You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@hbase.apache.org by gi...@apache.org on 2018/12/14 14:53:00 UTC

[2/6] hbase-site git commit: Published site at 1b08ba7385d0dd914a6fb9722b786e4ece116b28.

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/StoreScanner.html
----------------------------------------------------------------------
diff --git a/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/StoreScanner.html b/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/StoreScanner.html
index 4041360..24feb2d 100644
--- a/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/StoreScanner.html
+++ b/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/StoreScanner.html
@@ -810,360 +810,368 @@
 <span class="sourceLineNo">802</span>  @VisibleForTesting<a name="line.802"></a>
 <span class="sourceLineNo">803</span>  protected boolean trySkipToNextRow(Cell cell) throws IOException {<a name="line.803"></a>
 <span class="sourceLineNo">804</span>    Cell nextCell = null;<a name="line.804"></a>
-<span class="sourceLineNo">805</span>    do {<a name="line.805"></a>
-<span class="sourceLineNo">806</span>      Cell nextIndexedKey = getNextIndexedKey();<a name="line.806"></a>
-<span class="sourceLineNo">807</span>      if (nextIndexedKey != null &amp;&amp; nextIndexedKey != KeyValueScanner.NO_NEXT_INDEXED_KEY<a name="line.807"></a>
-<span class="sourceLineNo">808</span>          &amp;&amp; matcher.compareKeyForNextRow(nextIndexedKey, cell) &gt;= 0) {<a name="line.808"></a>
-<span class="sourceLineNo">809</span>        this.heap.next();<a name="line.809"></a>
-<span class="sourceLineNo">810</span>        ++kvsScanned;<a name="line.810"></a>
-<span class="sourceLineNo">811</span>      } else {<a name="line.811"></a>
-<span class="sourceLineNo">812</span>        return false;<a name="line.812"></a>
-<span class="sourceLineNo">813</span>      }<a name="line.813"></a>
-<span class="sourceLineNo">814</span>    } while ((nextCell = this.heap.peek()) != null &amp;&amp; CellUtil.matchingRows(cell, nextCell));<a name="line.814"></a>
-<span class="sourceLineNo">815</span>    return true;<a name="line.815"></a>
-<span class="sourceLineNo">816</span>  }<a name="line.816"></a>
-<span class="sourceLineNo">817</span><a name="line.817"></a>
-<span class="sourceLineNo">818</span>  /**<a name="line.818"></a>
-<span class="sourceLineNo">819</span>   * See {@link org.apache.hadoop.hbase.regionserver.StoreScanner#trySkipToNextRow(Cell)}<a name="line.819"></a>
-<span class="sourceLineNo">820</span>   * @param cell current cell<a name="line.820"></a>
-<span class="sourceLineNo">821</span>   * @return true means skip to next column, false means not<a name="line.821"></a>
-<span class="sourceLineNo">822</span>   */<a name="line.822"></a>
-<span class="sourceLineNo">823</span>  @VisibleForTesting<a name="line.823"></a>
-<span class="sourceLineNo">824</span>  protected boolean trySkipToNextColumn(Cell cell) throws IOException {<a name="line.824"></a>
-<span class="sourceLineNo">825</span>    Cell nextCell = null;<a name="line.825"></a>
-<span class="sourceLineNo">826</span>    do {<a name="line.826"></a>
-<span class="sourceLineNo">827</span>      Cell nextIndexedKey = getNextIndexedKey();<a name="line.827"></a>
-<span class="sourceLineNo">828</span>      if (nextIndexedKey != null &amp;&amp; nextIndexedKey != KeyValueScanner.NO_NEXT_INDEXED_KEY<a name="line.828"></a>
-<span class="sourceLineNo">829</span>          &amp;&amp; matcher.compareKeyForNextColumn(nextIndexedKey, cell) &gt;= 0) {<a name="line.829"></a>
-<span class="sourceLineNo">830</span>        this.heap.next();<a name="line.830"></a>
-<span class="sourceLineNo">831</span>        ++kvsScanned;<a name="line.831"></a>
-<span class="sourceLineNo">832</span>      } else {<a name="line.832"></a>
-<span class="sourceLineNo">833</span>        return false;<a name="line.833"></a>
-<span class="sourceLineNo">834</span>      }<a name="line.834"></a>
-<span class="sourceLineNo">835</span>    } while ((nextCell = this.heap.peek()) != null &amp;&amp; CellUtil.matchingRowColumn(cell, nextCell));<a name="line.835"></a>
-<span class="sourceLineNo">836</span>    // We need this check because it may happen that the new scanner that we get<a name="line.836"></a>
-<span class="sourceLineNo">837</span>    // during heap.next() is requiring reseek due of fake KV previously generated for<a name="line.837"></a>
-<span class="sourceLineNo">838</span>    // ROWCOL bloom filter optimization. See HBASE-19863 for more details<a name="line.838"></a>
-<span class="sourceLineNo">839</span>    if (nextCell != null &amp;&amp; matcher.compareKeyForNextColumn(nextCell, cell) &lt; 0) {<a name="line.839"></a>
-<span class="sourceLineNo">840</span>      return false;<a name="line.840"></a>
-<span class="sourceLineNo">841</span>    }<a name="line.841"></a>
-<span class="sourceLineNo">842</span>    return true;<a name="line.842"></a>
-<span class="sourceLineNo">843</span>  }<a name="line.843"></a>
-<span class="sourceLineNo">844</span><a name="line.844"></a>
-<span class="sourceLineNo">845</span>  @Override<a name="line.845"></a>
-<span class="sourceLineNo">846</span>  public long getReadPoint() {<a name="line.846"></a>
-<span class="sourceLineNo">847</span>    return this.readPt;<a name="line.847"></a>
-<span class="sourceLineNo">848</span>  }<a name="line.848"></a>
-<span class="sourceLineNo">849</span><a name="line.849"></a>
-<span class="sourceLineNo">850</span>  private static void clearAndClose(List&lt;KeyValueScanner&gt; scanners) {<a name="line.850"></a>
-<span class="sourceLineNo">851</span>    for (KeyValueScanner s : scanners) {<a name="line.851"></a>
-<span class="sourceLineNo">852</span>      s.close();<a name="line.852"></a>
-<span class="sourceLineNo">853</span>    }<a name="line.853"></a>
-<span class="sourceLineNo">854</span>    scanners.clear();<a name="line.854"></a>
-<span class="sourceLineNo">855</span>  }<a name="line.855"></a>
-<span class="sourceLineNo">856</span><a name="line.856"></a>
-<span class="sourceLineNo">857</span>  // Implementation of ChangedReadersObserver<a name="line.857"></a>
-<span class="sourceLineNo">858</span>  @Override<a name="line.858"></a>
-<span class="sourceLineNo">859</span>  public void updateReaders(List&lt;HStoreFile&gt; sfs, List&lt;KeyValueScanner&gt; memStoreScanners)<a name="line.859"></a>
-<span class="sourceLineNo">860</span>      throws IOException {<a name="line.860"></a>
-<span class="sourceLineNo">861</span>    if (CollectionUtils.isEmpty(sfs) &amp;&amp; CollectionUtils.isEmpty(memStoreScanners)) {<a name="line.861"></a>
-<span class="sourceLineNo">862</span>      return;<a name="line.862"></a>
-<span class="sourceLineNo">863</span>    }<a name="line.863"></a>
-<span class="sourceLineNo">864</span>    flushLock.lock();<a name="line.864"></a>
-<span class="sourceLineNo">865</span>    try {<a name="line.865"></a>
-<span class="sourceLineNo">866</span>      flushed = true;<a name="line.866"></a>
-<span class="sourceLineNo">867</span>      final boolean isCompaction = false;<a name="line.867"></a>
-<span class="sourceLineNo">868</span>      boolean usePread = get || scanUsePread;<a name="line.868"></a>
-<span class="sourceLineNo">869</span>      // SEE HBASE-19468 where the flushed files are getting compacted even before a scanner<a name="line.869"></a>
-<span class="sourceLineNo">870</span>      // calls next(). So its better we create scanners here rather than next() call. Ensure<a name="line.870"></a>
-<span class="sourceLineNo">871</span>      // these scanners are properly closed() whether or not the scan is completed successfully<a name="line.871"></a>
-<span class="sourceLineNo">872</span>      // Eagerly creating scanners so that we have the ref counting ticking on the newly created<a name="line.872"></a>
-<span class="sourceLineNo">873</span>      // store files. In case of stream scanners this eager creation does not induce performance<a name="line.873"></a>
-<span class="sourceLineNo">874</span>      // penalty because in scans (that uses stream scanners) the next() call is bound to happen.<a name="line.874"></a>
-<span class="sourceLineNo">875</span>      List&lt;KeyValueScanner&gt; scanners = store.getScanners(sfs, cacheBlocks, get, usePread,<a name="line.875"></a>
-<span class="sourceLineNo">876</span>        isCompaction, matcher, scan.getStartRow(), scan.getStopRow(), this.readPt, false);<a name="line.876"></a>
-<span class="sourceLineNo">877</span>      flushedstoreFileScanners.addAll(scanners);<a name="line.877"></a>
-<span class="sourceLineNo">878</span>      if (!CollectionUtils.isEmpty(memStoreScanners)) {<a name="line.878"></a>
-<span class="sourceLineNo">879</span>        clearAndClose(memStoreScannersAfterFlush);<a name="line.879"></a>
-<span class="sourceLineNo">880</span>        memStoreScannersAfterFlush.addAll(memStoreScanners);<a name="line.880"></a>
-<span class="sourceLineNo">881</span>      }<a name="line.881"></a>
-<span class="sourceLineNo">882</span>    } finally {<a name="line.882"></a>
-<span class="sourceLineNo">883</span>      flushLock.unlock();<a name="line.883"></a>
-<span class="sourceLineNo">884</span>    }<a name="line.884"></a>
-<span class="sourceLineNo">885</span>    // Let the next() call handle re-creating and seeking<a name="line.885"></a>
-<span class="sourceLineNo">886</span>  }<a name="line.886"></a>
-<span class="sourceLineNo">887</span><a name="line.887"></a>
-<span class="sourceLineNo">888</span>  /**<a name="line.888"></a>
-<span class="sourceLineNo">889</span>   * @return if top of heap has changed (and KeyValueHeap has to try the next KV)<a name="line.889"></a>
-<span class="sourceLineNo">890</span>   */<a name="line.890"></a>
-<span class="sourceLineNo">891</span>  protected final boolean reopenAfterFlush() throws IOException {<a name="line.891"></a>
-<span class="sourceLineNo">892</span>    // here we can make sure that we have a Store instance so no null check on store.<a name="line.892"></a>
