Java tutorial
/******************************************************************************* * Copyright (c) 2012 Nikos Papailiou. * All rights reserved. This program and the accompanying materials * are made available under the terms of the GNU Public License v3.0 * which accompanies this distribution, and is available at * http://www.gnu.org/licenses/gpl.html * * Contributors: * Nikos Papailiou - initial API and implementation ******************************************************************************/ package gr.ntua.h2rdf.inputFormat; import java.io.IOException; import java.util.Iterator; import javaewah.EWAHCompressedBitmap; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.FileUtil; import org.apache.hadoop.fs.Path; import org.apache.hadoop.hbase.HBaseConfiguration; import org.apache.hadoop.hbase.KeyValue; import org.apache.hadoop.hbase.client.HTable; import org.apache.hadoop.hbase.io.ImmutableBytesWritable; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.mapreduce.InputSplit; import org.apache.hadoop.mapreduce.RecordReader; import org.apache.hadoop.mapreduce.TaskAttemptContext; import org.apache.hadoop.io.Text; import org.apache.hadoop.hbase.io.hfile.HFile.Reader; import org.apache.hadoop.hbase.io.hfile.CacheConfig; import org.apache.hadoop.hbase.io.hfile.HFile; import org.apache.hadoop.hbase.io.hfile.HFileScanner; public class HFileRecordReaderBitmapBufferedNoScan extends RecordReader<ImmutableBytesWritable, Text> { private ImmutableBytesWritable key = null; private Text value = null; private TableColumnSplit tsplit = null; private Reader reader = null; private HFileScanner scanner = null; private KeyValue kv = null; private boolean more = false; private int regions = 0, first; private HBaseConfiguration HBconf = new HBaseConfiguration(); private byte[] stopr, startr; private HTable table; private Iterator<Integer> BitmapIter; private static float progress = 0; /** * Closes the split. * * @see org.apache.hadoop.mapreduce.RecordReader#close() */ @Override public void close() { try { reader.close(); } catch (IOException e) { e.printStackTrace(); } } /** * Returns the current key. * * @return The current key. * @throws IOException * @throws InterruptedException When the job is aborted. * @see org.apache.hadoop.mapreduce.RecordReader#getCurrentKey() */ @Override public ImmutableBytesWritable getCurrentKey() throws IOException, InterruptedException { return key; } /** * Returns the current value. * * @return The current value. * @throws IOException When the value is faulty. * @throws InterruptedException When the job is aborted. * @see org.apache.hadoop.mapreduce.RecordReader#getCurrentValue() */ @Override public Text getCurrentValue() throws IOException, InterruptedException { return value; } /** * Initializes the reader. * * @param inputsplit The split to work with. * @param context The current task context. * @throws IOException When setting up the reader fails. * @throws InterruptedException When the job is aborted. * @see org.apache.hadoop.mapreduce.RecordReader#initialize( * org.apache.hadoop.mapreduce.InputSplit, * org.apache.hadoop.mapreduce.TaskAttemptContext) */ @Override public void initialize(InputSplit inputsplit, TaskAttemptContext context) throws IOException, InterruptedException { tsplit = (TableColumnSplit) inputsplit; EWAHCompressedBitmap regionBitmap = tsplit.getRegionBitmap(); BitmapIter = regionBitmap.iterator(); //System.out.println("contains: "+regionBitmap.cardinality()+" size:"+regionBitmap.sizeInBytes()); table = new HTable(HBconf, tsplit.getTable()); //table.flushCommits(); startr = tsplit.getStartRow(); stopr = tsplit.getStopRow(); System.out.println("start: " + Bytes.toStringBinary(startr)); System.out.println("stop: " + Bytes.toStringBinary(stopr)); FileSystem fs = FileSystem.get(HBconf); String dir = ""; if (startr.length == 1) { byte[] st = new byte[stopr.length - 1]; for (int i = 