public boolean rebuildMeta()

in hbase-hbck2/src/main/java/org/apache/hbase/hbck1/HBaseFsck.java [1884:1940]
42 lines of code
6 McCabe index (conditional complexity)

  public boolean rebuildMeta() throws IOException, InterruptedException {
    // TODO check to make sure hbase is offline. (or at least the table
    // currently being worked on is off line)

    // Determine what's on HDFS
    loadHdfsRegionDirs(); // populating regioninfo table.

    int errs = errors.getErrorList().size();
    tablesInfo = loadHdfsRegionInfos(); // update tableInfos based on region info in fs.
    checkHdfsIntegrity(false, false);

    // make sure ok.
    if (errors.getErrorList().size() != errs) {
      // While in error state, iterate until no more fixes possible
      while(true) {
        fixes = 0;
        suggestFixes(tablesInfo);
        errors.clear();
        loadHdfsRegionInfos(); // update tableInfos based on region info in fs.
        checkHdfsIntegrity(shouldFixHdfsHoles(), shouldFixHdfsOverlaps());

        int errCount = errors.getErrorList().size();

        if (fixes == 0) {
          if (errCount > 0) {
            return false; // failed to fix problems.
          } else {
            break; // no fixes and no problems? drop out and fix stuff!
          }
        }
      }
    }

    // we can rebuild, move old meta out of the way and start
    LOG.info("HDFS regioninfo's seems good.  Sidelining old hbase:meta");
    Path backupDir = sidelineOldMeta();
    HRegion meta = createNewMeta();
    // Save off the waldir we're writing to so we can delete it when done.
    Path waldir = ((AbstractFSWAL)meta.getWAL()).getCurrentFileName().getParent();
    try {
      // populate meta
      List<Put> puts = generatePuts(tablesInfo);
      if (puts == null) {
        LOG.error("Problem encountered when creating new hbase:meta entries.  " +
            "You may need to restore the previously sidelined hbase:meta");
        return false;
      }
      meta.batchMutate(puts.toArray(new Put[puts.size()]));
    } finally {
      HBaseTestingUtility.closeRegionAndWAL(meta);
      // Clean out the WAL we created and used here.
      boolean deleteWalDir = HBCKFsUtils.delete(waldir.getFileSystem(getConf()), waldir, true);
      LOG.info("Deleting WAL directory {}, result={}", waldir, deleteWalDir);
    }
    LOG.info("Success! hbase:meta table rebuilt. Old hbase:meta moved into " + backupDir);
    return true;
  }