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Posted to commits@tephra.apache.org by po...@apache.org on 2016/05/11 20:15:23 UTC

[23/56] [abbrv] [partial] incubator-tephra git commit: Rename package to org.apache.tephra

http://git-wip-us.apache.org/repos/asf/incubator-tephra/blob/9c693743/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/TransactionAwareHTable.java
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diff --git a/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/TransactionAwareHTable.java b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/TransactionAwareHTable.java
new file mode 100644
index 0000000..f9a3ff3
--- /dev/null
+++ b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/TransactionAwareHTable.java
@@ -0,0 +1,615 @@
+/*
+ * 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.tephra.hbase96;
+
+import com.google.protobuf.Service;
+import com.google.protobuf.ServiceException;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.Append;
+import org.apache.hadoop.hbase.client.Delete;
+import org.apache.hadoop.hbase.client.Durability;
+import org.apache.hadoop.hbase.client.Get;
+import org.apache.hadoop.hbase.client.HTableInterface;
+import org.apache.hadoop.hbase.client.Increment;
+import org.apache.hadoop.hbase.client.Mutation;
+import org.apache.hadoop.hbase.client.OperationWithAttributes;
+import org.apache.hadoop.hbase.client.Put;
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.client.ResultScanner;
+import org.apache.hadoop.hbase.client.Row;
+import org.apache.hadoop.hbase.client.RowMutations;
+import org.apache.hadoop.hbase.client.Scan;
+import org.apache.hadoop.hbase.client.coprocessor.Batch;
+import org.apache.hadoop.hbase.ipc.CoprocessorRpcChannel;
+import org.apache.tephra.AbstractTransactionAwareTable;
+import org.apache.tephra.Transaction;
+import org.apache.tephra.TransactionAware;
+import org.apache.tephra.TxConstants;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.NavigableMap;
+import java.util.Set;
+
+/**
+ * A Transaction Aware HTable implementation for HBase 0.96. Operations are committed as usual,
+ * but upon a failed or aborted transaction, they are rolled back to the state before the transaction
+ * was started.
+ */
+public class TransactionAwareHTable extends AbstractTransactionAwareTable
+    implements HTableInterface, TransactionAware {
+
+  private static final Logger LOG = LoggerFactory.getLogger(TransactionAwareHTable.class);
+  private final HTableInterface hTable;
+
+  /**
+   * Create a transactional aware instance of the passed HTable
+   *
+   * @param hTable underlying HBase table to use
+   */
+  public TransactionAwareHTable(HTableInterface hTable) {
+    this(hTable, false);
+  }
+
+  /**
+   * Create a transactional aware instance of the passed HTable
+   *
+   * @param hTable underlying HBase table to use
+   * @param conflictLevel level of conflict detection to perform (defaults to {@code COLUMN})
+   */
+  public TransactionAwareHTable(HTableInterface hTable, TxConstants.ConflictDetection conflictLevel) {
+    this(hTable, conflictLevel, false);
+  }
+
+  /**
+   * Create a transactional aware instance of the passed HTable, with the option
+   * of allowing non-transactional operations.
+   * @param hTable underlying HBase table to use
+   * @param allowNonTransactional if true, additional operations (checkAndPut, increment, checkAndDelete)
+   *                              will be available, though non-transactional
+   */
+  public TransactionAwareHTable(HTableInterface hTable, boolean allowNonTransactional) {
+    this(hTable, TxConstants.ConflictDetection.COLUMN, allowNonTransactional);
+  }
+
+  /**
+   * Create a transactional aware instance of the passed HTable, with the option
+   * of allowing non-transactional operations.
+   * @param hTable underlying HBase table to use
+   * @param conflictLevel level of conflict detection to perform (defaults to {@code COLUMN})
+   * @param allowNonTransactional if true, additional operations (checkAndPut, increment, checkAndDelete)
+   *                              will be available, though non-transactional
+   */
+  public TransactionAwareHTable(HTableInterface hTable, TxConstants.ConflictDetection conflictLevel,
+                                boolean allowNonTransactional) {
+    super(conflictLevel, allowNonTransactional);
+    this.hTable = hTable;
+  }
+
+  /* AbstractTransactionAwareTable implementation */
+
+  @Override
+  protected byte[] getTableKey() {
+    return getTableName();
+  }
+
+  @Override
+  protected boolean doCommit() throws IOException {
+    hTable.flushCommits();
+    return true;
+  }
+
+  @Override
+  protected boolean doRollback() throws Exception {
+    try {
+      // pre-size arraylist of deletes
+      int size = 0;
+      for (Set<ActionChange> cs : changeSets.values()) {
+        size += cs.size();
+      }
+      List<Delete> rollbackDeletes = new ArrayList<>(size);
+      for (Map.Entry<Long, Set<ActionChange>> entry : changeSets.entrySet()) {
+        long transactionTimestamp = entry.getKey();
+        for (ActionChange change : entry.getValue()) {
+          byte[] row = change.getRow();
+          byte[] family = change.getFamily();
+          byte[] qualifier = change.getQualifier();
+          Delete rollbackDelete = new Delete(row);
+          rollbackDelete.setAttribute(TxConstants.TX_ROLLBACK_ATTRIBUTE_KEY, new byte[0]);
+          switch (conflictLevel) {
+            case ROW:
+            case NONE:
+              // issue family delete for the tx write pointer
+              rollbackDelete.deleteFamilyVersion(change.getFamily(), transactionTimestamp);
+              break;
+            case COLUMN:
+              if (family != null && qualifier == null) {
+                rollbackDelete.deleteFamilyVersion(family, transactionTimestamp);
+              } else if (family != null && qualifier != null) {
+                rollbackDelete.deleteColumn(family, qualifier, transactionTimestamp);
+              }
+              break;
+            default:
+              throw new IllegalStateException("Unknown conflict detection level: " + conflictLevel);
+          }
+          rollbackDeletes.add(rollbackDelete);
+        }
+      }
+      hTable.delete(rollbackDeletes);
+      return true;
+    } finally {
+      try {
+        hTable.flushCommits();
+      } catch (Exception e) {
+        LOG.error("Could not flush HTable commits", e);
+      }
+      tx = null;
+      changeSets.clear();
+    }
+  }
+
+  /* HTableInterface implementation */
+
+  @Override
+  public byte[] getTableName() {
+    return hTable.getTableName();
+  }
+
+  @Override
+  public TableName getName() {
+    return hTable.getName();
+  }
+
+  @Override
+  public Configuration getConfiguration() {
+    return hTable.getConfiguration();
+  }
+
+  @Override
+  public HTableDescriptor getTableDescriptor() throws IOException {
+    return hTable.getTableDescriptor();
+  }
+
+  @Override
+  public boolean exists(Get get) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    return hTable.exists(transactionalizeAction(get));
+  }
+
+  @Override
+  public Boolean[] exists(List<Get> gets) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    List<Get> transactionalizedGets = new ArrayList<Get>(gets.size());
+    for (Get get : gets) {
+      transactionalizedGets.add(transactionalizeAction(get));
+    }
+    return hTable.exists(transactionalizedGets);
+  }
+
+  @Override
