ARROW-9: Replace straggler references to Drill

- Renaming drill to arrow for TestBaseAllocator
- Fix ArrowBuffer as ArrowBuf
- Replace Drill with Arrow for ValueHolder

This closes #2.

Author: lw-lin

java/memory/src/main/java/io/netty/buffer/ArrowBuf.java

@@ -56,7 +56,7 @@ public final class ArrowBuf extends AbstractByteBuf implements AutoCloseable {
   private final boolean isEmpty;
   private volatile int length;
   private final HistoricalLog historicalLog = BaseAllocator.DEBUG ?
-      new HistoricalLog(BaseAllocator.DEBUG_LOG_LENGTH, "DrillBuf[%d]", id) : null;
+      new HistoricalLog(BaseAllocator.DEBUG_LOG_LENGTH, "ArrowBuf[%d]", id) : null;
 
   public ArrowBuf(
       final AtomicInteger refCnt,
@@ -155,18 +155,18 @@ private void ensure(int width) {
   }
 
   /**
-   * Create a new DrillBuf that is associated with an alternative allocator for the purposes of memory ownership and
-   * accounting. This has no impact on the reference counting for the current DrillBuf except in the situation where the
+   * Create a new ArrowBuf that is associated with an alternative allocator for the purposes of memory ownership and
+   * accounting. This has no impact on the reference counting for the current ArrowBuf except in the situation where the
    * passed in Allocator is the same as the current buffer.
    *
-   * This operation has no impact on the reference count of this DrillBuf. The newly created DrillBuf with either have a
+   * This operation has no impact on the reference count of this ArrowBuf. The newly created ArrowBuf with either have a
    * reference count of 1 (in the case that this is the first time this memory is being associated with the new
    * allocator) or the current value of the reference count + 1 for the other AllocationManager/BufferLedger combination
    * in the case that the provided allocator already had an association to this underlying memory.
    *
    * @param target
    *          The target allocator to create an association with.
-   * @return A new DrillBuf which shares the same underlying memory as this DrillBuf.
+   * @return A new ArrowBuf which shares the same underlying memory as this ArrowBuf.
    */
   public ArrowBuf retain(BufferAllocator target) {
 
@@ -178,17 +178,17 @@ public ArrowBuf retain(BufferAllocator target) {
       historicalLog.recordEvent("retain(%s)", target.getName());
     }
     final BufferLedger otherLedger = this.ledger.getLedgerForAllocator(target);
-    return otherLedger.newDrillBuf(offset, length, null);
+    return otherLedger.newArrowBuf(offset, length, null);
   }
 
   /**
-   * Transfer the memory accounting ownership of this DrillBuf to another allocator. This will generate a new DrillBuf
-   * that carries an association with the underlying memory of this DrillBuf. If this DrillBuf is connected to the
+   * Transfer the memory accounting ownership of this ArrowBuf to another allocator. This will generate a new ArrowBuf
+   * that carries an association with the underlying memory of this ArrowBuf. If this ArrowBuf is connected to the
    * owning BufferLedger of this memory, that memory ownership/accounting will be transferred to the taret allocator. If
-   * this DrillBuf does not currently own the memory underlying it (and is only associated with it), this does not
-   * transfer any ownership to the newly created DrillBuf.
+   * this ArrowBuf does not currently own the memory underlying it (and is only associated with it), this does not
+   * transfer any ownership to the newly created ArrowBuf.
    *
-   * This operation has no impact on the reference count of this DrillBuf. The newly created DrillBuf with either have a
+   * This operation has no impact on the reference count of this ArrowBuf. The newly created ArrowBuf with either have a
    * reference count of 1 (in the case that this is the first time this memory is being associated with the new
    * allocator) or the current value of the reference count for the other AllocationManager/BufferLedger combination in
    * the case that the provided allocator already had an association to this underlying memory.
@@ -203,7 +203,7 @@ public ArrowBuf retain(BufferAllocator target) {
    * @param target
    *          The allocator to transfer ownership to.
    * @return A new transfer result with the impact of the transfer (whether it was overlimit) as well as the newly
-   *         created DrillBuf.
+   *         created ArrowBuf.
    */
   public TransferResult transferOwnership(BufferAllocator target) {
 
