Class RangeIntersectionIterator.BounceIntersectionIterator<K extends java.lang.Comparable<K>,D extends CombinedValue<K>>
- java.lang.Object
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- org.apache.cassandra.index.sasi.utils.AbstractIterator<T>
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- org.apache.cassandra.index.sasi.utils.RangeIterator<K,D>
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- org.apache.cassandra.index.sasi.utils.RangeIntersectionIterator.BounceIntersectionIterator<K,D>
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- Type Parameters:
K
- The type used to sort ranges.D
- The container type which is going to be returned byIterator.next()
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- All Implemented Interfaces:
com.google.common.collect.PeekingIterator<D>
,java.io.Closeable
,java.lang.AutoCloseable
,java.util.Iterator<D>
- Enclosing class:
- RangeIntersectionIterator
protected static class RangeIntersectionIterator.BounceIntersectionIterator<K extends java.lang.Comparable<K>,D extends CombinedValue<K>> extends RangeIterator<K,D>
Iterator which performs intersection of multiple ranges by using bouncing (merge-join) technique to identify common elements in the given ranges. Aforementioned "bounce" works as follows: range queue is poll'ed for the range with the smallest current token (main loop), that token is used toRangeIterator.skipTo(Comparable)
other ranges, if token produced byRangeIterator.skipTo(Comparable)
is equal to current "candidate" token, both get merged together and the same operation is repeated for next range from the queue, if returned token is not equal than candidate, candidate's range gets put back into the queue and the main loop gets repeated until next intersection token is found or at least one iterator runs out of tokens. This technique is every efficient to jump over gaps in the ranges.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.cassandra.index.sasi.utils.RangeIterator
RangeIterator.Builder<K extends java.lang.Comparable<K>,D extends CombinedValue<K>>
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Nested classes/interfaces inherited from class org.apache.cassandra.index.sasi.utils.AbstractIterator
AbstractIterator.State
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Field Summary
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Fields inherited from class org.apache.cassandra.index.sasi.utils.AbstractIterator
next, state
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected D
computeNext()
Returns the next element.protected void
performSkipTo(K nextToken)
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Methods inherited from class org.apache.cassandra.index.sasi.utils.RangeIterator
getCount, getCurrent, getMaximum, getMinimum, isOverlapping, isOverlapping, recomputeNext, skipTo, tryToComputeNext
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Methods inherited from class org.apache.cassandra.index.sasi.utils.AbstractIterator
endOfData, hasNext, next, peek, remove
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Method Detail
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computeNext
protected D computeNext()
Description copied from class:AbstractIterator
Returns the next element. Note: the implementation must callAbstractIterator.endOfData()
when there are no elements left in the iteration. Failure to do so could result in an infinite loop.The initial invocation of
AbstractIterator.hasNext()
orAbstractIterator.next()
calls this method, as does the first invocation ofhasNext
ornext
following each successful call tonext
. Once the implementation either invokesendOfData
or throws an exception,computeNext
is guaranteed to never be called again.If this method throws an exception, it will propagate outward to the
hasNext
ornext
invocation that invoked this method. Any further attempts to use the iterator will result in anIllegalStateException
.The implementation of this method may not invoke the
hasNext
,next
, orAbstractIterator.peek()
methods on this instance; if it does, anIllegalStateException
will result.- Specified by:
computeNext
in classAbstractIterator<D extends CombinedValue<K>>
- Returns:
- the next element if there was one. If
endOfData
was called during execution, the return value will be ignored.
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performSkipTo
protected void performSkipTo(K nextToken)
- Specified by:
performSkipTo
in classRangeIterator<K extends java.lang.Comparable<K>,D extends CombinedValue<K>>
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