+  public void batch(List<? extends Row> actions, Object[] results) throws IOException, InterruptedException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    hTable.batch(transactionalizeActions(actions), results);
+  }
+
+  @Override
+  public Object[] batch(List<? extends Row> actions) throws IOException, InterruptedException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    return hTable.batch(transactionalizeActions(actions));
+  }
+
+  @Override
+  public <R> void batchCallback(List<? extends Row> actions, Object[] results, Batch.Callback<R> callback) throws
+    IOException, InterruptedException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    hTable.batchCallback(transactionalizeActions(actions), results, callback);
+  }
+
+  @Override
+  public <R> Object[] batchCallback(List<? extends Row> actions, Batch.Callback<R> callback) throws IOException,
+    InterruptedException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    return hTable.batchCallback(transactionalizeActions(actions), callback);
+  }
+
+  @Override
+  public Result get(Get get) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    return hTable.get(transactionalizeAction(get));
+  }
+
+  @Override
+  public Result[] get(List<Get> gets) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    ArrayList<Get> transactionalizedGets = new ArrayList<Get>();
+    for (Get get : gets) {
+      transactionalizedGets.add(transactionalizeAction(get));
+    }
+    return hTable.get(transactionalizedGets);
+  }
+
+  @Override
+  public Result getRowOrBefore(byte[] row, byte[] family) throws IOException {
+    if (allowNonTransactional) {
+      return hTable.getRowOrBefore(row, family);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public ResultScanner getScanner(Scan scan) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    return hTable.getScanner(transactionalizeAction(scan));
+  }
+
+  @Override
+  public ResultScanner getScanner(byte[] family) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    Scan scan = new Scan();
+    scan.addFamily(family);
+    return hTable.getScanner(transactionalizeAction(scan));
+  }
+
+  @Override
+  public ResultScanner getScanner(byte[] family, byte[] qualifier) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    Scan scan = new Scan();
+    scan.addColumn(family, qualifier);
+    return hTable.getScanner(transactionalizeAction(scan));
+  }
+
+  @Override
+  public void put(Put put) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    Put txPut = transactionalizeAction(put);
+    hTable.put(txPut);
+  }
+
+  @Override
+  public void put(List<Put> puts) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    List<Put> transactionalizedPuts = new ArrayList<Put>(puts.size());
+    for (Put put : puts) {
+      Put txPut = transactionalizeAction(put);
+      transactionalizedPuts.add(txPut);
+    }
+    hTable.put(transactionalizedPuts);
+  }
+
+  @Override
+  public boolean checkAndPut(byte[] row, byte[] family, byte[] qualifier, byte[] value, Put put) throws IOException {
+    if (allowNonTransactional) {
+      return hTable.checkAndPut(row, family, qualifier, value, put);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public void delete(Delete delete) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    hTable.delete(transactionalizeAction(delete));
+  }
+
+  @Override
+  public void delete(List<Delete> deletes) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    List<Delete> transactionalizedDeletes = new ArrayList<Delete>(deletes.size());
+    for (Delete delete : deletes) {
+      Delete txDelete = transactionalizeAction(delete);
+      transactionalizedDeletes.add(txDelete);
+    }
+    hTable.delete(transactionalizedDeletes);
+  }
+
+  @Override
+  public boolean checkAndDelete(byte[] row, byte[] family, byte[] qualifier, byte[] value, Delete delete)
+    throws IOException {
+    if (allowNonTransactional) {
+      return hTable.checkAndDelete(row, family, qualifier, value, delete);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public void mutateRow(RowMutations rm) throws IOException {
+    if (tx == null) {
+      throw new IOException("Transaction not started");
+    }
+    RowMutations transactionalMutations = new RowMutations();
+    for (Mutation mutation : rm.getMutations()) {
+      if (mutation instanceof Put) {
+        transactionalMutations.add(transactionalizeAction((Put) mutation));
+      } else if (mutation instanceof Delete) {
+        transactionalMutations.add(transactionalizeAction((Delete) mutation));
+      }
+    }
+    hTable.mutateRow(transactionalMutations);
+  }
+
+  @Override
+  public Result append(Append append) throws IOException {
+    if (allowNonTransactional) {
+      return hTable.append(append);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public Result increment(Increment increment) throws IOException {
+    if (allowNonTransactional) {
+      return hTable.increment(increment);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount) throws IOException {
+    if (allowNonTransactional) {
+      return hTable.incrementColumnValue(row, family, qualifier, amount);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount, Durability durability)
+    throws IOException {
+    if (allowNonTransactional) {
+      return hTable.incrementColumnValue(row, family, qualifier, amount, durability);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public long incrementColumnValue(byte[] row, byte[] family, byte[] qualifier, long amount, boolean writeToWAL)
+    throws IOException {
+    if (allowNonTransactional) {
+      return hTable.incrementColumnValue(row, family, qualifier, amount, writeToWAL);
+    } else {
+      throw new UnsupportedOperationException("Operation is not supported transactionally");
+    }
+  }
+
+  @Override
+  public boolean isAutoFlush() {
+    return hTable.isAutoFlush();
+  }
+
+  @Override
+  public void flushCommits() throws IOException {
+    hTable.flushCommits();
+  }
+
+  @Override
+  public void close() throws IOException {
+    hTable.close();
+  }
+
+  @Override
+  public CoprocessorRpcChannel coprocessorService(byte[] row) {
+    return hTable.coprocessorService(row);
+  }
+
+  @Override
+  public <T extends Service, R> Map<byte[], R> coprocessorService(Class<T> service, byte[] startKey, byte[] endKey,
+                                                                  Batch.Call<T, R> callable)
+    throws ServiceException, Throwable {
+    return hTable.coprocessorService(service, startKey, endKey, callable);
+  }
+
+  @Override
+  public <T extends Service, R> void coprocessorService(Class<T> service, byte[] startKey, byte[] endKey,
+                                                        Batch.Call<T, R> callable, Batch.Callback<R> callback)
+    throws ServiceException, Throwable {
+    hTable.coprocessorService(service, startKey, endKey, callable, callback);
+  }
+
+  @Override
+  public void setAutoFlush(boolean autoFlush) {
+    setAutoFlushTo(autoFlush);
+  }
+
+  @Override
+  public void setAutoFlush(boolean autoFlush, boolean clearBufferOnFail) {
+    hTable.setAutoFlush(autoFlush, clearBufferOnFail);
+  }
+
+  @Override
+  public void setAutoFlushTo(boolean autoFlush) {
+    hTable.setAutoFlushTo(autoFlush);
+  }
+
+  @Override
+  public long getWriteBufferSize() {
+    return hTable.getWriteBufferSize();
+  }
+
+  @Override
+  public void setWriteBufferSize(long writeBufferSize) throws IOException {
+    hTable.setWriteBufferSize(writeBufferSize);
+  }
+
+  // Helpers to get copies of objects with the timestamp set to the current transaction timestamp.
