org.apache.cassandra.cql3.ResultSet Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cassandra-all Show documentation
Show all versions of cassandra-all Show documentation
The Apache Cassandra Project develops a highly scalable second-generation distributed database, bringing together Dynamo's fully distributed design and Bigtable's ColumnFamily-based data model.
/*
* 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.cql3;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumSet;
import java.util.List;
import java.util.Objects;
import com.google.common.annotations.VisibleForTesting;
import io.netty.buffer.ByteBuf;
import org.apache.cassandra.cql3.statements.SelectStatement;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.service.pager.PagingState;
import org.apache.cassandra.transport.CBCodec;
import org.apache.cassandra.transport.CBUtil;
import org.apache.cassandra.transport.DataType;
import org.apache.cassandra.transport.ProtocolVersion;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.apache.cassandra.utils.MD5Digest;
public class ResultSet
{
public static final Codec codec = new Codec();
public final ResultMetadata metadata;
public final List> rows;
public ResultSet(ResultMetadata resultMetadata)
{
this(resultMetadata, new ArrayList>());
}
public ResultSet(ResultMetadata resultMetadata, List> rows)
{
this.metadata = resultMetadata;
this.rows = rows;
}
public int size()
{
return rows.size();
}
public boolean isEmpty()
{
return size() == 0;
}
public void addRow(List row)
{
assert row.size() == metadata.valueCount();
rows.add(row);
}
public void addColumnValue(ByteBuffer value)
{
if (rows.isEmpty() || lastRow().size() == metadata.valueCount())
rows.add(new ArrayList(metadata.valueCount()));
lastRow().add(value);
}
private List lastRow()
{
return rows.get(rows.size() - 1);
}
public void reverse()
{
Collections.reverse(rows);
}
public void trim(int limit)
{
int toRemove = rows.size() - limit;
if (toRemove > 0)
{
for (int i = 0; i < toRemove; i++)
rows.remove(rows.size() - 1);
}
}
@Override
public String toString()
{
try
{
StringBuilder sb = new StringBuilder();
sb.append(metadata).append('\n');
for (List row : rows)
{
for (int i = 0; i < row.size(); i++)
{
ByteBuffer v = row.get(i);
if (v == null)
{
sb.append(" | null");
}
else
{
sb.append(" | ");
if (metadata.flags.contains(Flag.NO_METADATA))
sb.append("0x").append(ByteBufferUtil.bytesToHex(v));
else
sb.append(metadata.names.get(i).type.getString(v));
}
}
sb.append('\n');
}
sb.append("---");
return sb.toString();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
public static class Codec implements CBCodec
{
/*
* Format:
* - metadata
* - rows count (4 bytes)
* - rows
*/
public ResultSet decode(ByteBuf body, ProtocolVersion version)
{
ResultMetadata m = ResultMetadata.codec.decode(body, version);
int rowCount = body.readInt();
ResultSet rs = new ResultSet(m, new ArrayList>(rowCount));
// rows
int totalValues = rowCount * m.columnCount;
for (int i = 0; i < totalValues; i++)
rs.addColumnValue(CBUtil.readValue(body));
return rs;
}
public void encode(ResultSet rs, ByteBuf dest, ProtocolVersion version)
{
ResultMetadata.codec.encode(rs.metadata, dest, version);
dest.writeInt(rs.rows.size());
for (List row : rs.rows)
{
// Note that we do only want to serialize only the first columnCount values, even if the row
// as more: see comment on ResultMetadata.names field.
for (int i = 0; i < rs.metadata.columnCount; i++)
CBUtil.writeValue(row.get(i), dest);
}
}
public int encodedSize(ResultSet rs, ProtocolVersion version)
{
int size = ResultMetadata.codec.encodedSize(rs.metadata, version) + 4;
for (List row : rs.rows)
{
for (int i = 0; i < rs.metadata.columnCount; i++)
size += CBUtil.sizeOfValue(row.get(i));
}
return size;
}
}
/**
* The metadata for the results of executing a query or prepared statement.
