HBASE-11424 Avoid usage of CellUtil#getTagArray(Cell cell) within server. (Anoop)

hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/ProtobufUtil.java

@@ -1108,7 +1108,8 @@ public final class ProtobufUtil {
             kv.getValueArray(), kv.getValueOffset(), kv.getValueLength()));
         valueBuilder.setTimestamp(kv.getTimestamp());
         if(cell.getTagsLength() > 0) {
-          valueBuilder.setTags(ByteString.copyFrom(CellUtil.getTagArray(kv)));
+          valueBuilder.setTags(HBaseZeroCopyByteString.wrap(kv.getTagsArray(), kv.getTagsOffset(),
+              kv.getTagsLength()));
         }
         if (type == MutationType.DELETE) {
           KeyValue.Type keyValueType = KeyValue.Type.codeToType(kv.getType());

hbase-common/src/main/java/org/apache/hadoop/hbase/CellUtil.java

@@ -83,6 +83,13 @@ public final class CellUtil {
     return output;
   }
 
+  /**
+   * Returns tag value in a new byte array. If server-side, use
+   * {@link Tag#getBuffer()} with appropriate {@link Tag#getTagOffset()} and
+   * {@link Tag#getTagLength()} instead to save on allocations.
+   * @param cell
+   * @return tag value in a new byte array.
+   */
   public static byte[] getTagArray(Cell cell){
     byte[] output = new byte[cell.getTagsLength()];
     copyTagTo(cell, output, 0);

hbase-common/src/main/java/org/apache/hadoop/hbase/Tag.java

@@ -130,6 +130,13 @@ public class Tag {
     return this.offset + INFRASTRUCTURE_SIZE;
   }
 
+  /**
+   * Returns tag value in a new byte array.
+   * Primarily for use client-side. If server-side, use
+   * {@link #getBuffer()} with appropriate {@link #getTagOffset()} and {@link #getTagLength()}
+   * instead to save on allocations.
+   * @return tag value in a new byte array.
+   */
   public byte[] getValue() {
     int tagLength = getTagLength();
     byte[] tag = new byte[tagLength];

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessControlLists.java

@@ -685,8 +685,8 @@ public class AccessControlLists {
    public static List<Permission> getCellPermissionsForUser(User user, Cell cell)
        throws IOException {
      List<Permission> results = Lists.newArrayList();
-     byte[] tags = CellUtil.getTagArray(cell);
+     Iterator<Tag> tagsIterator = CellUtil.tagsIterator(cell.getTagsArray(), cell.getTagsOffset(),
-     Iterator<Tag> tagsIterator = CellUtil.tagsIterator(tags, 0, tags.length);
+        cell.getTagsLength());
      while (tagsIterator.hasNext()) {
        Tag tag = tagsIterator.next();
        if (tag.getType() == ACL_TAG_TYPE) {

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java

@@ -88,7 +88,6 @@ import org.apache.hadoop.hbase.regionserver.MiniBatchOperationInProgress;
 import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.regionserver.ScanType;
 import org.apache.hadoop.hbase.regionserver.Store;
-import org.apache.hadoop.hbase.regionserver.StoreFile;
 import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
 import org.apache.hadoop.hbase.security.AccessDeniedException;
 import org.apache.hadoop.hbase.security.User;
@@ -753,8 +752,8 @@ public class AccessController extends BaseRegionObserver
       List<Cell> newCells = Lists.newArrayList();
       for (Cell cell: e.getValue()) {
         List<Tag> tags = Lists.newArrayList(new Tag(AccessControlLists.ACL_TAG_TYPE, perms));
-        byte[] tagBytes = CellUtil.getTagArray(cell);
+        Iterator<Tag> tagIterator = CellUtil.tagsIterator(cell.getTagsArray(),
-        Iterator<Tag> tagIterator = CellUtil.tagsIterator(tagBytes, 0, tagBytes.length);
+            cell.getTagsOffset(), cell.getTagsLength());
         while (tagIterator.hasNext()) {
           tags.add(tagIterator.next());
         }
@@ -1808,14 +1807,14 @@ public class AccessController extends BaseRegionObserver
     List<Tag> tags = Lists.newArrayList();
     ListMultimap<String,Permission> perms = ArrayListMultimap.create();
     if (oldCell != null) {
-      byte[] tagBytes = CellUtil.getTagArray(oldCell);
+      Iterator<Tag> tagIterator = CellUtil.tagsIterator(oldCell.getTagsArray(),
-      Iterator<Tag> tagIterator = CellUtil.tagsIterator(tagBytes, 0, tagBytes.length);
+          oldCell.getTagsOffset(), oldCell.getTagsLength());
       while (tagIterator.hasNext()) {
         Tag tag = tagIterator.next();
         if (tag.getType() != AccessControlLists.ACL_TAG_TYPE) {
           if (LOG.isTraceEnabled()) {
             LOG.trace("Carrying forward tag from " + oldCell + ": type " + tag.getType() +
-              " length " + tag.getValue().length);
+              " length " + tag.getTagLength());
           }
           tags.add(tag);
         } else {