+
+  private Get transactionalizeAction(Get get) throws IOException {
+    addToOperation(get, tx);
+    return get;
+  }
+
+  private Scan transactionalizeAction(Scan scan) throws IOException {
+    addToOperation(scan, tx);
+    return scan;
+  }
+
+  private Put transactionalizeAction(Put put) throws IOException {
+    Put txPut = new Put(put.getRow(), tx.getWritePointer());
+    Set<Map.Entry<byte[], List<Cell>>> familyMap = put.getFamilyCellMap().entrySet();
+    if (!familyMap.isEmpty()) {
+      for (Map.Entry<byte[], List<Cell>> family : familyMap) {
+        List<Cell> familyValues = family.getValue();
+        if (!familyValues.isEmpty()) {
+          for (Cell value : familyValues) {
+            txPut.add(value.getFamily(), value.getQualifier(), tx.getWritePointer(), value.getValue());
+            addToChangeSet(txPut.getRow(), value.getFamily(), value.getQualifier());
+          }
+        }
+      }
+    }
+    for (Map.Entry<String, byte[]> entry : put.getAttributesMap().entrySet()) {
+      txPut.setAttribute(entry.getKey(), entry.getValue());
+    }
+    txPut.setDurability(put.getDurability());
+    addToOperation(txPut, tx);
+    return txPut;
+  }
+
+  private Delete transactionalizeAction(Delete delete) throws IOException {
+    long transactionTimestamp = tx.getWritePointer();
+
+    byte[] deleteRow = delete.getRow();
+    Delete txDelete = new Delete(deleteRow, transactionTimestamp);
+
+    Map<byte[], List<Cell>> familyToDelete = delete.getFamilyCellMap();
+    if (familyToDelete.isEmpty()) {
+      // perform a row delete if we are using row-level conflict detection
+      if (conflictLevel == TxConstants.ConflictDetection.ROW ||
+          conflictLevel == TxConstants.ConflictDetection.NONE) {
+        // Row delete leaves delete markers in all column families of the table
+        // Therefore get all the column families of the hTable from the HTableDescriptor and add them to the changeSet
+        for (HColumnDescriptor columnDescriptor : hTable.getTableDescriptor().getColumnFamilies()) {
+          // no need to identify individual columns deleted
+          addToChangeSet(deleteRow, columnDescriptor.getName(), null);
+        }
+      } else {
+        Result result = get(new Get(delete.getRow()));
+        // Delete everything
+        NavigableMap<byte[], NavigableMap<byte[], byte[]>> resultMap = result.getNoVersionMap();
+        for (Map.Entry<byte[], NavigableMap<byte[], byte[]>> familyEntry : resultMap.entrySet()) {
+          NavigableMap<byte[], byte[]> familyColumns = result.getFamilyMap(familyEntry.getKey());
+          for (Map.Entry<byte[], byte[]> column : familyColumns.entrySet()) {
+            txDelete.deleteColumns(familyEntry.getKey(), column.getKey(), transactionTimestamp);
+            addToChangeSet(deleteRow, familyEntry.getKey(), column.getKey());
+          }
+        }
+      }
+    } else {
+      for (Map.Entry<byte [], List<Cell>> familyEntry : familyToDelete.entrySet()) {
+        byte[] family = familyEntry.getKey();
+        List<Cell> entries = familyEntry.getValue();
+        boolean isFamilyDelete = false;
+        if (entries.size() == 1) {
+          Cell cell = entries.get(0);
+          isFamilyDelete = CellUtil.isDeleteFamily(cell);
+        }
+        if (isFamilyDelete) {
+          if (conflictLevel == TxConstants.ConflictDetection.ROW ||
+              conflictLevel == TxConstants.ConflictDetection.NONE) {
+            // no need to identify individual columns deleted
+            // Older versions of HBase 0.96 lack HBASE-10964, so family deletes do not correctly
+            // inherit the common Delete timestamp, so must explicitly set the timestamp here.
+            txDelete.deleteFamily(family, transactionTimestamp);
+            addToChangeSet(deleteRow, family, null);
+          } else {
+            Result result = get(new Get(delete.getRow()).addFamily(family));
+            // Delete entire family
+            NavigableMap<byte[], byte[]> familyColumns = result.getFamilyMap(family);
+            for (Map.Entry<byte[], byte[]> column : familyColumns.entrySet()) {
+              txDelete.deleteColumns(family, column.getKey(), transactionTimestamp);
+              addToChangeSet(deleteRow, family, column.getKey());
+            }
+          }
+        } else {
+          for (Cell value : entries) {
+            txDelete.deleteColumns(value.getFamily(), value.getQualifier(), transactionTimestamp);
+            addToChangeSet(deleteRow, value.getFamily(), value.getQualifier());
+          }
+        }
+      }
+    }
+    for (Map.Entry<String, byte[]> entry : delete.getAttributesMap().entrySet()) {
+        txDelete.setAttribute(entry.getKey(), entry.getValue());
+    }
+    txDelete.setDurability(delete.getDurability());
+    return txDelete;
+  }
+
+  private List<? extends Row> transactionalizeActions(List<? extends Row> actions) throws IOException {
+    List<Row> transactionalizedActions = new ArrayList<>(actions.size());
+    for (Row action : actions) {
+      if (action instanceof Get) {
+        transactionalizedActions.add(transactionalizeAction((Get) action));
+      } else if (action instanceof Put) {
+        transactionalizedActions.add(transactionalizeAction((Put) action));
+      } else if (action instanceof Delete) {
+        transactionalizedActions.add(transactionalizeAction((Delete) action));
+      } else {
+        transactionalizedActions.add(action);
+      }
+    }
+    return transactionalizedActions;
+  }
+
+  public void addToOperation(OperationWithAttributes op, Transaction tx) throws IOException {
+    op.setAttribute(TxConstants.TX_OPERATION_ATTRIBUTE_KEY, txCodec.encode(tx));
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-tephra/blob/9c693743/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/CellSkipFilter.java
----------------------------------------------------------------------
diff --git a/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/CellSkipFilter.java b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/CellSkipFilter.java
new file mode 100644
index 0000000..526498d
--- /dev/null
+++ b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/CellSkipFilter.java
@@ -0,0 +1,134 @@
+/*
+ * 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.tephra.hbase96.coprocessor;
+
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.KeyValue;
+import org.apache.hadoop.hbase.filter.Filter;
+import org.apache.hadoop.hbase.filter.FilterBase;
+
+import java.io.IOException;
+import java.util.List;
+
+/**
+ * {@link Filter} that encapsulates another {@link Filter}. It remembers the last {@link KeyValue}
+ * for which the underlying filter returned the {@link ReturnCode#NEXT_COL} or {@link ReturnCode#INCLUDE_AND_NEXT_COL},
+ * so that when {@link #filterKeyValue} is called again for the same {@link KeyValue} with different
+ * version, it returns {@link ReturnCode#NEXT_COL} directly without consulting the underlying {@link Filter}.
+ * Please see TEPHRA-169 for more details.
+ */
+public class CellSkipFilter extends FilterBase {
+  private final Filter filter;
+  // remember the previous keyvalue processed by filter when the return code was NEXT_COL or INCLUDE_AND_NEXT_COL
+  private KeyValue skipColumn = null;
+
+  public CellSkipFilter(Filter filter) {
+    this.filter = filter;
+  }
+
+  /**
+   * Determines whether the current cell should be skipped. The cell will be skipped
+   * if the previous keyvalue had the same key as the current cell. This means filter already responded
+   * for the previous keyvalue with ReturnCode.NEXT_COL or ReturnCode.INCLUDE_AND_NEXT_COL.
+   * @param cell the {@link Cell} to be tested for skipping
+   * @return true is current cell should be skipped, false otherwise
+   */
+  private boolean skipCellVersion(Cell cell) {
+    return skipColumn != null
+      && skipColumn.matchingRow(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength())
+      && skipColumn.matchingColumn(cell.getFamilyArray(), cell.getFamilyOffset(), cell.getFamilyLength(),
+                                     cell.getQualifierArray(), cell.getQualifierOffset(), cell.getQualifierLength());
+  }
+
+  @Override
+  public ReturnCode filterKeyValue(Cell cell) throws IOException {
+    if (skipCellVersion(cell)) {
+      return ReturnCode.NEXT_COL;
+    }
+
+    ReturnCode code = filter.filterKeyValue(cell);
+    if (code == ReturnCode.NEXT_COL || code == ReturnCode.INCLUDE_AND_NEXT_COL) {
+      // only store the reference to the keyvalue if we are returning NEXT_COL or INCLUDE_AND_NEXT_COL
+      skipColumn = KeyValue.createFirstOnRow(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength(),
+                                               cell.getFamilyArray(), cell.getFamilyOffset(), cell.getFamilyLength(),
+                                               cell.getQualifierArray(), cell.getQualifierOffset(),
+                                               cell.getQualifierLength());
+    } else {
+      skipColumn = null;
+    }
+    return code;
+  }
+
+  @Override
+  public boolean filterRow() throws IOException {
+    return filter.filterRow();
+  }
+
+  @Override
+  public Cell transformCell(Cell cell) throws IOException {
+    return filter.transformCell(cell);
+  }
+
+  @Override
+  public void reset() throws IOException {
+    filter.reset();
+  }
+
+  @Override
+  public boolean filterRowKey(byte[] buffer, int offset, int length) throws IOException {
+    return filter.filterRowKey(buffer, offset, length);
+  }
+
+  @Override
+  public boolean filterAllRemaining() throws IOException {
+    return filter.filterAllRemaining();
+  }
+
+  @Override
+  public void filterRowCells(List<Cell> kvs) throws IOException {
+    filter.filterRowCells(kvs);
+  }
+
+  @Override
+  public boolean hasFilterRow() {
+    return filter.hasFilterRow();
+  }
+
+  @SuppressWarnings("deprecation")
+  @Override
+  public KeyValue getNextKeyHint(KeyValue currentKV) throws IOException {
+    return filter.getNextKeyHint(currentKV);
+  }
+
+  @Override
+  public Cell getNextCellHint(Cell currentKV) throws IOException {
+    return filter.getNextCellHint(currentKV);
+  }
+
+  @Override
+  public boolean isFamilyEssential(byte[] name) throws IOException {
+    return filter.isFamilyEssential(name);
+  }
+
+  @Override
+  public byte[] toByteArray() throws IOException {
+    return filter.toByteArray();
+  }
+}
+

http://git-wip-us.apache.org/repos/asf/incubator-tephra/blob/9c693743/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionFilters.java
----------------------------------------------------------------------
diff --git a/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionFilters.java b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionFilters.java
new file mode 100644
index 0000000..e6334ed
--- /dev/null
+++ b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionFilters.java
@@ -0,0 +1,62 @@
+/*
+ * 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.tephra.hbase96.coprocessor;
+
+import org.apache.hadoop.hbase.filter.Filter;
+import org.apache.hadoop.hbase.regionserver.ScanType;
+import org.apache.tephra.Transaction;
+
+import java.util.Map;
+import javax.annotation.Nullable;
+
+/**
+ * Factory class for providing {@link Filter} instances.
+ */
+public class TransactionFilters {
+  /**
+   * Creates a new {@link org.apache.hadoop.hbase.filter.Filter} for returning data only from visible transactions.
+   *
+   * @param tx the current transaction to apply.  Only data visible to this transaction will be returned.
+   * @param ttlByFamily map of time-to-live (TTL) (in milliseconds) by column family name
+   * @param allowEmptyValues if {@code true} cells with empty {@code byte[]} values will be returned, if {@code false}
+   *                         these will be interpreted as "delete" markers and the column will be filtered out
+   * @param scanType the type of scan operation being performed
+   */
+  public static Filter getVisibilityFilter(Transaction tx, Map<byte[], Long> ttlByFamily, boolean allowEmptyValues,
+                                           ScanType scanType) {
+    return new CellSkipFilter(new TransactionVisibilityFilter(tx, ttlByFamily, allowEmptyValues, scanType, null));
+  }
+
+  /**
+   * Creates a new {@link org.apache.hadoop.hbase.filter.Filter} for returning data only from visible transactions.
+   *
+   * @param tx the current transaction to apply.  Only data visible to this transaction will be returned.
+   * @param ttlByFamily map of time-to-live (TTL) (in milliseconds) by column family name
+   * @param allowEmptyValues if {@code true} cells with empty {@code byte[]} values will be returned, if {@code false}
+   *                         these will be interpreted as "delete" markers and the column will be filtered out
+   * @param scanType the type of scan operation being performed
+   * @param cellFilter if non-null, this filter will be applied to all cells visible to the current transaction, by
+   *                   calling {@link Filter#filterKeyValue(org.apache.hadoop.hbase.Cell)}.  If null, then
+   *                   {@link Filter.ReturnCode#INCLUDE_AND_NEXT_COL} will be returned instead.
