org.apache.gora.hbase.store

Class HBaseStore<K,T extends PersistentBase>

java.lang.Object

org.apache.gora.store.impl.DataStoreBase<K,T>

org.apache.gora.hbase.store.HBaseStore<K,T>

All Implemented Interfaces:

Closeable, AutoCloseable, DataStore<K,T>, org.apache.hadoop.conf.Configurable, org.apache.hadoop.io.Writable

public class HBaseStore<K,T extends PersistentBase>
extends DataStoreBase<K,T>
implements org.apache.hadoop.conf.Configurable

DataStore for HBase. Thread safe.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_MAPPING_FILE
static org.slf4j.Logger	LOG
static String	PARSE_MAPPING_FILE_KEY

Fields inherited from class org.apache.gora.store.impl.DataStoreBase

beanFactory, conf, datumReader, datumWriter, fieldMap, keyClass, persistentClass, properties, schema

Constructor Summary

Constructors

Constructor and Description
HBaseStore()

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the DataStore.
org.apache.hadoop.hbase.client.ResultScanner	createScanner(Query<K,T> query)
void	createSchema() Creates the optional schema or table (or similar) in the datastore to hold the objects.
boolean	delete(K key) Deletes the object with the given key.
void	delete(T obj)
long	deleteByQuery(Query<K,T> query) Deletes all the objects matching the query.
void	deleteSchema() Deletes the underlying schema or table (or similar) in the datastore that holds the objects.
Result<K,T>	execute(Query<K,T> query) Executes the given query and returns the results.
void	flush() Forces the write caches to be flushed.
T	get(K key, String[] fields) Returns the object corresponding to the given key.
org.apache.hadoop.conf.Configuration	getConf()
HBaseMapping	getMapping()
List<PartitionQuery<K,T>>	getPartitions(Query<K,T> query) Partitions the given query and returns a list of PartitionQuerys, which will execute on local data.
int	getScannerCaching() Gets the Scanner Caching optimization value
String	getSchemaName() Returns the schema name given to this DataStore
void	initialize(Class<K> keyClass, Class<T> persistentClass, Properties properties) Initializes this DataStore.
T	newInstance(org.apache.hadoop.hbase.client.Result result, String[] fields) Creates a new Persistent instance with the values in 'result' for the fields listed.
Query<K,T>	newQuery() Constructs and returns a new Query.
void	put(K key, T persistent) Inserts the persistent object with the given key.
boolean	schemaExists() Returns whether the schema that holds the data exists in the datastore.
void	setConf(org.apache.hadoop.conf.Configuration conf)
HBaseStore<K,T>	setScannerCaching(int numRows) Sets the value for Scanner Caching optimization

Methods inherited from class org.apache.gora.store.impl.DataStoreBase

equals, get, getBeanFactory, getFields, getFieldsToQuery, getKeyClass, getOrCreateConf, getPersistentClass, getSchemaName, newKey, newPersistent, readFields, setBeanFactory, setKeyClass, setPersistentClass, truncateSchema, write

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

PARSE_MAPPING_FILE_KEY

public static final String PARSE_MAPPING_FILE_KEY

See Also:

Constant Field Values

DEFAULT_MAPPING_FILE

public static final String DEFAULT_MAPPING_FILE

See Also:

Constant Field Values

Constructor Detail

HBaseStore

public HBaseStore()

Method Detail

initialize

public void initialize(Class<K> keyClass,
              Class<T> persistentClass,
              Properties properties)

Description copied from interface: DataStore

Initializes this DataStore.

Specified by:

initialize in interface DataStore<K,T extends PersistentBase>

Overrides:

initialize in class DataStoreBase<K,T extends PersistentBase>

Parameters:

keyClass - the class of the keys

persistentClass - the class of the persistent objects

properties - extra metadata

getSchemaName

public String getSchemaName()

Description copied from interface: DataStore

Returns the schema name given to this DataStore

Specified by:

getSchemaName in interface DataStore<K,T extends PersistentBase>

Returns:

schema name

getMapping

public HBaseMapping getMapping()

createSchema

public void createSchema()

Description copied from interface: DataStore

Creates the optional schema or table (or similar) in the datastore to hold the objects. If the schema is already created previously, or the underlying data model does not support or need this operation, the operation is ignored.

Specified by:

createSchema in interface DataStore<K,T extends PersistentBase>

deleteSchema

public void deleteSchema()

Description copied from interface: DataStore

Deletes the underlying schema or table (or similar) in the datastore that holds the objects. This also deletes all the data associated with the schema.

