com.cloudant.sync.datastore

Class DatastoreManager

java.lang.Object

com.cloudant.sync.datastore.DatastoreManager

public class DatastoreManager
extends java.lang.Object

Manages a set of Datastore objects, with their underlying disk storage residing in a given directory.

In general, a directory used for storing datastores -- that is, managed by this manager -- shouldn't be used for storing other data. The manager object assumes all data within is managed by itself, so adding other files to the directory may cause them to be deleted.

A datastore's on-disk representation is a single file containing all its data. In future, there may be other files and folders per datastore.

API Status: Public

Constructor Summary

Constructors

Constructor and Description
DatastoreManager(java.io.File directoryPath) Constructs a DatastoreManager to manage a directory.
DatastoreManager(java.lang.String directoryPath) Constructs a DatastoreManager to manage a directory.

Method Summary

Modifier and Type	Method and Description
void	deleteDatastore(java.lang.String dbName) Deletes a datastore's files from disk.
EventBus	getEventBus() Returns the EventBus which this DatastoreManager posts Database Notification Events to.
java.lang.String	getPath() Returns the path to the directory this object manages.
java.util.List<java.lang.String>	listAllDatastores() Lists all the names of Datastores managed by this DatastoreManager
void	onDatabaseClosed(DatabaseClosed databaseClosed)
Datastore	openDatastore(java.lang.String dbName) Opens a datastore.
Datastore	openDatastore(java.lang.String dbName, KeyProvider provider) Opens a datastore.

Methods inherited from class java.lang.Object

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

Constructor Detail

DatastoreManager

public DatastoreManager(java.lang.String directoryPath)

Constructs a DatastoreManager to manage a directory.

Datastores are created within the directoryPath directory. In general, this folder should be under the control of, and only used by, a single DatastoreManager object at any time.

Parameters:

directoryPath - root directory to manage

See Also:

DatastoreManager(java.io.File)

DatastoreManager

public DatastoreManager(java.io.File directoryPath)

Constructs a DatastoreManager to manage a directory.

Datastores are created within the directoryPath directory. In general, this folder should be under the control of, and only used by, a single DatastoreManager object at any time.

Parameters:

directoryPath - root directory to manage

Throws:

java.lang.IllegalArgumentException - if the directoryPath is not a directory or isn't writable.

Method Detail

listAllDatastores

public java.util.List<java.lang.String> listAllDatastores()

Lists all the names of Datastores managed by this DatastoreManager

Returns:

List of Datastores names.

getPath

public java.lang.String getPath()

Returns the path to the directory this object manages.

Returns:

the absolute path to the directory this object manages.

openDatastore

public Datastore openDatastore(java.lang.String dbName)
                        throws DatastoreNotCreatedException

Opens a datastore.

Equivalent to calling openDatastore(String, KeyProvider) with a NullKeyProvider.

Parameters:

dbName - name of datastore to open

Returns:

Datastore with the given name

Throws:

DatastoreNotCreatedException - Thrown when the datastore could not be created or opened.

See Also:

getEventBus()

openDatastore

public Datastore openDatastore(java.lang.String dbName,
                               KeyProvider provider)
                        throws DatastoreNotCreatedException

Opens a datastore.

Opens an existing datastore on disk, or creates a new one with the given name.

If encryption is enabled for this platform, passing a KeyProvider containing a non-null key will open or create an encrypted database. If opening a database, the key used to create the database must be used. If encryption is not enabled for this platform, returning a non-null key will result in an exception.

If there is no existing datastore with the given name, and one is successfully created, a DatabaseOpened event is posted on the event bus.

Datastores are uniqued: calling this method with the name of an already open datastore will return the existing Datastore object.

Parameters:

dbName - name of datastore to open

provider - KeyProvider object; use a NullKeyProvider if database shouldn't be encrypted.

Returns:

Datastore with the given name

Throws:

DatastoreNotCreatedException - if the database cannot be opened

See Also:

getEventBus()

deleteDatastore

public void deleteDatastore(java.lang.String dbName)
                     throws java.io.IOException

Deletes a datastore's files from disk.

This operation deletes a datastore's files from disk. It is therefore a not undo-able. To confirm, this only deletes local data; data replicated to remote databases is not affected.

Any Datastore objects referring to the deleted files will be in an unknown state. Therefore, they should be disposed of prior to deleting the data. Currently, no checks for open datastores are carried out before attempting the delete.

If the datastore was successfully deleted, a DatabaseDeleted event is posted on the event bus.

Parameters:

dbName - Name of database to create

Throws:

java.io.IOException - if the datastore doesn't exist on disk or there is a problem deleting the files.

See Also:

getEventBus()

getEventBus

public EventBus getEventBus()

Returns the EventBus which this DatastoreManager posts Database Notification Events to.

Returns:

the DatastoreManager's EventBus

See Also:

Google Guava EventBus documentation

onDatabaseClosed

public void onDatabaseClosed(DatabaseClosed databaseClosed)