Package io.kcache

Interface Cache<K,V>

All Superinterfaces:

AutoCloseable, Closeable, org.apache.kafka.common.Configurable, Map<K,V>, SortedMap<K,V>

All Known Implementing Classes:

InMemoryBoundedCache, InMemoryCache, KafkaCache, PersistentCache, TransformedRawCache

public interface Cache<K,V>
extends SortedMap<K,V>, org.apache.kafka.common.Configurable, Closeable

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K extends Object,V extends Object>

Method Summary

Modifier and Type	Method	Description
KeyValueIterator<K,V>	all()	Returns an iterator over all key-value pairs in this cache.
default void	configure(Map<String,?> configs)	Configures the cache.
Cache<K,V>	descendingCache()	Returns a reverse order view of the mappings contained in this cache.
void	destroy()	Destroys the cache, if persistent.
void	flush()	Flushes the cache.
default SortedMap<K,V>	headMap(K toKey)
void	init()	Initializes the cache.
default boolean	isPersistent()	Whether the cache is persistent.
KeyValueIterator<K,V>	range(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)	Returns an iterator over the portion of this cache whose keys range from fromKey to toKey.
void	reset()	Resets the cache, clearing stale data before a sync.
Cache<K,V>	subCache(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)	Returns a view of the portion of this cache whose keys range from fromKey to toKey.
default SortedMap<K,V>	subMap(K fromKey, K toKey)
void	sync()	Syncs (or re-initializes) the cache with the backing store.
default SortedMap<K,V>	tailMap(K fromKey)

Methods inherited from interface java.io.Closeable

close

Methods inherited from interface java.util.Map

clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, equals, forEach, get, getOrDefault, hashCode, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size

Methods inherited from interface java.util.SortedMap

comparator, entrySet, firstKey, keySet, lastKey, values

Method Detail

isPersistent

default boolean isPersistent()

Whether the cache is persistent.

Returns:

whether the cache is persistent

configure

default void configure(Map<String,?> configs)

Configures the cache.

Specified by:

configure in interface org.apache.kafka.common.Configurable

init

void init()
   throws CacheInitializationException

Initializes the cache.

Throws:

CacheInitializationException

reset

void reset()

Resets the cache, clearing stale data before a sync. This can be used if the leader changes in a cluster.

sync

void sync()

Syncs (or re-initializes) the cache with the backing store.

subCache

Cache<K,V> subCache(K fromKey,
                          boolean fromInclusive,
                          K toKey,
                          boolean toInclusive)

Returns a view of the portion of this cache whose keys range from fromKey to toKey. If fromKey and toKey are equal, the returned cache is empty unless fromInclusive and toInclusive are both true. The returned cache is backed by this cache, so changes in the returned cache are reflected in this cache, and vice-versa. The returned cache supports all optional cache operations that this cache supports.

The returned cache will throw an IllegalArgumentException on an attempt to insert a key outside of its range, or to construct a subcache either of whose endpoints lie outside its range.

Parameters:

fromKey - low endpoint of the keys in the returned cache; null indicates the beginning

fromInclusive - true if the low endpoint is to be included in the returned view

toKey - high endpoint of the keys in the returned cache; null indicates the end

toInclusive - true if the high endpoint is to be included in the returned view

Returns:

a view of the portion of this cache whose keys range from fromKey to toKey

Throws:

ClassCastException - if fromKey and toKey cannot be compared to one another using this cache's comparator (or, if the cache has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if fromKey or toKey cannot be compared to keys currently in the cache.

IllegalArgumentException - if fromKey is greater than toKey; or if this cache itself has a restricted range, and fromKey or toKey lies outside the bounds of the range

range

KeyValueIterator<K,V> range(K fromKey,
                                  boolean fromInclusive,
                                  K toKey,
                                  boolean toInclusive)

Returns an iterator over the portion of this cache whose keys range from fromKey to toKey. If fromKey and toKey are equal, the returned iterator is empty unless fromInclusive and toInclusive are both true.

Parameters:

fromKey - low endpoint of the keys in the returned iterator; null indicates the beginning

fromInclusive - true if the low endpoint is to be included in the returned view

toKey - high endpoint of the keys in the returned iterator; null indicates the end

toInclusive - true if the high endpoint is to be included in the returned view

Returns:

an iterator over the portion of this cache whose keys range from fromKey to toKey

Throws:

ClassCastException - if fromKey and toKey cannot be compared to one another using this cache's comparator (or, if the cache has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if fromKey or toKey cannot be compared to keys currently in the cache.

IllegalArgumentException - if fromKey is greater than toKey; or if this cache itself has a restricted range, and fromKey or toKey lies outside the bounds of the range

all

KeyValueIterator<K,V> all()

Returns an iterator over all key-value pairs in this cache.

Returns:

a KeyValueIterator over the elements in this collection

descendingCache

Cache<K,V> descendingCache()

Returns a reverse order view of the mappings contained in this cache. The descending cache is backed by this cache, so changes to the cache are reflected in the descending cache, and vice-versa. If either cache is modified while an iteration over a collection view of either cache is in progress (except through the iterator's own remove operation), the results of the iteration are undefined.

Returns:

a reverse order view of this cache

flush

void flush()

Flushes the cache.

destroy

void destroy()
      throws IOException

Destroys the cache, if persistent.

Throws:

IOException

subMap

default SortedMap<K,V> subMap(K fromKey,
                                    K toKey)

Specified by:

subMap in interface SortedMap<K,V>

headMap

default SortedMap<K,V> headMap(K toKey)

Specified by:

headMap in interface SortedMap<K,V>

tailMap

default SortedMap<K,V> tailMap(K fromKey)

Specified by:

tailMap in interface SortedMap<K,V>