.java   | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java b/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
index 12ad6a7c3746e..cbcab958c05a9 100644
--- a/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
+++ b/unsafe/src/main/java/org/apache/spark/unsafe/types/UTF8String.java
@@ -990,10 +990,6 @@ public void writeExternal(ObjectOutput out) throws IOException {
     out.write(bytes);
   }
 
-  static {
-
-  }
-
   public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
     offset = BYTE_ARRAY_OFFSET;
     numBytes = in.readInt();