de.schlichtherle.io.archive.spi
Class MultiplexedOutputArchive

java.lang.Object
  de.schlichtherle.io.archive.spi.MultiplexedOutputArchive

All Implemented Interfaces:

OutputArchive

Direct Known Subclasses:

OdfOutputArchive

public class MultiplexedOutputArchive
extends Object
implements OutputArchive

A decorator for output archives which allows to write an unlimited number of entries concurrently while actually only one entry is written at a time to the target output archive. If there is more than one entry to be written concurrently, the additional entries are actually written to temp files and copied to the target output archive upon a call to their OutputStream.close() method. Note that this implies that the close() method may fail with an IOException.

Since:

TrueZIP 6.5

Version:

$Id: MultiplexedOutputArchive.java 06f3ba684701 2010/11/04 01:15:55 christian $

Author:

Christian Schlichtherle

Nested Class Summary

private class	MultiplexedOutputArchive.EntryOutputStream This entry output stream writes directly to the target output archive.
private class	MultiplexedOutputArchive.TempEntriesEnumeration
private class	MultiplexedOutputArchive.TempEntryOutputStream This entry output stream writes the entry to a temporary file.

Field Summary

private OutputArchive	target The decorated output archive.
private boolean	targetBusy
(package private) static String	TEMP_FILE_PREFIX Prefix for temporary files created by the multiplexer.
private Map	temps The map of temporary archive entries which have not yet been written to the target output archive.

Constructor Summary

MultiplexedOutputArchive(OutputArchive target)
Constructs a new MultiplexedOutputArchive.

Method Summary

void	close() Closes this output archive and releases any system resources associated with it.
Enumeration	getArchiveEntries() Returns an enumeration of the ArchiveEntry instances in this archive (i.e. written so far).
ArchiveEntry	getArchiveEntry(String entryName) Returns the ArchiveEntry for the given entry name or null if no entry with this name has been written or started to be written.
OutputArchiveMetaData	getMetaData() Returns the meta data for this input archive.
int	getNumArchiveEntries() Returns the number of ArchiveEntry instances in this archive.
OutputStream	getOutputStream(ArchiveEntry entry, ArchiveEntry srcEntry) Returns a new OutputStream for writing the contents of the given archive entry.
boolean	isTargetBusy() Returns whether the target output archive is busy writing an archive entry or not.
void	setMetaData(OutputArchiveMetaData metaData) Sets the meta data for this input archive.
private void	setSize(ArchiveEntry entry, long size)
void	storeDirectory(ArchiveEntry entry) Deprecated. This method will be removed in the next major version number release and should be implemented as getOutputStream(entry, null).close().
private void	storeTempEntries()

Methods inherited from class java.lang.Object

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

Field Detail

TEMP_FILE_PREFIX

static final String TEMP_FILE_PREFIX

Prefix for temporary files created by the multiplexer.

See Also:

Constant Field Values

target

private final OutputArchive target

The decorated output archive.

temps

private final Map temps

The map of temporary archive entries which have not yet been written to the target output archive. Maps from entry names [String] to temporary entry output streams [MultiplexedOutputArchive.TempEntryOutputStream].

targetBusy

private boolean targetBusy

See Also:

isTargetBusy()

Constructor Detail

MultiplexedOutputArchive

public MultiplexedOutputArchive(OutputArchive target)

Constructs a new MultiplexedOutputArchive.

Parameters:

target - The decorated output archive.

Throws:

NullPointerException - Iff target is null.

Method Detail

getNumArchiveEntries

public int getNumArchiveEntries()

Description copied from interface: OutputArchive

Returns the number of ArchiveEntry instances in this archive.

This method may be called before the archive is closed and must also reflect entries which have not yet been closed.

Specified by:

getNumArchiveEntries in interface OutputArchive

getArchiveEntries

public Enumeration getArchiveEntries()

Description copied from interface: OutputArchive

Returns an enumeration of the ArchiveEntry instances in this archive (i.e. written so far).

This method may be called before the archive is closed and must also reflect entries which have not yet been closed.

Specified by:

getArchiveEntries in interface OutputArchive

getArchiveEntry

public ArchiveEntry getArchiveEntry(String entryName)

Description copied from interface: OutputArchive

Returns the ArchiveEntry for the given entry name or null if no entry with this name has been written or started to be written.

This method may be called before the archive is closed and must also reflect entries which have not yet been closed.

Specified by:

getArchiveEntry in interface OutputArchive

Parameters:

entryName - A valid archive entry name - never null.

See Also:

Requirements for Archive Entry Names

getOutputStream

public OutputStream getOutputStream(ArchiveEntry entry,
                                    ArchiveEntry srcEntry)
                             throws IOException

Description copied from interface: OutputArchive

Returns a new OutputStream for writing the contents of the given archive entry.

The returned stream should preferrably be unbuffered, as buffering is usually done in higher layers (all copy routines in TrueZIP do this and most client applications do it, too). Buffering twice does not increase, but decrease performance.

Note that the stream is guaranteed to be closed before the OutputArchive.close() method of this archive is called!

Specified by:

getOutputStream in interface OutputArchive

Parameters:

entry - A valid reference to an archive entry. The runtime class of this entry is the same as the runtime class of the entries returned by ArchiveDriver.createArchiveEntry(de.schlichtherle.io.archive.Archive, java.lang.String, de.schlichtherle.io.archive.spi.ArchiveEntry).

srcEntry - If not null, this identifies the entry from which TrueZIP is actually copying data from and should be used to implement the Direct Data Copying (DDC) feature. Note that there is no guarantee on the runtime type of this object; it may have been created by other drivers. Furthermore, this not exclusively used for archive copies, so you should not simply copy all properties of the source entry to the entry (see ArchiveDriver.createArchiveEntry(Archive, String, ArchiveEntry) for comparison).

For example, the ZIP driver family uses this to copy the already deflated data if the source entry is another ZIP file entry. As another example, the TarDriver uses this to determine the size of the input file, thereby removing the need to create (yet another) temporary file.

Returns:

A (preferrably unbuffered) OutputStream to write the archive entry data to. null is not allowed!

Throws:

OutputArchiveBusyException - If the archive is currently busy on output for another entry. This exception is guaranteed to be recoverable, meaning it should be possible to write the same entry again as soon as the archive is not busy on output anymore.

FileNotFoundException - If the archive entry is not accessible for some reason.

IOException - On any other exceptional condition.

isTargetBusy

public boolean isTargetBusy()

Returns whether the target output archive is busy writing an archive entry or not.

setSize

private void setSize(ArchiveEntry entry,
                     long size)

storeTempEntries

private void storeTempEntries()
                       throws IOException

Throws:

IOException

storeDirectory

public final void storeDirectory(ArchiveEntry entry)
                          throws IOException

Deprecated. This method will be removed in the next major version number release and should be implemented as getOutputStream(entry, null).close().

Description copied from interface: OutputArchive

Writes the given entry as a directory enry.

Specified by:

storeDirectory in interface OutputArchive

Parameters:

entry - The archive entry to write. This is never null and safe to be casted to the archive entry type actually created by the ArchiveDriver.createArchiveEntry(de.schlichtherle.io.archive.Archive, java.lang.String, de.schlichtherle.io.archive.spi.ArchiveEntry) method.

Throws:

IOException - On any exceptional condition.

close

public void close()
           throws IOException

Description copied from interface: OutputArchive

Closes this output archive and releases any system resources associated with it.

Specified by:

close in interface OutputArchive

Throws:

IOException - On any I/O related issue.

getMetaData

public OutputArchiveMetaData getMetaData()

Description copied from interface: OutputArchive

Returns the meta data for this input archive. The default value is null.

Specified by:

getMetaData in interface OutputArchive

setMetaData

public void setMetaData(OutputArchiveMetaData metaData)

Description copied from interface: OutputArchive

Sets the meta data for this input archive.

Specified by:

setMetaData in interface OutputArchive

Parameters:

metaData - The meta data - may not be null.