@@ -212,7 +212,7 @@ public TransferResult transferOwnership(BufferAllocator target) {
     }
 
     final BufferLedger otherLedger = this.ledger.getLedgerForAllocator(target);
-    final ArrowBuf newBuf = otherLedger.newDrillBuf(offset, length, null);
+    final ArrowBuf newBuf = otherLedger.newArrowBuf(offset, length, null);
     final boolean allocationFit = this.ledger.transferBalance(otherLedger);
     return new TransferResult(allocationFit, newBuf);
   }
@@ -267,7 +267,7 @@ public boolean release(int decrement) {
 
     if (refCnt < 0) {
       throw new IllegalStateException(
-          String.format("DrillBuf[%d] refCnt has gone negative. Buffer Info: %s", id, toVerboseString()));
+          String.format("ArrowBuf[%d] refCnt has gone negative. Buffer Info: %s", id, toVerboseString()));
     }
 
     return refCnt == 0;
@@ -370,7 +370,7 @@ public ArrowBuf slice(int index, int length) {
      * Re the behavior of reference counting, see http://netty.io/wiki/reference-counted-objects.html#wiki-h3-5, which
      * explains that derived buffers share their reference count with their parent
      */
-    final ArrowBuf newBuf = ledger.newDrillBuf(offset + index, length);
+    final ArrowBuf newBuf = ledger.newArrowBuf(offset + index, length);
     newBuf.writerIndex(length);
     return newBuf;
   }
@@ -437,7 +437,7 @@ public long memoryAddress() {
 
   @Override
   public String toString() {
-    return String.format("DrillBuf[%d], udle: [%d %d..%d]", id, udle.id, offset, offset + capacity());
+    return String.format("ArrowBuf[%d], udle: [%d %d..%d]", id, udle.id, offset, offset + capacity());
   }
 
   @Override
@@ -782,7 +782,7 @@ public void close() {
   }
 
   /**
-   * Returns the possible memory consumed by this DrillBuf in the worse case scenario. (not shared, connected to larger
+   * Returns the possible memory consumed by this ArrowBuf in the worse case scenario. (not shared, connected to larger
    * underlying buffer of allocated memory)
    *
    * @return Size in bytes.
@@ -833,7 +833,7 @@ public String toHexString(final int start, final int length) {
   }
 
   /**
-   * Get the integer id assigned to this DrillBuf for debugging purposes.
+   * Get the integer id assigned to this ArrowBuf for debugging purposes.
    *
    * @return integer id
    */

java/memory/src/main/java/io/netty/buffer/ExpandableByteBuf.java

@@ -20,7 +20,7 @@
 import org.apache.arrow.memory.BufferAllocator;
 
 /**
- * Allows us to decorate DrillBuf to make it expandable so that we can use them in the context of the Netty framework
+ * Allows us to decorate ArrowBuf to make it expandable so that we can use them in the context of the Netty framework
  * (thus supporting RPC level memory accounting).
  */
 public class ExpandableByteBuf extends MutableWrappedByteBuf {

java/memory/src/main/java/io/netty/buffer/PooledByteBufAllocatorL.java

@@ -32,7 +32,7 @@
 import com.codahale.metrics.MetricRegistry;
 
 /**
- * The base allocator that we use for all of Drill's memory management. Returns UnsafeDirectLittleEndian buffers.
+ * The base allocator that we use for all of Arrow's memory management. Returns UnsafeDirectLittleEndian buffers.
  */
 public class PooledByteBufAllocatorL {
   private static final org.slf4j.Logger memoryLogger = org.slf4j.LoggerFactory.getLogger("drill.allocator");
@@ -184,7 +184,7 @@ private UnsafeDirectLittleEndian newDirectBufferL(int initialCapacity, int maxCa
 
     private UnsupportedOperationException fail() {
       return new UnsupportedOperationException(
-          "Drill requries that the JVM used supports access sun.misc.Unsafe.  This platform didn't provide that functionality.");
+          "Arrow requries that the JVM used supports access sun.misc.Unsafe.  This platform didn't provide that functionality.");
     }
 
     public UnsafeDirectLittleEndian directBuffer(int initialCapacity, int maxCapacity) {
@@ -197,7 +197,7 @@ public UnsafeDirectLittleEndian directBuffer(int initialCapacity, int maxCapacit
 
