maedhroz commented on code in PR #2267: URL: https://github.com/apache/cassandra/pull/2267#discussion_r1180563816
########## src/java/org/apache/cassandra/io/sstable/format/bti/RowIndexWriter.java: ########## @@ -0,0 +1,122 @@ +/* + * 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.bti; + +import java.io.IOException; + +import org.apache.cassandra.db.ClusteringComparator; +import org.apache.cassandra.db.ClusteringPrefix; +import org.apache.cassandra.db.DeletionTime; +import org.apache.cassandra.io.sstable.format.bti.RowIndexReader.IndexInfo; +import org.apache.cassandra.io.tries.IncrementalTrieWriter; +import org.apache.cassandra.io.tries.Walker; +import org.apache.cassandra.io.util.DataOutputPlus; +import org.apache.cassandra.utils.bytecomparable.ByteComparable; +import org.apache.cassandra.utils.bytecomparable.ByteSource; + +/** + * Preparer / writer of row index tries. + * <p> + * Uses IncrementalTrieWriter to build a trie of index section separators of the shortest possible length such that + * prevMax < separator <= nextMin. + */ +class RowIndexWriter implements AutoCloseable +{ + private final ClusteringComparator comparator; + private final IncrementalTrieWriter<IndexInfo> trie; + private ByteComparable prevMax = null; + private ByteComparable prevSep = null; + + RowIndexWriter(ClusteringComparator comparator, DataOutputPlus out) + { + this.comparator = comparator; + this.trie = IncrementalTrieWriter.open(RowIndexReader.trieSerializer, out); + } + + void reset() + { + prevMax = null; + prevSep = null; + trie.reset(); + } + + @Override + public void close() + { + trie.close(); + } + + void add(ClusteringPrefix<?> firstName, ClusteringPrefix<?> lastName, IndexInfo info) throws IOException + { + assert info.openDeletion != null; + ByteComparable sep = prevMax == null + ? ByteComparable.EMPTY + : ByteComparable.separatorGt(prevMax, comparator.asByteComparable(firstName)); + trie.add(sep, info); + prevSep = sep; + prevMax = comparator.asByteComparable(lastName); + } + + public long complete(long endPos) throws IOException + { + // Add a separator after the last section, so that greater inputs can be quickly rejected. + // To maximize its efficiency we add it with the length of the last added separator. + int i = 0; + ByteSource max = prevMax.asComparableBytes(Walker.BYTE_COMPARABLE_VERSION); + ByteSource sep = prevSep.asComparableBytes(Walker.BYTE_COMPARABLE_VERSION); + int c; + while ((c = max.next()) == sep.next() && c != ByteSource.END_OF_STREAM) + ++i; + assert c != ByteSource.END_OF_STREAM : "Corrupted row order, max=" + prevMax; + + trie.add(nudge(prevMax, i), new IndexInfo(endPos, DeletionTime.LIVE)); + + return trie.complete(); + } + + /** + * Produces a source that is slightly greater than argument with length at least nudgeAt. + */ + private ByteComparable nudge(ByteComparable value, int nudgeAt) + { + return version -> new ByteSource() + { + private final ByteSource v = value.asComparableBytes(version); + private int cur = 0; + + @Override + public int next() + { + int b = ByteSource.END_OF_STREAM; + if (cur <= nudgeAt) + { + b = v.next(); + if (cur == nudgeAt) + { + if (b < 255) Review Comment: Works for me. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
