Class: TokenRange

TokenRange()

Represents a range of tokens on a Cassandra ring.

A range is start-exclusive and end-inclusive. It is empty when start and end are the same token, except if that is the minimum token, in which case the range covers the whole ring (this is consistent with the behavior of CQL range queries).

Note that CQL does not handle wrapping. To query all partitions in a range, see unwrap.

Constructor

new TokenRange()

Source:

Methods

compare(other) → {Number}

Returns 0 if the values are equal, otherwise compares against start, if start is equal, compares against end.

Parameters:
Name Type Description
other TokenRange

Range to compare with.
Source:
Returns:
Type
Number

contains(token) → {boolean}

Whether this range contains a given Token.

Parameters:
Name Type Description
token *

Token to check for.
Source:
Returns:

Whether or not the Token is in this range.

Type
boolean

equals(other) → {boolean}

Determines if the input range is equivalent to this one.

Parameters:
Name Type Description
other TokenRange

Range to compare with.
Source:
Returns:

Whether or not the ranges are equal.

Type
boolean

isEmpty() → {boolean}

A range is empty when start and end are the same token, except if that is the minimum token, in which case the range covers the whole ring. This is consistent with the behavior of CQL range queries.

Source:
Returns:

Whether this range is empty.

Type
boolean

isWrappedAround() → {boolean}

A range wraps around the end of the ring when the start token is greater than the end token and the end token is not the minimum token.

Source:
Returns:

Whether this range wraps around.

Type
boolean

splitEvenly(numberOfSplits) → {Array.<TokenRange>}

Splits this range into a number of smaller ranges of equal "size" (referring to the number of tokens, not the actual amount of data).

Splitting an empty range is not permitted. But not that, in edge cases, splitting a range might produce one or more empty ranges.

Parameters:
Name Type Description
numberOfSplits Number

Number of splits to make.
Source:
Throws:

If splitting an empty range.

Type
Error
Returns:

Split ranges.

Type
Array.<TokenRange>

unwrap() → {Array.<TokenRange>}

Splits this range into a list of two non-wrapping ranges.

This will return the range itself if it is non-wrapped, or two ranges otherwise.

This is useful for CQL range queries, which do not handle wrapping.

Source:
Returns:

The list of non-wrapping ranges.

Type
Array.<TokenRange>