+   */
+  public static Filter getVisibilityFilter(Transaction tx, Map<byte[], Long> ttlByFamily, boolean allowEmptyValues,
+                                           ScanType scanType, @Nullable Filter cellFilter) {
+    return new CellSkipFilter(new TransactionVisibilityFilter(tx, ttlByFamily, allowEmptyValues, scanType, cellFilter));
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-tephra/blob/9c693743/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionProcessor.java
----------------------------------------------------------------------
diff --git a/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionProcessor.java b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionProcessor.java
new file mode 100644
index 0000000..136dedc
--- /dev/null
+++ b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionProcessor.java
@@ -0,0 +1,349 @@
+/*
+ * 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.tephra.hbase96.coprocessor;
+
+import com.google.common.base.Supplier;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.Cell;
+import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.CoprocessorEnvironment;
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.client.Delete;
+import org.apache.hadoop.hbase.client.Durability;
+import org.apache.hadoop.hbase.client.Get;
+import org.apache.hadoop.hbase.client.OperationWithAttributes;
+import org.apache.hadoop.hbase.client.Put;
+import org.apache.hadoop.hbase.client.Scan;
+import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
+import org.apache.hadoop.hbase.coprocessor.ObserverContext;
+import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
+import org.apache.hadoop.hbase.filter.Filter;
+import org.apache.hadoop.hbase.filter.FilterBase;
+import org.apache.hadoop.hbase.regionserver.InternalScanner;
+import org.apache.hadoop.hbase.regionserver.KeyValueScanner;
+import org.apache.hadoop.hbase.regionserver.RegionScanner;
+import org.apache.hadoop.hbase.regionserver.ScanType;
+import org.apache.hadoop.hbase.regionserver.Store;
+import org.apache.hadoop.hbase.regionserver.StoreScanner;
+import org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;
+import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.tephra.Transaction;
+import org.apache.tephra.TransactionCodec;
+import org.apache.tephra.TxConstants;
+import org.apache.tephra.coprocessor.TransactionStateCache;
+import org.apache.tephra.coprocessor.TransactionStateCacheSupplier;
+import org.apache.tephra.persist.TransactionVisibilityState;
+import org.apache.tephra.util.TxUtils;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.NavigableSet;
+import java.util.Set;
+
+/**
+ * {@code org.apache.hadoop.hbase.coprocessor.RegionObserver} coprocessor that handles server-side processing
+ * for transactions:
+ * <ul>
+ *   <li>applies filtering to exclude data from invalid and in-progress transactions</li>
+ *   <li>overrides the scanner returned for flush and compaction to drop data written by invalidated transactions,
+ *   or expired due to TTL.</li>
+ * </ul>
+ *
+ * <p>In order to use this coprocessor for transactions, configure the class on any table involved in transactions,
+ * or on all user tables by adding the following to hbase-site.xml:
+ * {@code
+ * <property>
+ *   <name>hbase.coprocessor.region.classes</name>
+ *   <value>TransactionProcessor</value>
+ * </property>
+ * }
+ * </p>
+ *
+ * <p>HBase {@code Get} and {@code Scan} operations should have the current transaction serialized on to the operation
+ * as an attribute:
+ * {@code
+ * Transaction t = ...;
+ * Get get = new Get(...);
+ * TransactionCodec codec = new TransactionCodec();
+ * codec.addToOperation(get, t);
+ * }
+ * </p>
+ */
+public class TransactionProcessor extends BaseRegionObserver {
+  private static final Log LOG = LogFactory.getLog(TransactionProcessor.class);
+
+  private TransactionStateCache cache;
+  private final TransactionCodec txCodec;
+  protected Map<byte[], Long> ttlByFamily = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
+  protected boolean allowEmptyValues = TxConstants.ALLOW_EMPTY_VALUES_DEFAULT;
+  protected boolean readNonTxnData = TxConstants.DEFAULT_READ_NON_TX_DATA;
+
+  public TransactionProcessor() {
+    this.txCodec = new TransactionCodec();
+  }
+
+  /* RegionObserver implementation */
+
+  @Override
+  public void start(CoprocessorEnvironment e) throws IOException {
+    if (e instanceof RegionCoprocessorEnvironment) {
+      RegionCoprocessorEnvironment env = (RegionCoprocessorEnvironment) e;
+      Supplier<TransactionStateCache> cacheSupplier = getTransactionStateCacheSupplier(env);
+      this.cache = cacheSupplier.get();
+
+      HTableDescriptor tableDesc = env.getRegion().getTableDesc();
+      for (HColumnDescriptor columnDesc : tableDesc.getFamilies()) {
+        String columnTTL = columnDesc.getValue(TxConstants.PROPERTY_TTL);
+        long ttl = 0;
+        if (columnTTL != null) {
+          try {
+            ttl = Long.parseLong(columnTTL);
+            LOG.info("Family " + columnDesc.getNameAsString() + " has TTL of " + columnTTL);
+          } catch (NumberFormatException nfe) {
+            LOG.warn("Invalid TTL value configured for column family " + columnDesc.getNameAsString() +
+                       ", value = " + columnTTL);
+          }
+        }
+        ttlByFamily.put(columnDesc.getName(), ttl);
+      }
+
+      this.allowEmptyValues = env.getConfiguration().getBoolean(TxConstants.ALLOW_EMPTY_VALUES_KEY,
+                                                                TxConstants.ALLOW_EMPTY_VALUES_DEFAULT);
+      this.readNonTxnData = Boolean.valueOf(tableDesc.getValue(TxConstants.READ_NON_TX_DATA));
+      if (readNonTxnData) {
+        LOG.info("Reading pre-existing data enabled for table " + tableDesc.getNameAsString());
+      }
+    }
+  }
+
+  protected Supplier<TransactionStateCache> getTransactionStateCacheSupplier(RegionCoprocessorEnvironment env) {
+    return new TransactionStateCacheSupplier(env.getConfiguration());
+  }
+
+  @Override
+  public void stop(CoprocessorEnvironment e) throws IOException {
+    // nothing to do
+  }
+
+  @Override
+  public void preGetOp(ObserverContext<RegionCoprocessorEnvironment> e, Get get, List<Cell> results)
+    throws IOException {
+    Transaction tx = getFromOperation(get);
+    if (tx != null) {
+      projectFamilyDeletes(get);
+      get.setMaxVersions();
+      get.setTimeRange(TxUtils.getOldestVisibleTimestamp(ttlByFamily, tx, readNonTxnData),
+                       TxUtils.getMaxVisibleTimestamp(tx));
+      Filter newFilter = getTransactionFilter(tx, ScanType.USER_SCAN, get.getFilter());
+      get.setFilter(newFilter);
+    }
+  }
+
+  @Override
+  public void preDelete(ObserverContext<RegionCoprocessorEnvironment> e, Delete delete, WALEdit edit,
+                        Durability durability) throws IOException {
+    // Translate deletes into our own delete tombstones
+    // Since HBase deletes cannot be undone, we need to translate deletes into special puts, which allows
+    // us to rollback the changes (by a real delete) if the transaction fails
+
+    // Deletes that are part of a transaction rollback do not need special handling.
+    // They will never be rolled back, so are performed as normal HBase deletes.
+    if (delete.getAttribute(TxConstants.TX_ROLLBACK_ATTRIBUTE_KEY) != null) {
+      return;
+    }
+
+    // Other deletes are client-initiated and need to be translated into our own tombstones
+    // TODO: this should delegate to the DeleteStrategy implementation.