*/
public static class ResultMetadata
{
public static final CBCodec codec = new Codec();
public static final ResultMetadata EMPTY = new ResultMetadata(MD5Digest.compute(new byte[0]), EnumSet.of(Flag.NO_METADATA), null, 0, null);
private final EnumSet flags;
// Please note that columnCount can actually be smaller than names, even if names is not null. This is
// used to include columns in the resultSet that we need to do post-query re-orderings
// (SelectStatement.orderResults) but that shouldn't be sent to the user as they haven't been requested
// (CASSANDRA-4911). So the serialization code will exclude any columns in name whose index is >= columnCount.
public final List names;
private final int columnCount;
private PagingState pagingState;
private final MD5Digest resultMetadataId;
public ResultMetadata(MD5Digest digest, List names)
{
this(digest, EnumSet.noneOf(Flag.class), names, names.size(), null);
if (!names.isEmpty() && ColumnSpecification.allInSameTable(names))
flags.add(Flag.GLOBAL_TABLES_SPEC);
}
// Problem is that we compute the metadata from the columns on creation;
// when re-preparing we create the intermediate object
public ResultMetadata(List names)
{
this(names, null);
}
// Problem is that we compute the metadata from the columns on creation;
// when re-preparing we create the intermediate object
public ResultMetadata(List names, PagingState pagingState)
{
this(computeResultMetadataId(names), EnumSet.noneOf(Flag.class), names, names.size(), pagingState);
if (!names.isEmpty() && ColumnSpecification.allInSameTable(names))
flags.add(Flag.GLOBAL_TABLES_SPEC);
}
private ResultMetadata(MD5Digest resultMetadataId, EnumSet flags, List names, int columnCount, PagingState pagingState)
{
this.resultMetadataId = resultMetadataId;
this.flags = flags;
this.names = names;
this.columnCount = columnCount;
this.pagingState = pagingState;
}
public ResultMetadata copy()
{
return new ResultMetadata(resultMetadataId, EnumSet.copyOf(flags), names, columnCount, pagingState);
}
/**
* Return only the column names requested by the user, excluding those added for post-query re-orderings,
* see definition of names and columnCount.
**/
public List requestNames()
{
return names.subList(0, columnCount);
}
// The maximum number of values that the ResultSet can hold. This can be bigger than columnCount due to CASSANDRA-4911
public int valueCount()
{
return names == null ? columnCount : names.size();
}
@VisibleForTesting
public EnumSet getFlags()
{
return flags;
}
@VisibleForTesting
public int getColumnCount()
{
return columnCount;
}
@VisibleForTesting
public PagingState getPagingState()
{
return pagingState;
}
/**
* Adds the specified columns which will not be serialized.
*
* @param columns the columns
*/
public ResultMetadata addNonSerializedColumns(Collection columns)
{
// See comment above. Because columnCount doesn't account the newly added name, it
// won't be serialized.
names.addAll(columns);
return this;
}
public void setHasMorePages(PagingState pagingState)
{
this.pagingState = pagingState;
if (pagingState == null)
flags.remove(Flag.HAS_MORE_PAGES);
else
flags.add(Flag.HAS_MORE_PAGES);
}
public void setSkipMetadata()
{
flags.add(Flag.NO_METADATA);
}
public void setMetadataChanged()
{
flags.add(Flag.METADATA_CHANGED);
}
public MD5Digest getResultMetadataId()
{
return resultMetadataId;
}
public static ResultMetadata fromPrepared(CQLStatement statement)
{
if (statement instanceof SelectStatement)
return ((SelectStatement)statement).getResultMetadata();
return ResultSet.ResultMetadata.EMPTY;
}
@Override
public boolean equals(Object other)
{
if (this == other)
return true;
if (!(other instanceof ResultMetadata))
return false;
ResultMetadata that = (ResultMetadata) other;
return Objects.equals(flags, that.flags)
&& Objects.equals(names, that.names)
&& columnCount == that.columnCount
&& Objects.equals(pagingState, that.pagingState);
}
@Override
public int hashCode()
{
return Objects.hash(flags, names, columnCount, pagingState);
}
@Override
public String toString()
{
StringBuilder sb = new StringBuilder();
if (names == null)
{
sb.append("[").append(columnCount).append(" columns]");
}
else
{
for (ColumnSpecification name : names)
{
sb.append("[").append(name.name);
sb.append("(").append(name.ksName).append(", ").append(name.cfName).append(")");