-<span class="sourceLineNo">893</span>    Cell lastTop = heap.peek();<a name="line.893"></a>
-<span class="sourceLineNo">894</span>    // When we have the scan object, should we not pass it to getScanners() to get a limited set of<a name="line.894"></a>
-<span class="sourceLineNo">895</span>    // scanners? We did so in the constructor and we could have done it now by storing the scan<a name="line.895"></a>
-<span class="sourceLineNo">896</span>    // object from the constructor<a name="line.896"></a>
-<span class="sourceLineNo">897</span>    List&lt;KeyValueScanner&gt; scanners;<a name="line.897"></a>
-<span class="sourceLineNo">898</span>    flushLock.lock();<a name="line.898"></a>
-<span class="sourceLineNo">899</span>    try {<a name="line.899"></a>
-<span class="sourceLineNo">900</span>      List&lt;KeyValueScanner&gt; allScanners =<a name="line.900"></a>
-<span class="sourceLineNo">901</span>          new ArrayList&lt;&gt;(flushedstoreFileScanners.size() + memStoreScannersAfterFlush.size());<a name="line.901"></a>
-<span class="sourceLineNo">902</span>      allScanners.addAll(flushedstoreFileScanners);<a name="line.902"></a>
-<span class="sourceLineNo">903</span>      allScanners.addAll(memStoreScannersAfterFlush);<a name="line.903"></a>
-<span class="sourceLineNo">904</span>      scanners = selectScannersFrom(store, allScanners);<a name="line.904"></a>
-<span class="sourceLineNo">905</span>      // Clear the current set of flushed store files scanners so that they don't get added again<a name="line.905"></a>
-<span class="sourceLineNo">906</span>      flushedstoreFileScanners.clear();<a name="line.906"></a>
-<span class="sourceLineNo">907</span>      memStoreScannersAfterFlush.clear();<a name="line.907"></a>
-<span class="sourceLineNo">908</span>    } finally {<a name="line.908"></a>
-<span class="sourceLineNo">909</span>      flushLock.unlock();<a name="line.909"></a>
-<span class="sourceLineNo">910</span>    }<a name="line.910"></a>
-<span class="sourceLineNo">911</span><a name="line.911"></a>
-<span class="sourceLineNo">912</span>    // Seek the new scanners to the last key<a name="line.912"></a>
-<span class="sourceLineNo">913</span>    seekScanners(scanners, lastTop, false, parallelSeekEnabled);<a name="line.913"></a>
-<span class="sourceLineNo">914</span>    // remove the older memstore scanner<a name="line.914"></a>
-<span class="sourceLineNo">915</span>    for (int i = currentScanners.size() - 1; i &gt;=0; i--) {<a name="line.915"></a>
-<span class="sourceLineNo">916</span>      if (!currentScanners.get(i).isFileScanner()) {<a name="line.916"></a>
-<span class="sourceLineNo">917</span>        scannersForDelayedClose.add(currentScanners.remove(i));<a name="line.917"></a>
-<span class="sourceLineNo">918</span>      } else {<a name="line.918"></a>
-<span class="sourceLineNo">919</span>        // we add the memstore scanner to the end of currentScanners<a name="line.919"></a>
-<span class="sourceLineNo">920</span>        break;<a name="line.920"></a>
-<span class="sourceLineNo">921</span>      }<a name="line.921"></a>
-<span class="sourceLineNo">922</span>    }<a name="line.922"></a>
-<span class="sourceLineNo">923</span>    // add the newly created scanners on the flushed files and the current active memstore scanner<a name="line.923"></a>
-<span class="sourceLineNo">924</span>    addCurrentScanners(scanners);<a name="line.924"></a>
-<span class="sourceLineNo">925</span>    // Combine all seeked scanners with a heap<a name="line.925"></a>
-<span class="sourceLineNo">926</span>    resetKVHeap(this.currentScanners, store.getComparator());<a name="line.926"></a>
-<span class="sourceLineNo">927</span>    resetQueryMatcher(lastTop);<a name="line.927"></a>
-<span class="sourceLineNo">928</span>    if (heap.peek() == null || store.getComparator().compareRows(lastTop, this.heap.peek()) != 0) {<a name="line.928"></a>
-<span class="sourceLineNo">929</span>      LOG.info("Storescanner.peek() is changed where before = " + lastTop.toString() +<a name="line.929"></a>
-<span class="sourceLineNo">930</span>          ",and after = " + heap.peek());<a name="line.930"></a>
-<span class="sourceLineNo">931</span>      topChanged = true;<a name="line.931"></a>
-<span class="sourceLineNo">932</span>    } else {<a name="line.932"></a>
-<span class="sourceLineNo">933</span>      topChanged = false;<a name="line.933"></a>
-<span class="sourceLineNo">934</span>    }<a name="line.934"></a>
-<span class="sourceLineNo">935</span>    return topChanged;<a name="line.935"></a>
-<span class="sourceLineNo">936</span>  }<a name="line.936"></a>
-<span class="sourceLineNo">937</span><a name="line.937"></a>
-<span class="sourceLineNo">938</span>  private void resetQueryMatcher(Cell lastTopKey) {<a name="line.938"></a>
-<span class="sourceLineNo">939</span>    // Reset the state of the Query Matcher and set to top row.<a name="line.939"></a>
-<span class="sourceLineNo">940</span>    // Only reset and call setRow if the row changes; avoids confusing the<a name="line.940"></a>
-<span class="sourceLineNo">941</span>    // query matcher if scanning intra-row.<a name="line.941"></a>
-<span class="sourceLineNo">942</span>    Cell cell = heap.peek();<a name="line.942"></a>
-<span class="sourceLineNo">943</span>    if (cell == null) {<a name="line.943"></a>
-<span class="sourceLineNo">944</span>      cell = lastTopKey;<a name="line.944"></a>
-<span class="sourceLineNo">945</span>    }<a name="line.945"></a>
-<span class="sourceLineNo">946</span>    if ((matcher.currentRow() == null) || !CellUtil.matchingRows(cell, matcher.currentRow())) {<a name="line.946"></a>
-<span class="sourceLineNo">947</span>      this.countPerRow = 0;<a name="line.947"></a>
-<span class="sourceLineNo">948</span>      // The setToNewRow will call reset internally<a name="line.948"></a>
-<span class="sourceLineNo">949</span>      matcher.setToNewRow(cell);<a name="line.949"></a>
-<span class="sourceLineNo">950</span>    }<a name="line.950"></a>
-<span class="sourceLineNo">951</span>  }<a name="line.951"></a>
-<span class="sourceLineNo">952</span><a name="line.952"></a>
-<span class="sourceLineNo">953</span>  /**<a name="line.953"></a>
-<span class="sourceLineNo">954</span>   * Check whether scan as expected order<a name="line.954"></a>
-<span class="sourceLineNo">955</span>   * @param prevKV<a name="line.955"></a>
-<span class="sourceLineNo">956</span>   * @param kv<a name="line.956"></a>
-<span class="sourceLineNo">957</span>   * @param comparator<a name="line.957"></a>
-<span class="sourceLineNo">958</span>   * @throws IOException<a name="line.958"></a>
-<span class="sourceLineNo">959</span>   */<a name="line.959"></a>
-<span class="sourceLineNo">960</span>  protected void checkScanOrder(Cell prevKV, Cell kv,<a name="line.960"></a>
-<span class="sourceLineNo">961</span>      CellComparator comparator) throws IOException {<a name="line.961"></a>
-<span class="sourceLineNo">962</span>    // Check that the heap gives us KVs in an increasing order.<a name="line.962"></a>
-<span class="sourceLineNo">963</span>    assert prevKV == null || comparator == null<a name="line.963"></a>
-<span class="sourceLineNo">964</span>        || comparator.compare(prevKV, kv) &lt;= 0 : "Key " + prevKV<a name="line.964"></a>
-<span class="sourceLineNo">965</span>        + " followed by a " + "smaller key " + kv + " in cf " + store;<a name="line.965"></a>
-<span class="sourceLineNo">966</span>  }<a name="line.966"></a>
-<span class="sourceLineNo">967</span><a name="line.967"></a>
-<span class="sourceLineNo">968</span>  protected boolean seekToNextRow(Cell c) throws IOException {<a name="line.968"></a>
-<span class="sourceLineNo">969</span>    return reseek(PrivateCellUtil.createLastOnRow(c));<a name="line.969"></a>
-<span class="sourceLineNo">970</span>  }<a name="line.970"></a>
-<span class="sourceLineNo">971</span><a name="line.971"></a>
-<span class="sourceLineNo">972</span>  /**<a name="line.972"></a>
-<span class="sourceLineNo">973</span>   * Do a reseek in a normal StoreScanner(scan forward)<a name="line.973"></a>
-<span class="sourceLineNo">974</span>   * @param kv<a name="line.974"></a>
-<span class="sourceLineNo">975</span>   * @return true if scanner has values left, false if end of scanner<a name="line.975"></a>
-<span class="sourceLineNo">976</span>   * @throws IOException<a name="line.976"></a>
-<span class="sourceLineNo">977</span>   */<a name="line.977"></a>
-<span class="sourceLineNo">978</span>  protected boolean seekAsDirection(Cell kv)<a name="line.978"></a>
-<span class="sourceLineNo">979</span>      throws IOException {<a name="line.979"></a>
-<span class="sourceLineNo">980</span>    return reseek(kv);<a name="line.980"></a>
-<span class="sourceLineNo">981</span>  }<a name="line.981"></a>
-<span class="sourceLineNo">982</span><a name="line.982"></a>
-<span class="sourceLineNo">983</span>  @Override<a name="line.983"></a>
-<span class="sourceLineNo">984</span>  public boolean reseek(Cell kv) throws IOException {<a name="line.984"></a>
-<span class="sourceLineNo">985</span>    if (checkFlushed()) {<a name="line.985"></a>
-<span class="sourceLineNo">986</span>      reopenAfterFlush();<a name="line.986"></a>
-<span class="sourceLineNo">987</span>    }<a name="line.987"></a>
-<span class="sourceLineNo">988</span>    if (explicitColumnQuery &amp;&amp; lazySeekEnabledGlobally) {<a name="line.988"></a>
-<span class="sourceLineNo">989</span>      return heap.requestSeek(kv, true, useRowColBloom);<a name="line.989"></a>
-<span class="sourceLineNo">990</span>    }<a name="line.990"></a>
-<span class="sourceLineNo">991</span>    return heap.reseek(kv);<a name="line.991"></a>
-<span class="sourceLineNo">992</span>  }<a name="line.992"></a>
-<span class="sourceLineNo">993</span><a name="line.993"></a>
-<span class="sourceLineNo">994</span>  @VisibleForTesting<a name="line.994"></a>