     @Override
     public ByteBuf heapBuffer(int initialCapacity, int maxCapacity) {
-      throw new UnsupportedOperationException("Drill doesn't support using heap buffers.");
+      throw new UnsupportedOperationException("Arrow doesn't support using heap buffers.");
     }
 
 

java/memory/src/main/java/io/netty/buffer/UnsafeDirectLittleEndian.java

@@ -24,7 +24,7 @@
 import java.util.concurrent.atomic.AtomicLong;
 
 /**
- * The underlying class we use for little-endian access to memory. Is used underneath DrillBufs to abstract away the
+ * The underlying class we use for little-endian access to memory. Is used underneath ArrowBufs to abstract away the
  * Netty classes and underlying Netty memory management.
  */
 public final class UnsafeDirectLittleEndian extends WrappedByteBuf {
@@ -55,7 +55,7 @@ public final class UnsafeDirectLittleEndian extends WrappedByteBuf {
   private UnsafeDirectLittleEndian(AbstractByteBuf buf, boolean fake, AtomicLong bufferCount, AtomicLong bufferSize) {
     super(buf);
     if (!NATIVE_ORDER || buf.order() != ByteOrder.BIG_ENDIAN) {
-      throw new IllegalStateException("Drill only runs on LittleEndian systems.");
+      throw new IllegalStateException("Arrow only runs on LittleEndian systems.");
     }
 
     this.bufferCount = bufferCount;

java/memory/src/main/java/org/apache/arrow/memory/AllocationManager.java

@@ -41,7 +41,7 @@
  * This class is also responsible for managing when memory is allocated and returned to the Netty-based
  * PooledByteBufAllocatorL.
  *
- * The only reason that this isn't package private is we're forced to put DrillBuf in Netty's package which need access
+ * The only reason that this isn't package private is we're forced to put ArrowBuf in Netty's package which need access
  * to these objects or methods.
  *
  * Threading: AllocationManager manages thread-safety internally. Operations within the context of a single BufferLedger
@@ -185,8 +185,8 @@ public void release() {
 
   /**
    * The reference manager that binds an allocator manager to a particular BaseAllocator. Also responsible for creating
-   * a set of DrillBufs that share a common fate and set of reference counts.
-   * As with AllocationManager, the only reason this is public is due to DrillBuf being in io.netty.buffer package.
+   * a set of ArrowBufs that share a common fate and set of reference counts.
+   * As with AllocationManager, the only reason this is public is due to ArrowBuf being in io.netty.buffer package.
    */
   public class BufferLedger {
 
@@ -322,7 +322,7 @@ public int decrement(int decrement) {
     /**
      * Returns the ledger associated with a particular BufferAllocator. If the BufferAllocator doesn't currently have a
      * ledger associated with this AllocationManager, a new one is created. This is placed on BufferLedger rather than
-     * AllocationManager directly because DrillBufs don't have access to AllocationManager and they are the ones
+     * AllocationManager directly because ArrowBufs don't have access to AllocationManager and they are the ones
      * responsible for exposing the ability to associate multiple allocators with a particular piece of underlying
      * memory. Note that this will increment the reference count of this ledger by one to ensure the ledger isn't
      * destroyed before use.
@@ -335,32 +335,32 @@ public BufferLedger getLedgerForAllocator(BufferAllocator allocator) {
     }
 
     /**
-     * Create a new DrillBuf associated with this AllocationManager and memory. Does not impact reference count.
+     * Create a new ArrowBuf associated with this AllocationManager and memory. Does not impact reference count.
      * Typically used for slicing.
      * @param offset
-     *          The offset in bytes to start this new DrillBuf.
+     *          The offset in bytes to start this new ArrowBuf.
      * @param length
-     *          The length in bytes that this DrillBuf will provide access to.
-     * @return A new DrillBuf that shares references with all DrillBufs associated with this BufferLedger
+     *          The length in bytes that this ArrowBuf will provide access to.
+     * @return A new ArrowBuf that shares references with all ArrowBufs associated with this BufferLedger
      */
-    public ArrowBuf newDrillBuf(int offset, int length) {
+    public ArrowBuf newArrowBuf(int offset, int length) {
       allocator.assertOpen();
-      return newDrillBuf(offset, length, null);
+      return newArrowBuf(offset, length, null);
     }
 