sb.append(", ").append(name.type).append("]");
}
}
if (flags.contains(Flag.HAS_MORE_PAGES))
sb.append(" (to be continued)");
return sb.toString();
}
private static class Codec implements CBCodec
{
public ResultMetadata decode(ByteBuf body, ProtocolVersion version)
{
// flags & column count
int iflags = body.readInt();
int columnCount = body.readInt();
EnumSet flags = Flag.deserialize(iflags);
MD5Digest resultMetadataId = null;
if (flags.contains(Flag.METADATA_CHANGED))
{
assert version.isGreaterOrEqualTo(ProtocolVersion.V5) : "MetadataChanged flag is not supported before native protocol v5";
assert !flags.contains(Flag.NO_METADATA) : "MetadataChanged and NoMetadata are mutually exclusive flags";
resultMetadataId = MD5Digest.wrap(CBUtil.readBytes(body));
}
PagingState state = null;
if (flags.contains(Flag.HAS_MORE_PAGES))
state = PagingState.deserialize(CBUtil.readValueNoCopy(body), version);
if (flags.contains(Flag.NO_METADATA))
return new ResultMetadata(null, flags, null, columnCount, state);
boolean globalTablesSpec = flags.contains(Flag.GLOBAL_TABLES_SPEC);
String globalKsName = null;
String globalCfName = null;
if (globalTablesSpec)
{
globalKsName = CBUtil.readString(body);
globalCfName = CBUtil.readString(body);
}
// metadata (names/types)
List names = new ArrayList(columnCount);
for (int i = 0; i < columnCount; i++)
{
String ksName = globalTablesSpec ? globalKsName : CBUtil.readString(body);
String cfName = globalTablesSpec ? globalCfName : CBUtil.readString(body);
ColumnIdentifier colName = new ColumnIdentifier(CBUtil.readString(body), true);
AbstractType type = DataType.toType(DataType.codec.decodeOne(body, version));
names.add(new ColumnSpecification(ksName, cfName, colName, type));
}
return new ResultMetadata(resultMetadataId, flags, names, names.size(), state);
}
public void encode(ResultMetadata m, ByteBuf dest, ProtocolVersion version)
{
boolean noMetadata = m.flags.contains(Flag.NO_METADATA);
boolean globalTablesSpec = m.flags.contains(Flag.GLOBAL_TABLES_SPEC);
boolean hasMorePages = m.flags.contains(Flag.HAS_MORE_PAGES);
boolean metadataChanged = m.flags.contains(Flag.METADATA_CHANGED);
assert version.isGreaterThan(ProtocolVersion.V1) || (!hasMorePages && !noMetadata)
: "version = " + version + ", flags = " + m.flags;
dest.writeInt(Flag.serialize(m.flags));
dest.writeInt(m.columnCount);
if (hasMorePages)
CBUtil.writeValue(m.pagingState.serialize(version), dest);
if (version.isGreaterOrEqualTo(ProtocolVersion.V5) && metadataChanged)
{
assert !noMetadata : "MetadataChanged and NoMetadata are mutually exclusive flags";
CBUtil.writeBytes(m.getResultMetadataId().bytes, dest);
}
if (!noMetadata)
{
if (globalTablesSpec)
{
CBUtil.writeAsciiString(m.names.get(0).ksName, dest);
CBUtil.writeAsciiString(m.names.get(0).cfName, dest);
}
for (int i = 0; i < m.columnCount; i++)
{
ColumnSpecification name = m.names.get(i);
if (!globalTablesSpec)
{
CBUtil.writeAsciiString(name.ksName, dest);
CBUtil.writeAsciiString(name.cfName, dest);
}
CBUtil.writeString(name.name.toString(), dest);
DataType.codec.writeOne(DataType.fromType(name.type, version), dest, version);
}
}
}
public int encodedSize(ResultMetadata m, ProtocolVersion version)
{
boolean noMetadata = m.flags.contains(Flag.NO_METADATA);
boolean globalTablesSpec = m.flags.contains(Flag.GLOBAL_TABLES_SPEC);
boolean hasMorePages = m.flags.contains(Flag.HAS_MORE_PAGES);
boolean metadataChanged = m.flags.contains(Flag.METADATA_CHANGED);
int size = 8;
if (hasMorePages)
size += CBUtil.sizeOfValue(m.pagingState.serializedSize(version));
if (version.isGreaterOrEqualTo(ProtocolVersion.V5) && metadataChanged)
size += CBUtil.sizeOfBytes(m.getResultMetadataId().bytes);
if (!noMetadata)
{
if (globalTablesSpec)
{
size += CBUtil.sizeOfAsciiString(m.names.get(0).ksName);
size += CBUtil.sizeOfAsciiString(m.names.get(0).cfName);
}
for (int i = 0; i < m.columnCount; i++)
{
ColumnSpecification name = m.names.get(i);
if (!globalTablesSpec)
{
size += CBUtil.sizeOfAsciiString(name.ksName);
size += CBUtil.sizeOfAsciiString(name.cfName);
}
size += CBUtil.sizeOfString(name.name.toString());
size += DataType.codec.oneSerializedSize(DataType.fromType(name.type, version), version);
}
}
return size;
}
}
}
/**
* The metadata for the query parameters in a prepared statement.
