org.apache.gora.memory.store
Class MemStore<K,T extends Persistent>

java.lang.Object
  org.apache.gora.store.impl.DataStoreBase<K,T>
      org.apache.gora.memory.store.MemStore<K,T>

All Implemented Interfaces:

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

public class MemStore<K,T extends Persistent>
extends DataStoreBase<K,T>

Memory based DataStore implementation for tests.

Nested Class Summary

static class	MemStore.MemQuery<K,T extends Persistent>
static class	MemStore.MemResult<K,T extends Persistent>

Field Summary

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

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

Constructor Summary

MemStore()

Method Summary

void	close() Close the DataStore.
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
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.
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.
String	getSchemaName() Returns the schema name given to this DataStore
Query<K,T>	newQuery() Constructs and returns a new Query.
void	put(K key, T obj) Inserts the persistent object with the given key.
boolean	schemaExists() Returns whether the schema that holds the data exists in the datastore.

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

MemStore

public MemStore()

Method Detail

getSchemaName

public String getSchemaName()

Description copied from interface: DataStore

Returns the schema name given to this DataStore

Returns:

schema name

delete

public boolean delete(K key)
               throws IOException

Description copied from interface: DataStore

Deletes the object with the given key

Parameters:

key - the key of the object

Returns:

whether the object was successfully deleted

Throws:

IOException

deleteByQuery

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

Description copied from interface: DataStore

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

Parameters:

query - matching records to this query will be deleted

Returns:

number of deleted records

Throws:

IOException

execute

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

Description copied from interface: DataStore

Executes the given query and returns the results.

Parameters:

query - the query to execute.

Returns:

the results as a Result object.

Throws:

IOException

get

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

Description copied from interface: DataStore

Returns the object corresponding to the given key.

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

Throws:

IOException

newQuery

public Query<K,T> newQuery()

Description copied from interface: DataStore

Constructs and returns a new Query.

Returns:

a new Query.

put

public void put(K key,
                T obj)
         throws IOException

Description copied from interface: DataStore

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.

Throws:

IOException

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.

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

close

public void close()
           throws IOException

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.

Throws:

IOException

createSchema

public void createSchema()
                  throws IOException

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.

Throws:

IOException

deleteSchema

public void deleteSchema()
                  throws IOException

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.

Throws:

IOException

schemaExists

public boolean schemaExists()
                     throws IOException

Description copied from interface: DataStore

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

Returns:

whether schema exists

Throws:

IOException

flush

public void flush()
           throws IOException

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.

Throws:

IOException