-<span class="sourceLineNo">995</span>  void trySwitchToStreamRead() {<a name="line.995"></a>
-<span class="sourceLineNo">996</span>    if (readType != Scan.ReadType.DEFAULT || !scanUsePread || closing ||<a name="line.996"></a>
-<span class="sourceLineNo">997</span>        heap.peek() == null || bytesRead &lt; preadMaxBytes) {<a name="line.997"></a>
-<span class="sourceLineNo">998</span>      return;<a name="line.998"></a>
-<span class="sourceLineNo">999</span>    }<a name="line.999"></a>
-<span class="sourceLineNo">1000</span>    LOG.debug("Switch to stream read (scanned={} bytes) of {}", bytesRead,<a name="line.1000"></a>
-<span class="sourceLineNo">1001</span>        this.store.getColumnFamilyName());<a name="line.1001"></a>
-<span class="sourceLineNo">1002</span>    scanUsePread = false;<a name="line.1002"></a>
-<span class="sourceLineNo">1003</span>    Cell lastTop = heap.peek();<a name="line.1003"></a>
-<span class="sourceLineNo">1004</span>    List&lt;KeyValueScanner&gt; memstoreScanners = new ArrayList&lt;&gt;();<a name="line.1004"></a>
-<span class="sourceLineNo">1005</span>    List&lt;KeyValueScanner&gt; scannersToClose = new ArrayList&lt;&gt;();<a name="line.1005"></a>
-<span class="sourceLineNo">1006</span>    for (KeyValueScanner kvs : currentScanners) {<a name="line.1006"></a>
-<span class="sourceLineNo">1007</span>      if (!kvs.isFileScanner()) {<a name="line.1007"></a>
-<span class="sourceLineNo">1008</span>        // collect memstorescanners here<a name="line.1008"></a>
-<span class="sourceLineNo">1009</span>        memstoreScanners.add(kvs);<a name="line.1009"></a>
-<span class="sourceLineNo">1010</span>      } else {<a name="line.1010"></a>
-<span class="sourceLineNo">1011</span>        scannersToClose.add(kvs);<a name="line.1011"></a>
-<span class="sourceLineNo">1012</span>      }<a name="line.1012"></a>
-<span class="sourceLineNo">1013</span>    }<a name="line.1013"></a>
-<span class="sourceLineNo">1014</span>    List&lt;KeyValueScanner&gt; fileScanners = null;<a name="line.1014"></a>
-<span class="sourceLineNo">1015</span>    List&lt;KeyValueScanner&gt; newCurrentScanners;<a name="line.1015"></a>
-<span class="sourceLineNo">1016</span>    KeyValueHeap newHeap;<a name="line.1016"></a>
-<span class="sourceLineNo">1017</span>    try {<a name="line.1017"></a>
-<span class="sourceLineNo">1018</span>      // We must have a store instance here so no null check<a name="line.1018"></a>
-<span class="sourceLineNo">1019</span>      // recreate the scanners on the current file scanners<a name="line.1019"></a>
-<span class="sourceLineNo">1020</span>      fileScanners = store.recreateScanners(scannersToClose, cacheBlocks, false, false,<a name="line.1020"></a>
-<span class="sourceLineNo">1021</span>        matcher, scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(),<a name="line.1021"></a>
-<span class="sourceLineNo">1022</span>        scan.includeStopRow(), readPt, false);<a name="line.1022"></a>
-<span class="sourceLineNo">1023</span>      if (fileScanners == null) {<a name="line.1023"></a>
-<span class="sourceLineNo">1024</span>        return;<a name="line.1024"></a>
-<span class="sourceLineNo">1025</span>      }<a name="line.1025"></a>
-<span class="sourceLineNo">1026</span>      seekScanners(fileScanners, lastTop, false, parallelSeekEnabled);<a name="line.1026"></a>
-<span class="sourceLineNo">1027</span>      newCurrentScanners = new ArrayList&lt;&gt;(fileScanners.size() + memstoreScanners.size());<a name="line.1027"></a>
-<span class="sourceLineNo">1028</span>      newCurrentScanners.addAll(fileScanners);<a name="line.1028"></a>
-<span class="sourceLineNo">1029</span>      newCurrentScanners.addAll(memstoreScanners);<a name="line.1029"></a>
-<span class="sourceLineNo">1030</span>      newHeap = new KeyValueHeap(newCurrentScanners, comparator);<a name="line.1030"></a>
-<span class="sourceLineNo">1031</span>    } catch (Exception e) {<a name="line.1031"></a>
-<span class="sourceLineNo">1032</span>      LOG.warn("failed to switch to stream read", e);<a name="line.1032"></a>
-<span class="sourceLineNo">1033</span>      if (fileScanners != null) {<a name="line.1033"></a>
-<span class="sourceLineNo">1034</span>        fileScanners.forEach(KeyValueScanner::close);<a name="line.1034"></a>
-<span class="sourceLineNo">1035</span>      }<a name="line.1035"></a>
-<span class="sourceLineNo">1036</span>      return;<a name="line.1036"></a>
-<span class="sourceLineNo">1037</span>    }<a name="line.1037"></a>
-<span class="sourceLineNo">1038</span>    currentScanners.clear();<a name="line.1038"></a>
-<span class="sourceLineNo">1039</span>    addCurrentScanners(newCurrentScanners);<a name="line.1039"></a>
-<span class="sourceLineNo">1040</span>    this.heap = newHeap;<a name="line.1040"></a>
-<span class="sourceLineNo">1041</span>    resetQueryMatcher(lastTop);<a name="line.1041"></a>
-<span class="sourceLineNo">1042</span>    scannersToClose.forEach(KeyValueScanner::close);<a name="line.1042"></a>
-<span class="sourceLineNo">1043</span>  }<a name="line.1043"></a>
-<span class="sourceLineNo">1044</span><a name="line.1044"></a>
-<span class="sourceLineNo">1045</span>  protected final boolean checkFlushed() {<a name="line.1045"></a>
-<span class="sourceLineNo">1046</span>    // check the var without any lock. Suppose even if we see the old<a name="line.1046"></a>
-<span class="sourceLineNo">1047</span>    // value here still it is ok to continue because we will not be resetting<a name="line.1047"></a>
-<span class="sourceLineNo">1048</span>    // the heap but will continue with the referenced memstore's snapshot. For compactions<a name="line.1048"></a>
-<span class="sourceLineNo">1049</span>    // any way we don't need the updateReaders at all to happen as we still continue with<a name="line.1049"></a>
-<span class="sourceLineNo">1050</span>    // the older files<a name="line.1050"></a>
-<span class="sourceLineNo">1051</span>    if (flushed) {<a name="line.1051"></a>
-<span class="sourceLineNo">1052</span>      // If there is a flush and the current scan is notified on the flush ensure that the<a name="line.1052"></a>
-<span class="sourceLineNo">1053</span>      // scan's heap gets reset and we do a seek on the newly flushed file.<a name="line.1053"></a>
-<span class="sourceLineNo">1054</span>      if (this.closing) {<a name="line.1054"></a>
-<span class="sourceLineNo">1055</span>        return false;<a name="line.1055"></a>
-<span class="sourceLineNo">1056</span>      }<a name="line.1056"></a>
-<span class="sourceLineNo">1057</span>      // reset the flag<a name="line.1057"></a>
-<span class="sourceLineNo">1058</span>      flushed = false;<a name="line.1058"></a>
-<span class="sourceLineNo">1059</span>      return true;<a name="line.1059"></a>
-<span class="sourceLineNo">1060</span>    }<a name="line.1060"></a>
-<span class="sourceLineNo">1061</span>    return false;<a name="line.1061"></a>
-<span class="sourceLineNo">1062</span>  }<a name="line.1062"></a>
-<span class="sourceLineNo">1063</span><a name="line.1063"></a>
-<span class="sourceLineNo">1064</span><a name="line.1064"></a>
-<span class="sourceLineNo">1065</span>  /**<a name="line.1065"></a>
-<span class="sourceLineNo">1066</span>   * Seek storefiles in parallel to optimize IO latency as much as possible<a name="line.1066"></a>
-<span class="sourceLineNo">1067</span>   * @param scanners the list {@link KeyValueScanner}s to be read from<a name="line.1067"></a>
-<span class="sourceLineNo">1068</span>   * @param kv the KeyValue on which the operation is being requested<a name="line.1068"></a>
-<span class="sourceLineNo">1069</span>   * @throws IOException<a name="line.1069"></a>
-<span class="sourceLineNo">1070</span>   */<a name="line.1070"></a>
-<span class="sourceLineNo">1071</span>  private void parallelSeek(final List&lt;? extends KeyValueScanner&gt;<a name="line.1071"></a>
-<span class="sourceLineNo">1072</span>      scanners, final Cell kv) throws IOException {<a name="line.1072"></a>
-<span class="sourceLineNo">1073</span>    if (scanners.isEmpty()) return;<a name="line.1073"></a>
-<span class="sourceLineNo">1074</span>    int storeFileScannerCount = scanners.size();<a name="line.1074"></a>
-<span class="sourceLineNo">1075</span>    CountDownLatch latch = new CountDownLatch(storeFileScannerCount);<a name="line.1075"></a>
-<span class="sourceLineNo">1076</span>    List&lt;ParallelSeekHandler&gt; handlers = new ArrayList&lt;&gt;(storeFileScannerCount);<a name="line.1076"></a>
-<span class="sourceLineNo">1077</span>    for (KeyValueScanner scanner : scanners) {<a name="line.1077"></a>
-<span class="sourceLineNo">1078</span>      if (scanner instanceof StoreFileScanner) {<a name="line.1078"></a>
-<span class="sourceLineNo">1079</span>        ParallelSeekHandler seekHandler = new ParallelSeekHandler(scanner, kv,<a name="line.1079"></a>
-<span class="sourceLineNo">1080</span>          this.readPt, latch);<a name="line.1080"></a>
-<span class="sourceLineNo">1081</span>        executor.submit(seekHandler);<a name="line.1081"></a>
-<span class="sourceLineNo">1082</span>        handlers.add(seekHandler);<a name="line.1082"></a>
-<span class="sourceLineNo">1083</span>      } else {<a name="line.1083"></a>
-<span class="sourceLineNo">1084</span>        scanner.seek(kv);<a name="line.1084"></a>
-<span class="sourceLineNo">1085</span>        latch.countDown();<a name="line.1085"></a>
-<span class="sourceLineNo">1086</span>      }<a name="line.1086"></a>
-<span class="sourceLineNo">1087</span>    }<a name="line.1087"></a>
-<span class="sourceLineNo">1088</span><a name="line.1088"></a>
-<span class="sourceLineNo">1089</span>    try {<a name="line.1089"></a>
-<span class="sourceLineNo">1090</span>      latch.await();<a name="line.1090"></a>
-<span class="sourceLineNo">1091</span>    } catch (InterruptedException ie) {<a name="line.1091"></a>
-<span class="sourceLineNo">1092</span>      throw (InterruptedIOException)new InterruptedIOException().initCause(ie);<a name="line.1092"></a>
