org.qtunes.db.spi.simple
Class DatabaseImpl

java.lang.Object
  org.qtunes.db.spi.simple.DatabaseImpl

All Implemented Interfaces:

Service, Database

public class DatabaseImpl
extends java.lang.Object
implements Database, Service

The Database manages the Tracks and Playlists. It stores the Playlists as properties for this service.

The track database is done via a Store, and works in two stages. First, a MemoryStore is updated with the track information, then when commit() is called this temporary store is merged with the main Store (probably a FileStore at this stage. This is a flat-file which is designed for very quick random access to track data.

This class is necessarily one of the more complex and it may change over time. It must be thread safe (with java.util.concurrent).

Constructor Summary

DatabaseImpl()

Method Summary

void	abort() Abort the current pending transactions
void	commit() Commit any pending database changes (new or modified tracks) to the database.
Track	create(FieldMap map) Create a new Track entry.
ManualPlaylist	createManualPlaylist() Create a new ManualPlaylist
SmartPlaylist	createSmartPlaylist(java.lang.String query) Create a new ManualPlaylist
ServiceContext	getContext() Return the ServiceContext that was passed into Service.startService(org.qtunes.core.ServiceContext)
Playlist	getPlaylist(java.lang.String name) Get the Playlist with the specified name.
java.util.Collection<java.lang.String>	getPlaylists() Get the list of Playlist names
int	getRevision() Return the revision number of the Database
Track	getTrack(int tracknumber) Get the track with the specified track index
java.util.Collection<Track>	getTracks() Return a read-only Collection with all the Tracks in the Database in arbirary order.
java.util.List<Track>	getTracks(java.lang.String sort, java.lang.String filter) Return a List of the tracks in the database with the specified sort order and filter.
boolean	hasPending() Return true if a transaction has been begun with a call to begin())
void	lock(boolean hold) Lock or unlock the database for edits.
void	putPlaylist(java.lang.String name, Playlist playlist) Store (possibly overwriting) the playlist with the specified name.\ If the value is null the playlist will be removed.
java.util.Map<java.lang.String,java.lang.Object>	reportState() Return a Map describing the state of this Service, for serialization back to any client that needs to know (eg webplayer) - so values should be serializable objects, eg Lists, Maps or simple objects.
int	size() Return the number of tracks in this Database
void	startService(ServiceContext context) Start the Service
void	stopService(ServiceContext context) Stop the Service
void	updateTrack(int tracknumber, FieldMap changes) Update the fields on the specified Track.

Methods inherited from class java.lang.Object

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

Constructor Detail

DatabaseImpl

public DatabaseImpl()

Method Detail

startService

public void startService(ServiceContext context)

Description copied from interface: Service

Start the Service

Specified by:

startService in interface Service

Parameters:

context - the ServiceContext for this Service

stopService

public void stopService(ServiceContext context)

Description copied from interface: Service

Stop the Service

Specified by:

stopService in interface Service

Parameters:

context - the ServiceContext for this Service (same as was passed into start)

getContext

public ServiceContext getContext()

Description copied from interface: Service

Return the ServiceContext that was passed into Service.startService(org.qtunes.core.ServiceContext)

Specified by:

getContext in interface Service

create

public Track create(FieldMap map)

Create a new Track entry. The track will initially be created in the temporary store - whether this method runs an "update" or an "insert" depends on the Matcher, which will try to match the fields in the FieldMap against the existing tracks. This may be done by Filename, by Inode or by checksum of the audio data (for example). The fields are then stored and the Track returned.

Specified by:

create in interface Database

getTracks

public java.util.Collection<Track> getTracks()

Description copied from interface: Database

Return a read-only Collection with all the Tracks in the Database in arbirary order.

Specified by:

getTracks in interface Database

getTracks

public java.util.List<Track> getTracks(java.lang.String sort,
                                       java.lang.String filter)

Description copied from interface: Database

Return a List of the tracks in the database with the specified sort order and filter. This list will be regenerated on each call so should be called sparingly. The returned list may be modified

Specified by:

getTracks in interface Database

getRevision

public int getRevision()

Description copied from interface: Database

Return the revision number of the Database

Specified by:

getRevision in interface Database

size

public int size()

Description copied from interface: Database

Return the number of tracks in this Database

Specified by:

size in interface Database

getTrack

public Track getTrack(int tracknumber)

Get the track with the specified track index

Specified by:

getTrack in interface Database

lock

public void lock(boolean hold)

Description copied from interface: Database

Lock or unlock the database for edits. Use sparingly!

Specified by:

lock in interface Database

commit

public void commit()

Description copied from interface: Database

Commit any pending database changes (new or modified tracks) to the database.

Specified by:

commit in interface Database

abort

public void abort()

Abort the current pending transactions

hasPending

public boolean hasPending()

Return true if a transaction has been begun with a call to begin())

getPlaylist

public Playlist getPlaylist(java.lang.String name)

Description copied from interface: Database

Get the Playlist with the specified name. The special name "*" means the Playlist that matches all tracks in the database

Specified by:

getPlaylist in interface Database

getPlaylists

public java.util.Collection<java.lang.String> getPlaylists()

Description copied from interface: Database

Get the list of Playlist names

Specified by:

getPlaylists in interface Database

putPlaylist

public void putPlaylist(java.lang.String name,
                        Playlist playlist)

Description copied from interface: Database

Store (possibly overwriting) the playlist with the specified name.\ If the value is null the playlist will be removed.

Specified by:

putPlaylist in interface Database

updateTrack

public void updateTrack(int tracknumber,
                        FieldMap changes)
                 throws java.io.IOException

Description copied from interface: Database

Update the fields on the specified Track. The track file will be updated immediately, the database only on the next commit

Specified by:

updateTrack in interface Database

Throws:

java.io.IOException

createManualPlaylist

public ManualPlaylist createManualPlaylist()

Description copied from interface: Database

Create a new ManualPlaylist

Specified by:

createManualPlaylist in interface Database

createSmartPlaylist

public SmartPlaylist createSmartPlaylist(java.lang.String query)

Description copied from interface: Database

Create a new ManualPlaylist

Specified by:

createSmartPlaylist in interface Database

reportState

public java.util.Map<java.lang.String,java.lang.Object> reportState()

Description copied from interface: Service

Return a Map describing the state of this Service, for serialization back to any client that needs to know (eg webplayer) - so values should be serializable objects, eg Lists, Maps or simple objects. If no useful state, return null.

Specified by:

reportState in interface Service