HBASE-6562 Fake KVs are sometimes passed to filters

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1373650 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -1156,6 +1156,14 @@ public class KeyValue implements Writable, HeapSize {
       HConstants.LATEST_TIMESTAMP_BYTES, 0, Bytes.SIZEOF_LONG);
   }
 
+  /**
+   * @return True if this is a "fake" KV created for internal seeking purposes,
+   * which should not be seen by user code
+   */
+  public boolean isInternal() {
+    byte type = getType();
+    return type == Type.Minimum.code || type == Type.Maximum.code;
+  }
   /**
    * @param now Time to set into <code>this</code> IFF timestamp ==
    * {@link HConstants#LATEST_TIMESTAMP} (else, its a noop).

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

@@ -3567,14 +3567,15 @@ public class HRegion implements HeapSize { // , Writable{
           rpcCall.throwExceptionIfCallerDisconnected();
         }
 
-        byte [] currentRow = peekRow();
+        KeyValue kv = this.storeHeap.peek();
+        byte [] currentRow = kv == null ? null : kv.getRow();
         if (isStopRow(currentRow)) {
           if (filter != null && filter.hasFilterRow()) {
             filter.filterRow(results);
           }
           
           return false;
-        } else if (filterRowKey(currentRow)) {
+        } else if (kv != null && !kv.isInternal() && filterRowKey(currentRow)) {
           nextRow(currentRow);
         } else {
           byte [] nextRow;

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestFakeKeyInFilter.java

@@ -0,0 +1,84 @@
+/*
+ * 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.client;
+
+import java.util.ArrayList;
+
+import org.apache.hadoop.hbase.*;
+import org.apache.hadoop.hbase.filter.*;
+import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.regionserver.RegionScanner;
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.hbase.util.FSUtils;
+import org.junit.*;
+import org.junit.experimental.categories.Category;
+
+/**
+ * Make sure the fake KVs created internally are never user visible
+ * (not even to filters)
+ */
+@Category(SmallTests.class)
+public class TestFakeKeyInFilter extends BinaryComparator {
+  protected static HBaseTestingUtility UTIL = new HBaseTestingUtility();
+
+  public TestFakeKeyInFilter() {
+    super(Bytes.toBytes("foo"));
+  }
+
+  @Override
+  public int compareTo(byte[] value, int offset, int length) {
+    if (value.length == 0) {
+      throw new RuntimeException("Found mysterious empty row");
+    }
+    return 0;
+  }
+
+  /**
+   * Simple way to verify the scenario.
+   * There are no KVs with an empty row key in the
+   * table, yet such a KV is presented to the filter.
+   */
+  @Test
+  public void testForEmptyRowKey() throws Exception {
+    byte[] table = Bytes.toBytes("testForEmptyRowKey");
+    byte[] row = Bytes.toBytes("myRow");
+    byte[] cf = Bytes.toBytes("myFamily");
+    byte[] cq = Bytes.toBytes("myColumn");
+    HTableDescriptor desc = new HTableDescriptor(table);
+    desc.addFamily(new HColumnDescriptor(cf));
+    HRegionInfo hri = new HRegionInfo(desc.getName(), null, null);
+    HRegion region = HRegion.createHRegion(hri, FSUtils.getRootDir(UTIL.getConfiguration()), UTIL.getConfiguration(), desc);
+    Put put = new Put(row);
+    put.add(cf, cq, cq);
+    region.put(put);
+    region.flushcache();
+    Scan scan = new Scan();
+    scan.addColumn(cf, cq);
+    WritableByteArrayComparable comparable = new TestFakeKeyInFilter();
+    Filter filter = new RowFilter(CompareFilter.CompareOp.EQUAL, comparable);
+    scan.setFilter(filter);
+    RegionScanner scanner = region.getScanner(scan);
+    scanner.next(new ArrayList<KeyValue>());
+    scanner.close();
+    region.close();
+  }
+
+  @org.junit.Rule
+  public org.apache.hadoop.hbase.ResourceCheckerJUnitRule cu =
+    new org.apache.hadoop.hbase.ResourceCheckerJUnitRule();
+}