Example usage for org.apache.cassandra.dht IPartitioner midpoint

Introduction

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

Prototype

public Token midpoint(Token left, Token right);

Source Link

Document

Calculate a Token representing the approximate "middle" of the given range.

Usage

From source file:com.stratio.deep.cassandra.cql.RangeUtils.java

License:Apache License

/**
 * Recursive function that splits a given token range to a given number of token ranges.
 *
 * @param range        the token range to be splitted.
 * @param partitioner  the cassandra partitioner.
 * @param bisectFactor the actual number of pieces the original token range will be splitted to.
 * @param accumulator  a token range accumulator (ne
 *///w  w w.j  av  a2  s  .com
private static void bisectTokeRange(DeepTokenRange range, final IPartitioner partitioner,
        final int bisectFactor, final List<DeepTokenRange> accumulator) {

    final AbstractType tkValidator = partitioner.getTokenValidator();

    Token leftToken = partitioner.getTokenFactory().fromByteArray(tkValidator.decompose(range.getStartToken()));
    Token rightToken = partitioner.getTokenFactory().fromByteArray(tkValidator.decompose(range.getEndToken()));
    Token midToken = partitioner.midpoint(leftToken, rightToken);

    Comparable midpoint = (Comparable) tkValidator.compose(tkValidator.fromString(midToken.toString()));

    DeepTokenRange left = new DeepTokenRange(range.getStartToken(), midpoint, range.getReplicas());
    DeepTokenRange right = new DeepTokenRange(midpoint, range.getEndToken(), range.getReplicas());

    if (bisectFactor / 2 <= 1) {
        accumulator.add(left);
        accumulator.add(right);
    } else {
        bisectTokeRange(left, partitioner, bisectFactor / 2, accumulator);
        bisectTokeRange(right, partitioner, bisectFactor / 2, accumulator);
    }
}

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From source file:kina.cql.RangeUtils.java

License:Apache License

/**
 * Recursive function that splits a given token range to a given number of tolen ranges.
 *
 * @param range the token range to be splitted.
 * @param partitioner the cassandra partitioner.
 * @param bisectFactor the actual number of pieces the original token range will be splitted to.
 * @param accumulator a token range accumulator (ne
 *///ww  w .ja v a 2s . c  o  m
private static void bisectTokeRange(Range range, final IPartitioner partitioner, final int bisectFactor,
        final List<Range> accumulator) {

    final AbstractType tkValidator = partitioner.getTokenValidator();

    Token leftToken = partitioner.getTokenFactory().fromByteArray(tkValidator.decompose(range.getStartToken()));
    Token rightToken = partitioner.getTokenFactory().fromByteArray(tkValidator.decompose(range.getEndToken()));
    Token midToken = partitioner.midpoint(leftToken, rightToken);

    Comparable midpoint = (Comparable) tkValidator.compose(tkValidator.fromString(midToken.toString()));

    Range left = new Range(range.getStartToken(), midpoint, range.getReplicas());
    Range right = new Range(midpoint, range.getEndToken(), range.getReplicas());

    if (bisectFactor / 2 <= 1) {
        accumulator.add(left);
        accumulator.add(right);
    } else {
        bisectTokeRange(left, partitioner, bisectFactor / 2, accumulator);
        bisectTokeRange(right, partitioner, bisectFactor / 2, accumulator);
    }
}

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