pcmanus commented on code in PR #3695:
URL: https://github.com/apache/cassandra/pull/3695#discussion_r1865658640
##########
src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java:
##########
@@ -728,27 +728,104 @@ public List<PartitionPositionBounds>
getPositionsForRanges(Collection<Range<Toke
for (Range<Token> range : Range.normalize(ranges))
{
assert !range.isWrapAround() || range.right.isMinimum();
- // truncate the range so it at most covers the sstable
AbstractBounds<PartitionPosition> bounds =
Range.makeRowRange(range);
- PartitionPosition leftBound = bounds.left.compareTo(first) > 0 ?
bounds.left : first.getToken().minKeyBound();
- PartitionPosition rightBound = bounds.right.isMinimum() ?
last.getToken().maxKeyBound() : bounds.right;
+ PartitionPositionBounds pb = getPositionsForBounds(bounds);
+ if (pb != null)
+ positions.add(pb);
+ }
+ return positions;
+ }
- if (leftBound.compareTo(last) > 0 || rightBound.compareTo(first) <
0)
- continue;
+ /**
+ * Get a list of data positions in this SSTable that correspond to the
given list of bounds. This method will remove
+ * non-covered intervals, but will not correct order or overlap in the
supplied list, e.g. if bounds overlap, the
+ * result will be sections of the data file that repeat the same positions.
+ *
+ * @return A sorted list of [offset,end) pairs corresponding to the given
boundsList in the datafile for this
+ * SSTable.
+ */
+ public List<PartitionPositionBounds>
getPositionsForBoundsIterator(Iterator<AbstractBounds<PartitionPosition>>
boundsList)
+ {
+ // use the index to determine a minimal section for each range
+ List<PartitionPositionBounds> positions = new ArrayList<>();
+ while (boundsList.hasNext())
+ {
+ AbstractBounds<PartitionPosition> bounds = boundsList.next();
+ PartitionPositionBounds pb = getPositionsForBounds(bounds);
+ if (pb != null)
+ positions.add(pb);
+ }
+ return positions;
+ }
- long left = getPosition(leftBound, Operator.GT);
- long right = (rightBound.compareTo(last) > 0)
- ? uncompressedLength()
- : getPosition(rightBound, Operator.GT);
+ /**
+ * Determine the data positions in this SSTable that cover the given
bounds.
+ *
+ * @return An [offset,end) pair that cover the given bounds in the
datafile for this SSTable.
Review Comment:
We should specify that this can return `null`, and under which conditions.
##########
src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java:
##########
@@ -728,27 +728,104 @@ public List<PartitionPositionBounds>
getPositionsForRanges(Collection<Range<Toke
for (Range<Token> range : Range.normalize(ranges))
{
assert !range.isWrapAround() || range.right.isMinimum();
- // truncate the range so it at most covers the sstable
AbstractBounds<PartitionPosition> bounds =
Range.makeRowRange(range);
- PartitionPosition leftBound = bounds.left.compareTo(first) > 0 ?
bounds.left : first.getToken().minKeyBound();
- PartitionPosition rightBound = bounds.right.isMinimum() ?
last.getToken().maxKeyBound() : bounds.right;
+ PartitionPositionBounds pb = getPositionsForBounds(bounds);
+ if (pb != null)
+ positions.add(pb);
+ }
+ return positions;
+ }
- if (leftBound.compareTo(last) > 0 || rightBound.compareTo(first) <
0)
- continue;
+ /**
+ * Get a list of data positions in this SSTable that correspond to the
given list of bounds. This method will remove
+ * non-covered intervals, but will not correct order or overlap in the
supplied list, e.g. if bounds overlap, the
+ * result will be sections of the data file that repeat the same positions.
+ *
+ * @return A sorted list of [offset,end) pairs corresponding to the given
boundsList in the datafile for this
+ * SSTable.
+ */
+ public List<PartitionPositionBounds>
getPositionsForBoundsIterator(Iterator<AbstractBounds<PartitionPosition>>
boundsList)
+ {
+ // use the index to determine a minimal section for each range
+ List<PartitionPositionBounds> positions = new ArrayList<>();
+ while (boundsList.hasNext())
+ {
+ AbstractBounds<PartitionPosition> bounds = boundsList.next();
+ PartitionPositionBounds pb = getPositionsForBounds(bounds);
+ if (pb != null)
+ positions.add(pb);
+ }
+ return positions;
+ }
- long left = getPosition(leftBound, Operator.GT);
- long right = (rightBound.compareTo(last) > 0)
- ? uncompressedLength()
- : getPosition(rightBound, Operator.GT);
+ /**
+ * Determine the data positions in this SSTable that cover the given
bounds.
+ *
+ * @return An [offset,end) pair that cover the given bounds in the
datafile for this SSTable.
