org.rapidcontext.core.storage

Class MemoryStorage

java.lang.Object

org.rapidcontext.core.storage.StorableObject

org.rapidcontext.core.storage.Storage

org.rapidcontext.core.storage.MemoryStorage

All Implemented Interfaces:

java.lang.Comparable

public class MemoryStorage
extends Storage

A persistent data storage and retrieval handler based on an in-memory hash table. Naturally, this is not really persistent in case of server shutdown, so should normally be used only for run-time objects that need to be available. An advantage of the memory storage compared to other implementations is that no object serialization is performed, so any type of objects may be stored and retrieved.

Version:

1.0

Author:

Per Cederberg

Field Summary

Fields inherited from class org.rapidcontext.core.storage.Storage

KEY_MOUNT_OVERLAY_PATH, KEY_MOUNT_OVERLAY_PRIO, KEY_MOUNT_PATH, KEY_MOUNT_TIME, KEY_READWRITE, PATH_STORAGE, PATH_STORAGE_CACHE, PATH_STORAGEINFO

Fields inherited from class org.rapidcontext.core.storage.StorableObject

dict, KEY_CLASSNAME, KEY_ID, KEY_TYPE

Constructor Summary

Constructors

Constructor and Description
MemoryStorage(boolean readWrite, boolean storageInfo) Creates a new memory storage.

Method Summary

Modifier and Type	Method and Description
int	count() Returns the number of objects currently in this storage.
void	destroy() Destroys this storage.
boolean	isStorable(java.lang.Object obj) Checks if the specified object is supported in this storage.
java.lang.Object	load(Path path) Loads an object from the specified location.
Metadata	lookup(Path path) Searches for an object at the specified location and returns metadata about the object if found.
void	remove(Path path) Removes an object or an index at the specified location.
Dict	serialize() Returns a serialized representation of this object.
void	store(Path path, java.lang.Object data) Stores an object at the specified location.

Methods inherited from class org.rapidcontext.core.storage.Storage

compareTo, isReadWrite, loadAll, localPath, lookupAll, mountOverlayPath, mountOverlayPrio, mountTime, path, setMountInfo

Methods inherited from class org.rapidcontext.core.storage.StorableObject

activate, id, init, isActive, isModified, passivate, toString, type

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryStorage

public MemoryStorage(boolean readWrite,
                     boolean storageInfo)

Creates a new memory storage.

Parameters:

readWrite - the read write flag

storageInfo - the show storage info flag

Method Detail

isStorable

public boolean isStorable(java.lang.Object obj)

Checks if the specified object is supported in this storage.

Parameters:

obj - the object instance to check

Returns:

true if the object is supported, or false otherwise

destroy

public void destroy()

Destroys this storage. Note that the objects in the storage will NOT be destroyed by this method.

Overrides:

destroy in class StorableObject

serialize

public Dict serialize()

Returns a serialized representation of this object. Used when accessing the object from outside pure Java.

Overrides:

serialize in class StorableObject

Returns:

the serialized representation of this object

count

public int count()

Returns the number of objects currently in this storage. This number does not include indexes or metadata objects, since those are dynamically inserted and removed.

Returns:

the number of objects in the storage

lookup

public Metadata lookup(Path path)

Searches for an object at the specified location and returns metadata about the object if found. The path may locate either an index or a specific object.

Specified by:

lookup in class Storage

Parameters:

path - the storage location

Returns:

the metadata for the object, or null if not found

load

public java.lang.Object load(Path path)

Loads an object from the specified location. The path may locate either an index or a specific object. In case of an index, the data returned is an index dictionary listing of all objects in it.

Specified by:

load in class Storage

Parameters:

path - the storage location

Returns:

the data read, or null if not found

store

public void store(Path path,
                  java.lang.Object data)
           throws StorageException

Stores an object at the specified location. The path must locate a particular object or file, since direct manipulation of indices is not supported. Any previous data at the specified path will be overwritten or removed.

Specified by:

store in class Storage

Parameters:

path - the storage location

data - the data to store

Throws:

StorageException - if the data couldn't be written

remove

public void remove(Path path)
            throws StorageException

Removes an object or an index at the specified location. If the path refers to an index, all contained objects and indices will be removed recursively.

Specified by:

remove in class Storage

Parameters:

path - the storage location

Throws:

StorageException - if the data couldn't be removed