-<span class="sourceLineNo">1093</span>    }<a name="line.1093"></a>
-<span class="sourceLineNo">1094</span><a name="line.1094"></a>
-<span class="sourceLineNo">1095</span>    for (ParallelSeekHandler handler : handlers) {<a name="line.1095"></a>
-<span class="sourceLineNo">1096</span>      if (handler.getErr() != null) {<a name="line.1096"></a>
-<span class="sourceLineNo">1097</span>        throw new IOException(handler.getErr());<a name="line.1097"></a>
-<span class="sourceLineNo">1098</span>      }<a name="line.1098"></a>
-<span class="sourceLineNo">1099</span>    }<a name="line.1099"></a>
-<span class="sourceLineNo">1100</span>  }<a name="line.1100"></a>
-<span class="sourceLineNo">1101</span><a name="line.1101"></a>
-<span class="sourceLineNo">1102</span>  /**<a name="line.1102"></a>
-<span class="sourceLineNo">1103</span>   * Used in testing.<a name="line.1103"></a>
-<span class="sourceLineNo">1104</span>   * @return all scanners in no particular order<a name="line.1104"></a>
-<span class="sourceLineNo">1105</span>   */<a name="line.1105"></a>
-<span class="sourceLineNo">1106</span>  @VisibleForTesting<a name="line.1106"></a>
-<span class="sourceLineNo">1107</span>  List&lt;KeyValueScanner&gt; getAllScannersForTesting() {<a name="line.1107"></a>
-<span class="sourceLineNo">1108</span>    List&lt;KeyValueScanner&gt; allScanners = new ArrayList&lt;&gt;();<a name="line.1108"></a>
-<span class="sourceLineNo">1109</span>    KeyValueScanner current = heap.getCurrentForTesting();<a name="line.1109"></a>
-<span class="sourceLineNo">1110</span>    if (current != null)<a name="line.1110"></a>
-<span class="sourceLineNo">1111</span>      allScanners.add(current);<a name="line.1111"></a>
-<span class="sourceLineNo">1112</span>    for (KeyValueScanner scanner : heap.getHeap())<a name="line.1112"></a>
-<span class="sourceLineNo">1113</span>      allScanners.add(scanner);<a name="line.1113"></a>
-<span class="sourceLineNo">1114</span>    return allScanners;<a name="line.1114"></a>
-<span class="sourceLineNo">1115</span>  }<a name="line.1115"></a>
-<span class="sourceLineNo">1116</span><a name="line.1116"></a>
-<span class="sourceLineNo">1117</span>  static void enableLazySeekGlobally(boolean enable) {<a name="line.1117"></a>
-<span class="sourceLineNo">1118</span>    lazySeekEnabledGlobally = enable;<a name="line.1118"></a>
-<span class="sourceLineNo">1119</span>  }<a name="line.1119"></a>
-<span class="sourceLineNo">1120</span><a name="line.1120"></a>
-<span class="sourceLineNo">1121</span>  /**<a name="line.1121"></a>
-<span class="sourceLineNo">1122</span>   * @return The estimated number of KVs seen by this scanner (includes some skipped KVs).<a name="line.1122"></a>
-<span class="sourceLineNo">1123</span>   */<a name="line.1123"></a>
-<span class="sourceLineNo">1124</span>  public long getEstimatedNumberOfKvsScanned() {<a name="line.1124"></a>
-<span class="sourceLineNo">1125</span>    return this.kvsScanned;<a name="line.1125"></a>
-<span class="sourceLineNo">1126</span>  }<a name="line.1126"></a>
-<span class="sourceLineNo">1127</span><a name="line.1127"></a>
-<span class="sourceLineNo">1128</span>  @Override<a name="line.1128"></a>
-<span class="sourceLineNo">1129</span>  public Cell getNextIndexedKey() {<a name="line.1129"></a>
-<span class="sourceLineNo">1130</span>    return this.heap.getNextIndexedKey();<a name="line.1130"></a>
-<span class="sourceLineNo">1131</span>  }<a name="line.1131"></a>
-<span class="sourceLineNo">1132</span><a name="line.1132"></a>
-<span class="sourceLineNo">1133</span>  @Override<a name="line.1133"></a>
-<span class="sourceLineNo">1134</span>  public void shipped() throws IOException {<a name="line.1134"></a>
-<span class="sourceLineNo">1135</span>    if (prevCell != null) {<a name="line.1135"></a>
-<span class="sourceLineNo">1136</span>      // Do the copy here so that in case the prevCell ref is pointing to the previous<a name="line.1136"></a>
-<span class="sourceLineNo">1137</span>      // blocks we can safely release those blocks.<a name="line.1137"></a>
-<span class="sourceLineNo">1138</span>      // This applies to blocks that are got from Bucket cache, L1 cache and the blocks<a name="line.1138"></a>
-<span class="sourceLineNo">1139</span>      // fetched from HDFS. Copying this would ensure that we let go the references to these<a name="line.1139"></a>
-<span class="sourceLineNo">1140</span>      // blocks so that they can be GCed safely(in case of bucket cache)<a name="line.1140"></a>
-<span class="sourceLineNo">1141</span>      prevCell = KeyValueUtil.toNewKeyCell(this.prevCell);<a name="line.1141"></a>
-<span class="sourceLineNo">1142</span>    }<a name="line.1142"></a>
-<span class="sourceLineNo">1143</span>    matcher.beforeShipped();<a name="line.1143"></a>
-<span class="sourceLineNo">1144</span>    // There wont be further fetch of Cells from these scanners. Just close.<a name="line.1144"></a>
-<span class="sourceLineNo">1145</span>    clearAndClose(scannersForDelayedClose);<a name="line.1145"></a>
-<span class="sourceLineNo">1146</span>    if (this.heap != null) {<a name="line.1146"></a>
-<span class="sourceLineNo">1147</span>      this.heap.shipped();<a name="line.1147"></a>
-<span class="sourceLineNo">1148</span>      // When switching from pread to stream, we will open a new scanner for each store file, but<a name="line.1148"></a>
-<span class="sourceLineNo">1149</span>      // the old scanner may still track the HFileBlocks we have scanned but not sent back to client<a name="line.1149"></a>
-<span class="sourceLineNo">1150</span>      // yet. If we close the scanner immediately then the HFileBlocks may be messed up by others<a name="line.1150"></a>
-<span class="sourceLineNo">1151</span>      // before we serialize and send it back to client. The HFileBlocks will be released in shipped<a name="line.1151"></a>
-<span class="sourceLineNo">1152</span>      // method, so we here will also open new scanners and close old scanners in shipped method.<a name="line.1152"></a>
-<span class="sourceLineNo">1153</span>      // See HBASE-18055 for more details.<a name="line.1153"></a>
-<span class="sourceLineNo">1154</span>      trySwitchToStreamRead();<a name="line.1154"></a>
-<span class="sourceLineNo">1155</span>    }<a name="line.1155"></a>
-<span class="sourceLineNo">1156</span>  }<a name="line.1156"></a>
-<span class="sourceLineNo">1157</span>}<a name="line.1157"></a>
-<span class="sourceLineNo">1158</span><a name="line.1158"></a>
+<span class="sourceLineNo">805</span>    // used to guard against a changed next indexed key by doing a identity comparison<a name="line.805"></a>
+<span class="sourceLineNo">806</span>    // when the identity changes we need to compare the bytes again<a name="line.806"></a>
+<span class="sourceLineNo">807</span>    Cell previousIndexedKey = null;<a name="line.807"></a>
+<span class="sourceLineNo">808</span>    do {<a name="line.808"></a>
+<span class="sourceLineNo">809</span>      Cell nextIndexedKey = getNextIndexedKey();<a name="line.809"></a>
+<span class="sourceLineNo">810</span>      if (nextIndexedKey != null &amp;&amp; nextIndexedKey != KeyValueScanner.NO_NEXT_INDEXED_KEY<a name="line.810"></a>
+<span class="sourceLineNo">811</span>          &amp;&amp; (nextIndexedKey == previousIndexedKey || matcher.compareKeyForNextRow(nextIndexedKey, cell) &gt;= 0)) {<a name="line.811"></a>
+<span class="sourceLineNo">812</span>        this.heap.next();<a name="line.812"></a>
+<span class="sourceLineNo">813</span>        ++kvsScanned;<a name="line.813"></a>
+<span class="sourceLineNo">814</span>        previousIndexedKey = nextIndexedKey;<a name="line.814"></a>
+<span class="sourceLineNo">815</span>      } else {<a name="line.815"></a>
+<span class="sourceLineNo">816</span>        return false;<a name="line.816"></a>
+<span class="sourceLineNo">817</span>      }<a name="line.817"></a>
+<span class="sourceLineNo">818</span>    } while ((nextCell = this.heap.peek()) != null &amp;&amp; CellUtil.matchingRows(cell, nextCell));<a name="line.818"></a>
+<span class="sourceLineNo">819</span>    return true;<a name="line.819"></a>
+<span class="sourceLineNo">820</span>  }<a name="line.820"></a>
+<span class="sourceLineNo">821</span><a name="line.821"></a>
+<span class="sourceLineNo">822</span>  /**<a name="line.822"></a>
+<span class="sourceLineNo">823</span>   * See {@link org.apache.hadoop.hbase.regionserver.StoreScanner#trySkipToNextRow(Cell)}<a name="line.823"></a>
+<span class="sourceLineNo">824</span>   * @param cell current cell<a name="line.824"></a>
+<span class="sourceLineNo">825</span>   * @return true means skip to next column, false means not<a name="line.825"></a>
+<span class="sourceLineNo">826</span>   */<a name="line.826"></a>
+<span class="sourceLineNo">827</span>  @VisibleForTesting<a name="line.827"></a>
+<span class="sourceLineNo">828</span>  protected boolean trySkipToNextColumn(Cell cell) throws IOException {<a name="line.828"></a>
+<span class="sourceLineNo">829</span>    Cell nextCell = null;<a name="line.829"></a>
+<span class="sourceLineNo">830</span>    // used to guard against a changed next indexed key by doing a identity comparison<a name="line.830"></a>
+<span class="sourceLineNo">831</span>    // when the identity changes we need to compare the bytes again<a name="line.831"></a>
+<span class="sourceLineNo">832</span>    Cell previousIndexedKey = null;<a name="line.832"></a>
+<span class="sourceLineNo">833</span>    do {<a name="line.833"></a>
+<span class="sourceLineNo">834</span>      Cell nextIndexedKey = getNextIndexedKey();<a name="line.834"></a>
+<span class="sourceLineNo">835</span>      if (nextIndexedKey != null &amp;&amp; nextIndexedKey != KeyValueScanner.NO_NEXT_INDEXED_KEY<a name="line.835"></a>
+<span class="sourceLineNo">836</span>          &amp;&amp; (nextIndexedKey == previousIndexedKey || matcher.compareKeyForNextColumn(nextIndexedKey, cell) &gt;= 0)) {<a name="line.836"></a>