     /**
-     * Create a new DrillBuf associated with this AllocationManager and memory.
+     * Create a new ArrowBuf associated with this AllocationManager and memory.
      * @param offset
-     *          The offset in bytes to start this new DrillBuf.
+     *          The offset in bytes to start this new ArrowBuf.
      * @param length
-     *          The length in bytes that this DrillBuf will provide access to.
+     *          The length in bytes that this ArrowBuf will provide access to.
      * @param manager
-     *          An optional BufferManager argument that can be used to manage expansion of this DrillBuf
+     *          An optional BufferManager argument that can be used to manage expansion of this ArrowBuf
      * @param retain
      *          Whether or not the newly created buffer should get an additional reference count added to it.
-     * @return A new DrillBuf that shares references with all DrillBufs associated with this BufferLedger
+     * @return A new ArrowBuf that shares references with all ArrowBufs associated with this BufferLedger
      */
-    public ArrowBuf newDrillBuf(int offset, int length, BufferManager manager) {
+    public ArrowBuf newArrowBuf(int offset, int length, BufferManager manager) {
       allocator.assertOpen();
 
       final ArrowBuf buf = new ArrowBuf(
@@ -375,7 +375,7 @@ public ArrowBuf newDrillBuf(int offset, int length, BufferManager manager) {
 
       if (BaseAllocator.DEBUG) {
         historicalLog.recordEvent(
-            "DrillBuf(BufferLedger, BufferAllocator[%s], UnsafeDirectLittleEndian[identityHashCode == "
+            "ArrowBuf(BufferLedger, BufferAllocator[%s], UnsafeDirectLittleEndian[identityHashCode == "
                 + "%d](%s)) => ledger hc == %d",
             allocator.name, System.identityHashCode(buf), buf.toString(),
             System.identityHashCode(this));

java/memory/src/main/java/org/apache/arrow/memory/DrillByteBufAllocator.java java/memory/src/main/java/org/apache/arrow/memory/ArrowByteBufAllocator.java

@@ -23,19 +23,19 @@
 import io.netty.buffer.ExpandableByteBuf;
 
 /**
- * An implementation of ByteBufAllocator that wraps a Drill BufferAllocator. This allows the RPC layer to be accounted
- * and managed using Drill's BufferAllocator infrastructure. The only thin different from a typical BufferAllocator is
+ * An implementation of ByteBufAllocator that wraps a Arrow BufferAllocator. This allows the RPC layer to be accounted
+ * and managed using Arrow's BufferAllocator infrastructure. The only thin different from a typical BufferAllocator is
  * the signature and the fact that this Allocator returns ExpandableByteBufs which enable otherwise non-expandable
- * DrillBufs to be expandable.
+ * ArrowBufs to be expandable.
  */
-public class DrillByteBufAllocator implements ByteBufAllocator {
+public class ArrowByteBufAllocator implements ByteBufAllocator {
 
   private static final int DEFAULT_BUFFER_SIZE = 4096;
   private static final int DEFAULT_MAX_COMPOSITE_COMPONENTS = 16;
 
   private final BufferAllocator allocator;
 
-  public DrillByteBufAllocator(BufferAllocator allocator) {
+  public ArrowByteBufAllocator(BufferAllocator allocator) {
     this.allocator = allocator;
   }
 

java/memory/src/main/java/org/apache/arrow/memory/BaseAllocator.java

@@ -82,7 +82,7 @@ protected BaseAllocator(
     this.parentAllocator = parentAllocator;
     this.name = name;
 
-    this.thisAsByteBufAllocator = new DrillByteBufAllocator(this);
+    this.thisAsByteBufAllocator = new ArrowByteBufAllocator(this);
 
     if (DEBUG) {
       childAllocators = new IdentityHashMap<>();
@@ -236,7 +236,7 @@ private ArrowBuf bufferWithoutReservation(final int size, BufferManager bufferMa
 
     final AllocationManager manager = new AllocationManager(this, size);
     final BufferLedger ledger = manager.associate(this); // +1 ref cnt (required)
-    final ArrowBuf buffer = ledger.newDrillBuf(0, size, bufferManager);
+    final ArrowBuf buffer = ledger.newArrowBuf(0, size, bufferManager);
 
