Java WAL.Reader方法代码示例

import org.apache.hadoop.hbase.wal.WAL; //导入方法依赖的package包/类
private static void transformFile(Path input, Path output)
    throws IOException {
  Configuration conf = HBaseConfiguration.create();

  FileSystem inFS = input.getFileSystem(conf);
  FileSystem outFS = output.getFileSystem(conf);

  WAL.Reader in = WALFactory.createReaderIgnoreCustomClass(inFS, input, conf);
  WALProvider.Writer out = null;

  try {
    if (!(in instanceof ReaderBase)) {
      System.err.println("Cannot proceed, invalid reader type: " + in.getClass().getName());
      return;
    }
    boolean compress = ((ReaderBase)in).hasCompression();
    conf.setBoolean(HConstants.ENABLE_WAL_COMPRESSION, !compress);
    out = WALFactory.createWALWriter(outFS, output, conf);

    WAL.Entry e = null;
    while ((e = in.next()) != null) out.append(e);
  } finally {
    in.close();
    if (out != null) {
      out.close();
      out = null;
    }
  }
}
 

import org.apache.hadoop.hbase.wal.WAL; //导入方法依赖的package包/类
/**
 * Sanity check that we can move logs around while we are reading
 * from them. Should this test fail, ReplicationSource would have a hard
 * time reading logs that are being archived.
 * @throws Exception
 */
@Test
public void testLogMoving() throws Exception{
  Path logPath = new Path(logDir, "log");
  if (!FS.exists(logDir)) FS.mkdirs(logDir);
  if (!FS.exists(oldLogDir)) FS.mkdirs(oldLogDir);
  WALProvider.Writer writer = WALFactory.createWALWriter(FS, logPath,
      TEST_UTIL.getConfiguration());
  for(int i = 0; i < 3; i++) {
    byte[] b = Bytes.toBytes(Integer.toString(i));
    KeyValue kv = new KeyValue(b,b,b);
    WALEdit edit = new WALEdit();
    edit.add(kv);
    WALKey key = new WALKey(b, TableName.valueOf(b), 0, 0,
        HConstants.DEFAULT_CLUSTER_ID);
    writer.append(new WAL.Entry(key, edit));
    writer.sync();
  }
  writer.close();

  WAL.Reader reader = WALFactory.createReader(FS, logPath, TEST_UTIL.getConfiguration());
  WAL.Entry entry = reader.next();
  assertNotNull(entry);

  Path oldLogPath = new Path(oldLogDir, "log");
  FS.rename(logPath, oldLogPath);

  entry = reader.next();
  assertNotNull(entry);

  entry = reader.next();
  entry = reader.next();

  assertNull(entry);
  reader.close();
}
 

import org.apache.hadoop.hbase.wal.WAL; //导入方法依赖的package包/类
private void verifyWALCount(WALFactory wals, WAL log, int expected) throws Exception {
  Path walPath = DefaultWALProvider.getCurrentFileName(log);
  WAL.Reader reader = wals.createReader(FS, walPath);
  int count = 0;
  WAL.Entry entry = new WAL.Entry();
  while (reader.next(entry) != null) count++;
  reader.close();
  assertEquals(expected, count);
}
 

import org.apache.hadoop.hbase.wal.WAL; //导入方法依赖的package包/类
/**
 * @param fs
 * @param conf
 * @param edits
 * @param region
 * @return Return how many edits seen.
 * @throws IOException
 */
private int verifyAllEditsMadeItIn(final FileSystem fs, final Configuration conf,
    final Path edits, final HRegion region)
throws IOException {
  int count = 0;
  // Based on HRegion#replayRecoveredEdits
  WAL.Reader reader = null;
  try {
    reader = WALFactory.createReader(fs, edits, conf);
    WAL.Entry entry;
    while ((entry = reader.next()) != null) {
      WALKey key = entry.getKey();
      WALEdit val = entry.getEdit();
      count++;
      // Check this edit is for this region.
      if (!Bytes.equals(key.getEncodedRegionName(),
          region.getRegionInfo().getEncodedNameAsBytes())) {
        continue;
      }
      Cell previous = null;
      for (Cell cell: val.getCells()) {
        if (CellUtil.matchingFamily(cell, WALEdit.METAFAMILY)) continue;
        if (previous != null && CellComparator.compareRows(previous, cell) == 0) continue;
        previous = cell;
        Get g = new Get(CellUtil.cloneRow(cell));
        Result r = region.get(g);
        boolean found = false;
        for (CellScanner scanner = r.cellScanner(); scanner.advance();) {
          Cell current = scanner.current();
          if (CellComparator.compare(cell, current, true) == 0) {
            found = true;
            break;
          }
        }
        assertTrue("Failed to find " + cell, found);
      }
    }
  } finally {
    if (reader != null) reader.close();
  }
  return count;
}
 

import org.apache.hadoop.hbase.wal.WAL; //导入方法依赖的package包/类
WAL.Reader createWALReaderForPrimary() throws FileNotFoundException, IOException {
  return wals.createReader(TEST_UTIL.getTestFileSystem(),
    DefaultWALProvider.getCurrentFileName(walPrimary),
    TEST_UTIL.getConfiguration());
}