+<span class="sourceLineNo">837</span>        this.heap.next();<a name="line.837"></a>
+<span class="sourceLineNo">838</span>        ++kvsScanned;<a name="line.838"></a>
+<span class="sourceLineNo">839</span>        previousIndexedKey = nextIndexedKey;<a name="line.839"></a>
+<span class="sourceLineNo">840</span>      } else {<a name="line.840"></a>
+<span class="sourceLineNo">841</span>        return false;<a name="line.841"></a>
+<span class="sourceLineNo">842</span>      }<a name="line.842"></a>
+<span class="sourceLineNo">843</span>    } while ((nextCell = this.heap.peek()) != null &amp;&amp; CellUtil.matchingRowColumn(cell, nextCell));<a name="line.843"></a>
+<span class="sourceLineNo">844</span>    // We need this check because it may happen that the new scanner that we get<a name="line.844"></a>
+<span class="sourceLineNo">845</span>    // during heap.next() is requiring reseek due of fake KV previously generated for<a name="line.845"></a>
+<span class="sourceLineNo">846</span>    // ROWCOL bloom filter optimization. See HBASE-19863 for more details<a name="line.846"></a>
+<span class="sourceLineNo">847</span>    if (nextCell != null &amp;&amp; matcher.compareKeyForNextColumn(nextCell, cell) &lt; 0) {<a name="line.847"></a>
+<span class="sourceLineNo">848</span>      return false;<a name="line.848"></a>
+<span class="sourceLineNo">849</span>    }<a name="line.849"></a>
+<span class="sourceLineNo">850</span>    return true;<a name="line.850"></a>
+<span class="sourceLineNo">851</span>  }<a name="line.851"></a>
+<span class="sourceLineNo">852</span><a name="line.852"></a>
+<span class="sourceLineNo">853</span>  @Override<a name="line.853"></a>
+<span class="sourceLineNo">854</span>  public long getReadPoint() {<a name="line.854"></a>
+<span class="sourceLineNo">855</span>    return this.readPt;<a name="line.855"></a>
+<span class="sourceLineNo">856</span>  }<a name="line.856"></a>
+<span class="sourceLineNo">857</span><a name="line.857"></a>
+<span class="sourceLineNo">858</span>  private static void clearAndClose(List&lt;KeyValueScanner&gt; scanners) {<a name="line.858"></a>
+<span class="sourceLineNo">859</span>    for (KeyValueScanner s : scanners) {<a name="line.859"></a>
+<span class="sourceLineNo">860</span>      s.close();<a name="line.860"></a>
+<span class="sourceLineNo">861</span>    }<a name="line.861"></a>
+<span class="sourceLineNo">862</span>    scanners.clear();<a name="line.862"></a>
+<span class="sourceLineNo">863</span>  }<a name="line.863"></a>
+<span class="sourceLineNo">864</span><a name="line.864"></a>
+<span class="sourceLineNo">865</span>  // Implementation of ChangedReadersObserver<a name="line.865"></a>
+<span class="sourceLineNo">866</span>  @Override<a name="line.866"></a>
+<span class="sourceLineNo">867</span>  public void updateReaders(List&lt;HStoreFile&gt; sfs, List&lt;KeyValueScanner&gt; memStoreScanners)<a name="line.867"></a>
+<span class="sourceLineNo">868</span>      throws IOException {<a name="line.868"></a>
+<span class="sourceLineNo">869</span>    if (CollectionUtils.isEmpty(sfs) &amp;&amp; CollectionUtils.isEmpty(memStoreScanners)) {<a name="line.869"></a>
+<span class="sourceLineNo">870</span>      return;<a name="line.870"></a>
+<span class="sourceLineNo">871</span>    }<a name="line.871"></a>
+<span class="sourceLineNo">872</span>    flushLock.lock();<a name="line.872"></a>
+<span class="sourceLineNo">873</span>    try {<a name="line.873"></a>
+<span class="sourceLineNo">874</span>      flushed = true;<a name="line.874"></a>
+<span class="sourceLineNo">875</span>      final boolean isCompaction = false;<a name="line.875"></a>
+<span class="sourceLineNo">876</span>      boolean usePread = get || scanUsePread;<a name="line.876"></a>
+<span class="sourceLineNo">877</span>      // SEE HBASE-19468 where the flushed files are getting compacted even before a scanner<a name="line.877"></a>
+<span class="sourceLineNo">878</span>      // calls next(). So its better we create scanners here rather than next() call. Ensure<a name="line.878"></a>
+<span class="sourceLineNo">879</span>      // these scanners are properly closed() whether or not the scan is completed successfully<a name="line.879"></a>
+<span class="sourceLineNo">880</span>      // Eagerly creating scanners so that we have the ref counting ticking on the newly created<a name="line.880"></a>
+<span class="sourceLineNo">881</span>      // store files. In case of stream scanners this eager creation does not induce performance<a name="line.881"></a>
+<span class="sourceLineNo">882</span>      // penalty because in scans (that uses stream scanners) the next() call is bound to happen.<a name="line.882"></a>
+<span class="sourceLineNo">883</span>      List&lt;KeyValueScanner&gt; scanners = store.getScanners(sfs, cacheBlocks, get, usePread,<a name="line.883"></a>
+<span class="sourceLineNo">884</span>        isCompaction, matcher, scan.getStartRow(), scan.getStopRow(), this.readPt, false);<a name="line.884"></a>
+<span class="sourceLineNo">885</span>      flushedstoreFileScanners.addAll(scanners);<a name="line.885"></a>
+<span class="sourceLineNo">886</span>      if (!CollectionUtils.isEmpty(memStoreScanners)) {<a name="line.886"></a>
+<span class="sourceLineNo">887</span>        clearAndClose(memStoreScannersAfterFlush);<a name="line.887"></a>
+<span class="sourceLineNo">888</span>        memStoreScannersAfterFlush.addAll(memStoreScanners);<a name="line.888"></a>
+<span class="sourceLineNo">889</span>      }<a name="line.889"></a>
+<span class="sourceLineNo">890</span>    } finally {<a name="line.890"></a>
+<span class="sourceLineNo">891</span>      flushLock.unlock();<a name="line.891"></a>
+<span class="sourceLineNo">892</span>    }<a name="line.892"></a>
+<span class="sourceLineNo">893</span>    // Let the next() call handle re-creating and seeking<a name="line.893"></a>
+<span class="sourceLineNo">894</span>  }<a name="line.894"></a>
+<span class="sourceLineNo">895</span><a name="line.895"></a>
+<span class="sourceLineNo">896</span>  /**<a name="line.896"></a>
+<span class="sourceLineNo">897</span>   * @return if top of heap has changed (and KeyValueHeap has to try the next KV)<a name="line.897"></a>
+<span class="sourceLineNo">898</span>   */<a name="line.898"></a>
+<span class="sourceLineNo">899</span>  protected final boolean reopenAfterFlush() throws IOException {<a name="line.899"></a>
+<span class="sourceLineNo">900</span>    // here we can make sure that we have a Store instance so no null check on store.<a name="line.900"></a>
+<span class="sourceLineNo">901</span>    Cell lastTop = heap.peek();<a name="line.901"></a>
+<span class="sourceLineNo">902</span>    // When we have the scan object, should we not pass it to getScanners() to get a limited set of<a name="line.902"></a>
+<span class="sourceLineNo">903</span>    // scanners? We did so in the constructor and we could have done it now by storing the scan<a name="line.903"></a>
+<span class="sourceLineNo">904</span>    // object from the constructor<a name="line.904"></a>
+<span class="sourceLineNo">905</span>    List&lt;KeyValueScanner&gt; scanners;<a name="line.905"></a>
+<span class="sourceLineNo">906</span>    flushLock.lock();<a name="line.906"></a>
+<span class="sourceLineNo">907</span>    try {<a name="line.907"></a>
+<span class="sourceLineNo">908</span>      List&lt;KeyValueScanner&gt; allScanners =<a name="line.908"></a>
+<span class="sourceLineNo">909</span>          new ArrayList&lt;&gt;(flushedstoreFileScanners.size() + memStoreScannersAfterFlush.size());<a name="line.909"></a>
+<span class="sourceLineNo">910</span>      allScanners.addAll(flushedstoreFileScanners);<a name="line.910"></a>
+<span class="sourceLineNo">911</span>      allScanners.addAll(memStoreScannersAfterFlush);<a name="line.911"></a>
+<span class="sourceLineNo">912</span>      scanners = selectScannersFrom(store, allScanners);<a name="line.912"></a>
+<span class="sourceLineNo">913</span>      // Clear the current set of flushed store files scanners so that they don't get added again<a name="line.913"></a>
+<span class="sourceLineNo">914</span>      flushedstoreFileScanners.clear();<a name="line.914"></a>
+<span class="sourceLineNo">915</span>      memStoreScannersAfterFlush.clear();<a name="line.915"></a>
+<span class="sourceLineNo">916</span>    } finally {<a name="line.916"></a>
+<span class="sourceLineNo">917</span>      flushLock.unlock();<a name="line.917"></a>
+<span class="sourceLineNo">918</span>    }<a name="line.918"></a>
+<span class="sourceLineNo">919</span><a name="line.919"></a>
+<span class="sourceLineNo">920</span>    // Seek the new scanners to the last key<a name="line.920"></a>
+<span class="sourceLineNo">921</span>    seekScanners(scanners, lastTop, false, parallelSeekEnabled);<a name="line.921"></a>
+<span class="sourceLineNo">922</span>    // remove the older memstore scanner<a name="line.922"></a>
+<span class="sourceLineNo">923</span>    for (int i = currentScanners.size() - 1; i &gt;=0; i--) {<a name="line.923"></a>
+<span class="sourceLineNo">924</span>      if (!currentScanners.get(i).isFileScanner()) {<a name="line.924"></a>
+<span class="sourceLineNo">925</span>        scannersForDelayedClose.add(currentScanners.remove(i));<a name="line.925"></a>
+<span class="sourceLineNo">926</span>      } else {<a name="line.926"></a>
+<span class="sourceLineNo">927</span>        // we add the memstore scanner to the end of currentScanners<a name="line.927"></a>
+<span class="sourceLineNo">928</span>        break;<a name="line.928"></a>
+<span class="sourceLineNo">929</span>      }<a name="line.929"></a>
+<span class="sourceLineNo">930</span>    }<a name="line.930"></a>
+<span class="sourceLineNo">931</span>    // add the newly created scanners on the flushed files and the current active memstore scanner<a name="line.931"></a>
+<span class="sourceLineNo">932</span>    addCurrentScanners(scanners);<a name="line.932"></a>