+ */
+ public PartitionPositionBounds
getPositionsForBounds(AbstractBounds<PartitionPosition> bounds)
+ {
+ long left = getPosition(bounds.left, bounds.inclusiveLeft() ?
Operator.GE : Operator.GT);
+ // Note: getPosition will apply a moved start if the sstable is in
MOVED_START state.
+ if (left < 0) // empty range
+ return null;
- if (left == right)
- // empty range
- continue;
+ long right = bounds.right.isMinimum() ? -1
+ : getPosition(bounds.right,
bounds.inclusiveRight() ? Operator.GT
+
: Operator.GE);
+ if (right < 0) // right is beyond end
+ right = uncompressedLength(); // this should also be correct for
EARLY readers
- assert left < right : String.format("Range=%s openReason=%s
first=%s last=%s left=%d right=%d", range, openReason, first, last, left,
right);
- positions.add(new PartitionPositionBounds(left, right));
+ if (left >= right)
+ {
+ // empty range
+ return null;
+ }
+
+ return new PartitionPositionBounds(left, right);
+ }
+
+ /**
+ * Return a (offset, end] pair that covers the whole file.
+ */
+ public PartitionPositionBounds getPositionsForFullRange()
+ {
+ if (openReason != OpenReason.MOVED_START)
+ return new PartitionPositionBounds(0, uncompressedLength());
+ else
+ {
+ // query a full range, so that the required adjustments can be
applied
+ PartitionPosition minToken =
getPartitioner().getMinimumToken().minKeyBound();
+ return getPositionsForBounds(new Range<>(minToken, minToken));
}
- return positions;
+ }
+
+ /**
+ * Calculate a total on-disk (compressed) size for the given partition
positions.
Review Comment:
Maybe worth specifying:
1. what it returns exactly in the case of compression. Namely that it's the
size of the chunks covering the positions, and so technically can include more
than the requested bounds and how much is subject to the chunk size (yes, it's
unclear how this could be anything else if you think about it, but still worth
calling out imo).
2. that this assume the provided bounds are non-overlapping.
##########
src/java/org/apache/cassandra/io/sstable/format/SSTableReader.java:
##########
@@ -728,27 +728,104 @@ public List<PartitionPositionBounds>
getPositionsForRanges(Collection<Range<Toke
for (Range<Token> range : Range.normalize(ranges))
{
assert !range.isWrapAround() || range.right.isMinimum();
- // truncate the range so it at most covers the sstable
AbstractBounds<PartitionPosition> bounds =
Range.makeRowRange(range);
- PartitionPosition leftBound = bounds.left.compareTo(first) > 0 ?
bounds.left : first.getToken().minKeyBound();
- PartitionPosition rightBound = bounds.right.isMinimum() ?
last.getToken().maxKeyBound() : bounds.right;
+ PartitionPositionBounds pb = getPositionsForBounds(bounds);
+ if (pb != null)
+ positions.add(pb);
+ }
+ return positions;
+ }
- if (leftBound.compareTo(last) > 0 || rightBound.compareTo(first) <
0)
- continue;
+ /**
+ * Get a list of data positions in this SSTable that correspond to the
given list of bounds. This method will remove
+ * non-covered intervals, but will not correct order or overlap in the
supplied list, e.g. if bounds overlap, the
+ * result will be sections of the data file that repeat the same positions.
+ *
+ * @return A sorted list of [offset,end) pairs corresponding to the given
boundsList in the datafile for this
+ * SSTable.
+ */
+ public List<PartitionPositionBounds>
getPositionsForBoundsIterator(Iterator<AbstractBounds<PartitionPosition>>
boundsList)
+ {
+ // use the index to determine a minimal section for each range
+ List<PartitionPositionBounds> positions = new ArrayList<>();
+ while (boundsList.hasNext())
+ {
+ AbstractBounds<PartitionPosition> bounds = boundsList.next();
+ PartitionPositionBounds pb = getPositionsForBounds(bounds);
+ if (pb != null)
+ positions.add(pb);
+ }
+ return positions;
+ }
- long left = getPosition(leftBound, Operator.GT);
- long right = (rightBound.compareTo(last) > 0)
- ? uncompressedLength()
- : getPosition(rightBound, Operator.GT);
+ /**
+ * Determine the data positions in this SSTable that cover the given
bounds.
+ *
+ * @return An [offset,end) pair that cover the given bounds in the
datafile for this SSTable.
+ */
+ public PartitionPositionBounds
getPositionsForBounds(AbstractBounds<PartitionPosition> bounds)
+ {
+ long left = getPosition(bounds.left, bounds.inclusiveLeft() ?
Operator.GE : Operator.GT);
+ // Note: getPosition will apply a moved start if the sstable is in
MOVED_START state.
