| /* |
| * 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.cassandra.io.sstable.format.big; |
| |
| import java.io.IOException; |
| |
| import org.apache.cassandra.db.DecoratedKey; |
| import org.apache.cassandra.db.Slice; |
| import org.apache.cassandra.db.Slices; |
| import org.apache.cassandra.db.UnfilteredValidation; |
| import org.apache.cassandra.db.filter.ColumnFilter; |
| import org.apache.cassandra.db.rows.RangeTombstoneMarker; |
| import org.apache.cassandra.db.rows.Unfiltered; |
| import org.apache.cassandra.io.sstable.AbstractSSTableIterator; |
| import org.apache.cassandra.io.sstable.format.SSTableReader; |
| import org.apache.cassandra.io.util.FileDataInput; |
| import org.apache.cassandra.io.util.FileHandle; |
| |
| /** |
| * A Cell Iterator over SSTable |
| */ |
| public class SSTableIterator extends AbstractSSTableIterator<RowIndexEntry> |
| { |
| /** |
| * The index of the slice being processed. |
| */ |
| private int slice; |
| |
| public SSTableIterator(SSTableReader sstable, |
| FileDataInput file, |
| DecoratedKey key, |
| RowIndexEntry indexEntry, |
| Slices slices, |
| ColumnFilter columns, |
| FileHandle ifile) |
| { |
| super(sstable, file, key, indexEntry, slices, columns, ifile); |
| } |
| |
| @SuppressWarnings("resource") // caller to close |
| protected Reader createReaderInternal(RowIndexEntry indexEntry, FileDataInput file, boolean shouldCloseFile) |
| { |
| return indexEntry.isIndexed() |
| ? new ForwardIndexedReader(indexEntry, file, shouldCloseFile) |
| : new ForwardReader(file, shouldCloseFile); |
| } |
| |
| protected int nextSliceIndex() |
| { |
| int next = slice; |
| slice++; |
| return next; |
| } |
| |
| protected boolean hasMoreSlices() |
| { |
| return slice < slices.size(); |
| } |
| |
| public boolean isReverseOrder() |
| { |
| return false; |
| } |
| |
| private class ForwardIndexedReader extends ForwardReader |
| { |
| private final IndexState indexState; |
| |
| private int lastBlockIdx; // the last index block that has data for the current query |
| |
| private ForwardIndexedReader(RowIndexEntry indexEntry, FileDataInput file, boolean shouldCloseFile) |
| { |
| super(file, shouldCloseFile); |
| this.indexState = new IndexState(this, metadata.comparator, indexEntry, false, ifile); |
| this.lastBlockIdx = indexState.blocksCount(); // if we never call setForSlice, that's where we want to stop |
| } |
| |
| @Override |
| public void close() throws IOException |
| { |
| super.close(); |
| this.indexState.close(); |
| } |
| |
| @Override |
| public void setForSlice(Slice slice) throws IOException |
| { |
| super.setForSlice(slice); |
| |
| // if our previous slicing already got us the biggest row in the sstable, we're done |
| if (indexState.isDone()) |
| { |
| sliceDone = true; |
| return; |
| } |
| |
| // Find the first index block we'll need to read for the slice. |
| int startIdx = indexState.findBlockIndex(slice.start(), indexState.currentBlockIdx()); |
| if (startIdx >= indexState.blocksCount()) |
| { |
| sliceDone = true; |
| return; |
| } |
| |
| // Find the last index block we'll need to read for the slice. |
| lastBlockIdx = indexState.findBlockIndex(slice.end(), startIdx); |
| |
| // If the slice end is before the very first block, we have nothing for that slice |
| if (lastBlockIdx < 0) |
| { |
| assert startIdx < 0; |
| sliceDone = true; |
| return; |
| } |
| |
| // If we start before the very first block, just read from the first one. |
| if (startIdx < 0) |
| startIdx = 0; |
| |
| // If that's the last block we were reading, we're already where we want to be. Otherwise, |
| // seek to that first block |
| if (startIdx != indexState.currentBlockIdx()) |
| indexState.setToBlock(startIdx); |
| |
| // The index search is based on the last name of the index blocks, so at that point we have that: |
| // 1) indexes[currentIdx - 1].lastName < slice.start <= indexes[currentIdx].lastName |
| // 2) indexes[lastBlockIdx - 1].lastName < slice.end <= indexes[lastBlockIdx].lastName |
| // so if currentIdx == lastBlockIdx and slice.end < indexes[currentIdx].firstName, we're guaranteed that the |
| // whole slice is between the previous block end and this block start, and thus has no corresponding |
| // data. One exception is if the previous block ends with an openMarker as it will cover our slice |
| // and we need to return it. |
| if (indexState.currentBlockIdx() == lastBlockIdx |
| && metadata().comparator.compare(slice.end(), indexState.currentIndex().firstName) < 0 |
| && openMarker == null) |
| { |
| sliceDone = true; |
| } |
| } |
| |
| @Override |
| protected Unfiltered computeNext() throws IOException |
| { |
| while (true) |
| { |
| // Our previous read might have made us cross an index block boundary. If so, update our informations. |
| // If we read from the beginning of the partition, this is also what will initialize the index state. |
| indexState.updateBlock(); |
| |
| // Return the next unfiltered unless we've reached the end, or we're beyond our slice |
| // end (note that unless we're on the last block for the slice, there is no point |
| // in checking the slice end). |
| if (indexState.isDone() |
| || indexState.currentBlockIdx() > lastBlockIdx |
| || !deserializer.hasNext() |
| || (indexState.currentBlockIdx() == lastBlockIdx && deserializer.compareNextTo(end) >= 0)) |
| return null; |
| |
| |
| Unfiltered next = deserializer.readNext(); |
| UnfilteredValidation.maybeValidateUnfiltered(next, metadata(), key, sstable); |
| // We may get empty row for the same reason expressed on UnfilteredSerializer.deserializeOne. |
| if (next.isEmpty()) |
| continue; |
| |
| if (next.kind() == Unfiltered.Kind.RANGE_TOMBSTONE_MARKER) |
| updateOpenMarker((RangeTombstoneMarker) next); |
| return next; |
| } |
| } |
| } |
| } |