IPartitioner (apache-cassandra API)

All Known Implementing Classes:

ByteOrderedPartitioner, LocalPartitioner, Murmur3Partitioner, OrderPreservingPartitioner, RandomPartitioner
```
public interface IPartitioner
```

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`DecoratedKey`	`decorateKey(java.nio.ByteBuffer key)` Transform key to object representation of the on-disk format.
`java.util.Map<Token,java.lang.Float>`	`describeOwnership(java.util.List<Token> sortedTokens)` Calculate the deltas between tokens in the ring in order to compare relative sizes.
`default Token`	`getMaximumToken()` The biggest token for this partitioner, unlike getMinimumToken, this token is actually used and users wanting to include all tokens need to do getMaximumToken().maxKeyBound() Not implemented for the ordered partitioners
`default int`	`getMaxTokenSize()`
`Token`	`getMinimumToken()`
`Token`	`getRandomToken()`
`Token`	`getRandomToken(java.util.Random random)`
`Token`	`getToken(java.nio.ByteBuffer key)`
`Token.TokenFactory`	`getTokenFactory()`
`AbstractType<?>`	`getTokenValidator()`
`static IPartitioner`	`global()`
`Token`	`midpoint(Token left, Token right)` Calculate a Token representing the approximate "middle" of the given range.
`AbstractType<?>`	`partitionOrdering()` Abstract type that orders the same way as DecoratedKeys provided by this partitioner.
`boolean`	`preservesOrder()`
`Token`	`split(Token left, Token right, double ratioToLeft)` Calculate a Token which take `approximate 0 <= ratioToLeft <= 1` ownership of the given range.
`default java.util.Optional<Splitter>`	`splitter()`
`static void`	`validate(AbstractBounds<?> bounds)`
`static void`	`validate(java.util.Collection<? extends AbstractBounds<?>> allBounds)`

- Method Detail
  - global
```
static IPartitioner global()
```
  - validate
```
static void validate(java.util.Collection<? extends AbstractBounds<?>> allBounds)
```
  - validate
```
static void validate(AbstractBounds<?> bounds)
```
  - decorateKey
```
DecoratedKey decorateKey(java.nio.ByteBuffer key)
```
    Transform key to object representation of the on-disk format.
    
    Parameters:
    
    key - the raw, client-facing key
    
    Returns:
    
    decorated version of key
  - midpoint
```
Token midpoint(Token left,
               Token right)
```
    Calculate a Token representing the approximate "middle" of the given range.
    
    Returns:
    
    The approximate midpoint between left and right.
  - split
```
Token split(Token left,
            Token right,
            double ratioToLeft)
```
    Calculate a Token which take approximate 0 <= ratioToLeft <= 1 ownership of the given range.
  - getMinimumToken
```
Token getMinimumToken()
```
    Returns:
    
    A Token smaller than all others in the range that is being partitioned. Not legal to assign to a node or key. (But legal to use in range scans.)
  - getMaximumToken
```
default Token getMaximumToken()
```
    The biggest token for this partitioner, unlike getMinimumToken, this token is actually used and users wanting to include all tokens need to do getMaximumToken().maxKeyBound() Not implemented for the ordered partitioners
  - getToken
```
Token getToken(java.nio.ByteBuffer key)
```
    Returns:
    
    a Token that can be used to route a given key (This is NOT a method to create a Token from its string representation; for that, use TokenFactory.fromString.)
  - getRandomToken
```
Token getRandomToken()
```
    Returns:
    
    a randomly generated token
  - getRandomToken
```
Token getRandomToken(java.util.Random random)
```
    Parameters:
    
    random - instance of Random to use when generating the token
    
    Returns:
    
    a randomly generated token
  - getTokenFactory
```
Token.TokenFactory getTokenFactory()
```
  - preservesOrder
```
boolean preservesOrder()
```
    Returns:
    
    True if the implementing class preserves key order in the Tokens it generates.
  - describeOwnership
```
java.util.Map<Token,java.lang.Float> describeOwnership(java.util.List<Token> sortedTokens)
```
    Calculate the deltas between tokens in the ring in order to compare relative sizes.
    
    Parameters:
    
    sortedTokens - a sorted List of Tokens
    
    Returns:
    
    the mapping from 'token' to 'percentage of the ring owned by that token'.
  - getTokenValidator
```
AbstractType<?> getTokenValidator()
```
  - partitionOrdering
```
AbstractType<?> partitionOrdering()
```
    Abstract type that orders the same way as DecoratedKeys provided by this partitioner. Used by secondary indices.
  - splitter
```
default java.util.Optional<Splitter> splitter()
```
  - getMaxTokenSize
```
default int getMaxTokenSize()
```

Interface IPartitioner

Method Summary

Method Detail

global

validate

validate

decorateKey

midpoint

split

getMinimumToken

getMaximumToken

getToken

getRandomToken

getRandomToken

getTokenFactory

preservesOrder

describeOwnership

getTokenValidator

partitionOrdering

splitter

getMaxTokenSize