Specified by:

deleteSchema in interface DataStore<K,T extends PersistentBase>

schemaExists

public boolean schemaExists()

Description copied from interface: DataStore

Returns whether the schema that holds the data exists in the datastore.

Specified by:

schemaExists in interface DataStore<K,T extends PersistentBase>

Returns:

whether schema exists

get

public T get(K key,
    String[] fields)

Description copied from interface: DataStore

Returns the object corresponding to the given key.

Specified by:

get in interface DataStore<K,T extends PersistentBase>

Parameters:

key - the key of the object

fields - the fields required in the object. Pass null, to retrieve all fields

Returns:

the Object corresponding to the key or null if it cannot be found

put

public void put(K key,
       T persistent)

Inserts the persistent object with the given key. If an object with the same key already exists it will silently be replaced. See also the note on visibility. Serializes the Persistent data and saves in HBase. Topmost fields of the record are persisted in "raw" format (not avro serialized). This behavior happens in maps and arrays too. ["null","type"] type (a.k.a. optional field) is persisted like as if it is ["type"], but the column get deleted if value==null (so value read after will be null).

Specified by:

put in interface DataStore<K,T extends PersistentBase>

Parameters:

persistent - Record to be persisted in HBase

delete

public void delete(T obj)

delete

public boolean delete(K key)

Deletes the object with the given key.

Specified by:

delete in interface DataStore<K,T extends PersistentBase>

Parameters:

key - the key of the object

Returns:

always true

deleteByQuery

public long deleteByQuery(Query<K,T> query)

Description copied from interface: DataStore

Deletes all the objects matching the query. See also the note on visibility.

Specified by:

deleteByQuery in interface DataStore<K,T extends PersistentBase>

Parameters:

query - matching records to this query will be deleted

Returns:

number of deleted records

flush

public void flush()

Description copied from interface: DataStore

Forces the write caches to be flushed. DataStore implementations may optimize their writing by deferring the actual put / delete operations until this moment. See also the note on visibility.

Specified by:

flush in interface DataStore<K,T extends PersistentBase>

newQuery

public Query<K,T> newQuery()

Description copied from interface: DataStore

Constructs and returns a new Query.

Specified by:

newQuery in interface DataStore<K,T extends PersistentBase>

Returns:

a new Query.

getPartitions

public List<PartitionQuery<K,T>> getPartitions(Query<K,T> query)
                                                               throws IOException

Description copied from interface: DataStore

Partitions the given query and returns a list of PartitionQuerys, which will execute on local data.

Specified by:

getPartitions in interface DataStore<K,T extends PersistentBase>

Parameters:

query - the base query to create the partitions for. If the query is null, then the data store returns the partitions for the default query (returning every object)

Returns:

a List of PartitionQuery's

Throws:

IOException

execute

public Result<K,T> execute(Query<K,T> query)

Description copied from interface: DataStore

Executes the given query and returns the results.

Specified by:

execute in interface DataStore<K,T extends PersistentBase>

Parameters:

query - the query to execute.

Returns:

the results as a Result object.

createScanner

public org.apache.hadoop.hbase.client.ResultScanner createScanner(Query<K,T> query)
                                                           throws IOException

Throws:

IOException

newInstance

public T newInstance(org.apache.hadoop.hbase.client.Result result,
            String[] fields)
                                     throws IOException

Creates a new Persistent instance with the values in 'result' for the fields listed.

Parameters:

result - result form a HTable#get()

fields - List of fields queried, or null for all

Returns:

A new instance with default values for not listed fields null if 'result' is null.

Throws:

IOException

close

public void close()

Description copied from interface: DataStore

Close the DataStore. This should release any resources held by the implementation, so that the instance is ready for GC. All other DataStore methods cannot be used after this method was called. Subsequent calls of this method are ignored.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface DataStore<K,T extends PersistentBase>

getConf

public org.apache.hadoop.conf.Configuration getConf()

Specified by:

getConf in interface org.apache.hadoop.conf.Configurable

Overrides:

getConf in class DataStoreBase<K,T extends PersistentBase>

setConf

public void setConf(org.apache.hadoop.conf.Configuration conf)

Specified by:

setConf in interface org.apache.hadoop.conf.Configurable

Overrides:

setConf in class DataStoreBase<K,T extends PersistentBase>

getScannerCaching

public int getScannerCaching()

Gets the Scanner Caching optimization value

Returns:

The value used internally in Scan.setCaching(int)

setScannerCaching

public HBaseStore<K,T> setScannerCaching(int numRows)

Sets the value for Scanner Caching optimization

Parameters:

numRows - the number of rows for caching >= 0

Returns:

<<Fluent interface>>

See Also:

Scan.setCaching(int)