Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.io.vfmem.DataStore

Modifier and Type	Field and Description
private final String	databaseName The name of the database this store serves, expected to be the absolute path of the service root (i.e. /tmp/myDB if the database myDB is created in /tmp).
private boolean	deleteMe Tells if this store is scheduled for deletion.
private static final String[]	EMPTY_STR_ARR Constant for the empty String array.
private final Map<String, DataStoreEntry>	files The files exsiting in the store.
private final Object	LOCK Lock object for the file map.
private static final char	SEP The path separator used.
private final Object	TMP_COUNTER_LOCK Lock object for the temporary file counter.
private long	tmpFileCounter Counter used to generate unique temporary file names.

Access	Constructor and Description
public	DataStore(String the name of the assoicated database, expected to be the absolute path of the service root. databaseName) Creates a new data store.

Method Summary

Modifier and Type	Method and Description
private boolean	Returns: `true` if all children of the root path were deleted, `false` otherwise. _deleteAll(String the normalized root path to start deleting from prefixPath) Deletes every child of the root path specified.
public boolean	Returns: `true` if all parents either already existed as directories or were created, `false` otherwise createAllParents(String path) Creates all the parents of the specified path.
public DataStoreEntry	Returns: A `DataStoreEntry`-instance if the entry was successfully created, `null` otherwise createEntry(String the path of the entry iPath, boolean tells if the new entry shall be directory or a file isDir) Creates a new entry in the data store.
public boolean	Returns: `true` if the entry and all its children were deleted, `false` if the root doesn't exist. deleteAll(String the root entry iPath) Deletes the specified entry and all its children.
public boolean	Returns: `true` if the entry was deleted, `false` otherwise. deleteEntry(String path of the entry to delete iPath) Deletes the specified entry.
public String	Returns: The database name. getDatabaseName() Returns the database name, which is expected to equal the path of the service root.
public DataStoreEntry	Returns: `null` if the entry doesn't exist, the `DataStoreEntry`-object otherwise. getEntry(String path of the entry to fetch iPath) Returns the entry with the specified path.
private String[]	Returns: A list of parents. getParentList(String the normalized path to create a parent list for path) Returns the list of parents for the specified path.
public long	Returns: An integer uniquely identifying a temporary file. getTempFileCounter() Returns an identifier for a temporary file.
public String[]	Returns: An array with the relative paths of the children. listChildren(String the directory to list the children of iPath) Lists the childen of the specified path.
public boolean	Returns: `true` if the file was moved, `false` if the new file already existed or the existing file doesn't exist. move(StorageFile the current file currentFile, StorageFile the new file newFile) Moves / renames a file.
public void	purge() Purges the database and releases all files associated with it.
public boolean	Returns: `true` if the store is awaiting deletion, `false` otherwise. scheduledForDeletion() Tells if this data store is scheduled for deletion.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

databaseName	back to summary
private final String databaseName The name of the database this store serves, expected to be the absolute path of the service root (i.e. /tmp/myDB if the database myDB is created in /tmp).

deleteMe	back to summary
private boolean deleteMe Tells if this store is scheduled for deletion.

EMPTY_STR_ARR	back to summary
private static final String[] EMPTY_STR_ARR Constant for the empty String array.

files	back to summary
private final Map<String, DataStoreEntry> files The files exsiting in the store. The initial size is set to the number of initial files of a Derby database, pluss a few more.

files

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private final Map<String, DataStoreEntry> files

The files exsiting in the store.

The initial size is set to the number of initial files of a Derby database, pluss a few more.

LOCK	back to summary
private final Object LOCK Lock object for the file map.

SEP	back to summary
private static final char SEP The path separator used.

TMP_COUNTER_LOCK	back to summary
private final Object TMP_COUNTER_LOCK Lock object for the temporary file counter.

tmpFileCounter	back to summary
private long tmpFileCounter Counter used to generate unique temporary file names.

Constructor Detail

DataStore	back to summary
public DataStore(String databaseName) Creates a new data store. Parameters databaseName:String the name of the assoicated database, expected to be the absolute path of the service root.

DataStore

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public DataStore(String databaseName)

Creates a new data store.

Parameters

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

Method Detail

_deleteAll back to summary

_deleteAll	back to summary
private boolean _deleteAll(String prefixPath) Deletes every child of the root path specified. Note that the root itself must be removed outside of this method. Parameters prefixPath:String the normalized root path to start deleting from Returns:boolean `true` if all children of the root path were deleted, `false` otherwise.

private boolean _deleteAll(String prefixPath)

Deletes every child of the root path specified.