+    Put deleteMarkers = new Put(delete.getRow(), delete.getTimeStamp());
+    for (byte[] family : delete.getFamilyCellMap().keySet()) {
+      List<Cell> familyCells = delete.getFamilyCellMap().get(family);
+      if (isFamilyDelete(familyCells)) {
+        deleteMarkers.add(family, TxConstants.FAMILY_DELETE_QUALIFIER, familyCells.get(0).getTimestamp(),
+            HConstants.EMPTY_BYTE_ARRAY);
+      } else {
+        int cellSize = familyCells.size();
+        for (int i = 0; i < cellSize; i++) {
+          Cell cell = familyCells.get(i);
+          deleteMarkers.add(family, CellUtil.cloneQualifier(cell), cell.getTimestamp(),
+                  HConstants.EMPTY_BYTE_ARRAY);
+        }
+      }
+    }
+    for (Map.Entry<String, byte[]> entry : delete.getAttributesMap().entrySet()) {
+        deleteMarkers.setAttribute(entry.getKey(), entry.getValue());
+    }
+    e.getEnvironment().getRegion().put(deleteMarkers);
+    // skip normal delete handling
+    e.bypass();
+  }
+
+  private boolean isFamilyDelete(List<Cell> familyCells) {
+    return familyCells.size() == 1 && CellUtil.isDeleteFamily(familyCells.get(0));
+  }
+
+  @Override
+  public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan, RegionScanner s)
+    throws IOException {
+    Transaction tx = getFromOperation(scan);
+    if (tx != null) {
+      projectFamilyDeletes(scan);
+      scan.setMaxVersions();
+      scan.setTimeRange(TxUtils.getOldestVisibleTimestamp(ttlByFamily, tx, readNonTxnData),
+                        TxUtils.getMaxVisibleTimestamp(tx));
+      Filter newFilter = getTransactionFilter(tx, ScanType.USER_SCAN, scan.getFilter());
+      scan.setFilter(newFilter);
+    }
+    return s;
+  }
+
+  /**
+   * Ensures that family delete markers are present in the columns requested for any scan operation.
+   * @param scan The original scan request
+   * @return The modified scan request with the family delete qualifiers represented
+   */
+  private Scan projectFamilyDeletes(Scan scan) {
+    for (Map.Entry<byte[], NavigableSet<byte[]>> entry : scan.getFamilyMap().entrySet()) {
+      NavigableSet<byte[]> columns = entry.getValue();
+      // wildcard scans will automatically include the delete marker, so only need to add it when we have
+      // explicit columns listed
+      if (columns != null && !columns.isEmpty()) {
+        scan.addColumn(entry.getKey(), TxConstants.FAMILY_DELETE_QUALIFIER);
+      }
+    }
+    return scan;
+  }
+
+  /**
+   * Ensures that family delete markers are present in the columns requested for any get operation.
+   * @param get The original get request
+   * @return The modified get request with the family delete qualifiers represented
+   */
+  private Get projectFamilyDeletes(Get get) {
+    for (Map.Entry<byte[], NavigableSet<byte[]>> entry : get.getFamilyMap().entrySet()) {
+      NavigableSet<byte[]> columns = entry.getValue();
+      // wildcard scans will automatically include the delete marker, so only need to add it when we have
+      // explicit columns listed
+      if (columns != null && !columns.isEmpty()) {
+        get.addColumn(entry.getKey(), TxConstants.FAMILY_DELETE_QUALIFIER);
+      }
+    }
+    return get;
+  }
+
+  @Override
+  public InternalScanner preFlushScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Store store,
+                                             KeyValueScanner memstoreScanner, InternalScanner scanner)
+      throws IOException {
+    return createStoreScanner(c.getEnvironment(), "flush", cache.getLatestState(), store,
+                              Collections.singletonList(memstoreScanner), ScanType.COMPACT_RETAIN_DELETES,
+                              HConstants.OLDEST_TIMESTAMP);
+  }
+
+  @Override
+  public InternalScanner preCompactScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Store store,
+      List<? extends KeyValueScanner> scanners, ScanType scanType, long earliestPutTs, InternalScanner s,
+      CompactionRequest request)
+      throws IOException {
+    return createStoreScanner(c.getEnvironment(), "compaction", cache.getLatestState(), store, scanners, scanType,
+                              earliestPutTs);
+  }
+
+  protected InternalScanner createStoreScanner(RegionCoprocessorEnvironment env, String action,
+                                               TransactionVisibilityState snapshot, Store store,
+                                               List<? extends KeyValueScanner> scanners, ScanType type,
+                                               long earliestPutTs) throws IOException {
+    if (snapshot == null) {
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Region " + env.getRegion().getRegionNameAsString() +
+                    ", no current transaction state found, defaulting to normal " + action + " scanner");
+      }
+      return null;
+    }
+
+    // construct a dummy transaction from the latest snapshot
+    Transaction dummyTx = TxUtils.createDummyTransaction(snapshot);
+    Scan scan = new Scan();
+    // need to see all versions, since we filter out excludes and applications may rely on multiple versions
+    scan.setMaxVersions();
+    scan.setFilter(
+        new IncludeInProgressFilter(dummyTx.getVisibilityUpperBound(),
+            snapshot.getInvalid(),
+            getTransactionFilter(dummyTx, type, null)));
+
+    return new StoreScanner(store, store.getScanInfo(), scan, scanners,
+                            type, store.getSmallestReadPoint(), earliestPutTs);
+  }
+
+  private Transaction getFromOperation(OperationWithAttributes op) throws IOException {
+    byte[] encoded = op.getAttribute(TxConstants.TX_OPERATION_ATTRIBUTE_KEY);
+    if (encoded != null) {
+      return txCodec.decode(encoded);
+    }
+    return null;
+  }
+
+  /**
+   * Derived classes can override this method to customize the filter used to return data visible for the current
+   * transaction.
+   *
+   * @param tx the current transaction to apply
+   * @param type the type of scan operation being performed
+   */
+  protected Filter getTransactionFilter(Transaction tx, ScanType type, Filter filter) {
+    return TransactionFilters.getVisibilityFilter(tx, ttlByFamily, allowEmptyValues, type, filter);
+  }
+
+  /**
+   * Filter used to include cells visible to in-progress transactions on flush and commit.
+   */
+  static class IncludeInProgressFilter extends FilterBase {
+    private final long visibilityUpperBound;
+    private final Set<Long> invalidIds;
+    private final Filter txFilter;
+
+    public IncludeInProgressFilter(long upperBound, Collection<Long> invalids, Filter transactionFilter) {
+      this.visibilityUpperBound = upperBound;
+      this.invalidIds = Sets.newHashSet(invalids);
+      this.txFilter = transactionFilter;
+    }
+
+    @Override
+    public ReturnCode filterKeyValue(Cell cell) throws IOException {
+      // include all cells visible to in-progress transactions, except for those already marked as invalid
+      long ts = cell.getTimestamp();
+      if (ts > visibilityUpperBound) {
+        // include everything that could still be in-progress except invalids
+        if (invalidIds.contains(ts)) {
+          return ReturnCode.SKIP;
+        }
+        return ReturnCode.INCLUDE;
+      }
+      return txFilter.filterKeyValue(cell);
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-tephra/blob/9c693743/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionVisibilityFilter.java
----------------------------------------------------------------------
diff --git a/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionVisibilityFilter.java b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionVisibilityFilter.java
new file mode 100644
index 0000000..d675db7
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+++ b/tephra-hbase-compat-0.96/src/main/java/org/apache/tephra/hbase96/coprocessor/TransactionVisibilityFilter.java
@@ -0,0 +1,313 @@
+/*
+ * 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.tephra.hbase96.coprocessor;
+
+import com.google.common.collect.Maps;
+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.filter.Filter;
+import org.apache.hadoop.hbase.filter.FilterBase;
+import org.apache.hadoop.hbase.regionserver.ScanType;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.tephra.Transaction;
+import org.apache.tephra.TxConstants;
+import org.apache.tephra.util.TxUtils;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+import javax.annotation.Nullable;
+
+/**
+ * Applies filtering of data based on transactional visibility (HBase 0.96+ specific version).
+ * Note: this is intended for server-side use only, as additional properties need to be set on
+ * any {@code Scan} or {@code Get} operation performed.
+ */
+public class TransactionVisibilityFilter extends FilterBase {
+  private final Transaction tx;
+  // oldest visible timestamp by column family, used to apply TTL when reading
+  private final Map<byte[], Long> oldestTsByFamily;
+  // if false, empty values will be interpreted as deletes
+  private final boolean allowEmptyValues;
+  // whether or not we can remove delete markers
+  // these can only be safely removed when we are traversing all storefiles
+  private final boolean clearDeletes;
+  // optional sub-filter to apply to visible cells
+  private final Filter cellFilter;
+
+  // since we traverse KVs in order, cache the current oldest TS to avoid map lookups per KV
+  private byte[] currentFamily = new byte[0];
+  private long currentOldestTs;
+
+  private DeleteTracker deleteTracker = new DeleteTracker();
+
+  /**
+   * Creates a new {@link Filter} for returning data only from visible transactions.
+   *
+   * @param tx the current transaction to apply.  Only data visible to this transaction will be returned.
+   * @param ttlByFamily map of time-to-live (TTL) (in milliseconds) by column family name
+   * @param allowEmptyValues if {@code true} cells with empty {@code byte[]} values will be returned, if {@code false}
+   *                         these will be interpreted as "delete" markers and the column will be filtered out
+   * @param scanType the type of scan operation being performed
+   */
+  public TransactionVisibilityFilter(Transaction tx, Map<byte[], Long> ttlByFamily, boolean allowEmptyValues,
+                                     ScanType scanType) {
+    this(tx, ttlByFamily, allowEmptyValues, scanType, null);
+  }
+
+  /**
+   * Creates a new {@link Filter} for returning data only from visible transactions.
+   *
+   * @param tx the current transaction to apply.  Only data visible to this transaction will be returned.
+   * @param ttlByFamily map of time-to-live (TTL) (in milliseconds) by column family name
+   * @param allowEmptyValues if {@code true} cells with empty {@code byte[]} values will be returned, if {@code false}
+   *                         these will be interpreted as "delete" markers and the column will be filtered out
+   * @param scanType the type of scan operation being performed
+   * @param cellFilter if non-null, this filter will be applied to all cells visible to the current transaction, by
+   *                   calling {@link Filter#filterKeyValue(org.apache.hadoop.hbase.Cell)}.  If null, then
+   *                   {@link Filter.ReturnCode#INCLUDE_AND_NEXT_COL} will be returned instead.
+   */
+   public TransactionVisibilityFilter(Transaction tx, Map<byte[], Long> ttlByFamily, boolean allowEmptyValues,
+                               ScanType scanType, @Nullable Filter cellFilter) {
+    this.tx = tx;
+    this.oldestTsByFamily = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
+    for (Map.Entry<byte[], Long> ttlEntry : ttlByFamily.entrySet()) {
+      long familyTTL = ttlEntry.getValue();
+      oldestTsByFamily.put(ttlEntry.getKey(),
+                           familyTTL <= 0 ? 0 : tx.getVisibilityUpperBound() - familyTTL * TxConstants.MAX_TX_PER_MS);
+    }
+    this.allowEmptyValues = allowEmptyValues;
+    this.clearDeletes =
+        scanType == ScanType.COMPACT_DROP_DELETES ||
+          (scanType == ScanType.USER_SCAN && tx.getVisibilityLevel() != Transaction.VisibilityLevel.SNAPSHOT_ALL);
+    this.cellFilter = cellFilter;
+  }
+
+  @Override
+  public ReturnCode filterKeyValue(Cell cell) throws IOException {
+    if (!CellUtil.matchingFamily(cell, currentFamily)) {
+      // column family changed
+      currentFamily = CellUtil.cloneFamily(cell);
+      Long familyOldestTs = oldestTsByFamily.get(currentFamily);
+      currentOldestTs = familyOldestTs != null ? familyOldestTs : 0;
+      deleteTracker.reset();
+    }
+    // need to apply TTL for the column family here
+    long kvTimestamp = cell.getTimestamp();
+    if (TxUtils.getTimestampForTTL(kvTimestamp) < currentOldestTs) {
+      // passed TTL for this column, seek to next
+      return ReturnCode.NEXT_COL;
+    } else if (tx.isVisible(kvTimestamp)) {
+      // Return all writes done by current transaction (including deletes) for VisibilityLevel.SNAPSHOT_ALL
+      if (tx.getVisibilityLevel() == Transaction.VisibilityLevel.SNAPSHOT_ALL && tx.isCurrentWrite(kvTimestamp)) {
+        // cell is visible
+        // visibility SNAPSHOT_ALL needs all matches
+        return runSubFilter(ReturnCode.INCLUDE, cell);
+      }
+      if (DeleteTracker.isFamilyDelete(cell)) {
+        deleteTracker.addFamilyDelete(cell);
+        if (clearDeletes) {
+          return ReturnCode.NEXT_COL;
+        } else {
+          // cell is visible
+          // as soon as we find a KV to include we can move to the next column
+          return runSubFilter(ReturnCode.INCLUDE_AND_NEXT_COL, cell);
+        }
+      }
+      // check if masked by family delete
+      if (deleteTracker.isDeleted(cell)) {
+        return ReturnCode.NEXT_COL;
+      }
+      // check for column delete
+      if (isColumnDelete(cell)) {
+        if (clearDeletes) {
+          // skip "deleted" cell
+          return ReturnCode.NEXT_COL;
+        } else {
+          // keep the marker but skip any remaining versions
+          return runSubFilter(ReturnCode.INCLUDE_AND_NEXT_COL, cell);
+        }
+      }
+      // cell is visible
+      // as soon as we find a KV to include we can move to the next column
+      return runSubFilter(ReturnCode.INCLUDE_AND_NEXT_COL, cell);
+    } else {
+      return ReturnCode.SKIP;
+    }
+  }
+
+  private ReturnCode runSubFilter(ReturnCode txFilterCode, Cell cell) throws IOException {
+    if (cellFilter != null) {
+      ReturnCode subFilterCode = cellFilter.filterKeyValue(cell);
+      return determineReturnCode(txFilterCode, subFilterCode);
+    }
+    return txFilterCode;
+  }
+
+  /**
+   * Determines the return code of TransactionVisibilityFilter based on sub-filter's return code.
