HBASE-19092 Make Tag IA.LimitedPrivate and expose for CPs (Ram)

Signed-off-by: Chia-ping Tsai, Anoop Sam John, Stack

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Mutation.java

@@ -34,11 +34,9 @@ import org.apache.hadoop.hbase.CellScannable;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.io.HeapSize;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
@@ -48,14 +46,14 @@ import org.apache.hadoop.hbase.security.access.AccessControlUtil;
 import org.apache.hadoop.hbase.security.access.Permission;
 import org.apache.hadoop.hbase.security.visibility.CellVisibility;
 import org.apache.hadoop.hbase.security.visibility.VisibilityConstants;
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.hbase.util.ClassSize;
-
 import org.apache.hadoop.hbase.shaded.com.google.common.collect.ArrayListMultimap;
 import org.apache.hadoop.hbase.shaded.com.google.common.collect.ListMultimap;
 import org.apache.hadoop.hbase.shaded.com.google.common.io.ByteArrayDataInput;
 import org.apache.hadoop.hbase.shaded.com.google.common.io.ByteArrayDataOutput;
 import org.apache.hadoop.hbase.shaded.com.google.common.io.ByteStreams;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.ClassSize;
+import org.apache.yetus.audience.InterfaceAudience;
 
 @InterfaceAudience.Public
 public abstract class Mutation extends OperationWithAttributes implements Row, CellScannable,
@@ -230,7 +228,8 @@ public abstract class Mutation extends OperationWithAttributes implements Row, C
     if (tags != null) {
       List<String> tagsString = new ArrayList<>(tags.size());
       for (Tag t : tags) {
-        tagsString.add((t.getType()) + ":" + Bytes.toStringBinary(TagUtil.cloneValue(t)));
+        tagsString
+            .add((t.getType()) + ":" + Bytes.toStringBinary(Tag.cloneValue(t)));
       }
       stringMap.put("tag", tagsString);
     }

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

@@ -30,7 +30,6 @@ import java.util.NavigableSet;
 import java.util.function.Function;
 
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.CacheEvictionStats;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.CellScanner;
@@ -46,7 +45,6 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagUtil;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.Consistency;
 import org.apache.hadoop.hbase.client.Delete;
@@ -92,6 +90,7 @@ import org.apache.hadoop.hbase.util.DynamicClassLoader;
 import org.apache.hadoop.hbase.util.ExceptionUtil;
 import org.apache.hadoop.hbase.util.Methods;
 import org.apache.hadoop.ipc.RemoteException;
+import org.apache.yetus.audience.InterfaceAudience;
 
 import com.google.protobuf.ByteString;
 import com.google.protobuf.CodedInputStream;
@@ -539,7 +538,8 @@ public final class ProtobufUtil {
                       .setTags(allTagsBytes)
                       .build());
             } else {
-              List<Tag> tags = TagUtil.asList(allTagsBytes, 0, (short)allTagsBytes.length);
+              List<Tag> tags =
+                  TagUtil.asList(allTagsBytes, 0, (short) allTagsBytes.length);
               Tag[] tagsArray = new Tag[tags.size()];
               put.addImmutable(family, qualifier, ts, value, tags.toArray(tagsArray));
             }

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

@@ -673,7 +673,8 @@ public final class ProtobufUtil {
                       .setTags(allTagsBytes)
                       .build());
             } else {
-              List<Tag> tags = TagUtil.asList(allTagsBytes, 0, (short)allTagsBytes.length);
+              List<Tag> tags =
+                  TagUtil.asList(allTagsBytes, 0, (short) allTagsBytes.length);
               Tag[] tagsArray = new Tag[tags.size()];
               put.addImmutable(family, qualifier, ts, value, tags.toArray(tagsArray));
             }

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

@@ -184,9 +184,10 @@ public interface Cell {
   /**
    * HBase internally uses 2 bytes to store tags length in Cell.
    * As the tags length is always a non-negative number, to make good use of the sign bit,
-   * the max of tags length is defined as {@link TagUtil#MAX_TAGS_LENGTH}, which is 2 * Short.MAX_VALUE + 1 = 65535.
+   * the max of tags length is defined 2 * Short.MAX_VALUE + 1 = 65535.
    * As a result, the return type is int, because a short is not capable of handling that.
-   * Please note that even if the return type is int, the max tags length is far less than Integer.MAX_VALUE.
+   * Please note that even if the return type is int, the max tags length is far
+   * less than Integer.MAX_VALUE.
    *
    * @return the total length of the tags in the Cell.
    */

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

@@ -18,10 +18,10 @@
 
 package org.apache.hadoop.hbase;
 
-import static org.apache.hadoop.hbase.Tag.TAG_LENGTH_SIZE;
 import static org.apache.hadoop.hbase.KeyValue.COLUMN_FAMILY_DELIMITER;
-import static org.apache.hadoop.hbase.KeyValue.getDelimiter;
 import static org.apache.hadoop.hbase.KeyValue.COLUMN_FAMILY_DELIM_ARRAY;
+import static org.apache.hadoop.hbase.KeyValue.getDelimiter;
+import static org.apache.hadoop.hbase.Tag.TAG_LENGTH_SIZE;
 
 import java.io.DataOutput;
 import java.io.DataOutputStream;
@@ -33,17 +33,16 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map.Entry;
 import java.util.NavigableMap;
+import java.util.Optional;
 
 import org.apache.hadoop.hbase.KeyValue.Type;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.yetus.audience.InterfaceAudience.Private;
-
-import com.google.common.annotations.VisibleForTesting;
-
 import org.apache.hadoop.hbase.io.HeapSize;
+import org.apache.hadoop.hbase.shaded.com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.hbase.util.ByteBufferUtils;
 import org.apache.hadoop.hbase.util.ByteRange;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.apache.yetus.audience.InterfaceAudience.Private;
 
 /**
  * Utility methods helpful for slinging {@link Cell} instances. Some methods below are for internal
@@ -130,6 +129,7 @@ public final class CellUtil {
 
   /**
    * @deprecated As of HBase-2.0. Will be removed in HBase-3.0.
+   *             Use {@link RawCell#cloneTags()}
    */
   @Deprecated
   public static byte[] cloneTags(Cell cell) {
@@ -588,17 +588,21 @@ public final class CellUtil {
   }
 
   /**
+   * Note : Now only CPs can create cell with tags using the CP environment
    * @return A new cell which is having the extra tags also added to it.
    * @deprecated As of HBase-2.0. Will be removed in HBase-3.0.
+   *             Use CP environment to build Cell using {@link ExtendedCellBuilder}
    */
   @Deprecated
   public static Cell createCell(Cell cell, List<Tag> tags) {
-    return createCell(cell, TagUtil.fromList(tags));
+    return createCell(cell, Tag.fromList(tags));
   }
 
   /**
+   * Now only CPs can create cell with tags using the CP environment
    * @return A new cell which is having the extra tags also added to it.
    * @deprecated As of HBase-2.0. Will be removed in HBase-3.0.
+   *             Use CP environment to build Cell using {@link ExtendedCellBuilder}
    */
   @Deprecated
   public static Cell createCell(Cell cell, byte[] tags) {
@@ -609,7 +613,9 @@ public final class CellUtil {
   }
 
   /**
+   * Now only CPs can create cell with tags using the CP environment
    * @deprecated As of HBase-2.0. Will be removed in HBase-3.0.
+   *             Use CP environment to build Cell using {@link ExtendedCellBuilder}
    */
   @Deprecated
   public static Cell createCell(Cell cell, byte[] value, byte[] tags) {
@@ -1063,6 +1069,7 @@ public final class CellUtil {
    * @param cell
    * @return estimate of the heap space
    * @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0.
+   *             Use {@link RawCell#getTags()}
    */
   @Deprecated
   public static long estimatedHeapSizeOf(final Cell cell) {
@@ -1133,31 +1140,17 @@ public final class CellUtil {
    * @param type Type of the Tag to retrieve
    * @return null if there is no tag of the passed in tag type
    * @deprecated As of 2.0.0 and will be removed in HBase-3.0.0
+   *             Use {@link RawCell#getTag(byte)}
    */
   @Deprecated
   public static Tag getTag(Cell cell, byte type) {
-    boolean bufferBacked = cell instanceof ByteBufferCell;
+    Optional<Tag> tag = PrivateCellUtil.getTag(cell, type);
-    int length = cell.getTagsLength();
+    if (tag.isPresent()) {
-    int offset = bufferBacked ? ((ByteBufferCell) cell).getTagsPosition() : cell.getTagsOffset();
+      return tag.get();
-    int pos = offset;
-    while (pos < offset + length) {
-      int tagLen;
-      if (bufferBacked) {
-        ByteBuffer tagsBuffer = ((ByteBufferCell) cell).getTagsByteBuffer();
-        tagLen = ByteBufferUtils.readAsInt(tagsBuffer, pos, TAG_LENGTH_SIZE);
-        if (ByteBufferUtils.toByte(tagsBuffer, pos + TAG_LENGTH_SIZE) == type) {
-          return new ByteBufferTag(tagsBuffer, pos, tagLen + TAG_LENGTH_SIZE);
-        }
     } else {
-        tagLen = Bytes.readAsInt(cell.getTagsArray(), pos, TAG_LENGTH_SIZE);
-        if (cell.getTagsArray()[pos + TAG_LENGTH_SIZE] == type) {
-          return new ArrayBackedTag(cell.getTagsArray(), pos, tagLen + TAG_LENGTH_SIZE);
-        }
-      }
-      pos += TAG_LENGTH_SIZE + tagLen;
-    }
       return null;
     }
+  }
 
   /**
    * Returns true if the first range start1...end1 overlaps with the second range start2...end2,

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

@@ -21,8 +21,8 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.io.HeapSize;
+import org.apache.yetus.audience.InterfaceAudience;
 
 /**
  * Extension to {@link Cell} with server side required functions. Server side Cell implementations
@@ -30,8 +30,8 @@ import org.apache.hadoop.hbase.io.HeapSize;
  * @see SettableSequenceId
  * @see SettableTimestamp
  */
-@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
+@InterfaceAudience.Private
-public interface ExtendedCell extends Cell, SettableSequenceId, SettableTimestamp, HeapSize,
+public interface ExtendedCell extends RawCell, SettableSequenceId, SettableTimestamp, HeapSize,
     Cloneable {
 
   public static int CELL_NOT_BASED_ON_CHUNK = -1;

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

@@ -26,7 +26,7 @@ import org.apache.yetus.audience.InterfaceAudience;
  * Use {@link ExtendedCellBuilderFactory} to get ExtendedCellBuilder instance.
  * TODO: ditto for ByteBufferCell?
  */
-@InterfaceAudience.Private
+@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
 public interface ExtendedCellBuilder extends CellBuilder {
   @Override
   ExtendedCellBuilder setRow(final byte[] row);
@@ -62,8 +62,15 @@ public interface ExtendedCellBuilder extends CellBuilder {
   @Override
   ExtendedCellBuilder clear();
 
+  // TODO : While creating RawCellBuilder allow 'Tag' to be passed instead of byte[]
   ExtendedCellBuilder setTags(final byte[] tags);
+  // TODO : While creating RawCellBuilder allow 'Tag' to be passed instead of byte[]
   ExtendedCellBuilder setTags(final byte[] tags, int tagsOffset, int tagsLength);
 
+  /**
+   * Internal usage. Be careful before you use this while building a cell
+   * @param seqId set the seqId
+   * @return the current ExternalCellBuilder
+   */
   ExtendedCellBuilder setSequenceId(final long seqId);
 }

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

@@ -25,11 +25,24 @@ import org.apache.yetus.audience.InterfaceAudience;
 public final class ExtendedCellBuilderFactory {
 
   public static ExtendedCellBuilder create(CellBuilderType type) {
+    return create(type, true);
+  }
+
+  /**
+   * Allows creating a cell with the given CellBuilderType.
+   * @param type the type of CellBuilder(DEEP_COPY or SHALLOW_COPY).
+   * @param allowSeqIdUpdate if seqId can be updated. CPs are not allowed to update
+   *        the seqId
+   * @return the cell that is created
+   */
+  public static ExtendedCellBuilder create(CellBuilderType type, boolean allowSeqIdUpdate) {
     switch (type) {
       case SHALLOW_COPY:
+        // CPs are not allowed to update seqID and they always use DEEP_COPY. So we have not
+        // passing 'allowSeqIdUpdate' to IndividualBytesFieldCellBuilder
         return new IndividualBytesFieldCellBuilder();
       case DEEP_COPY:
-        return new KeyValueBuilder();
+        return new KeyValueBuilder(allowSeqIdUpdate);
       default:
         throw new UnsupportedOperationException("The type:" + type + " is unsupported");
     }

