Example usage for org.apache.cassandra.dht Bounds Bounds

Introduction

In this page you can find the example usage for org.apache.cassandra.dht Bounds Bounds.

Prototype

public Bounds(T left, T right) 

Source Link

Usage

From source file:org.janusgraph.diskstorage.cassandra.embedded.CassandraEmbeddedKeyColumnValueStore.java

License:Apache License

/**
 * Create a RangeSliceCommand and run it against the StorageProxy.
 * <p>/*from   ww  w .  j  av a2  s  .co m*/
 * To match the behavior of the standard Cassandra thrift API endpoint, the
 * {@code nowMillis} argument should be the number of milliseconds since the
 * UNIX Epoch (e.g. System.currentTimeMillis() or equivalent obtained
 * through a {@link TimestampProvider}). This is per
 * {@link org.apache.cassandra.thrift.CassandraServer#get_range_slices(ColumnParent, SlicePredicate, KeyRange, ConsistencyLevel)},
 * which passes the server's System.currentTimeMillis() to the
 * {@code RangeSliceCommand} constructor.
 */
private List<Row> getKeySlice(Token start, Token end, @Nullable SliceQuery sliceQuery, int pageSize,
        long nowMillis) throws BackendException {
    IPartitioner partitioner = StorageService.getPartitioner();

    SliceRange columnSlice = new SliceRange();
    if (sliceQuery == null) {
        columnSlice.setStart(ArrayUtils.EMPTY_BYTE_ARRAY).setFinish(ArrayUtils.EMPTY_BYTE_ARRAY).setCount(5);
    } else {
        columnSlice.setStart(sliceQuery.getSliceStart().asByteBuffer())
                .setFinish(sliceQuery.getSliceEnd().asByteBuffer())
                .setCount(sliceQuery.hasLimit() ? sliceQuery.getLimit() : Integer.MAX_VALUE);
    }
    /* Note: we need to fetch columns for each row as well to remove "range ghosts" */
    SlicePredicate predicate = new SlicePredicate().setSlice_range(columnSlice);

    RowPosition startPosition = start.minKeyBound(partitioner);
    RowPosition endPosition = end.minKeyBound(partitioner);

    List<Row> rows;

    try {
        CFMetaData cfm = Schema.instance.getCFMetaData(keyspace, columnFamily);
        IDiskAtomFilter filter = ThriftValidation.asIFilter(predicate, cfm, null);

        RangeSliceCommand cmd = new RangeSliceCommand(keyspace, columnFamily, nowMillis, filter,
                new Bounds<RowPosition>(startPosition, endPosition), pageSize);

        rows = StorageProxy.getRangeSlice(cmd, ConsistencyLevel.QUORUM);
    } catch (Exception e) {
        throw new PermanentBackendException(e);
    }

    return rows;
}

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