0; i < st.length; i++) { st[i] = stopr[i]; } dir = "/hbase/" + tsplit.getTable() + "/" + table.getRegionLocation(stopr).getRegionInfo().getEncodedName() + "/A"; } else { dir = "/hbase/" + tsplit.getTable() + "/" + table.getRegionLocation(startr).getRegionInfo().getEncodedName() + "/A"; } Path regionDir = new Path(dir); Path file = null; Path[] hfiles = FileUtil.stat2Paths(fs.listStatus(regionDir)); for (Path hfile : hfiles) { file = new Path(dir + "/" + hfile.getName()); } System.out.println(dir + "/" + file.getName()); reader = HFile.createReader(fs, file, new CacheConfig(HBconf)); //reader = new Reader(fs, file, null, false); // Load up the index. reader.loadFileInfo(); // Get a scanner that caches and that does not use pread. scanner = reader.getScanner(false, true); if (!BitmapIter.hasNext()) { more = false; return; } nextBitmapRegion(); /*if(!scanner.isSeeked()){ //System.out.println(table.getRegionLocation(startr).getRegionInfo().getRegionId()); scanner.seekTo(); }*/ first = 1; while (scanner.next()) { kv = scanner.getKeyValue(); if (Bytes.compareTo(kv.getRow(), startr) >= 0 && Bytes.compareTo(kv.getRow(), stopr) <= 0) { System.out.println("curkey: " + Bytes.toStringBinary(kv.getRow())); more = true; break; } if (Bytes.compareTo(kv.getRow(), stopr) > 0) { if (BitmapIter.hasNext()) { nextBitmapRegion(); } else { more = false; break; } } } } private void nextBitmapRegion() { regions++; System.out.println("next region: " + regions); int curBitmapInt = BitmapIter.next(); byte[] curBitmapByteInt = Bytes.toBytes(curBitmapInt); System.out.println("curInt: " + Bytes.toStringBinary(curBitmapByteInt)); startr = new byte[8 + 1]; stopr = new byte[8 + 1]; startr[0] = (byte) 1; stopr[0] = (byte) 1; for (int j = 1; j < curBitmapByteInt.length + 1; j++) { startr[j] = curBitmapByteInt[j - 1]; stopr[j] = curBitmapByteInt[j - 1]; } for (int j = 1 + curBitmapByteInt.length; j < startr.length; j++) { startr[j] = (byte) 0; stopr[j] = (byte) 255; } System.out.println("start: " + Bytes.toStringBinary(startr)); System.out.println("stop: " + Bytes.toStringBinary(stopr)); KeyValue rowKey = KeyValue.createFirstOnRow(startr); try { scanner.seekBefore(rowKey.getKey()); } catch (IOException e) { e.printStackTrace(); } } /** * Positions the record reader to the next record. * * @return <code>true</code> if there was another record. * @throws IOException When reading the record failed. * @throws InterruptedException When the job was aborted. * @see org.apache.hadoop.mapreduce.RecordReader#nextKeyValue() */ @Override public boolean nextKeyValue() throws IOException, InterruptedException { if (key == null) key = new ImmutableBytesWritable(); if (value == null) value = new Text(); /* if(!scanner.isSeeked()){//bug return false; }*/ if (first == 1) { if (more) { byte[] indexKey = kv.getRow(); byte[] indexKey1 = new byte[8]; for (int i = 0; i < indexKey1.length; i++) { indexKey1[i] = indexKey[i + 1]; } value.set(tsplit.getFname() + "!" + Bytes.toLong(indexKey1) + "$$" + Bytes.toString(kv.getValue())); } first = 2; return more; } while (scanner.next()) { kv = scanner.getKeyValue(); if (Bytes.compareTo(kv.getRow(), startr) >= 0 && Bytes.compareTo(kv.getRow(), stopr) <= 0) { byte[] indexKey = kv.getRow(); byte[] indexKey1 = new byte[8]; for (int i = 0; i < indexKey1.length; i++) { indexKey1[i] = indexKey[i + 1]; } value.set(tsplit.getFname() + "!" + Bytes.toLong(indexKey1) + "$$" + Bytes.toString(kv.getValue())); return true; } if (Bytes.compareTo(kv.getRow(), stopr) > 0) { if (BitmapIter.hasNext()) { nextBitmapRegion(); } else { return false; } } } return false; } /** * The current progress of the record reader through its data. * * @return A number between 0.0 and 1.0, the fraction of the data read. * @see org.apache.hadoop.mapreduce.RecordReader#getProgress() */ @Override public float getProgress() { // Depends on the total number of tuples return progress; } }