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

@@ -40,6 +40,12 @@ public abstract class ExtendedCellBuilderImpl implements ExtendedCellBuilder {
   protected byte[] tags = null;
   protected int tagsOffset = 0;
   protected int tagsLength = 0;
+  // Will go away once we do with RawCellBuilder
+  protected boolean allowSeqIdUpdate = false;
+
+  public ExtendedCellBuilderImpl(boolean allowSeqIdUpdate) {
+    this.allowSeqIdUpdate = allowSeqIdUpdate;
+  }
 
   @Override
   public ExtendedCellBuilder setRow(final byte[] row) {
@@ -126,9 +132,12 @@ public abstract class ExtendedCellBuilderImpl implements ExtendedCellBuilder {
 
   @Override
   public ExtendedCellBuilder setSequenceId(final long seqId) {
+    if (allowSeqIdUpdate) {
       this.seqId = seqId;
       return this;
     }
+    throw new UnsupportedOperationException("SeqId cannot be set on this cell");
+  }
 
   private void checkBeforeBuild() {
     if (type == null) {

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

@@ -94,7 +94,7 @@ public class IndividualBytesFieldCell implements ExtendedCell {
     }
 
     // Check tags
-    TagUtil.checkForTagsLength(tagsLength);
+    RawCell.checkForTagsLength(tagsLength);
     checkArrayBounds(row, rOffset, rLength);
     checkArrayBounds(family, fOffset, fLength);
     checkArrayBounds(qualifier, qOffset, qLength);

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

@@ -21,6 +21,15 @@ import org.apache.yetus.audience.InterfaceAudience;
 
 @InterfaceAudience.Private
 class IndividualBytesFieldCellBuilder extends ExtendedCellBuilderImpl {
+
+  public IndividualBytesFieldCellBuilder() {
+    this(true);
+  }
+
+  public IndividualBytesFieldCellBuilder(boolean allowSeqIdUpdate) {
+    super(allowSeqIdUpdate);
+  }
+
   @Override
   public ExtendedCell innerBuild() {
     return new IndividualBytesFieldCell(row, rOffset, rLength,

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

@@ -34,13 +34,12 @@ import java.util.Map;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-import org.apache.yetus.audience.InterfaceAudience;
+import org.apache.hadoop.hbase.shaded.com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.hbase.util.ByteBufferUtils;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.ClassSize;
 import org.apache.hadoop.io.RawComparator;
-
+import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.hadoop.hbase.shaded.com.google.common.annotations.VisibleForTesting;
 /**
  * An HBase Key/Value. This is the fundamental HBase Type.
  * <p>
@@ -766,7 +765,7 @@ public class KeyValue implements ExtendedCell {
     if (qlength > Integer.MAX_VALUE - rlength - flength) {
       throw new IllegalArgumentException("Qualifier > " + Integer.MAX_VALUE);
     }
-    TagUtil.checkForTagsLength(tagsLength);
+    RawCell.checkForTagsLength(tagsLength);
     // Key length
     long longkeylength = getKeyDataStructureSize(rlength, flength, qlength);
     if (longkeylength > Integer.MAX_VALUE) {
@@ -884,7 +883,7 @@ public class KeyValue implements ExtendedCell {
         tagsLength += t.getValueLength() + Tag.INFRASTRUCTURE_SIZE;
       }
     }
-    TagUtil.checkForTagsLength(tagsLength);
+    RawCell.checkForTagsLength(tagsLength);
     int keyLength = (int) getKeyDataStructureSize(rlength, flength, qlength);
     int keyValueLength = (int) getKeyValueDataStructureSize(rlength, flength, qlength, vlength,
         tagsLength);
@@ -918,7 +917,7 @@ public class KeyValue implements ExtendedCell {
         int tlen = t.getValueLength();
         pos = Bytes.putAsShort(buffer, pos, tlen + Tag.TYPE_LENGTH_SIZE);
         pos = Bytes.putByte(buffer, pos, t.getType());
-        TagUtil.copyValueTo(t, buffer, pos);
+        Tag.copyValueTo(t, buffer, pos);
         pos += tlen;
       }
     }
@@ -951,7 +950,7 @@ public class KeyValue implements ExtendedCell {
       int vlength, byte[] tags, int tagsOffset, int tagsLength) {
 
     checkParameters(row, rlength, family, flength, qlength, vlength);
-    TagUtil.checkForTagsLength(tagsLength);
+    RawCell.checkForTagsLength(tagsLength);
     // Allocate right-sized byte array.
     int keyLength = (int) getKeyDataStructureSize(rlength, flength, qlength);
     byte[] bytes = new byte[(int) getKeyValueDataStructureSize(rlength, flength, qlength, vlength,
@@ -1001,7 +1000,7 @@ public class KeyValue implements ExtendedCell {
         tagsLength += t.getValueLength() + Tag.INFRASTRUCTURE_SIZE;
       }
     }
-    TagUtil.checkForTagsLength(tagsLength);
+    RawCell.checkForTagsLength(tagsLength);
     // Allocate right-sized byte array.
     int keyLength = (int) getKeyDataStructureSize(rlength, flength, qlength);
     byte[] bytes = new byte[(int) getKeyValueDataStructureSize(rlength, flength, qlength, vlength,
@@ -1041,7 +1040,7 @@ public class KeyValue implements ExtendedCell {
         int tlen = t.getValueLength();
         pos = Bytes.putAsShort(bytes, pos, tlen + Tag.TYPE_LENGTH_SIZE);
         pos = Bytes.putByte(bytes, pos, t.getType());
-        TagUtil.copyValueTo(t, bytes, pos);
+        Tag.copyValueTo(t, bytes, pos);
         pos += tlen;
       }
     }

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

@@ -21,6 +21,15 @@ import org.apache.yetus.audience.InterfaceAudience;
 
 @InterfaceAudience.Private
 class KeyValueBuilder extends ExtendedCellBuilderImpl {
+
+  KeyValueBuilder() {
+    this(true);
+  }
+
+  KeyValueBuilder(boolean allowSeqIdUpdate) {
+    super(allowSeqIdUpdate);
+  }
+
   @Override
   protected ExtendedCell innerBuild() {
     KeyValue kv = new KeyValue(row, rOffset, rLength,

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

@@ -29,6 +29,7 @@ import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Optional;
 
 import org.apache.hadoop.hbase.KeyValue.Type;
 import org.apache.hadoop.hbase.filter.ByteArrayComparable;
@@ -49,14 +50,12 @@ import com.google.common.annotations.VisibleForTesting;
  * rich set of APIs than those in {@link CellUtil} for internal usage.
  */
 @InterfaceAudience.Private
-// TODO : Make Tag IA.LimitedPrivate and move some of the Util methods to CP exposed Util class
+public final class PrivateCellUtil {
-public class PrivateCellUtil {
 
   /**
    * Private constructor to keep this class from being instantiated.
    */
   private PrivateCellUtil() {
-
   }
 
   /******************* ByteRange *******************************/
@@ -82,64 +81,6 @@ public class PrivateCellUtil {
     return range.set(cell.getTagsArray(), cell.getTagsOffset(), cell.getTagsLength());
   }
 
-  /**
-   * Returns tag value in a new byte array. If server-side, use {@link Tag#getValueArray()} with
-   * appropriate {@link Tag#getValueOffset()} and {@link Tag#getValueLength()} instead to save on
-   * allocations.
-   * @param cell
-   * @return tag value in a new byte array.
-   */
-  public static byte[] getTagsArray(Cell cell) {
-    byte[] output = new byte[cell.getTagsLength()];
-    copyTagsTo(cell, output, 0);
-    return output;
-  }
-
-  public static byte[] cloneTags(Cell cell) {
-    byte[] output = new byte[cell.getTagsLength()];
-    copyTagsTo(cell, output, 0);
-    return output;
-  }
-
-  /**
-   * Copies the tags info into the tag portion of the cell
-   * @param cell
-   * @param destination
-   * @param destinationOffset
-   * @return position after tags
-   */
-  public static int copyTagsTo(Cell cell, byte[] destination, int destinationOffset) {
-    int tlen = cell.getTagsLength();
-    if (cell instanceof ByteBufferCell) {
-      ByteBufferUtils.copyFromBufferToArray(destination,
-        ((ByteBufferCell) cell).getTagsByteBuffer(), ((ByteBufferCell) cell).getTagsPosition(),
-        destinationOffset, tlen);
-    } else {
-      System.arraycopy(cell.getTagsArray(), cell.getTagsOffset(), destination, destinationOffset,
-        tlen);
-    }
-    return destinationOffset + tlen;
-  }
-
-  /**
-   * Copies the tags info into the tag portion of the cell
-   * @param cell
-   * @param destination
-   * @param destinationOffset
-   * @return the position after tags
-   */
-  public static int copyTagsTo(Cell cell, ByteBuffer destination, int destinationOffset) {
-    int tlen = cell.getTagsLength();
-    if (cell instanceof ByteBufferCell) {
-      ByteBufferUtils.copyFromBufferToBuffer(((ByteBufferCell) cell).getTagsByteBuffer(),
-        destination, ((ByteBufferCell) cell).getTagsPosition(), destinationOffset, tlen);
-    } else {
-      ByteBufferUtils.copyFromArrayToBuffer(destination, destinationOffset, cell.getTagsArray(),
-        cell.getTagsOffset(), tlen);
-    }
-    return destinationOffset + tlen;
-  }
-
   /********************* misc *************************************/
 
   public static byte getRowByte(Cell cell, int index) {
@@ -168,7 +109,7 @@ public class PrivateCellUtil {
    * @return A new cell which is having the extra tags also added to it.
    */
   public static Cell createCell(Cell cell, List<Tag> tags) {
-    return createCell(cell, TagUtil.fromList(tags));
+    return createCell(cell, Tag.fromList(tags));
   }
 
   /**
@@ -653,7 +594,9 @@ public class PrivateCellUtil {
       ByteBufferUtils.putInt(out, valLen);// Value length
       int len = 2 * Bytes.SIZEOF_INT;
       len += writeFlatKey(cell, out);// Key
-      if (valLen > 0) out.write(value);// Value
+      if (valLen > 0) {
+        out.write(value);// Value
+      }
       len += valLen;
       if (withTags && tags != null) {
         // Write the tagsLength 2 bytes
@@ -787,7 +730,7 @@ public class PrivateCellUtil {
 
   /**
    * Finds if the qualifier part of the cell and the KV serialized byte[] are equal
-   * @param left
+   * @param left the cell with which we need to match the qualifier
    * @param buf the serialized keyvalue format byte[]
    * @param offset the offset of the qualifier in the byte[]
    * @param length the length of the qualifier in the byte[]
@@ -809,7 +752,9 @@ public class PrivateCellUtil {
 
   public static boolean matchingColumn(final Cell left, final byte[] fam, final int foffset,
       final int flength, final byte[] qual, final int qoffset, final int qlength) {
-    if (!matchingFamily(left, fam, foffset, flength)) return false;
+    if (!matchingFamily(left, fam, foffset, flength)) {
+      return false;
+    }
     return matchingQualifier(left, qual, qoffset, qlength);
   }
 
@@ -878,6 +823,113 @@ public class PrivateCellUtil {
     return t == Type.DeleteColumn.getCode() || t == Type.DeleteFamily.getCode();
   }
 
