com.sleepycat.je.utilint

Class FileStoreInfo

java.lang.Object

com.sleepycat.je.utilint.FileStoreInfo

public abstract class FileStoreInfo
extends Object

Provides information about the file store associated with a specific file. This class is a wrapper for the information made available by the java.nio.file.FileStore class introduced in Java 7, but using reflection to permit Java 6 to determine cleanly at runtime that file stores are not supported. TODO: We no longer support Java 6 so much of this mechanism can be removed. Other code can assume that a FileStore is always available. Also, if an IOException is thrown by FileStore methods, instead of tolerating this we should invalidate the Environment, since this is standard JE policy. However, we may want to leave the factory interface in place to support testing with arbitrary disk space limits.

Field Summary

Fields

Modifier and Type	Field and Description
static String	FILE_STORE_CLASS The full name of the Java 7 FileStore class, which must be present for this class to be supported.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FileStoreInfo() Support subclasses.

Method Summary

Modifier and Type	Method and Description
static void	checkSupported() Checks whether the current Java runtime supports providing information about file stores.
static FileStoreInfo	getInfo(String file) Returns a FileStoreInfo instance that provides information about the file store associated with the specified file.
abstract long	getTotalSpace() Returns the size, in bytes, of the file store.
abstract long	getUsableSpace() Returns the number of bytes available in the file store.
static void	setFactory(com.sleepycat.je.utilint.FileStoreInfo.Factory factory) For testing: specifies the factory, or null for the default.

Methods inherited from class java.lang.Object

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

Field Detail

FILE_STORE_CLASS

public static final String FILE_STORE_CLASS

The full name of the Java 7 FileStore class, which must be present for this class to be supported.

See Also:

Constant Field Values

Constructor Detail

FileStoreInfo

protected FileStoreInfo()

Support subclasses.

Method Detail

checkSupported

public static final void checkSupported()

Checks whether the current Java runtime supports providing information about file stores. Returns normally if called on a Java 7 runtime or later, otherwise throws UnsupportedOperationException.

Throws:

UnsupportedOperationException - if the current runtime does not support file stores

setFactory

public static void setFactory(com.sleepycat.je.utilint.FileStoreInfo.Factory factory)

For testing: specifies the factory, or null for the default.

getInfo

public static FileStoreInfo getInfo(String file)
                             throws IOException

Returns a FileStoreInfo instance that provides information about the file store associated with the specified file. Throws UnsupportedOperationException if called on a Java runtime prior to Java 7. Equal objects will be returned for all files associated with the same file store.

Parameters:

file - the file

Returns:

an instance of FileStoreInfo

Throws:

UnsupportedOperationException - if called on a Java runtime prior to Java 7

IllegalStateException - if an unexpected exception occurs when attempting to use reflection to access the underlying implementation

IOException - if an I/O error occurs

getTotalSpace

public abstract long getTotalSpace()
                            throws IOException

Returns the size, in bytes, of the file store.

Returns:

the size of the file store, in bytes

Throws:

IOException - if an I/O error occurs

getUsableSpace

public abstract long getUsableSpace()
                             throws IOException

Returns the number of bytes available in the file store.

Returns:

the number of bytes available

Throws:

IOException - if an I/O error occurs