| /** |
| * 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.mapreduce.lib.db; |
| |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import java.sql.Time; |
| import java.sql.Timestamp; |
| import java.sql.Types; |
| import java.util.ArrayList; |
| import java.util.Date; |
| import java.util.List; |
| |
| 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.Configuration; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.MRJobConfig; |
| |
| /** |
| * Implement DBSplitter over date/time values. |
| * Make use of logic from IntegerSplitter, since date/time are just longs |
| * in Java. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class DateSplitter extends IntegerSplitter { |
| |
| private static final Log LOG = LogFactory.getLog(DateSplitter.class); |
| |
| public List<InputSplit> split(Configuration conf, ResultSet results, String colName) |
| throws SQLException { |
| |
| long minVal; |
| long maxVal; |
| |
| int sqlDataType = results.getMetaData().getColumnType(1); |
| minVal = resultSetColToLong(results, 1, sqlDataType); |
| maxVal = resultSetColToLong(results, 2, sqlDataType); |
| |
| String lowClausePrefix = colName + " >= "; |
| String highClausePrefix = colName + " < "; |
| |
| int numSplits = conf.getInt(MRJobConfig.NUM_MAPS, 1); |
| if (numSplits < 1) { |
| numSplits = 1; |
| } |
| |
| if (minVal == Long.MIN_VALUE && maxVal == Long.MIN_VALUE) { |
| // The range of acceptable dates is NULL to NULL. Just create a single split. |
| List<InputSplit> splits = new ArrayList<InputSplit>(); |
| splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit( |
| colName + " IS NULL", colName + " IS NULL")); |
| return splits; |
| } |
| |
| // Gather the split point integers |
| List<Long> splitPoints = split(numSplits, minVal, maxVal); |
| List<InputSplit> splits = new ArrayList<InputSplit>(); |
| |
| // Turn the split points into a set of intervals. |
| long start = splitPoints.get(0); |
| Date startDate = longToDate(start, sqlDataType); |
| if (sqlDataType == Types.TIMESTAMP) { |
| // The lower bound's nanos value needs to match the actual lower-bound nanos. |
| try { |
| ((java.sql.Timestamp) startDate).setNanos(results.getTimestamp(1).getNanos()); |
| } catch (NullPointerException npe) { |
| // If the lower bound was NULL, we'll get an NPE; just ignore it and don't set nanos. |
| } |
| } |
| |
| for (int i = 1; i < splitPoints.size(); i++) { |
| long end = splitPoints.get(i); |
| Date endDate = longToDate(end, sqlDataType); |
| |
| if (i == splitPoints.size() - 1) { |
| if (sqlDataType == Types.TIMESTAMP) { |
| // The upper bound's nanos value needs to match the actual upper-bound nanos. |
| try { |
| ((java.sql.Timestamp) endDate).setNanos(results.getTimestamp(2).getNanos()); |
| } catch (NullPointerException npe) { |
| // If the upper bound was NULL, we'll get an NPE; just ignore it and don't set nanos. |
| } |
| } |
| // This is the last one; use a closed interval. |
| splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit( |
| lowClausePrefix + dateToString(startDate), |
| colName + " <= " + dateToString(endDate))); |
| } else { |
| // Normal open-interval case. |
| splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit( |
| lowClausePrefix + dateToString(startDate), |
| highClausePrefix + dateToString(endDate))); |
| } |
| |
| start = end; |
| startDate = endDate; |
| } |
| |
| if (minVal == Long.MIN_VALUE || maxVal == Long.MIN_VALUE) { |
| // Add an extra split to handle the null case that we saw. |
| splits.add(new DataDrivenDBInputFormat.DataDrivenDBInputSplit( |
| colName + " IS NULL", colName + " IS NULL")); |
| } |
| |
| return splits; |
| } |
| |
| /** Retrieve the value from the column in a type-appropriate manner and return |
| its timestamp since the epoch. If the column is null, then return Long.MIN_VALUE. |
| This will cause a special split to be generated for the NULL case, but may also |
| cause poorly-balanced splits if most of the actual dates are positive time |
| since the epoch, etc. |
| */ |
| private long resultSetColToLong(ResultSet rs, int colNum, int sqlDataType) throws SQLException { |
| try { |
| switch (sqlDataType) { |
| case Types.DATE: |
| return rs.getDate(colNum).getTime(); |
| case Types.TIME: |
| return rs.getTime(colNum).getTime(); |
| case Types.TIMESTAMP: |
| return rs.getTimestamp(colNum).getTime(); |
| default: |
| throw new SQLException("Not a date-type field"); |
| } |
| } catch (NullPointerException npe) { |
| // null column. return minimum long value. |
| LOG.warn("Encountered a NULL date in the split column. Splits may be poorly balanced."); |
| return Long.MIN_VALUE; |
| } |
| } |
| |
| /** Parse the long-valued timestamp into the appropriate SQL date type. */ |
| private Date longToDate(long val, int sqlDataType) { |
| switch (sqlDataType) { |
| case Types.DATE: |
| return new java.sql.Date(val); |
| case Types.TIME: |
| return new java.sql.Time(val); |
| case Types.TIMESTAMP: |
| return new java.sql.Timestamp(val); |
| default: // Shouldn't ever hit this case. |
| return null; |
| } |
| } |
| |
| /** |
| * Given a Date 'd', format it as a string for use in a SQL date |
| * comparison operation. |
| * @param d the date to format. |
| * @return the string representing this date in SQL with any appropriate |
| * quotation characters, etc. |
| */ |
| protected String dateToString(Date d) { |
| return "'" + d.toString() + "'"; |
| } |
| } |