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* 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.db.columniterator;
import java.io.IOException;
import java.util.*;
import com.google.common.collect.AbstractIterator;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.composites.CellName;
import org.apache.cassandra.db.composites.CellNameType;
import org.apache.cassandra.io.sstable.CorruptSSTableException;
import org.apache.cassandra.io.sstable.IndexHelper;
import org.apache.cassandra.io.sstable.SSTableReader;
import org.apache.cassandra.io.util.FileDataInput;
import org.apache.cassandra.io.util.FileMark;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.utils.ByteBufferUtil;
public class SSTableNamesIterator extends AbstractIterator<OnDiskAtom> implements OnDiskAtomIterator
{
private ColumnFamily cf;
private final SSTableReader sstable;
private FileDataInput fileToClose;
private Iterator<OnDiskAtom> iter;
public final SortedSet<CellName> columns;
public final DecoratedKey key;
public SSTableNamesIterator(SSTableReader sstable, DecoratedKey key, SortedSet<CellName> columns)
{
assert columns != null;
this.sstable = sstable;
this.columns = columns;
this.key = key;
RowIndexEntry indexEntry = sstable.getPosition(key, SSTableReader.Operator.EQ);
if (indexEntry == null)
return;
try
{
read(sstable, null, indexEntry);
}
catch (IOException e)
{
sstable.markSuspect();
throw new CorruptSSTableException(e, sstable.getFilename());
}
finally
{
if (fileToClose != null)
FileUtils.closeQuietly(fileToClose);
}
}
public SSTableNamesIterator(SSTableReader sstable, FileDataInput file, DecoratedKey key, SortedSet<CellName> columns, RowIndexEntry indexEntry)
{
assert columns != null;
this.sstable = sstable;
this.columns = columns;
this.key = key;
try
{
read(sstable, file, indexEntry);
}
catch (IOException e)
{
sstable.markSuspect();
throw new CorruptSSTableException(e, sstable.getFilename());
}
}
private FileDataInput createFileDataInput(long position)
{
fileToClose = sstable.getFileDataInput(position);
return fileToClose;
}
private void read(SSTableReader sstable, FileDataInput file, RowIndexEntry indexEntry)
throws IOException
{
List<IndexHelper.IndexInfo> indexList;
// If the entry is not indexed or the index is not promoted, read from the row start
if (!indexEntry.isIndexed())
{
if (file == null)
file = createFileDataInput(indexEntry.position);
else
file.seek(indexEntry.position);
DecoratedKey keyInDisk = sstable.partitioner.decorateKey(ByteBufferUtil.readWithShortLength(file));
assert keyInDisk.equals(key) : String.format("%s != %s in %s", keyInDisk, key, file.getPath());
if (sstable.descriptor.version.hasRowSizeAndColumnCount)
file.readLong();
}
indexList = indexEntry.columnsIndex();
if (!indexEntry.isIndexed())
{
ColumnFamilySerializer serializer = ColumnFamily.serializer;
try
{
cf = ArrayBackedSortedColumns.factory.create(sstable.metadata);
cf.delete(DeletionTime.serializer.deserialize(file));
}
catch (Exception e)
{
throw new IOException(serializer + " failed to deserialize " + sstable.getColumnFamilyName() + " with " + sstable.metadata + " from " + file, e);
}
}
else
{
cf = ArrayBackedSortedColumns.factory.create(sstable.metadata);
cf.delete(indexEntry.deletionTime());
}
List<OnDiskAtom> result = new ArrayList<OnDiskAtom>();
if (indexList.isEmpty())
{
int columnCount = sstable.descriptor.version.hasRowSizeAndColumnCount ? file.readInt() : Integer.MAX_VALUE;
readSimpleColumns(file, columns, result, columnCount);
}
else
{
readIndexedColumns(sstable.metadata, file, columns, indexList, indexEntry.position, result);
}
// create an iterator view of the columns we read
iter = result.iterator();
}
private void readSimpleColumns(FileDataInput file, SortedSet<CellName> columnNames, List<OnDiskAtom> result, int columnCount)
{
Iterator<OnDiskAtom> atomIterator = cf.metadata().getOnDiskIterator(file, columnCount, sstable.descriptor.version);
int n = 0;
while (atomIterator.hasNext())
{
OnDiskAtom column = atomIterator.next();
if (column instanceof Cell)
{
if (columnNames.contains(column.name()))
{
result.add(column);
if (++n >= columns.size())
break;
}
}
else
{
result.add(column);
}
}
}
private void readIndexedColumns(CFMetaData metadata,
FileDataInput file,
SortedSet<CellName> columnNames,
List<IndexHelper.IndexInfo> indexList,
long basePosition,
List<OnDiskAtom> result)
throws IOException
{
/* get the various column ranges we have to read */
CellNameType comparator = metadata.comparator;
List<IndexHelper.IndexInfo> ranges = new ArrayList<IndexHelper.IndexInfo>();
int lastIndexIdx = -1;
for (CellName name : columnNames)
{
int index = IndexHelper.indexFor(name, indexList, comparator, false, lastIndexIdx);
if (index < 0 || index == indexList.size())
continue;
IndexHelper.IndexInfo indexInfo = indexList.get(index);
// Check the index block does contain the column names and that we haven't inserted this block yet.
if (comparator.compare(name, indexInfo.firstName) < 0 || index == lastIndexIdx)
continue;
ranges.add(indexInfo);
lastIndexIdx = index;
}
if (ranges.isEmpty())
return;
Iterator<CellName> toFetch = columnNames.iterator();
CellName nextToFetch = toFetch.next();
for (IndexHelper.IndexInfo indexInfo : ranges)
{
long positionToSeek = basePosition + indexInfo.offset;
// With new promoted indexes, our first seek in the data file will happen at that point.
if (file == null)
file = createFileDataInput(positionToSeek);
AtomDeserializer deserializer = cf.metadata().getOnDiskDeserializer(file, sstable.descriptor.version);
file.seek(positionToSeek);
FileMark mark = file.mark();
while (file.bytesPastMark(mark) < indexInfo.width && nextToFetch != null)
{
int cmp = deserializer.compareNextTo(nextToFetch);
if (cmp == 0)
{
nextToFetch = toFetch.hasNext() ? toFetch.next() : null;
result.add(deserializer.readNext());
continue;
}
deserializer.skipNext();
if (cmp > 0)
nextToFetch = toFetch.hasNext() ? toFetch.next() : null;
}
}
}
public DecoratedKey getKey()
{
return key;
}
public ColumnFamily getColumnFamily()
{
return cf;
}
protected OnDiskAtom computeNext()
{
if (iter == null || !iter.hasNext())
return endOfData();
return iter.next();
}
public void close() throws IOException { }
}