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* 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.filter;
import java.nio.ByteBuffer;
import java.util.*;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterators;
import org.apache.cassandra.db.marshal.CollectionType;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.ColumnDefinition;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.composites.CellName;
import org.apache.cassandra.db.composites.Composite;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.db.marshal.CompositeType;
/**
* Extends a column filter (IFilter) to include a number of IndexExpression.
*/
public abstract class ExtendedFilter
{
private static final Logger logger = LoggerFactory.getLogger(ExtendedFilter.class);
public final ColumnFamilyStore cfs;
public final long timestamp;
public final DataRange dataRange;
private final int maxResults;
private final boolean countCQL3Rows;
private volatile int currentLimit;
public static ExtendedFilter create(ColumnFamilyStore cfs,
DataRange dataRange,
List<IndexExpression> clause,
int maxResults,
boolean countCQL3Rows,
long timestamp)
{
if (clause == null || clause.isEmpty())
return new EmptyClauseFilter(cfs, dataRange, maxResults, countCQL3Rows, timestamp);
return new WithClauses(cfs, dataRange, clause, maxResults, countCQL3Rows, timestamp);
}
protected ExtendedFilter(ColumnFamilyStore cfs, DataRange dataRange, int maxResults, boolean countCQL3Rows, long timestamp)
{
assert cfs != null;
assert dataRange != null;
this.cfs = cfs;
this.dataRange = dataRange;
this.maxResults = maxResults;
this.timestamp = timestamp;
this.countCQL3Rows = countCQL3Rows;
this.currentLimit = maxResults;
if (countCQL3Rows)
dataRange.updateColumnsLimit(maxResults);
}
public int maxRows()
{
return countCQL3Rows ? Integer.MAX_VALUE : maxResults;
}
public int maxColumns()
{
return countCQL3Rows ? maxResults : Integer.MAX_VALUE;
}
public int currentLimit()
{
return currentLimit;
}
public IDiskAtomFilter columnFilter(ByteBuffer key)
{
return dataRange.columnFilter(key);
}
public int lastCounted(ColumnFamily data)
{
return dataRange.getLiveCount(data, timestamp);
}
public void updateFilter(int currentColumnsCount)
{
if (!countCQL3Rows)
return;
currentLimit = maxResults - currentColumnsCount;
// We propagate that limit to the underlying filter so each internal query don't
// fetch more than we needs it to.
dataRange.updateColumnsLimit(currentLimit);
}
public abstract List<IndexExpression> getClause();
/**
* Returns a filter to query the columns from the clause that the initial slice filter may not have caught.
* @param data the data retrieve by the initial filter
* @return a filter or null if there can't be any columns we missed with our initial filter (typically if it was a names query, or a slice of the entire row)
*/
public abstract IDiskAtomFilter getExtraFilter(DecoratedKey key, ColumnFamily data);
/**
* @return data pruned down to the columns originally asked for
*/
public abstract ColumnFamily prune(DecoratedKey key, ColumnFamily data);
/**
* @return true if the provided data satisfies all the expressions from
* the clause of this filter.
*/
public abstract boolean isSatisfiedBy(DecoratedKey rowKey, ColumnFamily data, Composite prefix, ByteBuffer collectionElement);
public static boolean satisfies(int comparison, IndexExpression.Operator op)
{
switch (op)
{
case EQ:
return comparison == 0;
case GTE:
return comparison >= 0;
case GT:
return comparison > 0;
case LTE:
return comparison <= 0;
case LT:
return comparison < 0;
default:
throw new IllegalStateException();
}
}
public static class WithClauses extends ExtendedFilter
{
private final List<IndexExpression> clause;
private final IDiskAtomFilter optimizedFilter;
public WithClauses(ColumnFamilyStore cfs,
DataRange range,
List<IndexExpression> clause,
int maxResults,
boolean countCQL3Rows,
long timestamp)
{
super(cfs, range, maxResults, countCQL3Rows, timestamp);
assert clause != null;
this.clause = clause;
this.optimizedFilter = computeOptimizedFilter();
}
/*
* Potentially optimize the column filter if we have a change to make it catch all clauses
* right away.
