@Test
  public void testSplitLogFileEmpty() throws IOException {
    LOG.info("testSplitLogFileEmpty");
    // we won't create the hlog dir until getWAL got called, so
    // make dir here when testing empty log file
    fs.mkdirs(WALDIR);
    injectEmptyFile(".empty", true);
    useDifferentDFSClient();

    WALSplitter.split(HBASELOGDIR, WALDIR, OLDLOGDIR, fs, conf, wals);
    Path tdir = CommonFSUtils.getTableDir(HBASEDIR, TABLE_NAME);
    assertFalse(fs.exists(tdir));

    assertEquals(0, countWAL(fs.listStatus(OLDLOGDIR)[0].getPath()));
  }
Sets up a log splitter with a mock reader and writer. The mock reader generates a specified
number of edits spread across 5 regions. The mock writer optionally sleeps for each edit it is
fed. After the split is complete, verifies that the statistics show the correct number of edits
output into each region.
@param numFakeEdits   number of fake edits to push through pipeline
@param bufferSize     size of in-memory buffer
@param writerSlowness writer threads will sleep this many ms per edit
hbase-server/src/test/java/org/apache/hadoop/hbase/wal/TestWALSplit.java