| /* |
| * 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; |
| |
| import org.apache.cassandra.db.filter.ColumnFilter; |
| import org.apache.cassandra.db.filter.DataLimits; |
| import org.apache.cassandra.db.filter.RowFilter; |
| import org.apache.cassandra.db.monitoring.MonitorableImpl; |
| import org.apache.cassandra.db.partitions.PartitionIterator; |
| import org.apache.cassandra.db.partitions.UnfilteredPartitionIterators; |
| import org.apache.cassandra.schema.TableMetadata; |
| |
| /** |
| * Base class for {@code ReadQuery} implementations. |
| */ |
| abstract class AbstractReadQuery extends MonitorableImpl implements ReadQuery |
| { |
| private final TableMetadata metadata; |
| private final int nowInSec; |
| |
| private final ColumnFilter columnFilter; |
| private final RowFilter rowFilter; |
| private final DataLimits limits; |
| |
| protected AbstractReadQuery(TableMetadata metadata, int nowInSec, ColumnFilter columnFilter, RowFilter rowFilter, DataLimits limits) |
| { |
| this.metadata = metadata; |
| this.nowInSec = nowInSec; |
| this.columnFilter = columnFilter; |
| this.rowFilter = rowFilter; |
| this.limits = limits; |
| } |
| |
| @Override |
| public TableMetadata metadata() |
| { |
| return metadata; |
| } |
| |
| // Monitorable interface |
| public String name() |
| { |
| return toCQLString(); |
| } |
| |
| @Override |
| public PartitionIterator executeInternal(ReadExecutionController controller) |
| { |
| return UnfilteredPartitionIterators.filter(executeLocally(controller), nowInSec()); |
| } |
| |
| @Override |
| public DataLimits limits() |
| { |
| return limits; |
| } |
| |
| @Override |
| public int nowInSec() |
| { |
| return nowInSec; |
| } |
| |
| @Override |
| public RowFilter rowFilter() |
| { |
| return rowFilter; |
| } |
| |
| @Override |
| public ColumnFilter columnFilter() |
| { |
| return columnFilter; |
| } |
| |
| /** |
| * Recreate the CQL string corresponding to this query. |
| * <p> |
| * Note that in general the returned string will not be exactly the original user string, first |
| * because there isn't always a single syntax for a given query, but also because we don't have |
| * all the information needed (we know the non-PK columns queried but not the PK ones as internally |
| * we query them all). So this shouldn't be relied too strongly, but this should be good enough for |
| * debugging purpose which is what this is for. |
| */ |
| public String toCQLString() |
| { |
| StringBuilder sb = new StringBuilder().append("SELECT ") |
| .append(columnFilter().toCQLString()) |
| .append(" FROM ") |
| .append(metadata().keyspace) |
| .append('.') |
| .append(metadata().name); |
| appendCQLWhereClause(sb); |
| |
| if (limits() != DataLimits.NONE) |
| sb.append(' ').append(limits()); |
| return sb.toString(); |
| } |
| |
| protected abstract void appendCQLWhereClause(StringBuilder sb); |
| } |