org.apache.nifi.distributed.cache.client

Class NettyDistributedMapCacheClient

java.lang.Object

org.apache.nifi.distributed.cache.client.DistributedCacheClient

org.apache.nifi.distributed.cache.client.NettyDistributedMapCacheClient

public class NettyDistributedMapCacheClient
extends DistributedCacheClient

The implementation of the DistributedMapCacheClient using the netty library to provide the remote communication services.

Constructor Summary

Constructors

Constructor and Description
NettyDistributedMapCacheClient(String hostname, int port, int timeoutMillis, SSLContextService sslContextService, VersionNegotiatorFactory factory) Constructor.

Method Summary

Modifier and Type	Method and Description
void	close() Perform a clean shutdown of the cache client.
boolean	containsKey(byte[] key) Determines if the given value is present in the cache and if so returns true, else returns false
<K,V> AtomicCacheEntry<K,V,Long>	fetch(byte[] key, AtomicCacheEntryInboundAdapter<K,V> inboundAdapter) Fetch a CacheEntry with a key.
<V> V	get(byte[] key, ValueInboundAdapter<V> valueAdapter) Returns the value in the cache for the given key, if one exists; otherwise returns null
<V> V	getAndPutIfAbsent(byte[] key, byte[] value, ValueInboundAdapter<V> valueAdapter) Adds the specified key and value to the cache, if they are not already present.
<K> Set<K>	keySet(SetInboundAdapter<K> setAdapter) Returns a set of all keys currently in the cache.
void	put(byte[] key, byte[] value) Adds the specified key and value to the cache, overwriting any value that is currently set.
boolean	putIfAbsent(byte[] key, byte[] value) Adds the specified key and value to the cache, if they are not already present.
boolean	remove(byte[] key) Removes the entry with the given key from the cache, if it is present.
<V> V	removeAndGet(byte[] key, ValueInboundAdapter<V> valueAdapter) Removes the entry with the given key from the cache, if it is present, and returns the value that was removed from the map.
long	removeByPattern(String regex) Removes entries whose keys match the specified pattern.
<K,V> Map<K,V>	removeByPatternAndGet(String regex, MapInboundAdapter<K,V> mapAdapter) Removes entries whose keys match the specified pattern, and returns a map of entries that were removed.
boolean	replace(byte[] key, byte[] value, long revision) Replace an existing key with new value.
<K,V> Map<K,V>	subMap(Collection<byte[]> keys, MapValuesInboundAdapter<K,V> mapAdapter) Returns the values in the cache for the given keys, if they exist.

Methods inherited from class org.apache.nifi.distributed.cache.client.DistributedCacheClient

closeChannelPool, invoke

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NettyDistributedMapCacheClient

public NettyDistributedMapCacheClient(String hostname,
                                      int port,
                                      int timeoutMillis,
                                      SSLContextService sslContextService,
                                      VersionNegotiatorFactory factory)

Constructor.

Parameters:

hostname - the network name / IP address of the server running the distributed cache service

port - the port on which the distributed cache service is running

timeoutMillis - the network timeout associated with requests to the service

sslContextService - the SSL context (if any) associated with requests to the service; if not specified, communications will not be encrypted

factory - creator of object used to broker the version of the distributed cache protocol with the service

Method Detail

putIfAbsent

public boolean putIfAbsent(byte[] key,
                           byte[] value)
                    throws IOException

Adds the specified key and value to the cache, if they are not already present.

Parameters:

key - the key to add to the map

value - the value to add to the map if and only if the key is absent

Returns:

true if the value was added to the cache, false if the value already existed in the cache

Throws:

IOException - if unable to communicate with the remote instance

put

public void put(byte[] key,
                byte[] value)
         throws IOException

Adds the specified key and value to the cache, overwriting any value that is currently set.

Parameters:

key - The key to set

value - The value to associate with the given Key

Throws:

IOException - if unable to communicate with the remote instance

containsKey

public boolean containsKey(byte[] key)
                    throws IOException

Determines if the given value is present in the cache and if so returns true, else returns false

Parameters:

key - key

Returns:

Determines if the given value is present in the cache and if so returns true, else returns false

Throws:

IOException - if unable to communicate with the remote instance

getAndPutIfAbsent

public <V> V getAndPutIfAbsent(byte[] key,
                               byte[] value,
                               ValueInboundAdapter<V> valueAdapter)
                        throws IOException

Adds the specified key and value to the cache, if they are not already present. If a value already exists in the cache for the given key, the value associated with the key is returned.