+  public static byte[] cloneTags(Cell cell) {
+    byte[] output = new byte[cell.getTagsLength()];
+    copyTagsTo(cell, output, 0);
+    return output;
+  }
+
+  /**
+   * Copies the tags info into the tag portion of the cell
+   * @param cell
+   * @param destination
+   * @param destinationOffset
+   * @return position after tags
+   */
+  public static int copyTagsTo(Cell cell, byte[] destination, int destinationOffset) {
+    int tlen = cell.getTagsLength();
+    if (cell instanceof ByteBufferCell) {
+      ByteBufferUtils.copyFromBufferToArray(destination,
+        ((ByteBufferCell) cell).getTagsByteBuffer(), ((ByteBufferCell) cell).getTagsPosition(),
+        destinationOffset, tlen);
+    } else {
+      System.arraycopy(cell.getTagsArray(), cell.getTagsOffset(), destination, destinationOffset,
+        tlen);
+    }
+    return destinationOffset + tlen;
+  }
+
+  /**
+   * Copies the tags info into the tag portion of the cell
+   * @param cell
+   * @param destination
+   * @param destinationOffset
+   * @return the position after tags
+   */
+  public static int copyTagsTo(Cell cell, ByteBuffer destination, int destinationOffset) {
+    int tlen = cell.getTagsLength();
+    if (cell instanceof ByteBufferCell) {
+      ByteBufferUtils.copyFromBufferToBuffer(((ByteBufferCell) cell).getTagsByteBuffer(),
+        destination, ((ByteBufferCell) cell).getTagsPosition(), destinationOffset, tlen);
+    } else {
+      ByteBufferUtils.copyFromArrayToBuffer(destination, destinationOffset, cell.getTagsArray(),
+        cell.getTagsOffset(), tlen);
+    }
+    return destinationOffset + tlen;
+  }
+
+  /**
+   * @param cell The Cell
+   * @return Tags in the given Cell as a List
+   */
+  public static List<Tag> getTags(Cell cell) {
+    List<Tag> tags = new ArrayList<>();
+    Iterator<Tag> tagsItr = tagsIterator(cell);
+    while (tagsItr.hasNext()) {
+      tags.add(tagsItr.next());
+    }
+    return tags;
+  }
+
+  /**
+   * Retrieve Cell's first tag, matching the passed in type
+   * @param cell The Cell
+   * @param type Type of the Tag to retrieve
+   * @return null if there is no tag of the passed in tag type
+   */
+  public static Optional<Tag> getTag(Cell cell, byte type) {
+    boolean bufferBacked = cell instanceof ByteBufferCell;
+    int length = cell.getTagsLength();
+    int offset = bufferBacked ? ((ByteBufferCell) cell).getTagsPosition() : cell.getTagsOffset();
+    int pos = offset;
+    while (pos < offset + length) {
+      int tagLen;
+      if (bufferBacked) {
+        ByteBuffer tagsBuffer = ((ByteBufferCell) cell).getTagsByteBuffer();
+        tagLen = ByteBufferUtils.readAsInt(tagsBuffer, pos, TAG_LENGTH_SIZE);
+        if (ByteBufferUtils.toByte(tagsBuffer, pos + TAG_LENGTH_SIZE) == type) {
+          return Optional.ofNullable(new ByteBufferTag(tagsBuffer, pos, tagLen + TAG_LENGTH_SIZE));
+        }
+      } else {
+        tagLen = Bytes.readAsInt(cell.getTagsArray(), pos, TAG_LENGTH_SIZE);
+        if (cell.getTagsArray()[pos + TAG_LENGTH_SIZE] == type) {
+          return Optional
+              .ofNullable(new ArrayBackedTag(cell.getTagsArray(), pos, tagLen + TAG_LENGTH_SIZE));
+        }
+      }
+      pos += TAG_LENGTH_SIZE + tagLen;
+    }
+    return Optional.ofNullable(null);
+  }
+
+  /**
+   * Util method to iterate through the tags in the given cell.
+   * @param cell The Cell over which tags iterator is needed.
+   * @return iterator for the tags
+   */
+  public static Iterator<Tag> tagsIterator(final Cell cell) {
+    final int tagsLength = cell.getTagsLength();
+    // Save an object allocation where we can
+    if (tagsLength == 0) {
+      return TagUtil.EMPTY_TAGS_ITR;
+    }
+    if (cell instanceof ByteBufferCell) {
+      return tagsIterator(((ByteBufferCell) cell).getTagsByteBuffer(),
+        ((ByteBufferCell) cell).getTagsPosition(), tagsLength);
+    }
+    return CellUtil.tagsIterator(cell.getTagsArray(), cell.getTagsOffset(), cell.getTagsLength());
+  }
+
   private static Iterator<Tag> tagsIterator(final ByteBuffer tags, final int offset,
       final int length) {
     return new Iterator<Tag>() {
@@ -907,95 +959,6 @@ public class PrivateCellUtil {
     };
   }
 
-  /**
-   * Util method to iterate through the tags in the given cell.
-   * @param cell The Cell over which tags iterator is needed.
-   * @return iterator for the tags
-   */
-  public static Iterator<Tag> tagsIterator(final Cell cell) {
-    final int tagsLength = cell.getTagsLength();
-    // Save an object allocation where we can
-    if (tagsLength == 0) {
-      return TagUtil.EMPTY_TAGS_ITR;
-    }
-    if (cell instanceof ByteBufferCell) {
-      return tagsIterator(((ByteBufferCell) cell).getTagsByteBuffer(),
-        ((ByteBufferCell) cell).getTagsPosition(), tagsLength);
-    }
-    return tagsIterator(cell.getTagsArray(), cell.getTagsOffset(), cell.getTagsLength());
-  }
-
-  private static Iterator<Tag> tagsIterator(final byte[] tags, final int offset, final int length) {
-    return new Iterator<Tag>() {
-      private int pos = offset;
-      private int endOffset = offset + length - 1;
-
-      @Override
-      public boolean hasNext() {
-        return this.pos < endOffset;
-      }
-
-      @Override
-      public Tag next() {
-        if (hasNext()) {
-          int curTagLen = Bytes.readAsInt(tags, this.pos, Tag.TAG_LENGTH_SIZE);
-          Tag tag = new ArrayBackedTag(tags, pos, curTagLen + TAG_LENGTH_SIZE);
-          this.pos += Bytes.SIZEOF_SHORT + curTagLen;
-          return tag;
-        }
-        return null;
-      }
-
-      @Override
-      public void remove() {
-        throw new UnsupportedOperationException();
-      }
-    };
-  }
-
-  /**
-   * @param cell The Cell
-   * @return Tags in the given Cell as a List
-   */
-  public static List<Tag> getTags(Cell cell) {
-    List<Tag> tags = new ArrayList<>();
-    Iterator<Tag> tagsItr = tagsIterator(cell);
-    while (tagsItr.hasNext()) {
-      tags.add(tagsItr.next());
-    }
-    return tags;
-  }
-
-  /**
-   * Retrieve Cell's first tag, matching the passed in type
-   * @param cell The Cell
-   * @param type Type of the Tag to retrieve
-   * @return null if there is no tag of the passed in tag type
-   */
-  public static Tag getTag(Cell cell, byte type) {
-    boolean bufferBacked = cell instanceof ByteBufferCell;
-    int length = cell.getTagsLength();
-    int offset = bufferBacked ? ((ByteBufferCell) cell).getTagsPosition() : cell.getTagsOffset();
-    int pos = offset;
-    while (pos < offset + length) {
-      int tagLen;
-      if (bufferBacked) {
-        ByteBuffer tagsBuffer = ((ByteBufferCell) cell).getTagsByteBuffer();
-        tagLen = ByteBufferUtils.readAsInt(tagsBuffer, pos, TAG_LENGTH_SIZE);
-        if (ByteBufferUtils.toByte(tagsBuffer, pos + TAG_LENGTH_SIZE) == type) {
-          return new ByteBufferTag(tagsBuffer, pos, tagLen + TAG_LENGTH_SIZE);
-        }
-      } else {
-        tagLen = Bytes.readAsInt(cell.getTagsArray(), pos, TAG_LENGTH_SIZE);
-        if (cell.getTagsArray()[pos + TAG_LENGTH_SIZE] == type) {
-          return new ArrayBackedTag(cell.getTagsArray(), pos, tagLen + TAG_LENGTH_SIZE);
-        }
-      }
-      pos += TAG_LENGTH_SIZE + tagLen;
-    }
-    return null;
-  }
-
   /**
    * Returns true if the first range start1...end1 overlaps with the second range start2...end2,
    * assuming the byte arrays represent row keys

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

@@ -0,0 +1,68 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase;
+
+import java.util.List;
+import java.util.Optional;
+
+import org.apache.yetus.audience.InterfaceAudience;
+
+/**
+ * An extended version of cell that gives more power to CPs
+ */
+@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
+public interface RawCell extends Cell {
+  static final int MAX_TAGS_LENGTH = (2 * Short.MAX_VALUE) + 1;
+
+  /**
+   * Allows cloning the tags in the cell to a new byte[]
+   * @return the byte[] having the tags
+   */
+  default byte[] cloneTags() {
+    return PrivateCellUtil.cloneTags(this);
+  }
+
+  /**
+   * Creates a list of tags in the current cell
+   * @return a list of tags
+   */
+  default List<Tag> getTags() {
+    return PrivateCellUtil.getTags(this);
+  }
+
+  /**
+   * Returns the specific tag of the given type
+   * @param type the type of the tag
+   * @return the specific tag if available or null
+   */
+  // TODO : Move to individual cell impl
+  default Optional<Tag> getTag(byte type) {
+    return PrivateCellUtil.getTag(this, type);
+  }
+
+  /**
+   * Check the length of tags. If it is invalid, throw IllegalArgumentException
+   * @param tagsLength the given length of tags
+   * @throws IllegalArgumentException if tagslength is invalid
+   */
+  public static void checkForTagsLength(int tagsLength) {
+    if (tagsLength > MAX_TAGS_LENGTH) {
+      throw new IllegalArgumentException("tagslength " + tagsLength + " > " + MAX_TAGS_LENGTH);
+    }
+  }
+}

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

@@ -20,10 +20,12 @@
 package org.apache.hadoop.hbase;
 
 import java.nio.ByteBuffer;
+import java.util.List;
 
+import org.apache.hadoop.hbase.util.ByteBufferUtils;
+import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.yetus.audience.InterfaceStability;
-import org.apache.hadoop.hbase.util.Bytes;
 
 /**
  * Tags are part of cells and helps to add metadata about them.
@@ -33,7 +35,7 @@ import org.apache.hadoop.hbase.util.Bytes;
  * <p>
  * See {@link TagType} for reserved tag types.
  */
-@InterfaceAudience.Private
+@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
 @InterfaceStability.Evolving
 public interface Tag {
 
@@ -42,6 +44,11 @@ public interface Tag {
   public final static int INFRASTRUCTURE_SIZE = TYPE_LENGTH_SIZE + TAG_LENGTH_SIZE;
   public static final int MAX_TAG_LENGTH = (2 * Short.MAX_VALUE) + 1 - TAG_LENGTH_SIZE;
 
