/**
* Copyright 2007 The Apache Software Foundation
*
* 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.hadoop.hbase.hql;
import java.io.IOException;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import org.apache.hadoop.hbase.HBaseAdmin;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.HConnection;
import org.apache.hadoop.hbase.HConnectionManager;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.hbase.BloomFilterDescriptor;
import org.apache.hadoop.hbase.BloomFilterDescriptor.BloomFilterType;
/**
* Alters tables.
*/
public class AlterCommand extends SchemaModificationCommand {
public enum OperationType {
ADD, DROP, CHANGE, NOOP
}
private OperationType operationType = OperationType.NOOP;
private Map<String, Map<String, Object>> columnSpecMap = new HashMap<String, Map<String, Object>>();
private String tableName;
private String column; // column to be dropped
public AlterCommand(Writer o) {
super(o);
}
@SuppressWarnings("unchecked")
public ReturnMsg execute(HBaseConfiguration conf) {
try {
HConnection conn = HConnectionManager.getConnection(conf);
if (!conn.tableExists(new Text(this.tableName))) {
return new ReturnMsg(0, "'" + this.tableName + "'" + TABLE_NOT_FOUND);
}
HBaseAdmin admin = new HBaseAdmin(conf);
Set<String> columns = null;
HColumnDescriptor columnDesc = null;
switch (operationType) {
case ADD:
disableTable(admin, tableName);
columns = columnSpecMap.keySet();
for (String c : columns) {
columnDesc = getColumnDescriptor(c, columnSpecMap.get(c));
println("Adding " + c + " to " + tableName + "... Please wait.");
admin.addColumn(new Text(tableName), columnDesc);
}
enableTable(admin, tableName);
break;
case DROP:
disableTable(admin, tableName);
println("Dropping " + column + " from " + tableName + "... Please wait.");
column = appendDelimiter(column);
admin.deleteColumn(new Text(tableName), new Text(column));
enableTable(admin, tableName);
break;
case CHANGE:
disableTable(admin, tableName);
Map.Entry<String, Map<String, Object>> columnEntry = (Map.Entry<String, Map<String, Object>>) columnSpecMap
.entrySet().toArray()[0];
// add the : if there isn't one
Text columnName = new Text(
columnEntry.getKey().endsWith(":") ? columnEntry.getKey()
: columnEntry.getKey() + ":");
// get the table descriptor so we can get the old column descriptor
HTableDescriptor tDesc = getTableDescByName(admin, tableName);
HColumnDescriptor oldColumnDesc = tDesc.families().get(columnName);
// combine the options specified in the shell with the options
// from the exiting descriptor to produce the new descriptor
columnDesc = getColumnDescriptor(columnName.toString(), columnEntry
.getValue(), oldColumnDesc);
// send the changes out to the master
admin.modifyColumn(new Text(tableName), columnName, columnDesc);
enableTable(admin, tableName);
break;
case NOOP:
return new ReturnMsg(0, "Invalid operation type.");
}
return new ReturnMsg(0, "Table altered successfully.");
} catch (Exception e) {
return new ReturnMsg(0, extractErrMsg(e));
}
}
private void disableTable(HBaseAdmin admin, String t) throws IOException {
println("Disabling " + t + "... Please wait.");
admin.disableTable(new Text(t));
}
private void enableTable(HBaseAdmin admin, String t) throws IOException {
println("Enabling " + t + "... Please wait.");
admin.enableTable(new Text(t));
}
/**
* Sets the table to be altered.
*
* @param t Table to be altered.
*/
public void setTable(String t) {
this.tableName = t;
}
/**
* Adds a column specification.
*
* @param columnSpec Column specification
*/
public void addColumnSpec(String c, Map<String, Object> columnSpec) {
columnSpecMap.put(c, columnSpec);
}
/**
* Sets the column to be dropped. Only applicable to the DROP operation.
*
* @param c Column to be dropped.
*/
public void setColumn(String c) {
this.column = c;
}
/**
* Sets the operation type of this alteration.
*
* @param operationType Operation type
* @see OperationType
*/
public void setOperationType(OperationType operationType) {
this.operationType = operationType;
}
@Override
public CommandType getCommandType() {
return CommandType.DDL;
}
private HTableDescriptor getTableDescByName(HBaseAdmin admin, String tableName)
throws IOException {
HTableDescriptor[] tables = admin.listTables();
for (HTableDescriptor tDesc : tables) {
if (tDesc.getName().toString().equals(tableName)) {
return tDesc;
}
}
return null;
}
/**
* Given a column name, column spec, and original descriptor, returns an
* instance of HColumnDescriptor representing the column spec, with empty
* values drawn from the original as defaults
*/
protected HColumnDescriptor getColumnDescriptor(String column,
Map<String, Object> columnSpec, HColumnDescriptor original)
throws IllegalArgumentException {
initOptions(original);
Set<String> specs = columnSpec.keySet();
for (String spec : specs) {
spec = spec.toUpperCase();
if (spec.equals("MAX_VERSIONS")) {
maxVersions = (Integer) columnSpec.get(spec);
} else if (spec.equals("MAX_LENGTH")) {
maxLength = (Integer) columnSpec.get(spec);
} else if (spec.equals("COMPRESSION")) {
compression = HColumnDescriptor.CompressionType.valueOf(((String) columnSpec
.get(spec)).toUpperCase());
} else if (spec.equals("IN_MEMORY")) {
inMemory = (Boolean) columnSpec.get(spec);
} else if (spec.equals("BLOOMFILTER")) {
bloomFilterType = BloomFilterType.valueOf(((String) columnSpec.get(spec))
.toUpperCase());
} else if (spec.equals("VECTOR_SIZE")) {
vectorSize = (Integer) columnSpec.get(spec);
} else if (spec.equals("NUM_HASH")) {
numHash = (Integer) columnSpec.get(spec);
} else if (spec.equals("NUM_ENTRIES")) {
numEntries = (Integer) columnSpec.get(spec);
} else {
throw new IllegalArgumentException("Invalid option: " + spec);
}
}
// Now we gather all the specified options for this column.
if (bloomFilterType != null) {
if (specs.contains("NUM_ENTRIES")) {
bloomFilterDesc = new BloomFilterDescriptor(bloomFilterType, numEntries);
} else {
bloomFilterDesc = new BloomFilterDescriptor(bloomFilterType, vectorSize,
numHash);
}
}
column = appendDelimiter(column);
HColumnDescriptor columnDesc = new HColumnDescriptor(new Text(column),
maxVersions, compression, inMemory, maxLength, bloomFilterDesc);
return columnDesc;
}
private void initOptions(HColumnDescriptor original) {
if (original == null) {
initOptions();
return;
}
maxVersions = original.getMaxVersions();
maxLength = original.getMaxValueLength();
compression = original.getCompression();
inMemory = original.isInMemory();
bloomFilterDesc = original.getBloomFilter();
}
}