Parameters:

key - the key to add to the map

value - the value to add to the map if and only if the key is absent

valueAdapter - the reader used to deserialize the service result

Returns:

If a value already exists in the cache for the given key, the value associated with the key is returned. If the key does not exist, the key and its value will be added to the cache.

Throws:

IOException - if unable to communicate with the remote instance

get

public <V> V get(byte[] key,
                 ValueInboundAdapter<V> valueAdapter)
          throws IOException

Returns the value in the cache for the given key, if one exists; otherwise returns null

Type Parameters:

V - the value type

Parameters:

key - the key to lookup in the map

valueAdapter - the reader used to deserialize the service result

Returns:

the value in the cache for the given key

Throws:

IOException - if unable to communicate with the remote instance

subMap

public <K,V> Map<K,V> subMap(Collection<byte[]> keys,
                             MapValuesInboundAdapter<K,V> mapAdapter)
                      throws IOException

Returns the values in the cache for the given keys, if they exist.

Type Parameters:

K - the key type

V - the value type

Parameters:

keys - a set of keys whose values to lookup in the map

mapAdapter - the reader used to deserialize the service result

Returns:

the value in the cache for the given key, if one exists

Throws:

IOException - if unable to communicate with the remote instance

remove

public boolean remove(byte[] key)
               throws IOException

Removes the entry with the given key from the cache, if it is present.

Parameters:

key - the key to remove from the map

Returns:

true if the entry is removed, false if the key did not exist in the cache

Throws:

IOException - if unable to communicate with the remote instance

removeAndGet

public <V> V removeAndGet(byte[] key,
                          ValueInboundAdapter<V> valueAdapter)
                   throws IOException

Removes the entry with the given key from the cache, if it is present, and returns the value that was removed from the map.

Type Parameters:

V - type of value

Parameters:

key - the key to remove from the map

valueAdapter - the reader used to deserialize the service result

Returns:

the value previously associated with the key, or null if there was no mapping

Throws:

IOException - if unable to communicate with the remote instance

removeByPattern

public long removeByPattern(String regex)
                     throws IOException

Removes entries whose keys match the specified pattern.

Parameters:

regex - The regular expression / pattern on which to match the keys to be removed

Returns:

The number of entries that were removed

Throws:

IOException - if unable to communicate with the remote instance

removeByPatternAndGet

public <K,V> Map<K,V> removeByPatternAndGet(String regex,
                                            MapInboundAdapter<K,V> mapAdapter)
                                     throws IOException

Removes entries whose keys match the specified pattern, and returns a map of entries that were removed.

Type Parameters:

K - type of key

V - type of value

Parameters:

regex - The regular expression / pattern on which to match the keys to be removed

Returns:

A map of key/value entries that were removed from the cache

Throws:

IOException - if unable to communicate with the remote instance

fetch

public <K,V> AtomicCacheEntry<K,V,Long> fetch(byte[] key,
                                              AtomicCacheEntryInboundAdapter<K,V> inboundAdapter)
                                       throws IOException

Fetch a CacheEntry with a key.

Type Parameters:

K - the key type

V - the value type

Parameters:

key - the key to lookup in the map

inboundAdapter - the reader used to deserialize the service result

Returns:

A CacheEntry instance if one exists

Throws:

IOException - if unable to communicate with the remote instance

replace

public boolean replace(byte[] key,
                       byte[] value,
                       long revision)
                throws IOException

Replace an existing key with new value.

Parameters:

key - the key of the map entry to be replaced

value - the new value

revision - the expected revision of the map entry; on no match, value will not be replaced

Returns:

true only if the key is replaced

Throws:

IOException - if unable to communicate with the remote instance

keySet

public <K> Set<K> keySet(SetInboundAdapter<K> setAdapter)
                  throws IOException

Returns a set of all keys currently in the cache.

Type Parameters:

K - type of key

Parameters:

setAdapter - the reader used to deserialize the service result

Returns:

a Set of all keys currently in the cache

Throws:

IOException - if unable to communicate with the remote instance

close

public void close()
           throws IOException

Perform a clean shutdown of the cache client.

Throws:

IOException - if unable to communicate with the remote instance