public SortedSet getIdleRegions()

in tephra-hbase-compat-2.4/src/main/java/org/apache/tephra/hbase/txprune/InvalidListPruningDebugTool.java [174:227]
42 lines of code
8 McCabe index (conditional complexity)

  public SortedSet<RegionPruneInfoPretty> getIdleRegions(Integer numRegions, String time) throws IOException {
    List<RegionPruneInfo> regionPruneInfos = dataJanitorState.getPruneInfoForRegions(null);
    if (regionPruneInfos.isEmpty()) {
      return new TreeSet<>();
    }

    // Create a set with region names
    Set<String> pruneRegionNameSet = new HashSet<>();
    for (RegionPruneInfo regionPruneInfo : regionPruneInfos) {
      pruneRegionNameSet.add(regionPruneInfo.getRegionNameAsString());
    }

    // Fetch the latest live regions
    RegionsAtTime latestRegions = getRegionsOnOrBeforeTime(NOW);

    // Fetch the regions at the given time
    RegionsAtTime timeRegions = getRegionsOnOrBeforeTime(time);
    Set<String> liveRegions = Sets.intersection(latestRegions.getRegions(), timeRegions.getRegions());
    Set<String> liveRegionsWithPruneInfo = Sets.intersection(liveRegions, pruneRegionNameSet);
    List<RegionPruneInfo> liveRegionWithPruneInfoList = new ArrayList<>();
    for (RegionPruneInfo regionPruneInfo : regionPruneInfos) {
      if (liveRegionsWithPruneInfo.contains(regionPruneInfo.getRegionNameAsString())) {
        liveRegionWithPruneInfoList.add(regionPruneInfo);
      }

      // Use the subset of live regions and prune regions
      regionPruneInfos = liveRegionWithPruneInfoList;
    }

    if (numRegions < 0) {
      numRegions = regionPruneInfos.size();
    }

    Comparator<RegionPruneInfo> comparator = new Comparator<RegionPruneInfo>() {
      @Override
      public int compare(RegionPruneInfo o1, RegionPruneInfo o2) {
        int result = Long.compare(o1.getPruneUpperBound(), o2.getPruneUpperBound());
        if (result == 0) {
          return o1.getRegionNameAsString().compareTo(o2.getRegionNameAsString());
        }
        return result;
      }
    };
    MinMaxPriorityQueue<RegionPruneInfoPretty> lowestPrunes =
      MinMaxPriorityQueue.orderedBy(comparator).maximumSize(numRegions).create();

    for (RegionPruneInfo pruneInfo : regionPruneInfos) {
      lowestPrunes.add(new RegionPruneInfoPretty(pruneInfo));
    }

    SortedSet<RegionPruneInfoPretty> regions = new TreeSet<>(comparator);
    regions.addAll(lowestPrunes);
    return regions;
  }