Module org.sejda.sambox

Package org.sejda.sambox.input

Class LazyIndirectObjectsProvider

java.lang.Object

org.sejda.sambox.input.LazyIndirectObjectsProvider

All Implemented Interfaces:

Closeable, AutoCloseable, IndirectObjectsProvider

class LazyIndirectObjectsProvider
extends Object
implements IndirectObjectsProvider

A lazy implementation of the IndirectObjectsProvider that retrieves COSBase objects parsing the underlying source on demand (ie. when the IndirectObjectsProvider.get(COSObjectKey) method is called). Parsed objects are stored in a cache to be reused. If for given a COSObjectKey no entry is found in the xref, a fallback mechanism is activated performing a full scan of the document to retrieve all the objects defined in it.

Field Summary

Fields

Modifier and Type	Field	Description
private final Set<COSObjectKey>	currentlyParsing
private static final org.slf4j.Logger	LOG
private COSParser	parser
private ObjectsFullScanner	scanner
private SecurityHandler	securityHandler
private final Map<COSObjectKey,COSBase>	store
private final Xref	xref

Constructor Summary

Constructors

Constructor	Description
LazyIndirectObjectsProvider()

Method Summary

Modifier and Type	Method	Description
XrefEntry	addEntry(XrefEntry entry)	Adds the given xref entry to the Xref
XrefEntry	addEntryIfAbsent(XrefEntry entry)	Adds the given xref entry to the Xref if absent
void	close()
private void	doParse(XrefEntry xrefEntry)
private void	doParseFallbackObject(COSObjectKey key)
COSBase	get(COSObjectKey key)
COSObjectKey	highestKey()
String	id()
LazyIndirectObjectsProvider	initializeWith(COSParser parser)	Initialize the component with the COSParser to use to retrieve and parse requested object
LazyIndirectObjectsProvider	initializeWith(SecurityHandler handler)	Initialize the component with the SecurityHandler to decrypt streams and strings.
private boolean	isIndirectContainedIn(COSBase item, XrefEntry containingStreamEntry)
private void	parseCompressedEntry(XrefEntry xrefEntry)
private void	parseInUseEntry(XrefEntry xrefEntry)
private void	parseObject(COSObjectKey key)
private void	parseObjectStream(XrefEntry containingStreamEntry, COSStream stream)
void	release(COSObjectKey key)	Signals that the object corresponding to the given key is no longer needed and can be released

Methods inherited from class java.lang.Object

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

Field Details

LOG

private static final org.slf4j.Logger LOG

xref

private final Xref xref

scanner

private ObjectsFullScanner scanner

store

private final Map<COSObjectKey,COSBase> store

currentlyParsing

private final Set<COSObjectKey> currentlyParsing

securityHandler

private SecurityHandler securityHandler

parser

private COSParser parser

Constructor Details

LazyIndirectObjectsProvider

LazyIndirectObjectsProvider()

Method Details

get

public COSBase get(COSObjectKey key)

Specified by:

get in interface IndirectObjectsProvider

Returns:

the COSBase corresponding to the given key.

release

public void release(COSObjectKey key)

Description copied from interface: IndirectObjectsProvider

Signals that the object corresponding to the given key is no longer needed and can be released

Specified by:

release in interface IndirectObjectsProvider

addEntryIfAbsent

public XrefEntry addEntryIfAbsent(XrefEntry entry)

Description copied from interface: IndirectObjectsProvider

Adds the given xref entry to the Xref if absent

Specified by:

addEntryIfAbsent in interface IndirectObjectsProvider

Returns:

null if the entry was added. The current entry with the given object number and generation if the entry was already present.

See Also:

• Xref.addIfAbsent(XrefEntry)

addEntry

public XrefEntry addEntry(XrefEntry entry)

Description copied from interface: IndirectObjectsProvider

Adds the given xref entry to the Xref

Specified by:

addEntry in interface IndirectObjectsProvider

Returns:

the previous value or null if no entry was previously associated to the given object number and generation.

See Also:

• Xref.add(XrefEntry)

highestKey

public COSObjectKey highestKey()

Specified by:

highestKey in interface IndirectObjectsProvider

Returns:

the highest key (object number + generation number) for this provider.

initializeWith

public LazyIndirectObjectsProvider initializeWith(COSParser parser)

Description copied from interface: IndirectObjectsProvider

Initialize the component with the COSParser to use to retrieve and parse requested object

Specified by:

initializeWith in interface IndirectObjectsProvider

Returns:

this provider

initializeWith

public LazyIndirectObjectsProvider initializeWith(SecurityHandler handler)

Description copied from interface: IndirectObjectsProvider

Initialize the component with the SecurityHandler to decrypt streams and strings.

Specified by:

initializeWith in interface IndirectObjectsProvider

Returns:

this provider

parseObject

private void parseObject(COSObjectKey key)

doParseFallbackObject

private void doParseFallbackObject(COSObjectKey key)

doParse

private void doParse(XrefEntry xrefEntry)
              throws IOException

Throws:

IOException

parseInUseEntry

private void parseInUseEntry(XrefEntry xrefEntry)
                      throws IOException

Throws:

IOException

parseCompressedEntry

private void parseCompressedEntry(XrefEntry xrefEntry)
                           throws IOException

Throws:

IOException

parseObjectStream

private void parseObjectStream(XrefEntry containingStreamEntry,
 COSStream stream)
                        throws IOException

Throws:

IOException

isIndirectContainedIn

private boolean isIndirectContainedIn(COSBase item,
 XrefEntry containingStreamEntry)

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

id

public String id()

Specified by:

id in interface IndirectObjectsProvider

Returns:

the unique id for the provider.