*/
private IDiskAtomFilter computeOptimizedFilter()
{
/*
* We shouldn't do the "optimization" for composites as the index names are not valid column names
* (which the rest of the method assumes). Said optimization is not useful for composites anyway.
* We also don't want to do for paging ranges as the actual filter depends on the row key (it would
* probably be possible to make it work but we won't really use it so we don't bother).
*/
if (cfs.getComparator().isCompound() || dataRange instanceof DataRange.Paging)
return null;
IDiskAtomFilter filter = dataRange.columnFilter(null); // ok since not a paging range
if (filter instanceof SliceQueryFilter)
{
// if we have a high chance of getting all the columns in a single index slice (and it's not too costly), do that.
// otherwise, the extraFilter (lazily created) will fetch by name the columns referenced by the additional expressions.
if (cfs.getMaxRowSize() < DatabaseDescriptor.getColumnIndexSize())
{
logger.trace("Expanding slice filter to entire row to cover additional expressions");
return new SliceQueryFilter(ColumnSlice.ALL_COLUMNS_ARRAY, ((SliceQueryFilter)filter).reversed, Integer.MAX_VALUE);
}
}
else
{
logger.trace("adding columns to original Filter to cover additional expressions");
assert filter instanceof NamesQueryFilter;
if (!clause.isEmpty())
{
SortedSet<CellName> columns = new TreeSet<CellName>(cfs.getComparator());
for (IndexExpression expr : clause)
columns.add(cfs.getComparator().cellFromByteBuffer(expr.column));
columns.addAll(((NamesQueryFilter) filter).columns);
return ((NamesQueryFilter) filter).withUpdatedColumns(columns);
}
}
return null;
}
@Override
public IDiskAtomFilter columnFilter(ByteBuffer key)
{
return optimizedFilter == null ? dataRange.columnFilter(key) : optimizedFilter;
}
public List<IndexExpression> getClause()
{
return clause;
}
/*
* We may need an extra query only if the original query wasn't selecting the row entirely.
* Furthermore, we only need the extra query if we haven't yet got all the expressions from the clause.
*/
private boolean needsExtraQuery(ByteBuffer rowKey, ColumnFamily data)
{
IDiskAtomFilter filter = columnFilter(rowKey);
if (filter instanceof SliceQueryFilter && DataRange.isFullRowSlice((SliceQueryFilter)filter))
return false;
for (IndexExpression expr : clause)
{
if (data.getColumn(data.getComparator().cellFromByteBuffer(expr.column)) == null)
{
logger.debug("adding extraFilter to cover additional expressions");
return true;
}
}
return false;
}
public IDiskAtomFilter getExtraFilter(DecoratedKey rowKey, ColumnFamily data)
{
/*
* This method assumes the IndexExpression names are valid column names, which is not the
* case with composites. This is ok for now however since:
* 1) CompositeSearcher doesn't use it.
* 2) We don't yet allow non-indexed range slice with filters in CQL3 (i.e. this will never be
* called by CFS.filter() for composites).
*/
assert !(cfs.getComparator().isCompound()) : "Sequential scan with filters is not supported (if you just created an index, you "
+ "need to wait for the creation to be propagated to all nodes before querying it)";
if (!needsExtraQuery(rowKey.getKey(), data))
return null;
// Note: for counters we must be careful to not add a column that was already there (to avoid overcount). That is
// why we do the dance of avoiding to query any column we already have (it's also more efficient anyway)
SortedSet<CellName> columns = new TreeSet<CellName>(cfs.getComparator());
for (IndexExpression expr : clause)
{
CellName name = data.getComparator().cellFromByteBuffer(expr.column);
if (data.getColumn(name) == null)
columns.add(name);
}
assert !columns.isEmpty();
return new NamesQueryFilter(columns);
}
public ColumnFamily prune(DecoratedKey rowKey, ColumnFamily data)
{
if (optimizedFilter == null)
return data;
ColumnFamily pruned = data.cloneMeShallow();
IDiskAtomFilter filter = dataRange.columnFilter(rowKey.getKey());
Iterator<Cell> iter = filter.getColumnIterator(data);
filter.collectReducedColumns(pruned, QueryFilter.gatherTombstones(pruned, iter), cfs.gcBefore(timestamp), timestamp);
return pruned;
}
public boolean isSatisfiedBy(DecoratedKey rowKey, ColumnFamily data, Composite prefix, ByteBuffer collectionElement)
{
for (IndexExpression expression : clause)
{
ColumnDefinition def = data.metadata().getColumnDefinition(expression.column);
ByteBuffer dataValue = null;
AbstractType<?> validator = null;
if (def == null)
{
// This can't happen with CQL3 as this should be rejected upfront. For thrift however,
// cell name are not predefined. But that means the cell name correspond to an internal one.
