Package cz.o2.proxima.direct.io.hbase

Class RandomHBaseReader

java.lang.Object

cz.o2.proxima.direct.io.hbase.RandomHBaseReader

All Implemented Interfaces:

RandomAccessReader, java.io.Closeable, java.lang.AutoCloseable

public class RandomHBaseReader
extends java.lang.Object
implements RandomAccessReader

RandomAccessReader for HBase.

Nested Class Summary

Nested classes/interfaces inherited from interface cz.o2.proxima.direct.core.randomaccess.RandomAccessReader

RandomAccessReader.Factory<T extends RandomAccessReader>, RandomAccessReader.GetRequest<T>, RandomAccessReader.Listing, RandomAccessReader.MultiFetch

Constructor Summary

Constructors

Constructor	Description
RandomHBaseReader(java.net.URI uri, org.apache.hadoop.conf.Configuration conf, java.util.Map<java.lang.String,java.lang.Object> cfg, EntityDescriptor entity)

Method Summary

Modifier and Type	Method	Description
RandomAccessReader.Factory<?>	asFactory()	Convert instance of this reader to RandomAccessReader.Factory suitable for serialization.
void	close()
RandomOffset	fetchOffset(RandomAccessReader.Listing type, java.lang.String key)	Construct Offset from string (representing either key of the entity or attribute).
<T> java.util.Optional<KeyValue<T>>	get(java.lang.String key, java.lang.String attribute, AttributeDescriptor<T> desc, long stamp)	Retrieve data stored under given (key, attribute) pair (if any).
EntityDescriptor	getEntityDescriptor()	Retrieve entity associated with this reader.
java.net.URI	getUri()
void	listEntities(RandomOffset offset, int limit, Consumer<Pair<RandomOffset,java.lang.String>> consumer)	List all entity keys with offset and limit.
<T> void	scanWildcard(java.lang.String key, AttributeDescriptor<T> wildcard, RandomOffset offset, long stamp, int limit, Consumer<KeyValue<T>> consumer)	List data stored for a particular wildcard attribute.
void	scanWildcardAll(java.lang.String key, RandomOffset offset, long stamp, int limit, Consumer<KeyValue<?>> consumer)	Scan all data stored per given key.

Methods inherited from class java.lang.Object

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

Methods inherited from interface cz.o2.proxima.direct.core.randomaccess.RandomAccessReader

get, get, get, get, listEntities, multiFetch, scanWildcard, scanWildcard, scanWildcard, scanWildcardAll, scanWildcardAll, scanWildcardAll

Constructor Detail

RandomHBaseReader

public RandomHBaseReader(java.net.URI uri,
                         org.apache.hadoop.conf.Configuration conf,
                         java.util.Map<java.lang.String,java.lang.Object> cfg,
                         EntityDescriptor entity)

Method Detail

fetchOffset

public RandomOffset fetchOffset(RandomAccessReader.Listing type,
                                java.lang.String key)

Description copied from interface: RandomAccessReader

Construct Offset from string (representing either key of the entity or attribute). The returned offset represents the first element that is following the given key, in case of equality.

Specified by:

fetchOffset in interface RandomAccessReader

Parameters:

type - the type of the key

key - the key of entity or attribute

Returns:

offset representation of the key

get

public <T> java.util.Optional<KeyValue<T>> get(java.lang.String key,
                                               java.lang.String attribute,
                                               AttributeDescriptor<T> desc,
                                               long stamp)

Description copied from interface: RandomAccessReader

Retrieve data stored under given (key, attribute) pair (if any).

Specified by:

get in interface RandomAccessReader

Type Parameters:

T - value type

Parameters:

key - key of the entity

attribute - name of the attribute

desc - the attribute to search for

stamp - timestamp to relatively to which retrieve the data

Returns:

optional KeyValue if present

scanWildcard

public <T> void scanWildcard(java.lang.String key,
                             AttributeDescriptor<T> wildcard,
                             RandomOffset offset,
                             long stamp,
                             int limit,
                             Consumer<KeyValue<T>> consumer)

Description copied from interface: RandomAccessReader

List data stored for a particular wildcard attribute.

Specified by:

scanWildcard in interface RandomAccessReader

Type Parameters:

T - value type

Parameters:

key - key of the entity

wildcard - wildcard attribute to scan

offset - name of attribute (including the prefix) to start from

stamp - timestamp to relatively to which retrieve the data

limit - maximal number of items to consume *

consumer - the consumer to stream data to

listEntities

public void listEntities(RandomOffset offset,
                         int limit,
                         Consumer<Pair<RandomOffset,java.lang.String>> consumer)

Description copied from interface: RandomAccessReader

List all entity keys with offset and limit.

Specified by:

listEntities in interface RandomAccessReader

Parameters:

offset - offset of the entities

limit - limit for number of results

consumer - consumer of results

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

getEntityDescriptor

public EntityDescriptor getEntityDescriptor()

Description copied from interface: RandomAccessReader

Retrieve entity associated with this reader.

Specified by:

getEntityDescriptor in interface RandomAccessReader

Returns:

entity associated with this reader

asFactory

public RandomAccessReader.Factory<?> asFactory()

Description copied from interface: RandomAccessReader

Convert instance of this reader to RandomAccessReader.Factory suitable for serialization.

Specified by:

asFactory in interface RandomAccessReader

Returns:

the RandomAccessReader.Factory representing this reader

scanWildcardAll

public void scanWildcardAll(java.lang.String key,
                            RandomOffset offset,
                            long stamp,
                            int limit,
                            Consumer<KeyValue<?>> consumer)

Description copied from interface: RandomAccessReader

Scan all data stored per given key.

Specified by:

scanWildcardAll in interface RandomAccessReader

Parameters:

key - the key whose KeyValues to scan

offset - offset to start from (next key value will be returned)

stamp - timestamp to relatively to which retrieve the data

limit - how many elements to process at most

consumer - consumer to use for scanning

getUri

public java.net.URI getUri()