org.entityfs.cap.compression.gzip
Class GZipCompressionCapabilityProvider

java.lang.Object
  org.entityfs.cap.compression.gzip.GZipCompressionCapabilityProvider

All Implemented Interfaces:

CapabilityProvider, CapabilityProviderImplementation

public class GZipCompressionCapabilityProvider
extends Object
implements CapabilityProviderImplementation

This capability provider provides the FSCCompression capability by compressing all file entities using the gzip compression algorithm.

It disables file system and entity capabilities that would allow clients to access the underlying files since those no longer contains data in the same format as the entities do.

This capability provider does not work with Zip file-based file systems (the Zip and Jar file systems) since they recognize gzip:ed entries as such, making them appear magically unzipped for the file system client.

Since:

1.0

Author:

Karl Gustafsson

See Also:

FSCCompression

In_jar:

entityfs-compression

Constructor Summary

GZipCompressionCapabilityProvider()

Method Summary

boolean	isReadOnlyFileSystemSupported()
boolean	isReadWriteFileSystemSupported()
AdapterFactory	proxyAdapterFactory(AdapterFactory af, LogAdapterHolder lah) This is called to let the capability provider proxy the file system's adapter factory before the file system is created.
FileSystemDelegate	proxyFileSystemDelegate(FileSystemDelegate fsd, SupportObjects so, boolean readOnly) This is used when creating the file system to let the capability provider proxy the file system delegate.
DirectoryDelegate	proxyRootDirectoryDelegate(FileSystemImplementation fs, FileSystemDelegate fsd, DirectoryDelegate dd, LogAdapterHolder lah) This is used when creating a file system to let the capability provider proxy the root directory delegate.

Methods inherited from class java.lang.Object

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

Constructor Detail

GZipCompressionCapabilityProvider

public GZipCompressionCapabilityProvider()

Method Detail

proxyAdapterFactory

public AdapterFactory proxyAdapterFactory(AdapterFactory af,
                                          LogAdapterHolder lah)

Description copied from interface: CapabilityProviderImplementation

This is called to let the capability provider proxy the file system's adapter factory before the file system is created.

Specified by:

proxyAdapterFactory in interface CapabilityProviderImplementation

Parameters:

af - The adapter factory.

lah - The (future) file system's log adapter holder.

Returns:

The (future) file system's adapter factory, possibly proxied. If the adapter factory should not be proxied, return the supplied factory, never return null.

proxyFileSystemDelegate

public FileSystemDelegate proxyFileSystemDelegate(FileSystemDelegate fsd,
                                                  SupportObjects so,
                                                  boolean readOnly)

Description copied from interface: CapabilityProviderImplementation

This is used when creating the file system to let the capability provider proxy the file system delegate.

This method can check that all capabilities that the capability provider require in order to work are present in the FileSystemDelegate to proxy. If not, the method throws an FileSystemConfigurationException.

When this method is called, no owning FileSystemImplementation is created yet, so a call to FileSystemDelegate.getOwner() will return null.

Specified by:

proxyFileSystemDelegate in interface CapabilityProviderImplementation

Parameters:

fsd - The file system delegate to proxy.

so - The file system's support objects. Maybe useful for implementations of this method, maybe not.

readOnly - Is the file system read only?

Returns:

A file system delegate. Either a proxy of fsd or fsd itself. Never null.

proxyRootDirectoryDelegate

public DirectoryDelegate proxyRootDirectoryDelegate(FileSystemImplementation fs,
                                                    FileSystemDelegate fsd,
                                                    DirectoryDelegate dd,
                                                    LogAdapterHolder lah)

Description copied from interface: CapabilityProviderImplementation

This is used when creating a file system to let the capability provider proxy the root directory delegate. Most capability providers do this.

Specified by:

proxyRootDirectoryDelegate in interface CapabilityProviderImplementation

Parameters:

fs - The file system object.

fsd - The file system delegate created by CapabilityProviderImplementation.proxyFileSystemDelegate(FileSystemDelegate, SupportObjects, boolean) .

dd - The root directory delegate.

Returns:

A directory delegate. Either a proxy of dd or dd itself. Never null.

isReadOnlyFileSystemSupported

public boolean isReadOnlyFileSystemSupported()

Specified by:

isReadOnlyFileSystemSupported in interface CapabilityProviderImplementation

Returns:

true, always.

isReadWriteFileSystemSupported

public boolean isReadWriteFileSystemSupported()

Specified by:

isReadWriteFileSystemSupported in interface CapabilityProviderImplementation

Returns:

true, always.