TestColumnPrefixFilter.java

package org.apache.hadoop.hbase.filter;

import static org.junit.Assert.*;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.KeyValueTestUtil;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.regionserver.InternalScanner;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Test;

public class TestColumnPrefixFilter {

  private final static HBaseTestingUtility TEST_UTIL = new
      HBaseTestingUtility();

  @Test
  public void testColumnPrefixFilter() throws IOException {
    String family = "Family";
    HTableDescriptor htd = new HTableDescriptor("TestColumnPrefixFilter");
    htd.addFamily(new HColumnDescriptor(family));
    HRegionInfo info = new HRegionInfo(htd, null, null, false);
    HRegion region = HRegion.createHRegion(info, HBaseTestingUtility.
        getTestDir(), TEST_UTIL.getConfiguration());

    List<String> rows = generateRandomWords(100, "row");
    List<String> columns = generateRandomWords(10000, "column");
    long maxTimestamp = 2;

    List<KeyValue> kvList = new ArrayList<KeyValue>();

    Map<String, List<KeyValue>> prefixMap = new HashMap<String,
        List<KeyValue>>();

    prefixMap.put("p", new ArrayList<KeyValue>());
    prefixMap.put("s", new ArrayList<KeyValue>());

    String valueString = "ValueString";

    for (String row: rows) {
      Put p = new Put(Bytes.toBytes(row));
      for (String column: columns) {
        for (long timestamp = 1; timestamp <= maxTimestamp; timestamp++) {
          KeyValue kv = KeyValueTestUtil.create(row, family, column, timestamp,
              valueString);
          p.add(kv);
          kvList.add(kv);
          for (String s: prefixMap.keySet()) {
            if (column.startsWith(s)) {
              prefixMap.get(s).add(kv);
            }
          }
        }
      }
      region.put(p);
    }

    ColumnPrefixFilter filter;
    Scan scan = new Scan();
    scan.setMaxVersions();
    for (String s: prefixMap.keySet()) {
      filter = new ColumnPrefixFilter(Bytes.toBytes(s));
      scan.setFilter(filter);
      InternalScanner scanner = region.getScanner(scan);
      List<KeyValue> results = new ArrayList<KeyValue>();
      while(scanner.next(results));
      assertEquals(prefixMap.get(s).size(), results.size());
    }
  }

  List<String> generateRandomWords(int numberOfWords, String suffix) {
    Set<String> wordSet = new HashSet<String>();
    for (int i = 0; i < numberOfWords; i++) {
      int lengthOfWords = (int) (Math.random()*2) + 1;
      char[] wordChar = new char[lengthOfWords];
      for (int j = 0; j < wordChar.length; j++) {
        wordChar[j] = (char) (Math.random() * 26 + 97);
      }
      String word;
      if (suffix == null) {
        word = new String(wordChar);
      } else {
        word = new String(wordChar) + suffix;
      }
      wordSet.add(word);
    }
    List<String> wordList = new ArrayList<String>(wordSet);
    return wordList;
  }
}