+<span class="sourceLineNo">933</span>    // Combine all seeked scanners with a heap<a name="line.933"></a>
+<span class="sourceLineNo">934</span>    resetKVHeap(this.currentScanners, store.getComparator());<a name="line.934"></a>
+<span class="sourceLineNo">935</span>    resetQueryMatcher(lastTop);<a name="line.935"></a>
+<span class="sourceLineNo">936</span>    if (heap.peek() == null || store.getComparator().compareRows(lastTop, this.heap.peek()) != 0) {<a name="line.936"></a>
+<span class="sourceLineNo">937</span>      LOG.info("Storescanner.peek() is changed where before = " + lastTop.toString() +<a name="line.937"></a>
+<span class="sourceLineNo">938</span>          ",and after = " + heap.peek());<a name="line.938"></a>
+<span class="sourceLineNo">939</span>      topChanged = true;<a name="line.939"></a>
+<span class="sourceLineNo">940</span>    } else {<a name="line.940"></a>
+<span class="sourceLineNo">941</span>      topChanged = false;<a name="line.941"></a>
+<span class="sourceLineNo">942</span>    }<a name="line.942"></a>
+<span class="sourceLineNo">943</span>    return topChanged;<a name="line.943"></a>
+<span class="sourceLineNo">944</span>  }<a name="line.944"></a>
+<span class="sourceLineNo">945</span><a name="line.945"></a>
+<span class="sourceLineNo">946</span>  private void resetQueryMatcher(Cell lastTopKey) {<a name="line.946"></a>
+<span class="sourceLineNo">947</span>    // Reset the state of the Query Matcher and set to top row.<a name="line.947"></a>
+<span class="sourceLineNo">948</span>    // Only reset and call setRow if the row changes; avoids confusing the<a name="line.948"></a>
+<span class="sourceLineNo">949</span>    // query matcher if scanning intra-row.<a name="line.949"></a>
+<span class="sourceLineNo">950</span>    Cell cell = heap.peek();<a name="line.950"></a>
+<span class="sourceLineNo">951</span>    if (cell == null) {<a name="line.951"></a>
+<span class="sourceLineNo">952</span>      cell = lastTopKey;<a name="line.952"></a>
+<span class="sourceLineNo">953</span>    }<a name="line.953"></a>
+<span class="sourceLineNo">954</span>    if ((matcher.currentRow() == null) || !CellUtil.matchingRows(cell, matcher.currentRow())) {<a name="line.954"></a>
+<span class="sourceLineNo">955</span>      this.countPerRow = 0;<a name="line.955"></a>
+<span class="sourceLineNo">956</span>      // The setToNewRow will call reset internally<a name="line.956"></a>
+<span class="sourceLineNo">957</span>      matcher.setToNewRow(cell);<a name="line.957"></a>
+<span class="sourceLineNo">958</span>    }<a name="line.958"></a>
+<span class="sourceLineNo">959</span>  }<a name="line.959"></a>
+<span class="sourceLineNo">960</span><a name="line.960"></a>
+<span class="sourceLineNo">961</span>  /**<a name="line.961"></a>
+<span class="sourceLineNo">962</span>   * Check whether scan as expected order<a name="line.962"></a>
+<span class="sourceLineNo">963</span>   * @param prevKV<a name="line.963"></a>
+<span class="sourceLineNo">964</span>   * @param kv<a name="line.964"></a>
+<span class="sourceLineNo">965</span>   * @param comparator<a name="line.965"></a>
+<span class="sourceLineNo">966</span>   * @throws IOException<a name="line.966"></a>
+<span class="sourceLineNo">967</span>   */<a name="line.967"></a>
+<span class="sourceLineNo">968</span>  protected void checkScanOrder(Cell prevKV, Cell kv,<a name="line.968"></a>
+<span class="sourceLineNo">969</span>      CellComparator comparator) throws IOException {<a name="line.969"></a>
+<span class="sourceLineNo">970</span>    // Check that the heap gives us KVs in an increasing order.<a name="line.970"></a>
+<span class="sourceLineNo">971</span>    assert prevKV == null || comparator == null<a name="line.971"></a>
+<span class="sourceLineNo">972</span>        || comparator.compare(prevKV, kv) &lt;= 0 : "Key " + prevKV<a name="line.972"></a>
+<span class="sourceLineNo">973</span>        + " followed by a " + "smaller key " + kv + " in cf " + store;<a name="line.973"></a>
+<span class="sourceLineNo">974</span>  }<a name="line.974"></a>
+<span class="sourceLineNo">975</span><a name="line.975"></a>
+<span class="sourceLineNo">976</span>  protected boolean seekToNextRow(Cell c) throws IOException {<a name="line.976"></a>
+<span class="sourceLineNo">977</span>    return reseek(PrivateCellUtil.createLastOnRow(c));<a name="line.977"></a>
+<span class="sourceLineNo">978</span>  }<a name="line.978"></a>
+<span class="sourceLineNo">979</span><a name="line.979"></a>
+<span class="sourceLineNo">980</span>  /**<a name="line.980"></a>
+<span class="sourceLineNo">981</span>   * Do a reseek in a normal StoreScanner(scan forward)<a name="line.981"></a>
+<span class="sourceLineNo">982</span>   * @param kv<a name="line.982"></a>
+<span class="sourceLineNo">983</span>   * @return true if scanner has values left, false if end of scanner<a name="line.983"></a>
+<span class="sourceLineNo">984</span>   * @throws IOException<a name="line.984"></a>
+<span class="sourceLineNo">985</span>   */<a name="line.985"></a>
+<span class="sourceLineNo">986</span>  protected boolean seekAsDirection(Cell kv)<a name="line.986"></a>
+<span class="sourceLineNo">987</span>      throws IOException {<a name="line.987"></a>
+<span class="sourceLineNo">988</span>    return reseek(kv);<a name="line.988"></a>
+<span class="sourceLineNo">989</span>  }<a name="line.989"></a>
+<span class="sourceLineNo">990</span><a name="line.990"></a>
+<span class="sourceLineNo">991</span>  @Override<a name="line.991"></a>
+<span class="sourceLineNo">992</span>  public boolean reseek(Cell kv) throws IOException {<a name="line.992"></a>
+<span class="sourceLineNo">993</span>    if (checkFlushed()) {<a name="line.993"></a>
+<span class="sourceLineNo">994</span>      reopenAfterFlush();<a name="line.994"></a>
+<span class="sourceLineNo">995</span>    }<a name="line.995"></a>
+<span class="sourceLineNo">996</span>    if (explicitColumnQuery &amp;&amp; lazySeekEnabledGlobally) {<a name="line.996"></a>
+<span class="sourceLineNo">997</span>      return heap.requestSeek(kv, true, useRowColBloom);<a name="line.997"></a>
+<span class="sourceLineNo">998</span>    }<a name="line.998"></a>
+<span class="sourceLineNo">999</span>    return heap.reseek(kv);<a name="line.999"></a>
+<span class="sourceLineNo">1000</span>  }<a name="line.1000"></a>
+<span class="sourceLineNo">1001</span><a name="line.1001"></a>
+<span class="sourceLineNo">1002</span>  @VisibleForTesting<a name="line.1002"></a>
+<span class="sourceLineNo">1003</span>  void trySwitchToStreamRead() {<a name="line.1003"></a>
+<span class="sourceLineNo">1004</span>    if (readType != Scan.ReadType.DEFAULT || !scanUsePread || closing ||<a name="line.1004"></a>
+<span class="sourceLineNo">1005</span>        heap.peek() == null || bytesRead &lt; preadMaxBytes) {<a name="line.1005"></a>
+<span class="sourceLineNo">1006</span>      return;<a name="line.1006"></a>
+<span class="sourceLineNo">1007</span>    }<a name="line.1007"></a>
+<span class="sourceLineNo">1008</span>    LOG.debug("Switch to stream read (scanned={} bytes) of {}", bytesRead,<a name="line.1008"></a>
+<span class="sourceLineNo">1009</span>        this.store.getColumnFamilyName());<a name="line.1009"></a>
+<span class="sourceLineNo">1010</span>    scanUsePread = false;<a name="line.1010"></a>
+<span class="sourceLineNo">1011</span>    Cell lastTop = heap.peek();<a name="line.1011"></a>
+<span class="sourceLineNo">1012</span>    List&lt;KeyValueScanner&gt; memstoreScanners = new ArrayList&lt;&gt;();<a name="line.1012"></a>
+<span class="sourceLineNo">1013</span>    List&lt;KeyValueScanner&gt; scannersToClose = new ArrayList&lt;&gt;();<a name="line.1013"></a>
+<span class="sourceLineNo">1014</span>    for (KeyValueScanner kvs : currentScanners) {<a name="line.1014"></a>
+<span class="sourceLineNo">1015</span>      if (!kvs.isFileScanner()) {<a name="line.1015"></a>
+<span class="sourceLineNo">1016</span>        // collect memstorescanners here<a name="line.1016"></a>
+<span class="sourceLineNo">1017</span>        memstoreScanners.add(kvs);<a name="line.1017"></a>
+<span class="sourceLineNo">1018</span>      } else {<a name="line.1018"></a>
+<span class="sourceLineNo">1019</span>        scannersToClose.add(kvs);<a name="line.1019"></a>
+<span class="sourceLineNo">1020</span>      }<a name="line.1020"></a>
+<span class="sourceLineNo">1021</span>    }<a name="line.1021"></a>
+<span class="sourceLineNo">1022</span>    List&lt;KeyValueScanner&gt; fileScanners = null;<a name="line.1022"></a>
+<span class="sourceLineNo">1023</span>    List&lt;KeyValueScanner&gt; newCurrentScanners;<a name="line.1023"></a>
+<span class="sourceLineNo">1024</span>    KeyValueHeap newHeap;<a name="line.1024"></a>
+<span class="sourceLineNo">1025</span>    try {<a name="line.1025"></a>
+<span class="sourceLineNo">1026</span>      // We must have a store instance here so no null check<a name="line.1026"></a>
+<span class="sourceLineNo">1027</span>      // recreate the scanners on the current file scanners<a name="line.1027"></a>
+<span class="sourceLineNo">1028</span>      fileScanners = store.recreateScanners(scannersToClose, cacheBlocks, false, false,<a name="line.1028"></a>
+<span class="sourceLineNo">1029</span>        matcher, scan.getStartRow(), scan.includeStartRow(), scan.getStopRow(),<a name="line.1029"></a>
+<span class="sourceLineNo">1030</span>        scan.includeStopRow(), readPt, false);<a name="line.1030"></a>
+<span class="sourceLineNo">1031</span>      if (fileScanners == null) {<a name="line.1031"></a>
+<span class="sourceLineNo">1032</span>        return;<a name="line.1032"></a>
+<span class="sourceLineNo">1033</span>      }<a name="line.1033"></a>
+<span class="sourceLineNo">1034</span>      seekScanners(fileScanners, lastTop, false, parallelSeekEnabled);<a name="line.1034"></a>
+<span class="sourceLineNo">1035</span>      newCurrentScanners = new ArrayList&lt;&gt;(fileScanners.size() + memstoreScanners.size());<a name="line.1035"></a>
+<span class="sourceLineNo">1036</span>      newCurrentScanners.addAll(fileScanners);<a name="line.1036"></a>
+<span class="sourceLineNo">1037</span>      newCurrentScanners.addAll(memstoreScanners);<a name="line.1037"></a>
+<span class="sourceLineNo">1038</span>      newHeap = new KeyValueHeap(newCurrentScanners, comparator);<a name="line.1038"></a>
+<span class="sourceLineNo">1039</span>    } catch (Exception e) {<a name="line.1039"></a>
+<span class="sourceLineNo">1040</span>      LOG.warn("failed to switch to stream read", e);<a name="line.1040"></a>
+<span class="sourceLineNo">1041</span>      if (fileScanners != null) {<a name="line.1041"></a>
+<span class="sourceLineNo">1042</span>        fileScanners.forEach(KeyValueScanner::close);<a name="line.1042"></a>
+<span class="sourceLineNo">1043</span>      }<a name="line.1043"></a>
+<span class="sourceLineNo">1044</span>      return;<a name="line.1044"></a>
+<span class="sourceLineNo">1045</span>    }<a name="line.1045"></a>
+<span class="sourceLineNo">1046</span>    currentScanners.clear();<a name="line.1046"></a>
+<span class="sourceLineNo">1047</span>    addCurrentScanners(newCurrentScanners);<a name="line.1047"></a>
+<span class="sourceLineNo">1048</span>    this.heap = newHeap;<a name="line.1048"></a>
+<span class="sourceLineNo">1049</span>    resetQueryMatcher(lastTop);<a name="line.1049"></a>
+<span class="sourceLineNo">1050</span>    scannersToClose.forEach(KeyValueScanner::close);<a name="line.1050"></a>
+<span class="sourceLineNo">1051</span>  }<a name="line.1051"></a>
+<span class="sourceLineNo">1052</span><a name="line.1052"></a>
+<span class="sourceLineNo">1053</span>  protected final boolean checkFlushed() {<a name="line.1053"></a>
+<span class="sourceLineNo">1054</span>    // check the var without any lock. Suppose even if we see the old<a name="line.1054"></a>
+<span class="sourceLineNo">1055</span>    // value here still it is ok to continue because we will not be resetting<a name="line.1055"></a>
+<span class="sourceLineNo">1056</span>    // the heap but will continue with the referenced memstore's snapshot. For compactions<a name="line.1056"></a>
+<span class="sourceLineNo">1057</span>    // any way we don't need the updateReaders at all to happen as we still continue with<a name="line.1057"></a>
+<span class="sourceLineNo">1058</span>    // the older files<a name="line.1058"></a>
+<span class="sourceLineNo">1059</span>    if (flushed) {<a name="line.1059"></a>
+<span class="sourceLineNo">1060</span>      // If there is a flush and the current scan is notified on the flush ensure that the<a name="line.1060"></a>
+<span class="sourceLineNo">1061</span>      // scan's heap gets reset and we do a seek on the newly flushed file.<a name="line.1061"></a>
+<span class="sourceLineNo">1062</span>      if (this.closing) {<a name="line.1062"></a>
+<span class="sourceLineNo">1063</span>        return false;<a name="line.1063"></a>
+<span class="sourceLineNo">1064</span>      }<a name="line.1064"></a>
+<span class="sourceLineNo">1065</span>      // reset the flag<a name="line.1065"></a>
+<span class="sourceLineNo">1066</span>      flushed = false;<a name="line.1066"></a>
+<span class="sourceLineNo">1067</span>      return true;<a name="line.1067"></a>
+<span class="sourceLineNo">1068</span>    }<a name="line.1068"></a>
+<span class="sourceLineNo">1069</span>    return false;<a name="line.1069"></a>
+<span class="sourceLineNo">1070</span>  }<a name="line.1070"></a>
+<span class="sourceLineNo">1071</span><a name="line.1071"></a>
+<span class="sourceLineNo">1072</span><a name="line.1072"></a>
+<span class="sourceLineNo">1073</span>  /**<a name="line.1073"></a>
+<span class="sourceLineNo">1074</span>   * Seek storefiles in parallel to optimize IO latency as much as possible<a name="line.1074"></a>
+<span class="sourceLineNo">1075</span>   * @param scanners the list {@link KeyValueScanner}s to be read from<a name="line.1075"></a>
+<span class="sourceLineNo">1076</span>   * @param kv the KeyValue on which the operation is being requested<a name="line.1076"></a>
+<span class="sourceLineNo">1077</span>   * @throws IOException<a name="line.1077"></a>
+<span class="sourceLineNo">1078</span>   */<a name="line.1078"></a>
+<span class="sourceLineNo">1079</span>  private void parallelSeek(final List&lt;? extends KeyValueScanner&gt;<a name="line.1079"></a>
+<span class="sourceLineNo">1080</span>      scanners, final Cell kv) throws IOException {<a name="line.1080"></a>
+<span class="sourceLineNo">1081</span>    if (scanners.isEmpty()) return;<a name="line.1081"></a>
+<span class="sourceLineNo">1082</span>    int storeFileScannerCount = scanners.size();<a name="line.1082"></a>
+<span class="sourceLineNo">1083</span>    CountDownLatch latch = new CountDownLatch(storeFileScannerCount);<a name="line.1083"></a>
+<span class="sourceLineNo">1084</span>    List&lt;ParallelSeekHandler&gt; handlers = new ArrayList&lt;&gt;(storeFileScannerCount);<a name="line.1084"></a>
+<span class="sourceLineNo">1085</span>    for (KeyValueScanner scanner : scanners) {<a name="line.1085"></a>
+<span class="sourceLineNo">1086</span>      if (scanner instanceof StoreFileScanner) {<a name="line.1086"></a>
+<span class="sourceLineNo">1087</span>        ParallelSeekHandler seekHandler = new ParallelSeekHandler(scanner, kv,<a name="line.1087"></a>
+<span class="sourceLineNo">1088</span>          this.readPt, latch);<a name="line.1088"></a>
+<span class="sourceLineNo">1089</span>        executor.submit(seekHandler);<a name="line.1089"></a>
+<span class="sourceLineNo">1090</span>        handlers.add(seekHandler);<a name="line.1090"></a>
+<span class="sourceLineNo">1091</span>      } else {<a name="line.1091"></a>
+<span class="sourceLineNo">1092</span>        scanner.seek(kv);<a name="line.1092"></a>
+<span class="sourceLineNo">1093</span>        latch.countDown();<a name="line.1093"></a>
+<span class="sourceLineNo">1094</span>      }<a name="line.1094"></a>
+<span class="sourceLineNo">1095</span>    }<a name="line.1095"></a>
+<span class="sourceLineNo">1096</span><a name="line.1096"></a>
+<span class="sourceLineNo">1097</span>    try {<a name="line.1097"></a>
+<span class="sourceLineNo">1098</span>      latch.await();<a name="line.1098"></a>
+<span class="sourceLineNo">1099</span>    } catch (InterruptedException ie) {<a name="line.1099"></a>
+<span class="sourceLineNo">1100</span>      throw (InterruptedIOException)new InterruptedIOException().initCause(ie);<a name="line.1100"></a>
+<span class="sourceLineNo">1101</span>    }<a name="line.1101"></a>
+<span class="sourceLineNo">1102</span><a name="line.1102"></a>
+<span class="sourceLineNo">1103</span>    for (ParallelSeekHandler handler : handlers) {<a name="line.1103"></a>
+<span class="sourceLineNo">1104</span>      if (handler.getErr() != null) {<a name="line.1104"></a>
+<span class="sourceLineNo">1105</span>        throw new IOException(handler.getErr());<a name="line.1105"></a>
+<span class="sourceLineNo">1106</span>      }<a name="line.1106"></a>
+<span class="sourceLineNo">1107</span>    }<a name="line.1107"></a>
+<span class="sourceLineNo">1108</span>  }<a name="line.1108"></a>
+<span class="sourceLineNo">1109</span><a name="line.1109"></a>
+<span class="sourceLineNo">1110</span>  /**<a name="line.1110"></a>
+<span class="sourceLineNo">1111</span>   * Used in testing.<a name="line.1111"></a>
+<span class="sourceLineNo">1112</span>   * @return all scanners in no particular order<a name="line.1112"></a>
+<span class="sourceLineNo">1113</span>   */<a name="line.1113"></a>
+<span class="sourceLineNo">1114</span>  @VisibleForTesting<a name="line.1114"></a>
+<span class="sourceLineNo">1115</span>  List&lt;KeyValueScanner&gt; getAllScannersForTesting() {<a name="line.1115"></a>
+<span class="sourceLineNo">1116</span>    List&lt;KeyValueScanner&gt; allScanners = new ArrayList&lt;&gt;();<a name="line.1116"></a>
+<span class="sourceLineNo">1117</span>    KeyValueScanner current = heap.getCurrentForTesting();<a name="line.1117"></a>
+<span class="sourceLineNo">1118</span>    if (current != null)<a name="line.1118"></a>
+<span class="sourceLineNo">1119</span>      allScanners.add(current);<a name="line.1119"></a>
+<span class="sourceLineNo">1120</span>    for (KeyValueScanner scanner : heap.getHeap())<a name="line.1120"></a>
+<span class="sourceLineNo">1121</span>      allScanners.add(scanner);<a name="line.1121"></a>
+<span class="sourceLineNo">1122</span>    return allScanners;<a name="line.1122"></a>
+<span class="sourceLineNo">1123</span>  }<a name="line.1123"></a>
+<span class="sourceLineNo">1124</span><a name="line.1124"></a>
+<span class="sourceLineNo">1125</span>  static void enableLazySeekGlobally(boolean enable) {<a name="line.1125"></a>
+<span class="sourceLineNo">1126</span>    lazySeekEnabledGlobally = enable;<a name="line.1126"></a>
+<span class="sourceLineNo">1127</span>  }<a name="line.1127"></a>
+<span class="sourceLineNo">1128</span><a name="line.1128"></a>
+<span class="sourceLineNo">1129</span>  /**<a name="line.1129"></a>
+<span class="sourceLineNo">1130</span>   * @return The estimated number of KVs seen by this scanner (includes some skipped KVs).<a name="line.1130"></a>
+<span class="sourceLineNo">1131</span>   */<a name="line.1131"></a>
+<span class="sourceLineNo">1132</span>  public long getEstimatedNumberOfKvsScanned() {<a name="line.1132"></a>
+<span class="sourceLineNo">1133</span>    return this.kvsScanned;<a name="line.1133"></a>
+<span class="sourceLineNo">1134</span>  }<a name="line.1134"></a>
+<span class="sourceLineNo">1135</span><a name="line.1135"></a>
+<span class="sourceLineNo">1136</span>  @Override<a name="line.1136"></a>
+<span class="sourceLineNo">1137</span>  public Cell getNextIndexedKey() {<a name="line.1137"></a>
+<span class="sourceLineNo">1138</span>    return this.heap.getNextIndexedKey();<a name="line.1138"></a>
+<span class="sourceLineNo">1139</span>  }<a name="line.1139"></a>
