clohfink commented on code in PR #3756: URL: https://github.com/apache/cassandra/pull/3756#discussion_r1902270821
########## src/java/org/apache/cassandra/db/virtual/PrimaryIdTable.java: ########## @@ -0,0 +1,350 @@ +/* + * 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.virtual; + +import java.io.IOException; +import java.math.BigInteger; +import java.nio.ByteBuffer; +import java.util.List; +import java.util.concurrent.CopyOnWriteArrayList; +import java.util.function.Consumer; + +import com.google.common.annotations.VisibleForTesting; +import com.google.common.collect.Lists; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import org.apache.cassandra.cql3.Operator; +import org.apache.cassandra.db.Clustering; +import org.apache.cassandra.db.ColumnFamilyStore; +import org.apache.cassandra.db.DataRange; +import org.apache.cassandra.db.DecoratedKey; +import org.apache.cassandra.db.DeletionTime; +import org.apache.cassandra.db.PartitionPosition; +import org.apache.cassandra.db.Slice; +import org.apache.cassandra.db.Slices; +import org.apache.cassandra.db.context.CounterContext; +import org.apache.cassandra.db.filter.ClusteringIndexFilter; +import org.apache.cassandra.db.filter.ColumnFilter; +import org.apache.cassandra.db.filter.RowFilter; +import org.apache.cassandra.db.marshal.CompositeType; +import org.apache.cassandra.db.marshal.CounterColumnType; +import org.apache.cassandra.db.marshal.IntegerType; +import org.apache.cassandra.db.marshal.UTF8Type; +import org.apache.cassandra.db.partitions.PartitionUpdate; +import org.apache.cassandra.db.partitions.SingletonUnfilteredPartitionIterator; +import org.apache.cassandra.db.partitions.UnfilteredPartitionIterator; +import org.apache.cassandra.db.rows.AbstractUnfilteredRowIterator; +import org.apache.cassandra.db.rows.BTreeRow; +import org.apache.cassandra.db.rows.BufferCell; +import org.apache.cassandra.db.rows.Cell; +import org.apache.cassandra.db.rows.EncodingStats; +import org.apache.cassandra.db.rows.Row; +import org.apache.cassandra.db.rows.Rows; +import org.apache.cassandra.db.rows.Unfiltered; +import org.apache.cassandra.db.rows.UnfilteredRowIterator; +import org.apache.cassandra.db.rows.UnfilteredRowIterators; +import org.apache.cassandra.dht.AbstractBounds; +import org.apache.cassandra.dht.Bounds; +import org.apache.cassandra.dht.LocalPartitioner; +import org.apache.cassandra.dht.Range; +import org.apache.cassandra.dht.Token; +import org.apache.cassandra.exceptions.InvalidRequestException; +import org.apache.cassandra.io.sstable.KeyReader; +import org.apache.cassandra.io.sstable.format.SSTableReader; +import org.apache.cassandra.schema.ColumnMetadata; +import org.apache.cassandra.schema.KeyspaceMetadata; +import org.apache.cassandra.schema.Schema; +import org.apache.cassandra.schema.TableMetadata; + +import static org.apache.cassandra.cql3.statements.RequestValidations.invalidRequest; + +/** + * A virtual table for querying primary IDs of SSTables in a specific keyspace. + * + * <p>This table is implemented as a virtual table in Cassandra, meaning it does not + * store data persistently on disk but instead derives its data from live metadata. + * + * <p>The CQL equivalent of this virtual table is: + * <pre> + * CREATE TABLE system_views.primary_ids ( + * keyspace_name TEXT, + * table_name TEXT, + * token_value INT, + * key TEXT, + * size_estimate COUNTER, + * sstables COUNTER, + * PRIMARY KEY ((keyspace_name, table_name), token_value, key) + * ); + * </pre> + * + * <p>Note: + * <ul> + * <li>The `size_estimate` and `sstables` columns represent aggregate information about SSTable sizes and counts.</li> + * <li>Range queries across multiple tables and updates are not supported as this is a read-only table.</li> + * </ul> + */ +public class PrimaryIdTable implements VirtualTable +{ + private static final Logger logger = LoggerFactory.getLogger(PrimaryIdTable.class); + public static final String NAME = "primary_ids"; + + private static final String TABLE_READ_ONLY_ERROR = "The specified table is read-only."; + private static final String UNSUPPORTED_RANGE_QUERY_ERROR = "Range queries are not supported. Please provide both a keyspace and a table name."; + private static final String REVERSED_QUERY_ERROR = "Reversed queries are not supported."; + private static final String KEYSPACE_NOT_EXIST_ERROR = "The keyspace '%s' does not exist."; + private static final String TABLE_NOT_EXIST_ERROR = "The table '%s' does not exist in the keyspace '%s'."; + private static final String KEY_ONLY_EQUALS_ERROR = "The 'key' column can only be used in an equality query for this virtual table."; + private static final String KEY_NOT_WITHIN_BOUNDS_ERROR = "The specified 'key' is not within the provided token value bounds."; + + private static final String COLUMN_KEYSPACE_NAME = "keyspace_name"; + private static final String COLUMN_TABLE_NAME = "table_name"; + private static final String COLUMN_TOKEN_VALUE = "token_value"; + private static final String COLUMN_KEY = "key"; + private static final String COLUMN_SIZE_ESTIMATE = "size_estimate"; + private static final String COLUMN_SSTABLES = "sstables"; + + private final TableMetadata metadata; + private final ColumnMetadata sizeEstimateColumn; + private final ColumnMetadata sstablesColumn; + + @VisibleForTesting + final CopyOnWriteArrayList<Consumer<DecoratedKey>> readListener = new CopyOnWriteArrayList<>(); + + public PrimaryIdTable(String keyspace) + { + this.metadata = TableMetadata.builder(keyspace, NAME) + .kind(TableMetadata.Kind.VIRTUAL) + .partitioner(new LocalPartitioner(CompositeType.getInstance(UTF8Type.instance, UTF8Type.instance))) + .addPartitionKeyColumn(COLUMN_KEYSPACE_NAME, UTF8Type.instance) + .addPartitionKeyColumn(COLUMN_TABLE_NAME, UTF8Type.instance) + .addClusteringColumn(COLUMN_TOKEN_VALUE, IntegerType.instance) + .addClusteringColumn(COLUMN_KEY, UTF8Type.instance) + .addRegularColumn(COLUMN_SIZE_ESTIMATE, CounterColumnType.instance) + .addRegularColumn(COLUMN_SSTABLES, CounterColumnType.instance) Review Comment: it doesnt actually use counters in normal sense, its because if theres 2 sstables, the cell resolver for the UnfilteredRowIterator will merge them by adding them together instead of replacing with lww -- This is an automated message from the Apache Git Service. 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