Cell cell = data.getColumn(data.getComparator().cellFromByteBuffer(expression.column));
if (cell != null)
{
dataValue = cell.value();
validator = data.metadata().getDefaultValidator();
}
}
else
{
if (def.type.isCollection())
{
if (!collectionSatisfies(def, data, prefix, expression, collectionElement))
return false;
continue;
}
dataValue = extractDataValue(def, rowKey.getKey(), data, prefix);
validator = def.type;
}
if (dataValue == null)
return false;
int v = validator.compare(dataValue, expression.value);
if (!satisfies(v, expression.operator))
return false;
}
return true;
}
private static boolean collectionSatisfies(ColumnDefinition def, ColumnFamily data, Composite prefix, IndexExpression expr, ByteBuffer collectionElement)
{
assert def.type.isCollection();
if (expr.operator == IndexExpression.Operator.CONTAINS)
{
// get a slice of the collection cells
Iterator<Cell> iter = data.iterator(new ColumnSlice[]{ data.getComparator().create(prefix, def).slice() });
while (iter.hasNext())
{
if (((CollectionType) def.type).valueComparator().compare(iter.next().value(), expr.value) == 0)
return true;
}
return false;
}
CollectionType type = (CollectionType)def.type;
switch (type.kind)
{
case LIST:
assert collectionElement != null;
return type.valueComparator().compare(data.getColumn(data.getComparator().create(prefix, def, collectionElement)).value(), expr.value) == 0;
case SET:
return data.getColumn(data.getComparator().create(prefix, def, expr.value)) != null;
case MAP:
if (expr.operator == IndexExpression.Operator.CONTAINS_KEY)
{
return data.getColumn(data.getComparator().create(prefix, def, expr.value)) != null;
}
else
{
assert collectionElement != null;
return type.valueComparator().compare(data.getColumn(data.getComparator().create(prefix, def, collectionElement)).value(), expr.value) == 0;
}
}
throw new AssertionError();
}
private ByteBuffer extractDataValue(ColumnDefinition def, ByteBuffer rowKey, ColumnFamily data, Composite prefix)
{
switch (def.kind)
{
case PARTITION_KEY:
return def.isOnAllComponents()
? rowKey
: ((CompositeType)data.metadata().getKeyValidator()).split(rowKey)[def.position()];
case CLUSTERING_COLUMN:
return prefix.get(def.position());
case REGULAR:
CellName cname = prefix == null
? data.getComparator().cellFromByteBuffer(def.name.bytes)
: data.getComparator().create(prefix, def);
Cell cell = data.getColumn(cname);
return cell == null ? null : cell.value();
case COMPACT_VALUE:
assert data.getColumnCount() == 1;
return data.getSortedColumns().iterator().next().value();
}
throw new AssertionError();
}
}
private static class EmptyClauseFilter extends ExtendedFilter
{
public EmptyClauseFilter(ColumnFamilyStore cfs, DataRange range, int maxResults, boolean countCQL3Rows, long timestamp)
{
super(cfs, range, maxResults, countCQL3Rows, timestamp);
}
public List<IndexExpression> getClause()
{
return Collections.<IndexExpression>emptyList();
}
public IDiskAtomFilter getExtraFilter(DecoratedKey key, ColumnFamily data)
{
return null;
}
public ColumnFamily prune(DecoratedKey rowKey, ColumnFamily data)
{
return data;
}
public boolean isSatisfiedBy(DecoratedKey rowKey, ColumnFamily data, Composite prefix, ByteBuffer collectionElement)
{
return true;
}
}
}