+<span class="sourceLineNo">1140</span><a name="line.1140"></a>
+<span class="sourceLineNo">1141</span>  @Override<a name="line.1141"></a>
+<span class="sourceLineNo">1142</span>  public void shipped() throws IOException {<a name="line.1142"></a>
+<span class="sourceLineNo">1143</span>    if (prevCell != null) {<a name="line.1143"></a>
+<span class="sourceLineNo">1144</span>      // Do the copy here so that in case the prevCell ref is pointing to the previous<a name="line.1144"></a>
+<span class="sourceLineNo">1145</span>      // blocks we can safely release those blocks.<a name="line.1145"></a>
+<span class="sourceLineNo">1146</span>      // This applies to blocks that are got from Bucket cache, L1 cache and the blocks<a name="line.1146"></a>
+<span class="sourceLineNo">1147</span>      // fetched from HDFS. Copying this would ensure that we let go the references to these<a name="line.1147"></a>
+<span class="sourceLineNo">1148</span>      // blocks so that they can be GCed safely(in case of bucket cache)<a name="line.1148"></a>
+<span class="sourceLineNo">1149</span>      prevCell = KeyValueUtil.toNewKeyCell(this.prevCell);<a name="line.1149"></a>
+<span class="sourceLineNo">1150</span>    }<a name="line.1150"></a>
+<span class="sourceLineNo">1151</span>    matcher.beforeShipped();<a name="line.1151"></a>
+<span class="sourceLineNo">1152</span>    // There wont be further fetch of Cells from these scanners. Just close.<a name="line.1152"></a>
+<span class="sourceLineNo">1153</span>    clearAndClose(scannersForDelayedClose);<a name="line.1153"></a>
+<span class="sourceLineNo">1154</span>    if (this.heap != null) {<a name="line.1154"></a>
+<span class="sourceLineNo">1155</span>      this.heap.shipped();<a name="line.1155"></a>
+<span class="sourceLineNo">1156</span>      // When switching from pread to stream, we will open a new scanner for each store file, but<a name="line.1156"></a>
+<span class="sourceLineNo">1157</span>      // the old scanner may still track the HFileBlocks we have scanned but not sent back to client<a name="line.1157"></a>
+<span class="sourceLineNo">1158</span>      // yet. If we close the scanner immediately then the HFileBlocks may be messed up by others<a name="line.1158"></a>
+<span class="sourceLineNo">1159</span>      // before we serialize and send it back to client. The HFileBlocks will be released in shipped<a name="line.1159"></a>
+<span class="sourceLineNo">1160</span>      // method, so we here will also open new scanners and close old scanners in shipped method.<a name="line.1160"></a>
+<span class="sourceLineNo">1161</span>      // See HBASE-18055 for more details.<a name="line.1161"></a>
+<span class="sourceLineNo">1162</span>      trySwitchToStreamRead();<a name="line.1162"></a>
+<span class="sourceLineNo">1163</span>    }<a name="line.1163"></a>
+<span class="sourceLineNo">1164</span>  }<a name="line.1164"></a>
+<span class="sourceLineNo">1165</span>}<a name="line.1165"></a>
+<span class="sourceLineNo">1166</span><a name="line.1166"></a>
 
 
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/downloads.html
----------------------------------------------------------------------
diff --git a/downloads.html b/downloads.html
index a64ca9b..cd7a8b7 100644
--- a/downloads.html
+++ b/downloads.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Apache HBase Downloads</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -463,7 +463,7 @@ under the License. -->
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/export_control.html
----------------------------------------------------------------------
diff --git a/export_control.html b/export_control.html
index 6fef896..20a2ed0 100644
--- a/export_control.html
+++ b/export_control.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; 
       Export Control
@@ -341,7 +341,7 @@ for more details.</p>
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/index.html
----------------------------------------------------------------------
diff --git a/index.html b/index.html
index f83d03e..34d3ebc 100644
--- a/index.html
+++ b/index.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Apache HBase™ Home</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -421,7 +421,7 @@ Apache HBase is an open-source, distributed, versioned, non-relational database
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/integration.html
----------------------------------------------------------------------
diff --git a/integration.html b/integration.html
index 9aa09c3..963fa36 100644
--- a/integration.html
+++ b/integration.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; CI Management</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -301,7 +301,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/issue-tracking.html
----------------------------------------------------------------------
diff --git a/issue-tracking.html b/issue-tracking.html
index bc74bc3..1be458e 100644
--- a/issue-tracking.html
+++ b/issue-tracking.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Issue Management</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -298,7 +298,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/license.html
----------------------------------------------------------------------
diff --git a/license.html b/license.html
index b442aef..11559b4 100644
--- a/license.html
+++ b/license.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Project Licenses</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -501,7 +501,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/mail-lists.html
----------------------------------------------------------------------
diff --git a/mail-lists.html b/mail-lists.html
index dfeb846..dd502f3 100644
--- a/mail-lists.html
+++ b/mail-lists.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Project Mailing Lists</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -351,7 +351,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/metrics.html
----------------------------------------------------------------------
diff --git a/metrics.html b/metrics.html
index f940182..5c1a977 100644
--- a/metrics.html
+++ b/metrics.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013;  
       Apache HBase (TM) Metrics
@@ -469,7 +469,7 @@ export HBASE_REGIONSERVER_OPTS=&quot;$HBASE_JMX_OPTS -Dcom.sun.management.jmxrem
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/old_news.html
----------------------------------------------------------------------
diff --git a/old_news.html b/old_news.html
index 3eff97d..94ad779 100644
--- a/old_news.html
+++ b/old_news.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; 
       Old Apache HBase (TM) News
@@ -450,7 +450,7 @@ under the License. -->
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/plugin-management.html
----------------------------------------------------------------------
diff --git a/plugin-management.html b/plugin-management.html
index d69226a..1cb4ecc 100644
--- a/plugin-management.html
+++ b/plugin-management.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Project Plugin Management</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -450,7 +450,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/plugins.html
----------------------------------------------------------------------
diff --git a/plugins.html b/plugins.html
index 53f1f95..7d74a3b 100644
--- a/plugins.html
+++ b/plugins.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Project Plugins</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -381,7 +381,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/poweredbyhbase.html
----------------------------------------------------------------------
diff --git a/poweredbyhbase.html b/poweredbyhbase.html
index e6f0c4f..89dbbac 100644
--- a/poweredbyhbase.html
+++ b/poweredbyhbase.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Powered By Apache HBase™</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -779,7 +779,7 @@ under the License. -->
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/project-info.html
----------------------------------------------------------------------
diff --git a/project-info.html b/project-info.html
index 0bfad8d..f4f2edc 100644
--- a/project-info.html
+++ b/project-info.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Project Information</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -345,7 +345,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/project-reports.html
----------------------------------------------------------------------
diff --git a/project-reports.html b/project-reports.html
index 3378fc4..bf9db35 100644
--- a/project-reports.html
+++ b/project-reports.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Generated Reports</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -315,7 +315,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>
 

http://git-wip-us.apache.org/repos/asf/hbase-site/blob/611be1f3/project-summary.html
----------------------------------------------------------------------
diff --git a/project-summary.html b/project-summary.html
index e2a1859..dfd0924 100644
--- a/project-summary.html
+++ b/project-summary.html
@@ -7,7 +7,7 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <meta name="Date-Revision-yyyymmdd" content="20181213" />
+    <meta name="Date-Revision-yyyymmdd" content="20181214" />
     <meta http-equiv="Content-Language" content="en" />
     <title>Apache HBase &#x2013; Project Summary</title>
     <link rel="stylesheet" href="./css/apache-maven-fluido-1.4-HBase.min.css" />
@@ -341,7 +341,7 @@
                         <a href="https://www.apache.org/">The Apache Software Foundation</a>.
             All rights reserved.      
                     
-                  <li id="publishDate" class="pull-right">Last Published: 2018-12-13</li>
+                  <li id="publishDate" class="pull-right">Last Published: 2018-12-14</li>
             </p>
                 </div>