*/
public static class PreparedMetadata
{
public static final CBCodec codec = new Codec();
private final EnumSet flags;
public final List names;
private final short[] partitionKeyBindIndexes;
public PreparedMetadata(List names, short[] partitionKeyBindIndexes)
{
this(EnumSet.noneOf(Flag.class), names, partitionKeyBindIndexes);
if (!names.isEmpty() && ColumnSpecification.allInSameTable(names))
flags.add(Flag.GLOBAL_TABLES_SPEC);
}
private PreparedMetadata(EnumSet flags, List names, short[] partitionKeyBindIndexes)
{
this.flags = flags;
this.names = names;
this.partitionKeyBindIndexes = partitionKeyBindIndexes;
}
public PreparedMetadata copy()
{
return new PreparedMetadata(EnumSet.copyOf(flags), names, partitionKeyBindIndexes);
}
@Override
public boolean equals(Object other)
{
if (this == other)
return true;
if (!(other instanceof PreparedMetadata))
return false;
PreparedMetadata that = (PreparedMetadata) other;
return this.names.equals(that.names) &&
this.flags.equals(that.flags) &&
Arrays.equals(this.partitionKeyBindIndexes, that.partitionKeyBindIndexes);
}
@Override
public int hashCode()
{
return Objects.hash(names, flags) + Arrays.hashCode(partitionKeyBindIndexes);
}
@Override
public String toString()
{
StringBuilder sb = new StringBuilder();
for (ColumnSpecification name : names)
{
sb.append("[").append(name.name);
sb.append("(").append(name.ksName).append(", ").append(name.cfName).append(")");
sb.append(", ").append(name.type).append("]");
}
sb.append(", bindIndexes=[");
if (partitionKeyBindIndexes != null)
{
for (int i = 0; i < partitionKeyBindIndexes.length; i++)
{
if (i > 0)
sb.append(", ");
sb.append(partitionKeyBindIndexes[i]);
}
}
sb.append("]");
return sb.toString();
}
public static PreparedMetadata fromPrepared(CQLStatement statement)
{
return new PreparedMetadata(statement.getBindVariables(), statement.getPartitionKeyBindVariableIndexes());
}
private static class Codec implements CBCodec
{
public PreparedMetadata decode(ByteBuf body, ProtocolVersion version)
{
// flags & column count
int iflags = body.readInt();
int columnCount = body.readInt();
EnumSet flags = Flag.deserialize(iflags);
short[] partitionKeyBindIndexes = null;
if (version.isGreaterOrEqualTo(ProtocolVersion.V4))
{
int numPKNames = body.readInt();
if (numPKNames > 0)
{
partitionKeyBindIndexes = new short[numPKNames];
for (int i = 0; i < numPKNames; i++)
partitionKeyBindIndexes[i] = body.readShort();
}
}
boolean globalTablesSpec = flags.contains(Flag.GLOBAL_TABLES_SPEC);
String globalKsName = null;
String globalCfName = null;
if (globalTablesSpec)
{
globalKsName = CBUtil.readString(body);
globalCfName = CBUtil.readString(body);
}
// metadata (names/types)
List names = new ArrayList<>(columnCount);
for (int i = 0; i < columnCount; i++)
{
String ksName = globalTablesSpec ? globalKsName : CBUtil.readString(body);
String cfName = globalTablesSpec ? globalCfName : CBUtil.readString(body);
ColumnIdentifier colName = new ColumnIdentifier(CBUtil.readString(body), true);
AbstractType type = DataType.toType(DataType.codec.decodeOne(body, version));
names.add(new ColumnSpecification(ksName, cfName, colName, type));