+ if (left < 0) // empty range
+ return null;
- if (left == right)
- // empty range
- continue;
+ long right = bounds.right.isMinimum() ? -1
+ : getPosition(bounds.right,
bounds.inclusiveRight() ? Operator.GT
+
: Operator.GE);
+ if (right < 0) // right is beyond end
+ right = uncompressedLength(); // this should also be correct for
EARLY readers
- assert left < right : String.format("Range=%s openReason=%s
first=%s last=%s left=%d right=%d", range, openReason, first, last, left,
right);
- positions.add(new PartitionPositionBounds(left, right));
+ if (left >= right)
+ {
+ // empty range
+ return null;
+ }
+
+ return new PartitionPositionBounds(left, right);
+ }
+
+ /**
+ * Return a (offset, end] pair that covers the whole file.
+ */
+ public PartitionPositionBounds getPositionsForFullRange()
+ {
+ if (openReason != OpenReason.MOVED_START)
+ return new PartitionPositionBounds(0, uncompressedLength());
+ else
+ {
+ // query a full range, so that the required adjustments can be
applied
+ PartitionPosition minToken =
getPartitioner().getMinimumToken().minKeyBound();
+ return getPositionsForBounds(new Range<>(minToken, minToken));
Review Comment:
I'd add an assertion that the return of `getPositionsForBounds` can never be
`null` here (since the method "can" return `null`, just not in that case (or at
least I think; I'm not that familiar with `OpenReason.MOVED_START` but I assume
we never move it to a point where the sstable is essentially empty?).
##########
src/java/org/apache/cassandra/io/sstable/format/SSTableSimpleScanner.java:
##########
@@ -0,0 +1,185 @@
+/*
+ * 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;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import com.google.common.collect.ImmutableSet;
+
+import org.apache.cassandra.db.DecoratedKey;
+import org.apache.cassandra.db.rows.UnfilteredRowIterator;
+import org.apache.cassandra.io.sstable.CorruptSSTableException;
+import org.apache.cassandra.io.sstable.ISSTableScanner;
+import org.apache.cassandra.io.sstable.SSTableIdentityIterator;
+import org.apache.cassandra.io.util.RandomAccessReader;
+import org.apache.cassandra.schema.TableMetadata;
+
+import static
org.apache.cassandra.io.sstable.format.SSTableReader.PartitionPositionBounds;
+
+/// Simple SSTable scanner that reads sequentially through an SSTable without
using the index.
Review Comment:
Nit: are we sure the project is ok with using this new style of javadoc? I'm
personally fine with it, but this imply someone interested by generating the
javadoc would now need to use a fairly recent java (a technically unsupported
by the project one) to get it javadoc-ified (which could slightly impact IDE
that aren't up to date on this too).
##########
src/java/org/apache/cassandra/io/sstable/format/SSTableSimpleScanner.java:
##########
@@ -0,0 +1,185 @@
+/*
+ * 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;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import com.google.common.collect.ImmutableSet;
+
+import org.apache.cassandra.db.DecoratedKey;
+import org.apache.cassandra.db.rows.UnfilteredRowIterator;
+import org.apache.cassandra.io.sstable.CorruptSSTableException;
+import org.apache.cassandra.io.sstable.ISSTableScanner;
+import org.apache.cassandra.io.sstable.SSTableIdentityIterator;
+import org.apache.cassandra.io.util.RandomAccessReader;
+import org.apache.cassandra.schema.TableMetadata;
+
+import static
org.apache.cassandra.io.sstable.format.SSTableReader.PartitionPositionBounds;
+
+/// Simple SSTable scanner that reads sequentially through an SSTable without
using the index.
+///
+/// This is a significant improvement for the performance of compaction over
using the full-blown DataRange-capable
+/// [SSTableScanner] and enables correct calculation of data sizes to process.
+public class SSTableSimpleScanner
+implements ISSTableScanner
+{
+ private final AtomicBoolean isClosed = new AtomicBoolean(false);
+ private final RandomAccessReader dfile;
+ private final SSTableReader sstable;
+
+ private final Iterator<PartitionPositionBounds> rangeIterator;
+
+ private long bytesScannedInPreviousRanges;
+
+ private final long sizeInBytes;
+ private final long compressedSizeInBytes;
+
+ private long currentEndPosition;
+ private long currentStartPosition;
+
+ private SSTableIdentityIterator currentIterator;
+ private DecoratedKey lastKey;
+
+ public SSTableSimpleScanner(SSTableReader sstable,
Review Comment:
Maybe worth specifying that `boundList` must be non-overlapping.
##########
src/java/org/apache/cassandra/io/sstable/format/bti/BtiTableReader.java:
##########
@@ -382,27 +380,6 @@ public UnfilteredRowIterator rowIterator(FileDataInput
dataFileInput,
return new SSTableIterator(this, dataFileInput, key, indexEntry,
slices, selectedColumns, rowIndexFile);
}
- @Override
Review Comment:
This makes a bunch of the static `BtiScanner#getScanner` methods unused, and
since we probably want those methods to never be used, they should probably be
removed. Same for `BigTableScanner`.
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