Maxwell-Guo commented on code in PR #2287: URL: https://github.com/apache/cassandra/pull/2287#discussion_r1267750443
########## src/java/org/apache/cassandra/db/compaction/unified/ShardedMultiWriter.java: ########## @@ -0,0 +1,254 @@ +/* + * 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.compaction.unified; + +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.cassandra.db.ColumnFamilyStore; +import org.apache.cassandra.db.DecoratedKey; +import org.apache.cassandra.db.SerializationHeader; +import org.apache.cassandra.db.commitlog.CommitLogPosition; +import org.apache.cassandra.db.commitlog.IntervalSet; +import org.apache.cassandra.db.compaction.ShardTracker; +import org.apache.cassandra.db.lifecycle.LifecycleNewTracker; +import org.apache.cassandra.db.rows.UnfilteredRowIterator; +import org.apache.cassandra.index.Index; +import org.apache.cassandra.io.sstable.Descriptor; +import org.apache.cassandra.io.sstable.SSTableMultiWriter; +import org.apache.cassandra.io.sstable.format.SSTableReader; +import org.apache.cassandra.io.sstable.format.SSTableWriter; +import org.apache.cassandra.io.sstable.metadata.MetadataCollector; +import org.apache.cassandra.schema.TableId; +import org.apache.cassandra.utils.FBUtilities; +import org.apache.cassandra.utils.TimeUUID; + +/** + * A {@link SSTableMultiWriter} that splits the output sstable at the partition boundaries of the compaction + * shards used by {@link org.apache.cassandra.db.compaction.UnifiedCompactionStrategy}. + * <p/> + * This is class is similar to {@link ShardedCompactionWriter} but for flushing. Unfortunately + * we currently have 2 separate writers hierarchy that are not compatible and so we must + * duplicate the functionality. + */ +public class ShardedMultiWriter implements SSTableMultiWriter +{ + protected final static Logger logger = LoggerFactory.getLogger(ShardedMultiWriter.class); + + private final ColumnFamilyStore cfs; + private final Descriptor descriptor; + private final long keyCount; + private final long repairedAt; + private final TimeUUID pendingRepair; + private final boolean isTransient; + private final IntervalSet<CommitLogPosition> commitLogPositions; + private final SerializationHeader header; + private final Collection<Index> indexes; + private final LifecycleNewTracker lifecycleNewTracker; + private final ShardTracker boundaries; + private final SSTableWriter[] writers; + private int currentWriter; + + public ShardedMultiWriter(ColumnFamilyStore cfs, + Descriptor descriptor, + long keyCount, + long repairedAt, + TimeUUID pendingRepair, + boolean isTransient, + IntervalSet<CommitLogPosition> commitLogPositions, + SerializationHeader header, + Collection<Index> indexes, + LifecycleNewTracker lifecycleNewTracker, + ShardTracker boundaries) + { + this.cfs = cfs; + this.descriptor = descriptor; + this.keyCount = keyCount; + this.repairedAt = repairedAt; + this.pendingRepair = pendingRepair; + this.isTransient = isTransient; + this.commitLogPositions = commitLogPositions; + this.header = header; + this.indexes = indexes; + this.lifecycleNewTracker = lifecycleNewTracker; + this.boundaries = boundaries; + this.writers = new SSTableWriter[this.boundaries.count()]; // at least one + + this.currentWriter = 0; + this.writers[currentWriter] = createWriter(descriptor); + } + + private SSTableWriter createWriter() + { + Descriptor newDesc = cfs.newSSTableDescriptor(descriptor.directory); + return createWriter(newDesc); + } + + private SSTableWriter createWriter(Descriptor descriptor) + { + MetadataCollector metadataCollector = new MetadataCollector(cfs.metadata().comparator) + .commitLogIntervals(commitLogPositions != null ? commitLogPositions : IntervalSet.empty()); + return descriptor.getFormat().getWriterFactory().builder(descriptor) + .setKeyCount(forSplittingKeysBy(boundaries.count())) + .setRepairedAt(repairedAt) + .setPendingRepair(pendingRepair) + .setTransientSSTable(isTransient) + .setTableMetadataRef(cfs.metadata) + .setMetadataCollector(metadataCollector) + .setSerializationHeader(header) + .addDefaultComponents() + .addFlushObserversForSecondaryIndexes(indexes, lifecycleNewTracker.opType()) + .build(lifecycleNewTracker, cfs); + } + + private long forSplittingKeysBy(long splits) { + return splits <= 1 ? keyCount : keyCount / splits; + } + + @Override + public void append(UnfilteredRowIterator partition) + { + DecoratedKey key = partition.partitionKey(); + + // If we have written anything and cross a shard boundary, switch to a new writer. + final long currentUncompressedSize = writers[currentWriter].getFilePointer(); + if (boundaries.advanceTo(key.getToken()) && currentUncompressedSize > 0) + { + logger.debug("Switching writer at boundary {}/{} index {}, with uncompressed size {} for {}.{}", + key.getToken(), boundaries.shardStart(), currentWriter, + FBUtilities.prettyPrintMemory(currentUncompressedSize), + cfs.getKeyspaceName(), cfs.getTableName()); + + writers[++currentWriter] = createWriter(); + } + + writers[currentWriter].append(partition); + } + + @Override + public Collection<SSTableReader> finish(boolean openResult) + { + List<SSTableReader> sstables = new ArrayList<>(writers.length); + for (SSTableWriter writer : writers) + if (writer != null) + { + boundaries.applyTokenSpaceCoverage(writer); + sstables.add(writer.finish(openResult)); + } + return sstables; + } + + @Override + public Collection<SSTableReader> finished() + { + List<SSTableReader> sstables = new ArrayList<>(writers.length); + for (SSTableWriter writer : writers) + if (writer != null) + sstables.add(writer.finished()); + return sstables; + } + + @Override + public SSTableMultiWriter setOpenResult(boolean openResult) + { + for (SSTableWriter writer : writers) + if (writer != null) + writer.setOpenResult(openResult); + return this; + } + + @Override + public String getFilename() + { + for (SSTableWriter writer : writers) + if (writer != null) + return writer.getFilename(); + return ""; Review Comment: ok -- This is an automated message from the Apache Git Service. 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