org.apache.derby.impl.io.vfmem

Class DataStore

java.lang.Object

org.apache.derby.impl.io.vfmem.DataStore

public final class DataStore
extends java.lang.Object

A virtual data store, keeping track of all the virtual files existing and offering a set of high-level operations on virtual files.

A newly created data store doesn't contain a single existing directory.

Constructor Summary

Constructors

Constructor and Description
DataStore(java.lang.String databaseName) Creates a new data store.

Method Summary

Modifier and Type	Method and Description
boolean	createAllParents(java.lang.String path) Creates all the parents of the specified path.
DataStoreEntry	createEntry(java.lang.String iPath, boolean isDir) Creates a new entry in the data store.
boolean	deleteAll(java.lang.String iPath) Deletes the specified entry and all its children.
boolean	deleteEntry(java.lang.String iPath) Deletes the specified entry.
java.lang.String	getDatabaseName() Returns the database name, which is expected to equal the path of the service root.
DataStoreEntry	getEntry(java.lang.String iPath) Returns the entry with the specified path.
long	getTempFileCounter() Returns an identifier for a temporary file.
java.lang.String[]	listChildren(java.lang.String iPath) Lists the childen of the specified path.
boolean	move(StorageFile currentFile, StorageFile newFile) Moves / renames a file.
void	purge() Purges the database and releases all files associated with it.
boolean	scheduledForDeletion() Tells if this data store is scheduled for deletion.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataStore

public DataStore(java.lang.String databaseName)

Creates a new data store.

Parameters:

databaseName - the name of the assoicated database, expected to be the absolute path of the service root.

Method Detail

getDatabaseName

public java.lang.String getDatabaseName()

Returns the database name, which is expected to equal the path of the service root.

Returns:

The database name.

scheduledForDeletion

public boolean scheduledForDeletion()

Tells if this data store is scheduled for deletion.

Returns:

true if the store is awaiting deletion, false otherwise.

createEntry

public DataStoreEntry createEntry(java.lang.String iPath,
                                  boolean isDir)

Creates a new entry in the data store.

This method returns null if the path already exists, if one of the parent directories doesn't exist, or if one of the parents is a file instead of a directory.

Parameters:

iPath - the path of the entry

isDir - tells if the new entry shall be directory or a file

Returns:

A DataStoreEntry-instance if the entry was successfully created, null otherwise

createAllParents

public boolean createAllParents(java.lang.String path)

Creates all the parents of the specified path.

Returns:

true if all parents either already existed as directories or were created, false otherwise

deleteEntry

public boolean deleteEntry(java.lang.String iPath)

Deletes the specified entry.

If the specified entry is a directory, it is only deleted if it is empty. Read-only entries are deleted.

Parameters:

iPath - path of the entry to delete

Returns:

true if the entry was deleted, false otherwise.

getEntry

public DataStoreEntry getEntry(java.lang.String iPath)

Returns the entry with the specified path.

Parameters:

iPath - path of the entry to fetch

Returns:

null if the entry doesn't exist, the DataStoreEntry-object otherwise.

deleteAll

public boolean deleteAll(java.lang.String iPath)

Deletes the specified entry and all its children.

Parameters:

iPath - the root entry

Returns:

true if the entry and all its children were deleted, false if the root doesn't exist.

listChildren

public java.lang.String[] listChildren(java.lang.String iPath)

Lists the childen of the specified path.

Parameters:

iPath - the directory to list the children of

Returns:

An array with the relative paths of the children.

move

public boolean move(StorageFile currentFile,
                    StorageFile newFile)

Moves / renames a file.

Parameters:

currentFile - the current file

newFile - the new file

Returns:

true if the file was moved, false if the new file already existed or the existing file doesn't exist.

purge

public void purge()

Purges the database and releases all files associated with it.

getTempFileCounter

public long getTempFileCounter()

Returns an identifier for a temporary file.

Returns:

An integer uniquely identifying a temporary file.