com.googlecode.n_orm.memory

Class Memory

java.lang.Object

com.googlecode.n_orm.memory.Memory

All Implemented Interfaces:

SimpleStore

public class Memory
extends Object
implements SimpleStore

Reference implementation for a store based on ConcurrentSkipListMap. This store entirely resides into memory, and is only available for the current JVM. It is well suited for testing. This store is thread-safe. This store does not supports mixing incrementing and absolute values.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Memory.Table An map to store rows within tables.

Field Summary

Fields

Modifier and Type	Field and Description
static Memory	INSTANCE

Method Summary

Modifier and Type	Method and Description
long	count(String table, Constraint c) Counts the number of element satisfying the constraint.
void	delete(String table, String id) Deletes the given row
boolean	exists(String table, String row) Tests for a row.
boolean	exists(String table, String row, String family) Tests whether a column family is empty.
CloseableKeyIterator	get(String table, Constraint c, int limit, Set<String> families) Rows matching constraint sorted according to their key in ascending order.
Row.ColumnFamilyData	get(String table, String id, Set<String> families) Returns all elements in families ; no side-effect.
Map<String,byte[]>	get(String table, String id, String family) Returns all elements in a family ; no side-effect.
Map<String,byte[]>	get(String table, String id, String family, Constraint c) Returns all elements in a family ; no side-effect.
byte[]	get(String table, String id, String family, String qualifer) Returns an element from a family.
Memory.Table.Row.ColumnFamily	getFamily(String table, String id, String family, boolean createIfNecessary) Returns the in-memory column family for a given row from a table.
Memory.Table.Row	getRow(String table, String id, boolean createIfNecessary) Returns the in-memory row (compatible with Row) from a table.
Memory.Table	getTable(String table, boolean createIfNecessary) Returns the in-memory table.
boolean	hasTable(String tableName) Checks whether the given table exists in this store.
void	reset()
void	start() Called once the store is created ; only one store is instanciated with the same properties.
void	storeChanges(String table, String id, Row.ColumnFamilyData changed, Map<String,Set<String>> removed, Map<String,Map<String,Number>> incremented) Stores given piece of information.
protected static <T> NavigableMap<String,T>	subMap(NavigableMap<String,T> map, String fromIncl, String toIncl) Utility method used internally to find a sub-map with inclusive nullable start and stop keys.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final Memory INSTANCE

Method Detail

subMap

protected static <T> NavigableMap<String,T> subMap(NavigableMap<String,T> map,
                                                   String fromIncl,
                                                   String toIncl)

Utility method used internally to find a sub-map with inclusive nullable start and stop keys.

Parameters:

map - the map to be searched-in

fromIncl - the start key ; can be null to state the start of the map

toIncl - the last key ; can be null to state the end of the map

Returns:

a sub-map (can be map or a view on map)

start

public void start()

Description copied from interface: SimpleStore

Called once the store is created ; only one store is instanciated with the same properties.

Specified by:

start in interface SimpleStore

getTable

public Memory.Table getTable(String table,
                             boolean createIfNecessary)

Returns the in-memory table.

Parameters:

table - the name of the expected table

createIfNecessary - whether to create the table if it does not exist

Returns:

the table ; can be null if createIfNecessary is set to false and the table does not exist

getRow

public Memory.Table.Row getRow(String table,
                               String id,
                               boolean createIfNecessary)

Returns the in-memory row (compatible with Row) from a table.

Parameters:

table - the name of the table in which to find the row

id - the unique identifier for the row within the table

createIfNecessary - whether to create the row if it does not exist (including in case table does not exists)

Returns:

the row ; can be null if createIfNecessary is set to false and the row or the table does not exist

getFamily

public Memory.Table.Row.ColumnFamily getFamily(String table,
                                               String id,
                                               String family,
                                               boolean createIfNecessary)

Returns the in-memory column family for a given row from a table.

Parameters:

table - the name of the table in which to find the column family for the row

id - the unique identifier for the row within the table

family - the name of the column family to be found within the row

createIfNecessary - whether to create the row if it does not exist (including in case table or row does not exists)

Returns:

the row ; can be null if createIfNecessary is set to false and the column family or the row or the table does not exist

hasTable

public boolean hasTable(String tableName)
                 throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Checks whether the given table exists in this store.

Specified by:

hasTable in interface SimpleStore

Throws:

DatabaseNotReachedException

get

public byte[] get(String table,
                  String id,
                  String family,
                  String qualifer)

Description copied from interface: SimpleStore

Returns an element from a family.

Specified by:

get in interface SimpleStore

get

public Map<String,byte[]> get(String table,
                              String id,
                              String family)

Description copied from interface: SimpleStore

Returns all elements in a family ; no side-effect. In case one element is missing, null is returned.

Specified by:

get in interface SimpleStore

get

public Map<String,byte[]> get(String table,
                              String id,
                              String family,
                              Constraint c)
                       throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Returns all elements in a family ; no side-effect. In case one element is missing, null is returned.

Specified by:

get in interface SimpleStore

Throws:

DatabaseNotReachedException

storeChanges

public void storeChanges(String table,
                         String id,
                         Row.ColumnFamilyData changed,
                         Map<String,Set<String>> removed,
                         Map<String,Map<String,Number>> incremented)

Description copied from interface: SimpleStore

Stores given piece of information. In case an element is missing in the data store (table, row, family, ...), it is created.

Specified by:

storeChanges in interface SimpleStore

count

public long count(String table,
                  Constraint c)
           throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Counts the number of element satisfying the constraint.

Specified by:

count in interface SimpleStore

Throws:

DatabaseNotReachedException

reset

public void reset()

delete

public void delete(String table,
                   String id)

Description copied from interface: SimpleStore

Deletes the given row

Specified by:

delete in interface SimpleStore

exists

public boolean exists(String table,
                      String row,
                      String family)
               throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Tests whether a column family is empty.

Specified by:

exists in interface SimpleStore

Throws:

DatabaseNotReachedException

exists

public boolean exists(String table,
                      String row)
               throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Tests for a row.

Specified by:

exists in interface SimpleStore

Throws:

DatabaseNotReachedException

get

public Row.ColumnFamilyData get(String table,
                                String id,
                                Set<String> families)
                         throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Returns all elements in families ; no side-effect. In case element with the given key is missing, null is returned.

Specified by:

get in interface SimpleStore

Parameters:

table - the table from which to find the element

id - the unique identifier (i.e. the key) with which the element was stored

families - the set of column families to be activated ; should never be null or empty

Returns:

the data stored for each family ; null if and only if the id does not exist in the table

Throws:

DatabaseNotReachedException

get

public CloseableKeyIterator get(String table,
                                Constraint c,
                                int limit,
                                Set<String> families)
                         throws DatabaseNotReachedException

Description copied from interface: SimpleStore

Rows matching constraint sorted according to their key in ascending order.

Specified by:

get in interface SimpleStore

families - TODO

Throws:

DatabaseNotReachedException