+  /**
+   * Custom tags if created are suggested to be above this range. So that
+   * it does not overlap with internal tag types
+   */
+  public static final byte CUSTOM_TAG_TYPE_RANGE = (byte)64;
   /**
    * @return the tag type
    */
@@ -75,4 +82,129 @@ public interface Tag {
    * @return The {@link java.nio.ByteBuffer} containing the value bytes.
    */
   ByteBuffer getValueByteBuffer();
+
+  /**
+   * Returns tag value in a new byte array. Primarily for use client-side. If server-side, use
+   * {@link Tag#getValueArray()} with appropriate {@link Tag#getValueOffset()} and
+   * {@link Tag#getValueLength()} instead to save on allocations.
+   * @param tag The Tag whose value to be returned
+   * @return tag value in a new byte array.
+   */
+  public static byte[] cloneValue(Tag tag) {
+    int tagLength = tag.getValueLength();
+    byte[] tagArr = new byte[tagLength];
+    if (tag.hasArray()) {
+      Bytes.putBytes(tagArr, 0, tag.getValueArray(), tag.getValueOffset(), tagLength);
+    } else {
+      ByteBufferUtils.copyFromBufferToArray(tagArr, tag.getValueByteBuffer(), tag.getValueOffset(),
+        0, tagLength);
+    }
+    return tagArr;
+  }
+
+  /**
+   * Converts the value bytes of the given tag into a String value
+   * @param tag The Tag
+   * @return value as String
+   */
+  public static String getValueAsString(Tag tag) {
+    if (tag.hasArray()) {
+      return Bytes.toString(tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
+    }
+    return Bytes.toString(cloneValue(tag));
+  }
+
+  /**
+   * Matches the value part of given tags
+   * @param t1 Tag to match the value
+   * @param t2 Tag to match the value
+   * @return True if values of both tags are same.
+   */
+  public static boolean matchingValue(Tag t1, Tag t2) {
+    if (t1.hasArray() && t2.hasArray()) {
+      return Bytes.equals(t1.getValueArray(), t1.getValueOffset(), t1.getValueLength(),
+        t2.getValueArray(), t2.getValueOffset(), t2.getValueLength());
+    }
+    if (t1.hasArray()) {
+      return ByteBufferUtils.equals(t2.getValueByteBuffer(), t2.getValueOffset(),
+        t2.getValueLength(), t1.getValueArray(), t1.getValueOffset(), t1.getValueLength());
+    }
+    if (t2.hasArray()) {
+      return ByteBufferUtils.equals(t1.getValueByteBuffer(), t1.getValueOffset(),
+        t1.getValueLength(), t2.getValueArray(), t2.getValueOffset(), t2.getValueLength());
+    }
+    return ByteBufferUtils.equals(t1.getValueByteBuffer(), t1.getValueOffset(), t1.getValueLength(),
+      t2.getValueByteBuffer(), t2.getValueOffset(), t2.getValueLength());
+  }
+
+  /**
+   * Copies the tag's value bytes to the given byte array
+   * @param tag The Tag
+   * @param out The byte array where to copy the Tag value.
+   * @param offset The offset within 'out' array where to copy the Tag value.
+   */
+  public static void copyValueTo(Tag tag, byte[] out, int offset) {
+    if (tag.hasArray()) {
+      Bytes.putBytes(out, offset, tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
+    } else {
+      ByteBufferUtils.copyFromBufferToArray(out, tag.getValueByteBuffer(), tag.getValueOffset(),
+        offset, tag.getValueLength());
+    }
+  }
+
+  /**
+   * Write a list of tags into a byte array
+   * @param tags The list of tags
+   * @return the serialized tag data as bytes
+   */
+  // TODO : Remove this when we move to RawCellBuilder
+  public static byte[] fromList(List<Tag> tags) {
+    if (tags == null || tags.isEmpty()) {
+      return HConstants.EMPTY_BYTE_ARRAY;
+    }
+    int length = 0;
+    for (Tag tag : tags) {
+      length += tag.getValueLength() + Tag.INFRASTRUCTURE_SIZE;
+    }
+    byte[] b = new byte[length];
+    int pos = 0;
+    int tlen;
+    for (Tag tag : tags) {
+      tlen = tag.getValueLength();
+      pos = Bytes.putAsShort(b, pos, tlen + Tag.TYPE_LENGTH_SIZE);
+      pos = Bytes.putByte(b, pos, tag.getType());
+      if (tag.hasArray()) {
+        pos = Bytes.putBytes(b, pos, tag.getValueArray(), tag.getValueOffset(), tlen);
+      } else {
+        ByteBufferUtils.copyFromBufferToArray(b, tag.getValueByteBuffer(), tag.getValueOffset(),
+          pos, tlen);
+        pos += tlen;
+      }
+    }
+    return b;
+  }
+
+  /**
+   * Converts the value bytes of the given tag into a long value
+   * @param tag The Tag
+   * @return value as long
+   */
+  public static long getValueAsLong(Tag tag) {
+    if (tag.hasArray()) {
+      return Bytes.toLong(tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
+    }
+    return ByteBufferUtils.toLong(tag.getValueByteBuffer(), tag.getValueOffset());
+  }
+
+  /**
+   * Converts the value bytes of the given tag into a byte value
+   * @param tag The Tag
+   * @return value as byte
+   */
+  public static byte getValueAsByte(Tag tag) {
+    if (tag.hasArray()) {
+      return tag.getValueArray()[tag.getValueOffset()];
+    }
+    return ByteBufferUtils.toByte(tag.getValueByteBuffer(), tag.getValueOffset());
+  }
 }

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

@@ -17,55 +17,24 @@
  */
 package org.apache.hadoop.hbase;
 
-import static org.apache.hadoop.hbase.Tag.TAG_LENGTH_SIZE;
-
 import java.io.IOException;
-import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.io.util.StreamUtils;
 import org.apache.hadoop.hbase.util.ByteBufferUtils;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.yetus.audience.InterfaceAudience;
 
 @InterfaceAudience.Private
 public final class TagUtil {
 
-  // If you would like to check the length of tags, please call {@link TagUtil#checkForTagsLength()}.
-  private static final int MAX_TAGS_LENGTH = (2 * Short.MAX_VALUE) + 1;
-
-  /**
-   * Private constructor to keep this class from being instantiated.
-   */
   private TagUtil(){}
 
-  /**
-   * Returns tag value in a new byte array.
-   * Primarily for use client-side. If server-side, use
-   * {@link Tag#getValueArray()} with appropriate {@link Tag#getValueOffset()}
-   * and {@link Tag#getValueLength()} instead to save on allocations.
-   *
-   * @param tag The Tag whose value to be returned
-   * @return tag value in a new byte array.
-   */
-  public static byte[] cloneValue(Tag tag) {
-    int tagLength = tag.getValueLength();
-    byte[] tagArr = new byte[tagLength];
-    if (tag.hasArray()) {
-      Bytes.putBytes(tagArr, 0, tag.getValueArray(), tag.getValueOffset(), tagLength);
-    } else {
-      ByteBufferUtils.copyFromBufferToArray(tagArr, tag.getValueByteBuffer(), tag.getValueOffset(),
-          0, tagLength);
-    }
-    return tagArr;
-  }
-
   /**
    * Creates list of tags from given byte array, expected that it is in the expected tag format.
-   *
    * @param b The byte array
    * @param offset The offset in array where tag bytes begin
    * @param length Total length of all tags bytes
@@ -75,138 +44,13 @@ public final class TagUtil {
     List<Tag> tags = new ArrayList<>();
     int pos = offset;
     while (pos < offset + length) {
-      int tagLen = Bytes.readAsInt(b, pos, TAG_LENGTH_SIZE);
+      int tagLen = Bytes.readAsInt(b, pos, Tag.TAG_LENGTH_SIZE);
-      tags.add(new ArrayBackedTag(b, pos, tagLen + TAG_LENGTH_SIZE));
+      tags.add(new ArrayBackedTag(b, pos, tagLen + Tag.TAG_LENGTH_SIZE));
-      pos += TAG_LENGTH_SIZE + tagLen;
+      pos += Tag.TAG_LENGTH_SIZE + tagLen;
     }
     return tags;
   }
 
-  /**
-   * Creates list of tags from given ByteBuffer, expected that it is in the expected tag format.
-   *
-   * @param b The ByteBuffer
-   * @param offset The offset in ByteBuffer where tag bytes begin
-   * @param length Total length of all tags bytes
-   * @return List of tags
-   */
-  public static List<Tag> asList(ByteBuffer b, int offset, int length) {
-    List<Tag> tags = new ArrayList<>();
-    int pos = offset;
-    while (pos < offset + length) {
-      int tagLen = ByteBufferUtils.readAsInt(b, pos, TAG_LENGTH_SIZE);
-      tags.add(new ByteBufferTag(b, pos, tagLen + TAG_LENGTH_SIZE));
-      pos += TAG_LENGTH_SIZE + tagLen;
-    }
-    return tags;
-  }
-
-  /**
-   * Write a list of tags into a byte array
-   *
-   * @param tags The list of tags
-   * @return the serialized tag data as bytes
-   */
-  public static byte[] fromList(List<Tag> tags) {
-    if (tags == null || tags.isEmpty()) {
-      return HConstants.EMPTY_BYTE_ARRAY;
-    }
-    int length = 0;
-    for (Tag tag : tags) {
-      length += tag.getValueLength() + Tag.INFRASTRUCTURE_SIZE;
-    }
-    byte[] b = new byte[length];
-    int pos = 0;
-    int tlen;
-    for (Tag tag : tags) {
-      tlen = tag.getValueLength();
-      pos = Bytes.putAsShort(b, pos, tlen + Tag.TYPE_LENGTH_SIZE);
-      pos = Bytes.putByte(b, pos, tag.getType());
-      if (tag.hasArray()) {
-        pos = Bytes.putBytes(b, pos, tag.getValueArray(), tag.getValueOffset(), tlen);
-      } else {
-        ByteBufferUtils.copyFromBufferToArray(b, tag.getValueByteBuffer(), tag.getValueOffset(),
-            pos, tlen);
-        pos += tlen;
-      }
-    }
-    return b;
-  }
-
-  /**
-   * Converts the value bytes of the given tag into a long value
-   * @param tag The Tag
-   * @return value as long
-   */
-  public static long getValueAsLong(Tag tag) {
-    if (tag.hasArray()) {
-      return Bytes.toLong(tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
-    }
-    return ByteBufferUtils.toLong(tag.getValueByteBuffer(), tag.getValueOffset());
-  }
-
-  /**
-   * Converts the value bytes of the given tag into a byte value
-   * @param tag The Tag
-   * @return value as byte
-   */
-  public static byte getValueAsByte(Tag tag) {
-    if (tag.hasArray()) {
-      return tag.getValueArray()[tag.getValueOffset()];
-    }
-    return ByteBufferUtils.toByte(tag.getValueByteBuffer(), tag.getValueOffset());
-  }
-
-  /**
-   * Converts the value bytes of the given tag into a String value
-   * @param tag The Tag
-   * @return value as String
-   */
-  public static String getValueAsString(Tag tag){
-    if(tag.hasArray()){
-      return Bytes.toString(tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
-    }
-    return Bytes.toString(cloneValue(tag));
-  }
-
-  /**
-   * Matches the value part of given tags
-   * @param t1 Tag to match the value
-   * @param t2 Tag to match the value
-   * @return True if values of both tags are same.
-   */
-  public static boolean matchingValue(Tag t1, Tag t2) {
-    if (t1.hasArray() && t2.hasArray()) {
-      return Bytes.equals(t1.getValueArray(), t1.getValueOffset(), t1.getValueLength(),
-          t2.getValueArray(), t2.getValueOffset(), t2.getValueLength());
-    }
-    if (t1.hasArray()) {
-      return ByteBufferUtils.equals(t2.getValueByteBuffer(), t2.getValueOffset(),
-          t2.getValueLength(), t1.getValueArray(), t1.getValueOffset(), t1.getValueLength());
-    }
-    if (t2.hasArray()) {
-      return ByteBufferUtils.equals(t1.getValueByteBuffer(), t1.getValueOffset(),
-          t1.getValueLength(), t2.getValueArray(), t2.getValueOffset(), t2.getValueLength());
-    }
-    return ByteBufferUtils.equals(t1.getValueByteBuffer(), t1.getValueOffset(), t1.getValueLength(),
-        t2.getValueByteBuffer(), t2.getValueOffset(), t2.getValueLength());
-  }
-
-  /**
-   * Copies the tag's value bytes to the given byte array
-   * @param tag The Tag
-   * @param out The byte array where to copy the Tag value.
-   * @param offset The offset within 'out' array where to copy the Tag value.
-   */
-  public static void copyValueTo(Tag tag, byte[] out, int offset) {
-    if (tag.hasArray()) {
-      Bytes.putBytes(out, offset, tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
-    } else {
-      ByteBufferUtils.copyFromBufferToArray(out, tag.getValueByteBuffer(), tag.getValueOffset(),
-          offset, tag.getValueLength());
-    }
-  }
-
   /**
    * Reads an int value stored as a VInt at tag's given offset.
    * @param tag The Tag
@@ -313,16 +157,4 @@ public final class TagUtil {
       throw new UnsupportedOperationException();
     }
   };
-
-  /**
-   * Check the length of tags. If it is invalid, throw IllegalArgumentException
-   *
-   * @param tagsLength
-   * @throws IllegalArgumentException if tagslength is invalid
-   */
-  public static void checkForTagsLength(int tagsLength) {
-    if (tagsLength > MAX_TAGS_LENGTH) {
-      throw new IllegalArgumentException("tagslength "+ tagsLength + " > " + MAX_TAGS_LENGTH);
-    }
-  }
 }