     // make sure that our allocation is equal to what we expected.
     Preconditions.checkArgument(buffer.capacity() == size,
@@ -314,9 +314,9 @@ public ArrowBuf allocateBuffer() {
       Preconditions.checkState(!closed, "Attempt to allocate after closed");
       Preconditions.checkState(!used, "Attempt to allocate more than once");
 
-      final ArrowBuf drillBuf = allocate(nBytes);
+      final ArrowBuf arrowBuf = allocate(nBytes);
       used = true;
-      return drillBuf;
+      return arrowBuf;
     }
 
     public int getSize() {
@@ -397,13 +397,13 @@ private ArrowBuf allocate(int nBytes) {
        * as well, so we need to return the same number back to avoid double-counting them.
        */
       try {
-        final ArrowBuf drillBuf = BaseAllocator.this.bufferWithoutReservation(nBytes, null);
+        final ArrowBuf arrowBuf = BaseAllocator.this.bufferWithoutReservation(nBytes, null);
 
         if (DEBUG) {
-          historicalLog.recordEvent("allocate() => %s", String.format("DrillBuf[%d]", drillBuf.getId()));
+          historicalLog.recordEvent("allocate() => %s", String.format("ArrowBuf[%d]", arrowBuf.getId()));
         }
         success = true;
-        return drillBuf;
+        return arrowBuf;
       } finally {
         if (!success) {
           releaseBytes(nBytes);
@@ -565,7 +565,7 @@ void verifyAllocator() {
    * Verifies the accounting state of the allocator. Only works for DEBUG.
    *
    * <p>
-   * This overload is used for recursive calls, allowing for checking that DrillBufs are unique across all allocators
+   * This overload is used for recursive calls, allowing for checking that ArrowBufs are unique across all allocators
    * that are checked.
    * </p>
    *
@@ -594,7 +594,7 @@ private void verifyAllocator(final IdentityHashMap<UnsafeDirectLittleEndian, Bas
        * Verify my relationships with my descendants.
        *
        * The sum of direct child allocators' owned memory must be <= my allocated memory; my allocated memory also
-       * includes DrillBuf's directly allocated by me.
+       * includes ArrowBuf's directly allocated by me.
        */
       long childTotal = 0;
       for (final BaseAllocator childAllocator : childSet) {
@@ -623,11 +623,11 @@ private void verifyAllocator(final IdentityHashMap<UnsafeDirectLittleEndian, Bas
 
         final UnsafeDirectLittleEndian udle = ledger.getUnderlying();
         /*
-         * Even when shared, DrillBufs are rewrapped, so we should never see the same instance twice.
+         * Even when shared, ArrowBufs are rewrapped, so we should never see the same instance twice.
          */
         final BaseAllocator otherOwner = buffersSeen.get(udle);
         if (otherOwner != null) {
-          throw new IllegalStateException("This allocator's drillBuf already owned by another allocator");
+          throw new IllegalStateException("This allocator's ArrowBuf already owned by another allocator");
         }
         buffersSeen.put(udle, this);
 

java/memory/src/main/java/org/apache/arrow/memory/BufferAllocator.java

@@ -30,7 +30,7 @@ public interface BufferAllocator extends AutoCloseable {
    *
    * @param size
    *          The size in bytes.
-   * @return a new DrillBuf, or null if the request can't be satisfied
+   * @return a new ArrowBuf, or null if the request can't be satisfied
    * @throws OutOfMemoryException
    *           if buffer cannot be allocated
    */
@@ -44,7 +44,7 @@ public interface BufferAllocator extends AutoCloseable {
    *          The size in bytes.
    * @param manager
    *          A buffer manager to manage reallocation.
-   * @return a new DrillBuf, or null if the request can't be satisfied
+   * @return a new ArrowBuf, or null if the request can't be satisfied
    * @throws OutOfMemoryException
    *           if buffer cannot be allocated
    */