Class LayerManager<T extends BloomFilter<T>>
java.lang.Object
org.apache.commons.collections4.bloomfilter.LayerManager<T>
- Type Parameters:
T- theBloomFiltertype.
- All Implemented Interfaces:
BloomFilterExtractor
Implementation of the methods to manage the layers in a layered Bloom filter.
The manager comprises a list of Bloom filters that are managed based on
various rules. The last filter in the list is known as the target and
is the filter into which merges are performed. The Layered manager utilizes
three methods to manage the list.
- ExtendCheck - A Predicate that if true causes a new Bloom filter to be created as the new target.
- FilterSupplier - A Supplier that produces empty Bloom filters to be used as a new target.
- Cleanup - A Consumer of a
LinkedListof BloomFilter that removes any expired or out dated filters from the list.
When extendCheck returns true the following steps are taken:
Cleanupis calledFilterSuplieris executed and the new filter added to the list as thetargetfilter.
- Since:
- 4.5.0-M1
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic classLayerManager.Builder<T extends BloomFilter<T>>Builds new instances ofLayerManager.static final classStatic methods to create a Consumer of a List of BloomFilter perform tests on whether to reduce the collection of Bloom filters.static final classA collection of common ExtendCheck implementations to test whether to extend the depth of a LayerManager. -
Method Summary
Modifier and TypeMethodDescriptionstatic <T extends BloomFilter<T>>
LayerManager.Builder<T> builder()Creates a new Builder with defaults ofLayerManager.ExtendCheck.neverAdvance()andLayerManager.Cleanup.noCleanup().final voidclear()Removes all the filters from the layer manager, and sets up a new one as the target.copy()Creates a deep copy of thisLayerManager.final Tfirst()Gets the Bloom filter from the first layer.final Tget(int depth) Gets the Bloom filter at the specified depth.final intgetDepth()Gets the number of filters in the LayerManager.final TGets the current target filter.final Tlast()Gets the Bloom filter from the last layer.booleanprocessBloomFilters(Predicate<BloomFilter> bloomFilterPredicate) Executes a Bloom filter Predicate on each Bloom filter in the manager in depth order.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitMethods inherited from interface org.apache.commons.collections4.bloomfilter.BloomFilterExtractor
asBloomFilterArray, flatten, processBloomFilterPair
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Method Details
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builder
Creates a new Builder with defaults ofLayerManager.ExtendCheck.neverAdvance()andLayerManager.Cleanup.noCleanup().- Type Parameters:
T- Type of BloomFilter.- Returns:
- A builder.
- See Also:
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clear
Removes all the filters from the layer manager, and sets up a new one as the target. -
copy
Creates a deep copy of thisLayerManager.Filters in the copy are deep copies, not references, so changes in the copy are NOT reflected in the original.
The
filterSupplier,extendCheck, and thefilterCleanupare shared between the copy and this instance.- Returns:
- a copy of this
LayerManager.
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first
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get
Gets the Bloom filter at the specified depth. The filter at depth 0 is the oldest filter.- Parameters:
depth- the depth at which the desired filter is to be found.- Returns:
- the filter.
- Throws:
NoSuchElementException- if depth is not in the range [0,filters.size())
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getDepth
Gets the number of filters in the LayerManager. In the default LayerManager implementation there is always at least one layer.- Returns:
- the current depth.
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getTarget
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last
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processBloomFilters
Executes a Bloom filter Predicate on each Bloom filter in the manager in depth order. Oldest filter first.- Specified by:
processBloomFiltersin interfaceBloomFilterExtractor- Parameters:
bloomFilterPredicate- the predicate to evaluate each Bloom filter with.- Returns:
falsewhen the a filter fails the predicate test. Returnstrueif all filters pass the test.
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