hbase-common/src/test/java/org/apache/hadoop/hbase/TestByteBufferKeyValue.java

@@ -17,7 +17,7 @@
 package org.apache.hadoop.hbase;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertFalse;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -56,7 +56,7 @@ public class TestByteBufferKeyValue {
     KeyValue kvCell = new KeyValue(row1, fam1, qual1, 0l, Type.Put, row1);
     ByteBuffer buf = ByteBuffer.allocateDirect(kvCell.getBuffer().length);
     ByteBufferUtils.copyFromArrayToBuffer(buf, kvCell.getBuffer(), 0, kvCell.getBuffer().length);
-    ByteBufferCell offheapKV = new ByteBufferKeyValue(buf, 0, buf.capacity(), 0l);
+    ByteBufferCell offheapKV = new ByteBufferKeyValue(buf, 0, buf.capacity(), 0L);
     assertEquals(
       ROW1,
       ByteBufferUtils.toStringBinary(offheapKV.getRowByteBuffer(),
@@ -138,7 +138,7 @@ public class TestByteBufferKeyValue {
     KeyValue kvCell = new KeyValue(row1, fam1, qual1, 0l, Type.Put, row1, tags);
     ByteBuffer buf = ByteBuffer.allocateDirect(kvCell.getBuffer().length);
     ByteBufferUtils.copyFromArrayToBuffer(buf, kvCell.getBuffer(), 0, kvCell.getBuffer().length);
-    ByteBufferCell offheapKV = new ByteBufferKeyValue(buf, 0, buf.capacity(), 0l);
+    ByteBufferKeyValue offheapKV = new ByteBufferKeyValue(buf, 0, buf.capacity(), 0l);
     assertEquals(
       ROW1,
       ByteBufferUtils.toStringBinary(offheapKV.getRowByteBuffer(),
@@ -158,18 +158,19 @@ public class TestByteBufferKeyValue {
     assertEquals(0L, offheapKV.getTimestamp());
     assertEquals(Type.Put.getCode(), offheapKV.getTypeByte());
     // change tags to handle both onheap and offheap stuff
-    List<Tag> resTags = TagUtil.asList(offheapKV.getTagsArray(), offheapKV.getTagsOffset(),
+    List<Tag> resTags = offheapKV.getTags();
-        offheapKV.getTagsLength());
     Tag tag1 = resTags.get(0);
     assertEquals(t1.getType(), tag1.getType());
-    assertEquals(TagUtil.getValueAsString(t1), TagUtil.getValueAsString(tag1));
+    assertEquals(Tag.getValueAsString(t1),
+      Tag.getValueAsString(tag1));
     Tag tag2 = resTags.get(1);
     assertEquals(tag2.getType(), tag2.getType());
-    assertEquals(TagUtil.getValueAsString(t2), TagUtil.getValueAsString(tag2));
+    assertEquals(Tag.getValueAsString(t2),
-    Tag res = PrivateCellUtil.getTag(offheapKV, (byte) 2);
+      Tag.getValueAsString(tag2));
-    assertEquals(TagUtil.getValueAsString(t2), TagUtil.getValueAsString(tag2));
+    Tag res = PrivateCellUtil.getTag(offheapKV, (byte) 2).get();
-    res = PrivateCellUtil.getTag(offheapKV, (byte) 3);
+    assertEquals(Tag.getValueAsString(t2),
-    assertNull(res);
+      Tag.getValueAsString(tag2));
+    assertFalse(PrivateCellUtil.getTag(offheapKV, (byte) 3).isPresent());
   }
 
   @Test

hbase-common/src/test/java/org/apache/hadoop/hbase/TestKeyValue.java

@@ -459,11 +459,11 @@ public class TestKeyValue extends TestCase {
     boolean meta1Ok = false, meta2Ok = false;
     for (Tag tag : tags) {
       if (tag.getType() == (byte) 1) {
-        if (Bytes.equals(TagUtil.cloneValue(tag), metaValue1)) {
+        if (Bytes.equals(Tag.cloneValue(tag), metaValue1)) {
           meta1Ok = true;
         }
       } else {
-        if (Bytes.equals(TagUtil.cloneValue(tag), metaValue2)) {
+        if (Bytes.equals(Tag.cloneValue(tag), metaValue2)) {
           meta2Ok = true;
         }
       }
@@ -476,12 +476,12 @@ public class TestKeyValue extends TestCase {
     Tag next = tagItr.next();
     assertEquals(10, next.getValueLength());
     assertEquals((byte) 1, next.getType());
-    Bytes.equals(TagUtil.cloneValue(next), metaValue1);
+    Bytes.equals(Tag.cloneValue(next), metaValue1);
     assertTrue(tagItr.hasNext());
     next = tagItr.next();
     assertEquals(10, next.getValueLength());
     assertEquals((byte) 2, next.getType());
-    Bytes.equals(TagUtil.cloneValue(next), metaValue2);
+    Bytes.equals(Tag.cloneValue(next), metaValue2);
     assertFalse(tagItr.hasNext());
 
     tagItr = PrivateCellUtil.tagsIterator(kv);
@@ -489,12 +489,12 @@ public class TestKeyValue extends TestCase {
     next = tagItr.next();
     assertEquals(10, next.getValueLength());
     assertEquals((byte) 1, next.getType());
-    Bytes.equals(TagUtil.cloneValue(next), metaValue1);
+    Bytes.equals(Tag.cloneValue(next), metaValue1);
     assertTrue(tagItr.hasNext());
     next = tagItr.next();
     assertEquals(10, next.getValueLength());
     assertEquals((byte) 2, next.getType());
-    Bytes.equals(TagUtil.cloneValue(next), metaValue2);
+    Bytes.equals(Tag.cloneValue(next), metaValue2);
     assertFalse(tagItr.hasNext());
   }
 

hbase-common/src/test/java/org/apache/hadoop/hbase/TestTagUtil.java

@@ -37,13 +37,13 @@ public class TestTagUtil {
     assertEquals(1, tags.size());
     Tag ttlTag = tags.get(0);
     assertEquals(TagType.TTL_TAG_TYPE, ttlTag.getType());
-    assertEquals(ttl, TagUtil.getValueAsLong(ttlTag));
+    assertEquals(ttl, Tag.getValueAsLong(ttlTag));
     // Already having a TTL tag in the list. So the call must remove the old tag
     long ttl2 = 30 * 1000;
     tags = TagUtil.carryForwardTTLTag(tags, ttl2);
     assertEquals(1, tags.size());
     ttlTag = tags.get(0);
     assertEquals(TagType.TTL_TAG_TYPE, ttlTag.getType());
-    assertEquals(ttl2, TagUtil.getValueAsLong(ttlTag));
+    assertEquals(ttl2, Tag.getValueAsLong(ttlTag));
   }
 }

hbase-common/src/test/java/org/apache/hadoop/hbase/codec/TestCellCodecWithTags.java

@@ -28,22 +28,21 @@ import java.io.DataOutputStream;
 import java.io.IOException;
 import java.util.List;
 
+import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
+import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingInputStream;
-import org.apache.hadoop.hbase.ArrayBackedTag;
+import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingOutputStream;
 import org.apache.hadoop.hbase.testclassification.MiscTests;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingInputStream;
-import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingOutputStream;
-
 @Category({MiscTests.class, SmallTests.class})
 public class TestCellCodecWithTags {
 
@@ -79,36 +78,37 @@ public class TestCellCodecWithTags {
     assertTrue(decoder.advance());
     Cell c = decoder.current();
     assertTrue(CellUtil.equals(c, cell1));
-    List<Tag> tags = TagUtil.asList(c.getTagsArray(), c.getTagsOffset(), c.getTagsLength());
+    List<Tag> tags =
+        ((RawCell)c).getTags();
     assertEquals(2, tags.size());
     Tag tag = tags.get(0);
     assertEquals(1, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring1"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring1"), Tag.cloneValue(tag)));
     tag = tags.get(1);
     assertEquals(2, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring2"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring2"), Tag.cloneValue(tag)));
     assertTrue(decoder.advance());
     c = decoder.current();
     assertTrue(CellUtil.equals(c, cell2));
-    tags = TagUtil.asList(c.getTagsArray(), c.getTagsOffset(), c.getTagsLength());
+    tags = ((RawCell)c).getTags();
     assertEquals(1, tags.size());
     tag = tags.get(0);
     assertEquals(1, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring3"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring3"), Tag.cloneValue(tag)));
     assertTrue(decoder.advance());
     c = decoder.current();
     assertTrue(CellUtil.equals(c, cell3));
-    tags = TagUtil.asList(c.getTagsArray(), c.getTagsOffset(), c.getTagsLength());
+    tags = ((RawCell)c).getTags();
     assertEquals(3, tags.size());
     tag = tags.get(0);
     assertEquals(2, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring4"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring4"), Tag.cloneValue(tag)));
     tag = tags.get(1);
     assertEquals(2, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring5"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring5"), Tag.cloneValue(tag)));
     tag = tags.get(2);
     assertEquals(1, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring6"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring6"), Tag.cloneValue(tag)));
     assertFalse(decoder.advance());
     dis.close();
     assertEquals(offset, cis.getCount());

hbase-common/src/test/java/org/apache/hadoop/hbase/codec/TestKeyValueCodecWithTags.java

@@ -28,22 +28,21 @@ import java.io.DataOutputStream;
 import java.io.IOException;
 import java.util.List;
 
+import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
+import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingInputStream;
-import org.apache.hadoop.hbase.ArrayBackedTag;
+import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingOutputStream;
 import org.apache.hadoop.hbase.testclassification.MiscTests;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingInputStream;
-import org.apache.hadoop.hbase.shaded.com.google.common.io.CountingOutputStream;
-
 @Category({MiscTests.class, SmallTests.class})
 public class TestKeyValueCodecWithTags {
 
@@ -79,36 +78,37 @@ public class TestKeyValueCodecWithTags {
     assertTrue(decoder.advance());
     Cell c = decoder.current();
     assertTrue(CellUtil.equals(c, kv1));
-    List<Tag> tags = TagUtil.asList(c.getTagsArray(), c.getTagsOffset(), c.getTagsLength());
+    List<Tag> tags =
+        ((RawCell)c).getTags();
     assertEquals(2, tags.size());
     Tag tag = tags.get(0);
     assertEquals(1, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring1"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring1"), Tag.cloneValue(tag)));
     tag = tags.get(1);
     assertEquals(2, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring2"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring2"), Tag.cloneValue(tag)));
     assertTrue(decoder.advance());
     c = decoder.current();
     assertTrue(CellUtil.equals(c, kv2));
-    tags = TagUtil.asList(c.getTagsArray(), c.getTagsOffset(), c.getTagsLength());
+    tags = ((RawCell)c).getTags();
     assertEquals(1, tags.size());
     tag = tags.get(0);
     assertEquals(1, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring3"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring3"), Tag.cloneValue(tag)));
     assertTrue(decoder.advance());
     c = decoder.current();
     assertTrue(CellUtil.equals(c, kv3));
-    tags = TagUtil.asList(c.getTagsArray(), c.getTagsOffset(), c.getTagsLength());
+    tags = ((RawCell)c).getTags();
     assertEquals(3, tags.size());
     tag = tags.get(0);
     assertEquals(2, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring4"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring4"), Tag.cloneValue(tag)));
     tag = tags.get(1);
     assertEquals(2, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring5"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring5"), Tag.cloneValue(tag)));
     tag = tags.get(2);
     assertEquals(1, tag.getType());
-    assertTrue(Bytes.equals(Bytes.toBytes("teststring6"), TagUtil.cloneValue(tag)));
+    assertTrue(Bytes.equals(Bytes.toBytes("teststring6"), Tag.cloneValue(tag)));
     assertFalse(decoder.advance());
     dis.close();
     assertEquals(offset, cis.getCount());

hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/mapreduce/TestHFileOutputFormat2.java

@@ -53,6 +53,7 @@ import org.apache.hadoop.hbase.CategoryBasedTimeout;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HColumnDescriptor;
@@ -65,7 +66,6 @@ import org.apache.hadoop.hbase.PerformanceEvaluation;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
@@ -492,8 +492,7 @@ public class TestHFileOutputFormat2  {
         HFileScanner scanner = reader.getScanner(false, false, false);
         scanner.seekTo();
         Cell cell = scanner.getCell();
-        List<Tag> tagsFromCell = TagUtil.asList(cell.getTagsArray(), cell.getTagsOffset(),
+        List<Tag> tagsFromCell = ((RawCell)cell).getTags();
-            cell.getTagsLength());
         assertTrue(tagsFromCell.size() > 0);
         for (Tag tag : tagsFromCell) {
           assertTrue(tag.getType() == TagType.TTL_TAG_TYPE);

hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/RegionCoprocessorEnvironment.java