}
return new PreparedMetadata(flags, names, partitionKeyBindIndexes);
}
public void encode(PreparedMetadata m, ByteBuf dest, ProtocolVersion version)
{
boolean globalTablesSpec = m.flags.contains(Flag.GLOBAL_TABLES_SPEC);
dest.writeInt(Flag.serialize(m.flags));
dest.writeInt(m.names.size());
if (version.isGreaterOrEqualTo(ProtocolVersion.V4))
{
// there's no point in providing partition key bind indexes if the statements affect multiple tables
if (m.partitionKeyBindIndexes == null || !globalTablesSpec)
{
dest.writeInt(0);
}
else
{
dest.writeInt(m.partitionKeyBindIndexes.length);
for (Short bindIndex : m.partitionKeyBindIndexes)
dest.writeShort(bindIndex);
}
}
if (globalTablesSpec)
{
CBUtil.writeAsciiString(m.names.get(0).ksName, dest);
CBUtil.writeAsciiString(m.names.get(0).cfName, dest);
}
for (ColumnSpecification name : m.names)
{
if (!globalTablesSpec)
{
CBUtil.writeAsciiString(name.ksName, dest);
CBUtil.writeAsciiString(name.cfName, dest);
}
CBUtil.writeString(name.name.toString(), dest);
DataType.codec.writeOne(DataType.fromType(name.type, version), dest, version);
}
}
public int encodedSize(PreparedMetadata m, ProtocolVersion version)
{
boolean globalTablesSpec = m.flags.contains(Flag.GLOBAL_TABLES_SPEC);
int size = 8;
if (globalTablesSpec)
{
size += CBUtil.sizeOfAsciiString(m.names.get(0).ksName);
size += CBUtil.sizeOfAsciiString(m.names.get(0).cfName);
}
if (m.partitionKeyBindIndexes != null && version.isGreaterOrEqualTo(ProtocolVersion.V4))
size += 4 + 2 * m.partitionKeyBindIndexes.length;
for (ColumnSpecification name : m.names)
{
if (!globalTablesSpec)
{
size += CBUtil.sizeOfAsciiString(name.ksName);
size += CBUtil.sizeOfAsciiString(name.cfName);
}
size += CBUtil.sizeOfString(name.name.toString());
size += DataType.codec.oneSerializedSize(DataType.fromType(name.type, version), version);
}
return size;
}
}
}
public enum Flag
{
// The order of that enum matters!!
GLOBAL_TABLES_SPEC,
HAS_MORE_PAGES,
NO_METADATA,
METADATA_CHANGED;
public static EnumSet deserialize(int flags)
{
EnumSet set = EnumSet.noneOf(Flag.class);
Flag[] values = Flag.values();
for (int n = 0; n < values.length; n++)
{
if ((flags & (1 << n)) != 0)
set.add(values[n]);
}
return set;
}
public static int serialize(EnumSet flags)
{
int i = 0;
for (Flag flag : flags)
i |= 1 << flag.ordinal();
return i;
}
}
static MD5Digest computeResultMetadataId(List columnSpecifications)
{
// still using the MD5 MessageDigest thread local here instead of a HashingUtils/Guava
// Hasher, as ResultSet will need to be changed alongside other usages of MD5
// in the native transport/protocol and it seems to make more sense to do that
// then than as part of the Guava Hasher refactor which is focused on non-client
// protocol digests
MessageDigest md = MD5Digest.threadLocalMD5Digest();
if (columnSpecifications != null)
{
for (ColumnSpecification cs : columnSpecifications)
{
md.update(cs.name.bytes.duplicate());
md.update((byte) 0);
md.update(cs.type.toString().getBytes(StandardCharsets.UTF_8));
md.update((byte) 0);
md.update((byte) 0);
}
}
return MD5Digest.wrap(md.digest());
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy