/**
*
* 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.mapreduce;
import java.io.IOException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.util.StringUtils;
/**
* Convert HBase tabular data into a format that is consumable by Map/Reduce.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class TableInputFormat extends TableInputFormatBase
implements Configurable {
private final Log LOG = LogFactory.getLog(TableInputFormat.class);
/** Job parameter that specifies the input table. */
public static final String INPUT_TABLE = "hbase.mapreduce.inputtable";
/** Base-64 encoded scanner. All other SCAN_ confs are ignored if this is specified.
* See {@link TableMapReduceUtil#convertScanToString(Scan)} for more details.
*/
public static final String SCAN = "hbase.mapreduce.scan";
/** Scan start row */
public static final String SCAN_ROW_START = "hbase.mapreduce.scan.row.start";
/** Scan stop row */
public static final String SCAN_ROW_STOP = "hbase.mapreduce.scan.row.stop";
/** Column Family to Scan */
public static final String SCAN_COLUMN_FAMILY = "hbase.mapreduce.scan.column.family";
/** Space delimited list of columns to scan. */
public static final String SCAN_COLUMNS = "hbase.mapreduce.scan.columns";
/** The timestamp used to filter columns with a specific timestamp. */
public static final String SCAN_TIMESTAMP = "hbase.mapreduce.scan.timestamp";
/** The starting timestamp used to filter columns with a specific range of versions. */
public static final String SCAN_TIMERANGE_START = "hbase.mapreduce.scan.timerange.start";
/** The ending timestamp used to filter columns with a specific range of versions. */
public static final String SCAN_TIMERANGE_END = "hbase.mapreduce.scan.timerange.end";
/** The maximum number of version to return. */
public static final String SCAN_MAXVERSIONS = "hbase.mapreduce.scan.maxversions";
/** Set to false to disable server-side caching of blocks for this scan. */
public static final String SCAN_CACHEBLOCKS = "hbase.mapreduce.scan.cacheblocks";
/** The number of rows for caching that will be passed to scanners. */
public static final String SCAN_CACHEDROWS = "hbase.mapreduce.scan.cachedrows";
/** The configuration. */
private Configuration conf = null;
/**
* Returns the current configuration.
*
* @return The current configuration.
* @see org.apache.hadoop.conf.Configurable#getConf()
*/
@Override
public Configuration getConf() {
return conf;
}
/**
* Sets the configuration. This is used to set the details for the table to
* be scanned.
*
* @param configuration The configuration to set.
* @see org.apache.hadoop.conf.Configurable#setConf(
* org.apache.hadoop.conf.Configuration)
*/
@Override
public void setConf(Configuration configuration) {
this.conf = configuration;
String tableName = conf.get(INPUT_TABLE);
try {
setHTable(new HTable(new Configuration(conf), tableName));
} catch (Exception e) {
LOG.error(StringUtils.stringifyException(e));
}
Scan scan = null;
if (conf.get(SCAN) != null) {
try {
scan = TableMapReduceUtil.convertStringToScan(conf.get(SCAN));
} catch (IOException e) {
LOG.error("An error occurred.", e);
}
} else {
try {
scan = new Scan();
if (conf.get(SCAN_ROW_START) != null) {
scan.setStartRow(Bytes.toBytes(conf.get(SCAN_ROW_START)));
}
if (conf.get(SCAN_ROW_STOP) != null) {
scan.setStopRow(Bytes.toBytes(conf.get(SCAN_ROW_STOP)));
}
if (conf.get(SCAN_COLUMNS) != null) {
addColumns(scan, conf.get(SCAN_COLUMNS));
}
if (conf.get(SCAN_COLUMN_FAMILY) != null) {
scan.addFamily(Bytes.toBytes(conf.get(SCAN_COLUMN_FAMILY)));
}
if (conf.get(SCAN_TIMESTAMP) != null) {
scan.setTimeStamp(Long.parseLong(conf.get(SCAN_TIMESTAMP)));
}
if (conf.get(SCAN_TIMERANGE_START) != null && conf.get(SCAN_TIMERANGE_END) != null) {
scan.setTimeRange(
Long.parseLong(conf.get(SCAN_TIMERANGE_START)),
Long.parseLong(conf.get(SCAN_TIMERANGE_END)));
}
if (conf.get(SCAN_MAXVERSIONS) != null) {
scan.setMaxVersions(Integer.parseInt(conf.get(SCAN_MAXVERSIONS)));
}
if (conf.get(SCAN_CACHEDROWS) != null) {
scan.setCaching(Integer.parseInt(conf.get(SCAN_CACHEDROWS)));
}
// false by default, full table scans generate too much BC churn
scan.setCacheBlocks((conf.getBoolean(SCAN_CACHEBLOCKS, false)));
} catch (Exception e) {
LOG.error(StringUtils.stringifyException(e));
}
}
setScan(scan);
}
/**
* Parses a combined family and qualifier and adds either both or just the
* family in case there is not qualifier. This assumes the older colon
* divided notation, e.g. "data:contents" or "meta:".
* <p>
* Note: It will through an error when the colon is missing.
*
* @param familyAndQualifier family and qualifier
* @return A reference to this instance.
* @throws IllegalArgumentException When the colon is missing.
*/
private static void addColumn(Scan scan, byte[] familyAndQualifier) {
byte [][] fq = KeyValue.parseColumn(familyAndQualifier);
if (fq.length > 1 && fq[1] != null && fq[1].length > 0) {
scan.addColumn(fq[0], fq[1]);
} else {
scan.addFamily(fq[0]);
}
}
/**
* Adds an array of columns specified using old format, family:qualifier.
* <p>
* Overrides previous calls to addFamily for any families in the input.
*
* @param columns array of columns, formatted as <pre>family:qualifier</pre>
*/
public static void addColumns(Scan scan, byte [][] columns) {
for (byte[] column : columns) {
addColumn(scan, column);
}
}
/**
* Convenience method to help parse old style (or rather user entry on the
* command line) column definitions, e.g. "data:contents mime:". The columns
* must be space delimited and always have a colon (":") to denote family
* and qualifier.
*
* @param columns The columns to parse.
* @return A reference to this instance.
*/
private static void addColumns(Scan scan, String columns) {
String[] cols = columns.split(" ");
for (String col : cols) {
addColumn(scan, Bytes.toBytes(col));
}
}
}