+   * Sub-filter can only exclude cells included by TransactionVisibilityFilter, i.e., sub-filter's
+   * INCLUDE will be ignored. This behavior makes sure that sub-filter only sees cell versions valid for the
+   * given transaction. If sub-filter needs to see older versions of cell, then this method can be overridden.
+   *
+   * @param txFilterCode return code from TransactionVisibilityFilter
+   * @param subFilterCode return code from sub-filter
+   * @return final return code
+   */
+  protected ReturnCode determineReturnCode(ReturnCode txFilterCode, ReturnCode subFilterCode) {
+    // Return the more restrictive of the two filter responses
+    switch (subFilterCode) {
+      case INCLUDE:
+        return txFilterCode;
+      case INCLUDE_AND_NEXT_COL:
+        return ReturnCode.INCLUDE_AND_NEXT_COL;
+      case SKIP:
+        return txFilterCode == ReturnCode.INCLUDE ? ReturnCode.SKIP : ReturnCode.NEXT_COL;
+      default:
+        return subFilterCode;
+    }
+  }
+
+  @Override
+  public boolean filterRow() throws IOException {
+    if (cellFilter != null) {
+      return cellFilter.filterRow();
+    }
+    return super.filterRow();
+  }
+
+  @Override
+  public Cell transformCell(Cell cell) throws IOException {
+    // Convert Tephra deletes back into HBase deletes
+    if (tx.getVisibilityLevel() == Transaction.VisibilityLevel.SNAPSHOT_ALL) {
+      if (DeleteTracker.isFamilyDelete(cell)) {
+        return new KeyValue(CellUtil.cloneRow(cell), CellUtil.cloneFamily(cell), null, cell.getTimestamp(),
+                            KeyValue.Type.DeleteFamily);
+      } else if (isColumnDelete(cell)) {
+        // Note: in some cases KeyValue.Type.Delete is used in Delete object,
+        // and in some other cases KeyValue.Type.DeleteColumn is used.
+        // Since Tephra cannot distinguish between the two, we return KeyValue.Type.DeleteColumn.
+        // KeyValue.Type.DeleteColumn makes both CellUtil.isDelete and CellUtil.isDeleteColumns return true, and will
+        // work in both cases.
+        return new KeyValue(CellUtil.cloneRow(cell), CellUtil.cloneFamily(cell), CellUtil.cloneQualifier(cell),
+                            cell.getTimestamp(), KeyValue.Type.DeleteColumn);
+      }
+    }
+    return cell;
+  }
+
+  @Override
+  public void reset() throws IOException {
+    deleteTracker.reset();
+    if (cellFilter != null) {
+      cellFilter.reset();
+    }
+  }
+
+  @Override
+  public boolean filterRowKey(byte[] buffer, int offset, int length) throws IOException {
+    if (cellFilter != null) {
+      return cellFilter.filterRowKey(buffer, offset, length);
+    }
+    return super.filterRowKey(buffer, offset, length);
+  }
+
+  @Override
+  public boolean filterAllRemaining() throws IOException {
+    if (cellFilter != null) {
+      return cellFilter.filterAllRemaining();
+    }
+    return super.filterAllRemaining();
+  }
+
+  @Override
+  public void filterRowCells(List<Cell> kvs) throws IOException {
+    if (cellFilter != null) {
+      cellFilter.filterRowCells(kvs);
+    } else {
+      super.filterRowCells(kvs);
+    }
+  }
+
+  @Override
+  public boolean hasFilterRow() {
+    if (cellFilter != null) {
+      return cellFilter.hasFilterRow();
+    }
+    return super.hasFilterRow();
+  }
+
+  @SuppressWarnings("deprecation")
+  @Override
+  public KeyValue getNextKeyHint(KeyValue currentKV) throws IOException {
+    if (cellFilter != null) {
+      return cellFilter.getNextKeyHint(currentKV);
+    }
+    return super.getNextKeyHint(currentKV);
+  }
+
+  @Override
+  public Cell getNextCellHint(Cell currentKV) throws IOException {
+    if (cellFilter != null) {
+      return cellFilter.getNextCellHint(currentKV);
+    }
+    return super.getNextCellHint(currentKV);
+  }
+
+  @Override
+  public boolean isFamilyEssential(byte[] name) throws IOException {
+    if (cellFilter != null) {
+      return cellFilter.isFamilyEssential(name);
+    }
+    return super.isFamilyEssential(name);
+  }
+
+  @Override
+  public byte[] toByteArray() throws IOException {
+    return super.toByteArray();
+  }
+
+  private boolean isColumnDelete(Cell cell) {
+    return !TxUtils.isPreExistingVersion(cell.getTimestamp()) && cell.getValueLength() == 0 && !allowEmptyValues;
+  }
+
+  private static final class DeleteTracker {
+    private long familyDeleteTs;
+
+    public static boolean isFamilyDelete(Cell cell) {
+      return !TxUtils.isPreExistingVersion(cell.getTimestamp()) &&
+        CellUtil.matchingQualifier(cell, TxConstants.FAMILY_DELETE_QUALIFIER) &&
+        CellUtil.matchingValue(cell, HConstants.EMPTY_BYTE_ARRAY);
+    }
+
+    public void addFamilyDelete(Cell delete) {
+      this.familyDeleteTs = delete.getTimestamp();
+    }
+
+    public boolean isDeleted(Cell cell) {
+      return cell.getTimestamp() <= familyDeleteTs;
+    }
+
+    public void reset() {
+      this.familyDeleteTs = 0;
+    }
+  }
+}

http://git-wip-us.apache.org/repos/asf/incubator-tephra/blob/9c693743/tephra-hbase-compat-0.96/src/test/java/co/cask/tephra/hbase96/HBase96ConfigurationProviderTest.java
----------------------------------------------------------------------
diff --git a/tephra-hbase-compat-0.96/src/test/java/co/cask/tephra/hbase96/HBase96ConfigurationProviderTest.java b/tephra-hbase-compat-0.96/src/test/java/co/cask/tephra/hbase96/HBase96ConfigurationProviderTest.java
deleted file mode 100644
index a1a2e97..0000000
--- a/tephra-hbase-compat-0.96/src/test/java/co/cask/tephra/hbase96/HBase96ConfigurationProviderTest.java
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * 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 co.cask.tephra.hbase96;
-
-import co.cask.tephra.util.AbstractConfigurationProviderTest;
-import co.cask.tephra.util.HBaseVersion;
-
-/**
- * Test for HBase 0.96 version specific behavior.
- */
-public class HBase96ConfigurationProviderTest extends AbstractConfigurationProviderTest {
-  @Override
-  protected HBaseVersion.Version getExpectedVersion() {
-    return HBaseVersion.Version.HBASE_96;
-  }
-}