Examples with Splitter org.apache.cassandra.dht.Splitter used on opensource projects

Example 1 with Splitter

use of org.apache.cassandra.dht.Splitter in project cassandra by apache.

the class DiskBoundaryManager method getDiskBoundaries.

/**
 * Returns a list of disk boundaries, the result will differ depending on whether vnodes are enabled or not.
 *
 * What is returned are upper bounds for the disks, meaning everything from partitioner.minToken up to
 * getDiskBoundaries(..).get(0) should be on the first disk, everything between 0 to 1 should be on the second disk
 * etc.
 *
 * The final entry in the returned list will always be the partitioner maximum tokens upper key bound
 */
private static List<PartitionPosition> getDiskBoundaries(RangesAtEndpoint replicas, IPartitioner partitioner, Directories.DataDirectory[] dataDirectories) {
    assert partitioner.splitter().isPresent();
    Splitter splitter = partitioner.splitter().get();
    boolean dontSplitRanges = DatabaseDescriptor.getNumTokens() > 1;
    List<Splitter.WeightedRange> weightedRanges = new ArrayList<>(replicas.size());
    // note that Range.sort unwraps any wraparound ranges, so we need to sort them here
    for (Range<Token> r : Range.sort(replicas.onlyFull().ranges())) weightedRanges.add(new Splitter.WeightedRange(1.0, r));
    for (Range<Token> r : Range.sort(replicas.onlyTransient().ranges())) weightedRanges.add(new Splitter.WeightedRange(0.1, r));
    weightedRanges.sort(Comparator.comparing(Splitter.WeightedRange::left));
    List<Token> boundaries = splitter.splitOwnedRanges(dataDirectories.length, weightedRanges, dontSplitRanges);
    // If we can't split by ranges, split evenly to ensure utilisation of all disks
    if (dontSplitRanges && boundaries.size() < dataDirectories.length)
        boundaries = splitter.splitOwnedRanges(dataDirectories.length, weightedRanges, false);
    List<PartitionPosition> diskBoundaries = new ArrayList<>();
    for (int i = 0; i < boundaries.size() - 1; i++) diskBoundaries.add(boundaries.get(i).maxKeyBound());
    diskBoundaries.add(partitioner.getMaximumToken().maxKeyBound());
    return diskBoundaries;
}