@@ -24,6 +24,7 @@ import java.util.concurrent.ConcurrentMap;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
+import org.apache.hadoop.hbase.ExtendedCellBuilder;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.Connection;
@@ -103,4 +104,11 @@ public interface RegionCoprocessorEnvironment extends CoprocessorEnvironment<Reg
   // so we do not want to allow coprocessors to export metrics at the region level. We can allow
   // getMetricRegistryForTable() to allow coprocessors to track metrics per-table, per-regionserver.
   MetricRegistry getMetricRegistryForRegionServer();
+
+  /**
+   * Returns a CellBuilder so that coprocessors can build cells. These cells can also include tags.
+   * Note that this builder does not support updating seqId of the cells
+   * @return the ExtendedCellBuilder
+   */
+  ExtendedCellBuilder getCellBuilder();
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/HFilePrettyPrinter.java

@@ -55,22 +55,20 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HRegionInfo;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.hadoop.hbase.regionserver.HStoreFile;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.yetus.audience.InterfaceStability;
 import org.apache.hadoop.hbase.io.FSDataInputStreamWrapper;
 import org.apache.hadoop.hbase.io.hfile.HFile.FileInfo;
 import org.apache.hadoop.hbase.mob.MobUtils;
+import org.apache.hadoop.hbase.regionserver.HStoreFile;
 import org.apache.hadoop.hbase.regionserver.TimeRangeTracker;
 import org.apache.hadoop.hbase.util.BloomFilter;
 import org.apache.hadoop.hbase.util.BloomFilterFactory;
@@ -80,6 +78,8 @@ import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.util.HFileArchiveUtil;
 import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.util.ToolRunner;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.apache.yetus.audience.InterfaceStability;
 
 import com.codahale.metrics.ConsoleReporter;
 import com.codahale.metrics.Counter;
@@ -399,8 +399,7 @@ public class HFilePrettyPrinter extends Configured implements Tool {
               + Bytes.toStringBinary(cell.getValueArray(), cell.getValueOffset(),
                   cell.getValueLength()));
           int i = 0;
-          List<Tag> tags = TagUtil.asList(cell.getTagsArray(), cell.getTagsOffset(),
+          List<Tag> tags = ((RawCell)cell).getTags();
-              cell.getTagsLength());
           for (Tag tag : tags) {
             out.print(String.format(" T[%d]: %s", i++, tag.toString()));
           }
@@ -442,7 +441,7 @@ public class HFilePrettyPrinter extends Configured implements Tool {
           System.err.println("ERROR, wrong value format in mob reference cell "
             + CellUtil.getCellKeyAsString(cell));
         } else {
-          TableName tn = TableName.valueOf(TagUtil.cloneValue(tnTag));
+          TableName tn = TableName.valueOf(Tag.cloneValue(tnTag));
           String mobFileName = MobUtils.getMobFileName(cell);
           boolean exist = mobFileExists(fs, tn, mobFileName,
             Bytes.toString(CellUtil.cloneFamily(cell)), foundMobFiles, missingMobFiles);

hbase-server/src/main/java/org/apache/hadoop/hbase/mob/MobUtils.java

@@ -27,6 +27,7 @@ import java.util.Calendar;
 import java.util.Collection;
 import java.util.Date;
 import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.RejectedExecutionException;
@@ -101,7 +102,7 @@ public final class MobUtils {
   static {
     List<Tag> tags = new ArrayList<>();
     tags.add(MobConstants.MOB_REF_TAG);
-    REF_DELETE_MARKER_TAG_BYTES = TagUtil.fromList(tags);
+    REF_DELETE_MARKER_TAG_BYTES = Tag.fromList(tags);
   }
 
   /**
@@ -175,8 +176,10 @@ public final class MobUtils {
    */
   public static boolean isMobReferenceCell(Cell cell) {
     if (cell.getTagsLength() > 0) {
-      Tag tag = PrivateCellUtil.getTag(cell, TagType.MOB_REFERENCE_TAG_TYPE);
+      Optional<Tag> tag = PrivateCellUtil.getTag(cell, TagType.MOB_REFERENCE_TAG_TYPE);
-      return tag != null;
+      if (tag.isPresent()) {
+        return true;
+      }
     }
     return false;
   }
@@ -188,7 +191,10 @@ public final class MobUtils {
    */
   public static Tag getTableNameTag(Cell cell) {
     if (cell.getTagsLength() > 0) {
-      return PrivateCellUtil.getTag(cell, TagType.MOB_TABLE_NAME_TAG_TYPE);
+      Optional<Tag> tag = PrivateCellUtil.getTag(cell, TagType.MOB_TABLE_NAME_TAG_TYPE);
+      if (tag.isPresent()) {
+        return tag.get();
+      }
     }
     return null;
   }
@@ -496,7 +502,7 @@ public final class MobUtils {
     // find the original mob files by this table name. For details please see cloning
     // snapshot for mob files.
     tags.add(tableNameTag);
-    return createMobRefCell(cell, fileName, TagUtil.fromList(tags));
+    return createMobRefCell(cell, fileName, Tag.fromList(tags));
   }
 
   public static Cell createMobRefCell(Cell cell, byte[] fileName, byte[] refCellTags) {

hbase-server/src/main/java/org/apache/hadoop/hbase/mob/compactions/PartitionedMobCompactor.java

@@ -54,7 +54,6 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
@@ -84,14 +83,13 @@ import org.apache.hadoop.hbase.regionserver.StoreFileScanner;
 import org.apache.hadoop.hbase.regionserver.StoreFileWriter;
 import org.apache.hadoop.hbase.regionserver.StoreScanner;
 import org.apache.hadoop.hbase.security.EncryptionUtil;
+import org.apache.hadoop.hbase.shaded.com.google.common.annotations.VisibleForTesting;
 import org.apache.hadoop.hbase.tool.LoadIncrementalHFiles;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.yetus.audience.InterfaceAudience;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.annotations.VisibleForTesting;
-
 /**
  * An implementation of {@link MobCompactor} that compacts the mob files in partitions.
  */
@@ -133,7 +131,7 @@ public class PartitionedMobCompactor extends MobCompactor {
     tags.add(MobConstants.MOB_REF_TAG);
     Tag tableNameTag = new ArrayBackedTag(TagType.MOB_TABLE_NAME_TAG_TYPE, tableName.getName());
     tags.add(tableNameTag);
-    this.refCellTags = TagUtil.fromList(tags);
+    this.refCellTags = Tag.fromList(tags);
     cryptoContext = EncryptionUtil.createEncryptionContext(copyOfConf, column);
   }
 

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HMobStore.java

@@ -42,7 +42,6 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.filter.Filter;
@@ -121,7 +120,7 @@ public class HMobStore extends HStore {
     Tag tableNameTag = new ArrayBackedTag(TagType.MOB_TABLE_NAME_TAG_TYPE,
         getTableName().getName());
     tags.add(tableNameTag);
-    this.refCellTags = TagUtil.fromList(tags);
+    this.refCellTags = Tag.fromList(tags);
   }
 
   /**
@@ -332,7 +331,7 @@ public class HMobStore extends HStore {
       String fileName = MobUtils.getMobFileName(reference);
       Tag tableNameTag = MobUtils.getTableNameTag(reference);
       if (tableNameTag != null) {
-        String tableNameString = TagUtil.getValueAsString(tableNameTag);
+        String tableNameString = Tag.getValueAsString(tableNameTag);
         List<Path> locations = map.get(tableNameString);
         if (locations == null) {
           IdLock.Entry lockEntry = keyLock.getLockEntry(tableNameString.hashCode());
@@ -359,12 +358,15 @@ public class HMobStore extends HStore {
           + "qualifier,timestamp,type and tags but with an empty value to return.");
       result = ExtendedCellBuilderFactory.create(CellBuilderType.DEEP_COPY)
               .setRow(reference.getRowArray(), reference.getRowOffset(), reference.getRowLength())
-              .setFamily(reference.getFamilyArray(), reference.getFamilyOffset(), reference.getFamilyLength())
+              .setFamily(reference.getFamilyArray(), reference.getFamilyOffset(),
-              .setQualifier(reference.getQualifierArray(), reference.getQualifierOffset(), reference.getQualifierLength())
+                reference.getFamilyLength())
+              .setQualifier(reference.getQualifierArray(),
+                reference.getQualifierOffset(), reference.getQualifierLength())
               .setTimestamp(reference.getTimestamp())
               .setType(reference.getTypeByte())
               .setValue(HConstants.EMPTY_BYTE_ARRAY)
-              .setTags(reference.getTagsArray(), reference.getTagsOffset(), reference.getTagsLength())
+              .setTags(reference.getTagsArray(), reference.getTagsOffset(),
+                reference.getTagsLength())
               .build();
     }
     return result;

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -7714,7 +7714,7 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
               .setTimestamp(Math.max(currentCell.getTimestamp() + 1, now))
               .setType(KeyValue.Type.Put.getCode())
               .setValue(newValue, 0, newValue.length)
-              .setTags(TagUtil.fromList(tags))
+              .setTags(Tag.fromList(tags))
               .build();
     } else {
       PrivateCellUtil.updateLatestStamp(delta, now);

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RegionCoprocessorHost.java

@@ -38,8 +38,11 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.CompareOperator;
 import org.apache.hadoop.hbase.Coprocessor;
+import org.apache.hadoop.hbase.ExtendedCellBuilder;
+import org.apache.hadoop.hbase.ExtendedCellBuilderFactory;
 import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.ServerName;
@@ -80,6 +83,7 @@ import org.apache.hadoop.hbase.regionserver.compactions.CompactionLifeCycleTrack
 import org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;
 import org.apache.hadoop.hbase.regionserver.querymatcher.DeleteTracker;
 import org.apache.hadoop.hbase.security.User;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.CoprocessorClassLoader;
 import org.apache.hadoop.hbase.util.Pair;
@@ -87,8 +91,6 @@ import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.wal.WALKey;
 import org.apache.yetus.audience.InterfaceAudience;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
-
 /**
  * Implements the coprocessor environment and runtime support for coprocessors
  * loaded within a {@link Region}.
@@ -179,6 +181,13 @@ public class RegionCoprocessorHost
     public MetricRegistry getMetricRegistryForRegionServer() {
       return metricRegistry;
     }
+
+    @Override
+    public ExtendedCellBuilder getCellBuilder() {
+      // do not allow seqId update.
+      // We always do a DEEP_COPY only
+      return ExtendedCellBuilderFactory.create(CellBuilderType.DEEP_COPY, false);
+    }
   }
 
   /**

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/querymatcher/ScanQueryMatcher.java

@@ -25,14 +25,12 @@ import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValue.Type;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost;
@@ -43,6 +41,7 @@ import org.apache.hadoop.hbase.security.visibility.VisibilityNewVersionBehaivorT
 import org.apache.hadoop.hbase.security.visibility.VisibilityScanDeleteTracker;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Pair;
+import org.apache.yetus.audience.InterfaceAudience;
 
 /**
  * A query matcher that is specifically designed for the scan case.
@@ -157,7 +156,7 @@ public abstract class ScanQueryMatcher implements ShipperListener {
         // to convert
         long ts = cell.getTimestamp();
         assert t.getValueLength() == Bytes.SIZEOF_LONG;
-        long ttl = TagUtil.getValueAsLong(t);
+        long ttl = Tag.getValueAsLong(t);
         if (ts + ttl < now) {
           return true;
         }

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

@@ -18,13 +18,6 @@
 
 package org.apache.hadoop.hbase.security.access;
 
-import org.apache.hadoop.hbase.CompareOperator;
-import org.apache.hadoop.hbase.PrivateCellUtil;
-import org.apache.hadoop.hbase.client.Admin;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.ArrayListMultimap;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.ListMultimap;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
-
 import java.io.ByteArrayInputStream;
 import java.io.DataInput;
 import java.io.DataInputStream;
@@ -45,12 +38,12 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.AuthUtil;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.CompareOperator;
 import org.apache.hadoop.hbase.NamespaceDescriptor;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.client.Delete;
@@ -69,12 +62,16 @@ import org.apache.hadoop.hbase.protobuf.generated.AccessControlProtos;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
 import org.apache.hadoop.hbase.regionserver.Region;
 import org.apache.hadoop.hbase.security.User;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.ArrayListMultimap;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.ListMultimap;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.io.Text;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableFactories;
 import org.apache.hadoop.io.WritableUtils;
+import org.apache.yetus.audience.InterfaceAudience;
 
 /**
  * Maintains lists of permission grants to users and groups to allow for
@@ -752,7 +749,7 @@ public class AccessControlLists {
         if (tag.hasArray()) {
           ProtobufUtil.mergeFrom(builder, tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
         } else {
-          ProtobufUtil.mergeFrom(builder, TagUtil.cloneValue(tag));
+          ProtobufUtil.mergeFrom(builder, Tag.cloneValue(tag));
         }
         ListMultimap<String,Permission> kvPerms =
             AccessControlUtil.toUsersAndPermissions(builder.build());

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

@@ -52,10 +52,10 @@ import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValue.Type;
 import org.apache.hadoop.hbase.NamespaceDescriptor;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
@@ -123,6 +123,13 @@ import org.apache.hadoop.hbase.security.Superusers;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.security.UserProvider;
 import org.apache.hadoop.hbase.security.access.Permission.Action;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.ArrayListMultimap;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.ImmutableSet;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.ListMultimap;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.MapMaker;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.Maps;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.Sets;
 import org.apache.hadoop.hbase.snapshot.SnapshotDescriptionUtils;
 import org.apache.hadoop.hbase.util.ByteRange;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -133,14 +140,6 @@ import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
 import org.apache.yetus.audience.InterfaceAudience;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.ArrayListMultimap;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.ImmutableSet;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.ListMultimap;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.MapMaker;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Maps;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Sets;
-
 /**
  * Provides basic authorization checks for data access and administrative
  * operations.

hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/DefaultVisibilityLabelServiceImpl.java

@@ -606,7 +606,7 @@ public class DefaultVisibilityLabelServiceImpl implements VisibilityLabelService
       for (Tag tag : deleteVisTags) {
         matchFound = false;
         for (Tag givenTag : putVisTags) {
-          if (TagUtil.matchingValue(tag, givenTag)) {
+          if (Tag.matchingValue(tag, givenTag)) {
             matchFound = true;
             break;
           }

hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityController.java

@@ -18,16 +18,16 @@
 
 package org.apache.hadoop.hbase.security.visibility;
 
-import static org.apache.hadoop.hbase.HConstants.OperationStatusCode.SANITY_CHECK_FAILURE;
-import static org.apache.hadoop.hbase.HConstants.OperationStatusCode.SUCCESS;
-import static org.apache.hadoop.hbase.security.visibility.VisibilityConstants.LABELS_TABLE_FAMILY;
-import static org.apache.hadoop.hbase.security.visibility.VisibilityConstants.LABELS_TABLE_NAME;
-
 import com.google.protobuf.ByteString;
 import com.google.protobuf.RpcCallback;
 import com.google.protobuf.RpcController;
 import com.google.protobuf.Service;
 
+import static org.apache.hadoop.hbase.HConstants.OperationStatusCode.SANITY_CHECK_FAILURE;
+import static org.apache.hadoop.hbase.HConstants.OperationStatusCode.SUCCESS;
+import static org.apache.hadoop.hbase.security.visibility.VisibilityConstants.LABELS_TABLE_FAMILY;
+import static org.apache.hadoop.hbase.security.visibility.VisibilityConstants.LABELS_TABLE_NAME;
+
 import java.io.IOException;
 import java.net.InetAddress;
 import java.util.ArrayList;
@@ -49,12 +49,11 @@ import org.apache.hadoop.hbase.DoNotRetryIOException;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HTableDescriptor;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.MetaTableAccessor;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.Delete;
@@ -109,14 +108,13 @@ import org.apache.hadoop.hbase.security.AccessDeniedException;
 import org.apache.hadoop.hbase.security.Superusers;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.security.access.AccessController;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
+import org.apache.hadoop.hbase.shaded.com.google.common.collect.MapMaker;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.yetus.audience.InterfaceAudience;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.Lists;
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.MapMaker;
-
 /**
  * Coprocessor that has both the MasterObserver and RegionObserver implemented that supports in
  * visibility labels
@@ -321,7 +319,7 @@ public class VisibilityController implements MasterCoprocessor, RegionCoprocesso
           Tag tag = pair.getSecond();
           if (cellVisibility == null && tag != null) {
             // May need to store only the first one
-            cellVisibility = new CellVisibility(TagUtil.getValueAsString(tag));
+            cellVisibility = new CellVisibility(Tag.getValueAsString(tag));
             modifiedTagFound = true;
           }
         }

hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityUtils.java

@@ -39,11 +39,9 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.filter.Filter;
@@ -217,7 +215,7 @@ public class VisibilityUtils {
     while (tagsIterator.hasNext()) {
       Tag tag = tagsIterator.next();
       if (tag.getType() == TagType.VISIBILITY_EXP_SERIALIZATION_FORMAT_TAG_TYPE) {
-        serializationFormat = TagUtil.getValueAsByte(tag);
+        serializationFormat = Tag.getValueAsByte(tag);
       } else if (tag.getType() == VISIBILITY_TAG_TYPE) {
         tags.add(tag);
       }
@@ -244,7 +242,7 @@ public class VisibilityUtils {
     while (tagsIterator.hasNext()) {
       Tag tag = tagsIterator.next();
       if (tag.getType() == TagType.VISIBILITY_EXP_SERIALIZATION_FORMAT_TAG_TYPE) {
-        serializationFormat = TagUtil.getValueAsByte(tag);
+        serializationFormat = Tag.getValueAsByte(tag);
       } else if (tag.getType() == VISIBILITY_TAG_TYPE) {
         visTags.add(tag);
       } else {

hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALPrettyPrinter.java

@@ -27,7 +27,6 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.CommandLineParser;
 import org.apache.commons.cli.HelpFormatter;
@@ -43,12 +42,13 @@ import org.apache.hadoop.hbase.HBaseConfiguration;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.yetus.audience.InterfaceStability;
 import org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.FSUtils;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.apache.yetus.audience.InterfaceStability;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
 
 /**
  * WALPrettyPrinter prints the contents of a given WAL with a variety of
@@ -343,7 +343,8 @@ public class WALPrettyPrinter {
       Iterator<Tag> tagsIterator = PrivateCellUtil.tagsIterator(cell);
       while (tagsIterator.hasNext()) {
         Tag tag = tagsIterator.next();
-        tagsString.add((tag.getType()) + ":" + Bytes.toStringBinary(TagUtil.cloneValue(tag)));
+        tagsString
+            .add((tag.getType()) + ":" + Bytes.toStringBinary(Tag.cloneValue(tag)));
       }
       stringMap.put("tag", tagsString);
     }

hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TagUsage.java

@@ -17,9 +17,13 @@
  * limitations under the License.
  */
 package org.apache.hadoop.hbase.io.hfile;
+
+import org.apache.yetus.audience.InterfaceAudience;
+
 /**
  * Used in testcases only.  
  */
+@InterfaceAudience.Private
 public enum TagUsage {
   // No tags would be added
   NO_TAG, 

hbase-server/src/test/java/org/apache/hadoop/hbase/io/hfile/TestSeekTo.java

@@ -18,37 +18,35 @@
  */
 package org.apache.hadoop.hbase.io.hfile;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Before;
-import org.junit.Test;
-
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.ArrayBackedTag;
+import org.apache.hadoop.hbase.ByteBufferKeyValue;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparatorImpl;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
-import org.apache.hadoop.hbase.ByteBufferKeyValue;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
 import org.apache.hadoop.hbase.testclassification.IOTests;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.junit.Before;
+import org.junit.Test;
 import org.junit.experimental.categories.Category;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
@@ -176,7 +174,7 @@ public class TestSeekTo {
       Iterator<Tag> tagsIterator = PrivateCellUtil.tagsIterator(cell);
       while (tagsIterator.hasNext()) {
         Tag next = tagsIterator.next();
-        assertEquals("myTag1", Bytes.toString(TagUtil.cloneValue(next)));
+        assertEquals("myTag1", Bytes.toString(Tag.cloneValue(next)));
       }
     }
     assertTrue(scanner.seekBefore(toKV("k", tagUsage)));

hbase-server/src/test/java/org/apache/hadoop/hbase/protobuf/TestProtobufUtil.java

@@ -20,20 +20,22 @@ package org.apache.hadoop.hbase.protobuf;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
+
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
+import org.apache.hadoop.hbase.ByteBufferKeyValue;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellBuilderType;
 import org.apache.hadoop.hbase.CellComparatorImpl;
 import org.apache.hadoop.hbase.ExtendedCellBuilderFactory;
 import org.apache.hadoop.hbase.KeyValue;
-import org.apache.hadoop.hbase.ByteBufferKeyValue;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.Delete;
 import org.apache.hadoop.hbase.client.Get;
 import org.apache.hadoop.hbase.client.Increment;
 import org.apache.hadoop.hbase.client.Put;
+import org.apache.hadoop.hbase.protobuf.generated.CellProtos;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.Column;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto;
@@ -42,7 +44,6 @@ import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto.Col
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto.DeleteType;
 import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutationProto.MutationType;
 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.NameBytesPair;
-import org.apache.hadoop.hbase.protobuf.generated.CellProtos;
 import org.apache.hadoop.hbase.testclassification.MiscTests;
 import org.apache.hadoop.hbase.testclassification.SmallTests;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -333,7 +334,8 @@ public class TestProtobufUtil {
     dbb.put(arr);
     ByteBufferKeyValue offheapKV = new ByteBufferKeyValue(dbb, kv1.getLength(), kv2.getLength());
     CellProtos.Cell cell = ProtobufUtil.toCell(offheapKV);
-    Cell newOffheapKV = ProtobufUtil.toCell(ExtendedCellBuilderFactory.create(CellBuilderType.SHALLOW_COPY), cell);
+    Cell newOffheapKV =
+        ProtobufUtil.toCell(ExtendedCellBuilderFactory.create(CellBuilderType.SHALLOW_COPY), cell);
     assertTrue(CellComparatorImpl.COMPARATOR.compare(offheapKV, newOffheapKV) == 0);
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestStoreFileScannerWithTagCompression.java

@@ -34,7 +34,6 @@ import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
 import org.apache.hadoop.hbase.io.hfile.CacheConfig;
 import org.apache.hadoop.hbase.io.hfile.HFileContext;
@@ -90,7 +89,7 @@ public class TestStoreFileScannerWithTagCompression {
           kv.getRowLength()));
       List<Tag> tags = KeyValueUtil.ensureKeyValue(kv).getTags();
       assertEquals(1, tags.size());
-      assertEquals("tag3", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+      assertEquals("tag3", Bytes.toString(Tag.cloneValue(tags.get(0))));
     } finally {
       s.close();
     }

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestTags.java

@@ -26,6 +26,7 @@ import java.util.List;
 import java.util.Optional;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
@@ -35,10 +36,9 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.CompactionState;
@@ -56,10 +56,10 @@ import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
 import org.apache.hadoop.hbase.io.encoding.DataBlockEncoding;
-import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.RegionServerTests;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.wal.WALEdit;
 import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -406,7 +406,7 @@ public class TestTags {
       List<Tag> tags = TestCoprocessorForTags.tags;
       assertEquals(3L, Bytes.toLong(kv.getValueArray(), kv.getValueOffset(), kv.getValueLength()));
       assertEquals(1, tags.size());
-      assertEquals("tag1", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+      assertEquals("tag1", Bytes.toString(Tag.cloneValue(tags.get(0))));
       TestCoprocessorForTags.checkTagPresence = false;
       TestCoprocessorForTags.tags = null;
 
@@ -424,7 +424,7 @@ public class TestTags {
       // We cannot assume the ordering of tags
       List<String> tagValues = new ArrayList<>();
       for (Tag tag: tags) {
-        tagValues.add(Bytes.toString(TagUtil.cloneValue(tag)));
+        tagValues.add(Bytes.toString(Tag.cloneValue(tag)));
       }
       assertTrue(tagValues.contains("tag1"));
       assertTrue(tagValues.contains("tag2"));
@@ -446,7 +446,7 @@ public class TestTags {
       tags = TestCoprocessorForTags.tags;
       assertEquals(4L, Bytes.toLong(kv.getValueArray(), kv.getValueOffset(), kv.getValueLength()));
       assertEquals(1, tags.size());
-      assertEquals("tag2", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+      assertEquals("tag2", Bytes.toString(Tag.cloneValue(tags.get(0))));
       TestCoprocessorForTags.checkTagPresence = false;
       TestCoprocessorForTags.tags = null;
 
@@ -465,7 +465,7 @@ public class TestTags {
       kv = KeyValueUtil.ensureKeyValue(result.getColumnLatestCell(f, q));
       tags = TestCoprocessorForTags.tags;
       assertEquals(1, tags.size());
-      assertEquals("tag1", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+      assertEquals("tag1", Bytes.toString(Tag.cloneValue(tags.get(0))));
       TestCoprocessorForTags.checkTagPresence = false;
       TestCoprocessorForTags.tags = null;
 
@@ -482,7 +482,7 @@ public class TestTags {
       // We cannot assume the ordering of tags
       tagValues.clear();
       for (Tag tag: tags) {
-        tagValues.add(Bytes.toString(TagUtil.cloneValue(tag)));
+        tagValues.add(Bytes.toString(Tag.cloneValue(tag)));
       }
       assertTrue(tagValues.contains("tag1"));
       assertTrue(tagValues.contains("tag2"));
@@ -503,7 +503,7 @@ public class TestTags {
       kv = KeyValueUtil.ensureKeyValue(result.getColumnLatestCell(f, q));
       tags = TestCoprocessorForTags.tags;
       assertEquals(1, tags.size());
-      assertEquals("tag2", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+      assertEquals("tag2", Bytes.toString(Tag.cloneValue(tags.get(0))));
     } finally {
       TestCoprocessorForTags.checkTagPresence = false;
       TestCoprocessorForTags.tags = null;
@@ -613,8 +613,7 @@ public class TestTags {
           CellScanner cellScanner = result.cellScanner();
           if (cellScanner.advance()) {
             Cell cell = cellScanner.current();
-            tags = TagUtil.asList(cell.getTagsArray(), cell.getTagsOffset(),
+            tags = ((RawCell)cell).getTags();
-                cell.getTagsLength());
           }
         }
       }

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestWALCellCodecWithCompression.java

@@ -28,12 +28,11 @@ import java.util.ArrayList;
 import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ArrayBackedTag;
+import org.apache.hadoop.hbase.ByteBufferKeyValue;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.KeyValue;
-import org.apache.hadoop.hbase.ByteBufferKeyValue;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.codec.Codec.Decoder;
 import org.apache.hadoop.hbase.codec.Codec.Encoder;
 import org.apache.hadoop.hbase.io.util.LRUDictionary;
@@ -84,7 +83,7 @@ public class TestWALCellCodecWithCompression {
     KeyValue kv = (KeyValue) decoder.current();
     List<Tag> tags = kv.getTags();
     assertEquals(1, tags.size());
-    assertEquals("tagValue1", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+    assertEquals("tagValue1", Bytes.toString(Tag.cloneValue(tags.get(0))));
     decoder.advance();
     kv = (KeyValue) decoder.current();
     tags = kv.getTags();
@@ -93,8 +92,8 @@ public class TestWALCellCodecWithCompression {
     kv = (KeyValue) decoder.current();
     tags = kv.getTags();
     assertEquals(2, tags.size());
-    assertEquals("tagValue1", Bytes.toString(TagUtil.cloneValue(tags.get(0))));
+    assertEquals("tagValue1", Bytes.toString(Tag.cloneValue(tags.get(0))));
-    assertEquals("tagValue2", Bytes.toString(TagUtil.cloneValue(tags.get(1))));
+    assertEquals("tagValue2", Bytes.toString(Tag.cloneValue(tags.get(1))));
   }
 
   private KeyValue createKV(int noOfTags) {

hbase-server/src/test/java/org/apache/hadoop/hbase/replication/TestReplicationWithTags.java

@@ -29,6 +29,7 @@ import java.util.Optional;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HBaseConfiguration;
@@ -38,10 +39,9 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
@@ -57,10 +57,10 @@ import org.apache.hadoop.hbase.coprocessor.ObserverContext;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
-import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.testclassification.LargeTests;
 import org.apache.hadoop.hbase.testclassification.ReplicationTests;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.zookeeper.MiniZooKeeperCluster;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -252,7 +252,7 @@ public class TestReplicationWithTags {
         // Check tag presence in the 1st cell in 1st Result
         if (!results.isEmpty()) {
           Cell cell = results.get(0);
-          tags = TagUtil.asList(cell.getTagsArray(), cell.getTagsOffset(), cell.getTagsLength());
+          tags = ((RawCell)cell).getTags();
         }
       }
     }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/token/TestTokenAuthentication.java

@@ -39,6 +39,7 @@ import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.hbase.ChoreService;
 import org.apache.hadoop.hbase.ClusterId;
 import org.apache.hadoop.hbase.CoordinatedStateManager;
+import org.apache.hadoop.hbase.ExtendedCellBuilder;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.Server;
@@ -328,6 +329,11 @@ public class TestTokenAuthentication {
         public Connection createConnection(Configuration conf) throws IOException {
           return null;
         }
+
+        @Override
+        public ExtendedCellBuilder getCellBuilder() {
+          return null;
+        }
       });
 
       started = true;

hbase-server/src/test/java/org/apache/hadoop/hbase/security/visibility/ExpAsStringVisibilityLabelServiceImpl.java

@@ -35,16 +35,13 @@ import java.util.Set;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.AuthUtil;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HConstants.OperationStatusCode;
 import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.client.Delete;
@@ -63,6 +60,7 @@ import org.apache.hadoop.hbase.security.visibility.expression.NonLeafExpressionN
 import org.apache.hadoop.hbase.security.visibility.expression.Operator;
 import org.apache.hadoop.hbase.util.ByteBufferUtils;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.yetus.audience.InterfaceAudience;
 
 /**
  * This is a VisibilityLabelService where labels in Mutation's visibility
@@ -430,7 +428,7 @@ public class ExpAsStringVisibilityLabelServiceImpl implements VisibilityLabelSer
       for (Tag tag : deleteVisTags) {
         matchFound = false;
         for (Tag givenTag : putVisTags) {
-          if (TagUtil.matchingValue(tag, givenTag)) {
+          if (Tag.matchingValue(tag, givenTag)) {
             matchFound = true;
             break;
           }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/visibility/TestVisibilityLabelReplicationWithExpAsString.java

@@ -37,7 +37,6 @@ import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
@@ -181,7 +180,7 @@ public class TestVisibilityLabelReplicationWithExpAsString extends TestVisibilit
           boolean foundNonVisTag = false;
           for(Tag t : TestCoprocessorForTagsAtSink.tags) {
             if(t.getType() == NON_VIS_TAG_TYPE) {
-              assertEquals(TEMP, Bytes.toString(TagUtil.cloneValue(t)));
+              assertEquals(TEMP, Bytes.toString(Tag.cloneValue(t)));
               foundNonVisTag = true;
               break;
             }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/visibility/TestVisibilityLabelsReplication.java

@@ -32,6 +32,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
@@ -40,14 +41,13 @@ import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.KeyValueUtil;
+import org.apache.hadoop.hbase.PrivateCellUtil;
+import org.apache.hadoop.hbase.RawCell;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
@@ -65,7 +65,6 @@ import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
 import org.apache.hadoop.hbase.protobuf.generated.VisibilityLabelsProtos.VisibilityLabelsResponse;
-import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.replication.ReplicationEndpoint;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
 import org.apache.hadoop.hbase.security.User;
@@ -73,6 +72,7 @@ import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.SecurityTests;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.wal.WAL.Entry;
+import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.zookeeper.MiniZooKeeperCluster;
 import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
 import org.junit.Assert;
@@ -285,11 +285,10 @@ public class TestVisibilityLabelsReplication {
     for (Cell cell : cells) {
       if ((Bytes.equals(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength(), row, 0,
           row.length))) {
-        List<Tag> tags = TagUtil.asList(cell.getTagsArray(), cell.getTagsOffset(),
+        List<Tag> tags = ((RawCell)cell).getTags();
-            cell.getTagsLength());
         for (Tag tag : tags) {
           if (tag.getType() == TagType.STRING_VIS_TAG_TYPE) {
-            assertEquals(visTag, TagUtil.getValueAsString(tag));
+            assertEquals(visTag, Tag.getValueAsString(tag));
             tagFound = true;
             break;
           }
@@ -331,7 +330,7 @@ public class TestVisibilityLabelsReplication {
           boolean foundNonVisTag = false;
           for (Tag t : TestCoprocessorForTagsAtSink.tags) {
             if (t.getType() == NON_VIS_TAG_TYPE) {
-              assertEquals(TEMP, TagUtil.getValueAsString(t));
+              assertEquals(TEMP, Tag.getValueAsString(t));
               foundNonVisTag = true;
               break;
             }
@@ -443,7 +442,7 @@ public class TestVisibilityLabelsReplication {
         // Check tag presence in the 1st cell in 1st Result
         if (!results.isEmpty()) {
           Cell cell = results.get(0);
-          tags = TagUtil.asList(cell.getTagsArray(), cell.getTagsOffset(), cell.getTagsLength());
+          tags = ((RawCell)cell).getTags();
         }
       }
     }

hbase-server/src/test/java/org/apache/hadoop/hbase/util/HFileTestUtil.java

@@ -25,19 +25,18 @@ import static org.junit.Assert.fail;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Locale;
+import java.util.Optional;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hbase.ArrayBackedTag;
 import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HColumnDescriptor;
-import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.Tag;
 import org.apache.hadoop.hbase.TagType;
-import org.apache.hadoop.hbase.TagUtil;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.ResultScanner;
 import org.apache.hadoop.hbase.client.Scan;
@@ -137,8 +136,8 @@ public class HFileTestUtil {
           kv = MobUtils.createMobRefCell(kv, key, tableNameTag);
 
           // verify that the kv has the tag.
-          Tag t = PrivateCellUtil.getTag(kv, TagType.MOB_TABLE_NAME_TAG_TYPE);
+          Optional<Tag> tag = PrivateCellUtil.getTag(kv, TagType.MOB_TABLE_NAME_TAG_TYPE);
-          if (t == null) {
+          if (!tag.isPresent()) {
             throw new IllegalStateException("Tag didn't stick to KV " + kv.toString());
           }
         }
@@ -161,12 +160,13 @@ public class HFileTestUtil {
     ResultScanner s = table.getScanner(new Scan());
     for (Result r : s) {
       for (Cell c : r.listCells()) {
-        Tag t = PrivateCellUtil.getTag(c, TagType.MOB_TABLE_NAME_TAG_TYPE);
+        Optional<Tag> tag = PrivateCellUtil.getTag(c, TagType.MOB_TABLE_NAME_TAG_TYPE);
-        if (t == null) {
+        if (!tag.isPresent()) {
           fail(c.toString() + " has null tag");
           continue;
         }
-        byte[] tval = TagUtil.cloneValue(t);
+        Tag t = tag.get();
+        byte[] tval = Tag.cloneValue(t);
         assertArrayEquals(c.toString() + " has tag" + Bytes.toString(tval),
             r.getRow(), tval);
       }

hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/ThriftUtilities.java

@@ -27,15 +27,14 @@ import java.util.List;
 import java.util.Map;
 
 import org.apache.commons.collections4.MapUtils;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.CompareOperator;
+import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.ServerName;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.hadoop.hbase.Cell;
-import org.apache.hadoop.hbase.CellUtil;
-import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.client.Append;
 import org.apache.hadoop.hbase.client.Delete;
 import org.apache.hadoop.hbase.client.Durability;
@@ -47,7 +46,6 @@ import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.RowMutations;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.Scan.ReadType;
-import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
 import org.apache.hadoop.hbase.filter.ParseFilter;
 import org.apache.hadoop.hbase.security.visibility.Authorizations;
 import org.apache.hadoop.hbase.security.visibility.CellVisibility;
@@ -71,6 +69,7 @@ import org.apache.hadoop.hbase.thrift2.generated.TScan;
 import org.apache.hadoop.hbase.thrift2.generated.TServerName;
 import org.apache.hadoop.hbase.thrift2.generated.TTimeRange;
 import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.yetus.audience.InterfaceAudience;
 
 @InterfaceAudience.Private
 public class ThriftUtilities {
@@ -172,7 +171,7 @@ public class ThriftUtilities {
       col.setTimestamp(kv.getTimestamp());
       col.setValue(CellUtil.cloneValue(kv));
       if (kv.getTagsLength() > 0) {
-        col.setTags(PrivateCellUtil.getTagsArray(kv));
+        col.setTags(PrivateCellUtil.cloneTags(kv));
       }
       columnValues.add(col);
     }