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A driver for Apache Cassandra 1.2+ that works exclusively with the Cassandra Query Language version 3
(CQL3) and Cassandra's binary protocol.
/*
* Copyright DataStax, Inc.
*
* Licensed 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 com.datastax.driver.core;
import com.datastax.driver.core.utils.MoreObjects;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
/** Describes a Column. */
public class ColumnMetadata {
static final String COLUMN_NAME = "column_name";
static final String VALIDATOR = "validator"; // v2 only
static final String TYPE = "type"; // replaces validator, v3 onwards
static final String COMPONENT_INDEX = "component_index"; // v2 only
static final String POSITION = "position"; // replaces component_index, v3 onwards
static final String KIND_V2 = "type"; // v2 only
static final String KIND_V3 = "kind"; // replaces type, v3 onwards
static final String CLUSTERING_ORDER = "clustering_order";
static final String DESC = "desc";
static final String INDEX_TYPE = "index_type";
static final String INDEX_OPTIONS = "index_options";
static final String INDEX_NAME = "index_name";
private final AbstractTableMetadata parent;
private final String name;
private final DataType type;
private final boolean isStatic;
private ColumnMetadata(
AbstractTableMetadata parent, String name, DataType type, boolean isStatic) {
this.parent = parent;
this.name = name;
this.type = type;
this.isStatic = isStatic;
}
static ColumnMetadata fromRaw(AbstractTableMetadata tm, Raw raw, DataType dataType) {
return new ColumnMetadata(tm, raw.name, dataType, raw.kind == Raw.Kind.STATIC);
}
static ColumnMetadata forAlias(TableMetadata tm, String name, DataType type) {
return new ColumnMetadata(tm, name, type, false);
}
/**
* Returns the name of the column.
*
* @return the name of the column.
*/
public String getName() {
return name;
}
/**
* Returns the parent object of this column. This can be a {@link TableMetadata} or a {@link
* MaterializedViewMetadata} object.
*
* @return the parent object of this column.
*/
public AbstractTableMetadata getParent() {
return parent;
}
/**
* Returns the type of the column.
*
* @return the type of the column.
*/
public DataType getType() {
return type;
}
/**
* Whether this column is a static column.
*
* @return Whether this column is a static column or not.
*/
public boolean isStatic() {
return isStatic;
}
@Override
public boolean equals(Object other) {
if (other == this) return true;
if (!(other instanceof ColumnMetadata)) return false;
ColumnMetadata that = (ColumnMetadata) other;
return this.name.equals(that.name)
&& this.isStatic == that.isStatic
&& this.type.equals(that.type);
}
@Override
public int hashCode() {
return MoreObjects.hashCode(name, isStatic, type);
}
@Override
public String toString() {
String str = Metadata.quoteIfNecessary(name) + ' ' + type;
return isStatic ? str + " static" : str;
}
// Temporary class that is used to make building the schema easier. Not meant to be
// exposed publicly at all.
static class Raw {
public enum Kind {
PARTITION_KEY("PARTITION_KEY", "PARTITION_KEY"),
CLUSTERING_COLUMN("CLUSTERING_KEY", "CLUSTERING"),
REGULAR("REGULAR", "REGULAR"),
COMPACT_VALUE("COMPACT_VALUE", ""), // v2 only
STATIC("STATIC", "STATIC");
final String v2;
final String v3;
Kind(String v2, String v3) {
this.v2 = v2;
this.v3 = v3;
}
static Kind fromStringV2(String s) {
for (Kind kind : Kind.values()) {
if (kind.v2.equalsIgnoreCase(s)) return kind;
}
throw new IllegalArgumentException(s);
}
static Kind fromStringV3(String s) {
for (Kind kind : Kind.values()) {
if (kind.v3.equalsIgnoreCase(s)) return kind;
}
throw new IllegalArgumentException(s);
}
}
public final String name;
public Kind kind;
public final int position;
public final String dataType;
public final boolean isReversed;
public final Map indexColumns = new HashMap();
Raw(String name, Kind kind, int position, String dataType, boolean isReversed) {
this.name = name;
this.kind = kind;
this.position = position;
this.dataType = dataType;
this.isReversed = isReversed;
}
static Raw fromRow(Row row, VersionNumber version) {
String name = row.getString(COLUMN_NAME);
Kind kind;
if (version.getMajor() < 2) {
kind = Kind.REGULAR;
} else if (version.getMajor() < 3) {
kind = row.isNull(KIND_V2) ? Kind.REGULAR : Kind.fromStringV2(row.getString(KIND_V2));
} else {
kind = row.isNull(KIND_V3) ? Kind.REGULAR : Kind.fromStringV3(row.getString(KIND_V3));
}
int position;
if (version.getMajor() >= 3) {
position =
row.getInt(
POSITION); // cannot be null, -1 is used as a special value instead of null to avoid
// tombstones
if (position == -1) position = 0;
} else {
position = row.isNull(COMPONENT_INDEX) ? 0 : row.getInt(COMPONENT_INDEX);
}
String dataType;
boolean reversed;
if (version.getMajor() >= 3) {
dataType = row.getString(TYPE);
String clusteringOrderStr = row.getString(CLUSTERING_ORDER);
reversed = clusteringOrderStr.equals(DESC);
} else {
dataType = row.getString(VALIDATOR);
reversed = DataTypeClassNameParser.isReversed(dataType);
}
Raw c = new Raw(name, kind, position, dataType, reversed);
// secondary indexes (C* < 3.0.0)
// from C* 3.0 onwards 2i are defined in a separate table
if (version.getMajor() < 3) {
for (String str : Arrays.asList(INDEX_TYPE, INDEX_NAME, INDEX_OPTIONS))
if (row.getColumnDefinitions().contains(str) && !row.isNull(str))
c.indexColumns.put(str, row.getString(str));
}
return c;
}
}
}