Note that the root itself must be removed outside of this method.

Parameters

prefixPath:String: the normalized root path to start deleting from

Returns:boolean

true if all children of the root path were deleted, false otherwise.

createAllParents back to summary

createAllParents	back to summary
public boolean createAllParents(String path) Creates all the parents of the specified path. Returns:boolean `true` if all parents either already existed as directories or were created, `false` otherwise

public boolean createAllParents(String path)

Creates all the parents of the specified path.

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

createEntry back to summary

createEntry	back to summary
public DataStoreEntry createEntry(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:String the path of the entry isDir:boolean tells if the new entry shall be directory or a file Returns:DataStoreEntry A `DataStoreEntry`-instance if the entry was successfully created, `null` otherwise

public DataStoreEntry createEntry(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:String: the path of the entry
isDir:boolean: tells if the new entry shall be directory or a file

Returns:DataStoreEntry

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

deleteAll back to summary

deleteAll	back to summary
public boolean deleteAll(String iPath) Deletes the specified entry and all its children. Parameters iPath:String the root entry Returns:boolean `true` if the entry and all its children were deleted, `false` if the root doesn't exist.

public boolean deleteAll(String iPath)

Deletes the specified entry and all its children.

Parameters

iPath:String: the root entry

Returns:boolean

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

deleteEntry back to summary

deleteEntry	back to summary
public boolean deleteEntry(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:String path of the entry to delete Returns:boolean `true` if the entry was deleted, `false` otherwise.

public boolean deleteEntry(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:String: path of the entry to delete

Returns:boolean

true if the entry was deleted, false otherwise.

getDatabaseName	back to summary
public String getDatabaseName() Returns the database name, which is expected to equal the path of the service root. Returns:String The database name.

getDatabaseName

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public String getDatabaseName()

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

Returns:String: The database name.

getEntry back to summary

getEntry	back to summary
public DataStoreEntry getEntry(String iPath) Returns the entry with the specified path. Parameters iPath:String path of the entry to fetch Returns:DataStoreEntry `null` if the entry doesn't exist, the `DataStoreEntry`-object otherwise.

public DataStoreEntry getEntry(String iPath)

Returns the entry with the specified path.

Parameters

iPath:String: path of the entry to fetch

Returns:DataStoreEntry

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

getParentList	back to summary
private String[] getParentList(String path) Returns the list of parents for the specified path. The lowest level parent is listed first in the list, so all absolute paths will have the root listed as the last element. Parameters path:String the normalized path to create a parent list for Returns:String[] A list of parents.

getParentList

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private String[] getParentList(String path)

Returns the list of parents for the specified path.

The lowest level parent is listed first in the list, so all absolute paths will have the root listed as the last element.

Parameters

path:String: the normalized path to create a parent list for

Returns:String[]

A list of parents.

getTempFileCounter	back to summary
public long getTempFileCounter() Returns an identifier for a temporary file. Returns:long An integer uniquely identifying a temporary file.

getTempFileCounter

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public long getTempFileCounter()

Returns an identifier for a temporary file.

Returns:long: An integer uniquely identifying a temporary file.

listChildren	back to summary
public String[] listChildren(String iPath) Lists the childen of the specified path. Parameters iPath:String the directory to list the children of Returns:String[] An array with the relative paths of the children.

listChildren

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public String[] listChildren(String iPath)

Lists the childen of the specified path.

Parameters

iPath:String: the directory to list the children of

Returns:String[]

An array with the relative paths of the children.

move back to summary

move	back to summary
public boolean move(StorageFile currentFile, StorageFile newFile) Moves / renames a file. Parameters currentFile:StorageFile the current file newFile:StorageFile the new file Returns:boolean `true` if the file was moved, `false` if the new file already existed or the existing file doesn't exist.

public boolean move(StorageFile currentFile, StorageFile newFile)

Moves / renames a file.

Parameters

currentFile:StorageFile: the current file
newFile:StorageFile: the new file

Returns:boolean

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

purge	back to summary
public void purge() Purges the database and releases all files associated with it.

scheduledForDeletion back to summary

scheduledForDeletion	back to summary
public boolean scheduledForDeletion() Tells if this data store is scheduled for deletion. Returns:boolean `true` if the store is awaiting deletion, `false` otherwise.

public boolean scheduledForDeletion()

Tells if this data store is scheduled for deletion.

Returns:boolean: true if the store is awaiting deletion, false otherwise.

public final Class DataStore

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail