org.jboss.cache.loader
Class FileCacheLoader

java.lang.Object
  org.jboss.cache.loader.FileCacheLoader

All Implemented Interfaces:

CacheLoader (src) , Service (src)

public class FileCacheLoader

extends java.lang.Object

implements CacheLoader (src)

Simple file-based CacheLoader implementation. Nodes are directories, attributes of a node is a file in the directory

DATA

public static final java.lang.String DATA

See Also:

Constant Field Values (src)

DIR_SUFFIX

public static final java.lang.String DIR_SUFFIX

See Also:

Constant Field Values (src)

FileCacheLoader

public FileCacheLoader()

setConfig

public void setConfig(java.util.Properties props)

Description copied from interface: CacheLoader (src)

Sets the configuration. Will be called before Service.create() and Service.start()

Specified by:

setConfig in interface CacheLoader (src)

Parameters:

props - A list of properties, defined in the XML file

setCache

public void setCache(TreeCache (src)  c)

Description copied from interface: CacheLoader (src)

This method allows the CacheLoader to set the TreeCache, therefore allowing the CacheLoader to invoke methods of the TreeCache. It can also use the TreeCache to fetch configuration information. Alternatively, the CacheLoader could maintain its own configuration
This method will be called directly after the CacheLoader instance has been created

Specified by:

setCache in interface CacheLoader (src)

Parameters:

c - The cache on which this loader works

create

public void create()
            throws java.lang.Exception

Description copied from interface: Service (src)

create the service, do expensive operations etc

Specified by:

create in interface Service (src)

Throws:

java.lang.Exception

start

public void start()
           throws java.lang.Exception

Description copied from interface: Service (src)

start the service, create is already called

Specified by:

start in interface Service (src)

Throws:

java.lang.Exception

stop

public void stop()

Description copied from interface: Service (src)

stop the service

Specified by:

stop in interface Service (src)

destroy

public void destroy()

Description copied from interface: Service (src)

destroy the service, tear down

Specified by:

destroy in interface Service (src)

getChildrenNames

public java.util.Set getChildrenNames(Fqn (src)  fqn)
                               throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Returns a list of children names, all names are relative. Returns null if the parent node is not found. The returned set must not be modified, e.g. use Collections.unmodifiableSet(s) to return the result

Specified by:

getChildrenNames in interface CacheLoader (src)

Parameters:

fqn - The FQN of the parent

Returns:

Set. A list of children. Returns null if no children nodes are present, or the parent is not present

Throws:

java.lang.Exception

get

public java.lang.Object get(Fqn (src)  fqn,
                            java.lang.Object key)
                     throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Returns the value for a given key. Returns null if the node doesn't exist, or the value is not bound

Specified by:

get in interface CacheLoader (src)

Parameters:

fqn -

Returns:

Throws:

java.lang.Exception

get

public java.util.Map get(Fqn (src)  fqn)
                  throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Returns all keys and values from the persistent store, given a fully qualified name

Specified by:

get in interface CacheLoader (src)

Parameters:

fqn -

Returns:

Map of keys and values for the given node. Returns null if the node was not found, or if the node has no attributes

Throws:

java.lang.Exception

exists

public boolean exists(Fqn (src)  fqn)
               throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Checks whether the CacheLoader has a node with Fqn

Specified by:

exists in interface CacheLoader (src)

Parameters:

fqn -

Returns:

True if node exists, false otherwise

Throws:

java.lang.Exception

put

public java.lang.Object put(Fqn (src)  fqn,
                            java.lang.Object key,
                            java.lang.Object value)
                     throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Inserts key and value into the attributes hashmap of the given node. If the node does not exist, all parent nodes from the root down are created automatically. Returns the old value

Specified by:

put in interface CacheLoader (src)

Throws:

java.lang.Exception

put

public void put(Fqn (src)  fqn,
                java.util.Map attributes)
         throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Inserts all elements of attributes into the attributes hashmap of the given node, overwriting existing attributes, but not clearing the existing hashmap before insertion (making it a union of existing and new attributes) If the node does not exist, all parent nodes from the root down are created automatically

Specified by:

put in interface CacheLoader (src)

Parameters:

fqn - The fully qualified name of the node

attributes - A Map of attributes. Can be null

Throws:

java.lang.Exception

put

public void put(Fqn (src)  fqn,
                java.util.Map attributes,
                boolean erase)
         throws java.lang.Exception

Throws:

java.lang.Exception

put

public void put(java.util.List modifications)
         throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Inserts all modifications to the backend store. Overwrite whatever is already in the datastore.

Specified by:

put in interface CacheLoader (src)

Parameters:

modifications - List

Throws:

java.lang.Exception

remove

public java.lang.Object remove(Fqn (src)  fqn,
                               java.lang.Object key)
                        throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Removes the given key and value from the attributes of the given node. No-op if node doesn't exist

Specified by:

remove in interface CacheLoader (src)

Throws:

java.lang.Exception

remove

public void remove(Fqn (src)  fqn)
            throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Removes the given node. If the node is the root of a subtree, this will recursively remove all subnodes, depth-first

Specified by:

remove in interface CacheLoader (src)

Throws:

java.lang.Exception

removeData

public void removeData(Fqn (src)  fqn)
                throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Removes all attributes from a given node, but doesn't delete the node itself

Specified by:

removeData in interface CacheLoader (src)

Parameters:

fqn -

Throws:

java.lang.Exception

prepare

public void prepare(java.lang.Object tx,
                    java.util.List modifications,
                    boolean one_phase)
             throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Prepare the modifications. For example, for a DB-based CacheLoader:

1. Create a local (JDBC) transaction
2. Associate the local transaction with tx (tx is the key)
3. Execute the coresponding SQL statements against the DB (statements derived from modifications)

For non-transactional CacheLoader (e.g. file-based), this could be a null operation

Specified by:

prepare in interface CacheLoader (src)

Parameters:

tx - The transaction, just used as a hashmap key

modifications - List, a list of all modifications within the given transaction

one_phase - Persist immediately and (for example) commit the local JDBC transaction as well. When true, we won't get a CacheLoader.commit(Object) or CacheLoader.rollback(Object) method call later

Throws:

java.lang.Exception

commit

public void commit(java.lang.Object tx)
            throws java.lang.Exception

Description copied from interface: CacheLoader (src)

Commit the transaction. A DB-based CacheLoader would look up the local JDBC transaction asociated with tx and commit that transaction
Non-transactional CacheLoaders could simply write the data that was previously saved transiently under the given tx key, to (for example) a file system (note this only holds if the previous prepare() did not define one_phase=true

Specified by:

commit in interface CacheLoader (src)

Parameters:

tx -

Throws:

java.lang.Exception

rollback

public void rollback(java.lang.Object tx)

Description copied from interface: CacheLoader (src)

Roll the transaction back. A DB-based CacheLoader would look up the local JDBC transaction asociated with tx and roll back that transaction

Specified by:

rollback in interface CacheLoader (src)

Parameters:

tx -

loadEntireState

public byte[] loadEntireState()
                       throws java.lang.Exception

Loads the entire state from the filesystem and returns it as a byte buffer. The format of the byte buffer must be a list of NodeData elements

Specified by:

loadEntireState in interface CacheLoader (src)

Returns:

Throws:

java.lang.Exception

storeEntireState

public void storeEntireState(byte[] state)
                      throws java.lang.Exception

Store the state given as a byte buffer to the filesystem. The byte buffer contains a list of zero or more NodeData elements

Specified by:

storeEntireState in interface CacheLoader (src)

Parameters:

state -

Throws:

java.lang.Exception