From 9d72ff22218b11d2301aaae6bbf43b1ebe45da91 Mon Sep 17 00:00:00 2001
From: Martin Bednar <mbednar@vendavo.com>
Date: Mon, 22 Oct 2018 10:38:10 +0200
Subject: [PATCH] #63 Fix LObjectArrayLarge allocation

---
 .../src/main/scala/xerial/larray/LArray.scala | 16 ++++----
 .../java/xerial/larray/japi/JLArrayTest.java  | 40 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/larray/src/main/scala/xerial/larray/LArray.scala b/larray/src/main/scala/xerial/larray/LArray.scala
index bc4d1e7..5dccb51 100644
--- a/larray/src/main/scala/xerial/larray/LArray.scala
+++ b/larray/src/main/scala/xerial/larray/LArray.scala
@@ -22,17 +22,17 @@
 
 package xerial.larray
 
-import scala.reflect.ClassTag
+import java.io.{File, FileInputStream, FileOutputStream}
+import java.nio.channels.WritableByteChannel
 import java.nio.{ByteBuffer, ByteOrder}
-import java.nio.channels.{FileChannel, WritableByteChannel}
 
 import sun.nio.ch.DirectBuffer
-import java.io.{File, FileInputStream, FileOutputStream}
-
 import wvlet.log.LogSupport
 import xerial.larray.buffer.{Memory, MemoryAllocator}
 import xerial.larray.mmap.MMapMode
 
+import scala.reflect.ClassTag
+
 
 /**
  * Read-only interface of [[xerial.larray.LArray]]
@@ -1096,15 +1096,15 @@ class LObjectArrayLarge[A: ClassTag](val size: Long) extends LArray[A] {
   /**
    * block size in pow(2, B)
    */
+  private val RESERVED = 3 // Due to JVM limitations
   private val B = 31
-  private val mask = (1L << B) - 1L
+  private val BLOCK_SIZE = ((1L << B) - RESERVED).toInt
 
-  @inline private def index(i: Long): Int = (i >>> B).toInt
+  @inline private def index(i: Long): Int = ((i + RESERVED) >>> B).toInt
 
-  @inline private def offset(i: Long): Int = (i & mask).toInt
+  @inline private def offset(i: Long): Int = (i - (index(i)) * BLOCK_SIZE).toInt
 
   private var array: Array[Array[A]] = {
-    val BLOCK_SIZE = (1L << B).toInt
     val NUM_BLOCKS = index(size - 1) + 1
     // initialize the array
     val a = new Array[Array[A]](NUM_BLOCKS)
diff --git a/larray/src/test/java/xerial/larray/japi/JLArrayTest.java b/larray/src/test/java/xerial/larray/japi/JLArrayTest.java
index c3ab01b..ee03e61 100644
--- a/larray/src/test/java/xerial/larray/japi/JLArrayTest.java
+++ b/larray/src/test/java/xerial/larray/japi/JLArrayTest.java
@@ -15,11 +15,15 @@
  *--------------------------------------------------------------------------*/
 package xerial.larray.japi;
 
-import junit.framework.Assert;
 import org.junit.Test;
+import scala.reflect.ClassTag;
+import xerial.larray.LArray;
 import xerial.larray.LIntArray;
+import xerial.larray.LObjectArray;
 import xerial.larray.util.Logger;
 
+import static org.junit.Assert.assertEquals;
+
 /**
  * @author Taro L. Saito
  */
@@ -36,8 +40,40 @@ public void constructor() {
         for (long i = 0; i < l.size(); ++i) l.update(i, (int) (i * i));
         _logger.debug(l.mkString(", "));
 
-        Assert.assertEquals(5L, l.size());
+        assertEquals(5L, l.size());
 
         l.free();
     }
+
+    @Test
+    public void testLObjectArray32() {
+
+        ClassTag<String> classTag = scala.reflect.ClassTag$.MODULE$.apply(String.class);
+        LArray<String> lObjectArray = LObjectArray.ofDim(10, classTag);
+
+        lObjectArray.update(0, "FOO");
+        lObjectArray.update(9, "BAR");
+
+        assertEquals(lObjectArray.apply(0), "FOO");
+        assertEquals(lObjectArray.apply(9), "BAR");
+        assertEquals(lObjectArray.size(), 10);
+
+    }
+
+    @Test
+    public void testLObjectArrayLarge() {
+
+        ClassTag<String> classTag = scala.reflect.ClassTag$.MODULE$.apply(String.class);
+        long oneMoreThanInt = (1L << 31) + 1; //2147483649L
+        LArray<String> lObjectArray = LObjectArray.ofDim(oneMoreThanInt, classTag);
+
+        lObjectArray.update(oneMoreThanInt - 2, "0,2147483644");
+        lObjectArray.update(oneMoreThanInt - 1, "0,0");
+
+        assertEquals("0,2147483644", lObjectArray.apply(oneMoreThanInt - 2));
+        assertEquals("0,0", lObjectArray.apply(oneMoreThanInt - 1));
+
+        assertEquals(oneMoreThanInt, lObjectArray.size());
+
+    }
 }