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https://issues.apache.org/jira/browse/PDFBOX-2301?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14138740#comment-14138740
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Andreas Lehmkühler commented on PDFBOX-2301:
--------------------------------------------
{quote}
Andreas Lehmkühler The NonSeqParser by design is an on-demand parser. Only
because other parts of PDFBOX require data already parsed it initializes/parses
all objects in the init procedure (see parseMinimalCatalog variable) as a work
around. So COSObject and its subclasses should only be a stub in the beginning
and if used (any method call) should trigger parsing the object by the parser
(NonSequentialPDFParser.parseObjectDynamically). Thus COSDocument needs to have
a reference to the parser.
{quote}
Maybe that was the origin intention, but the NonSequentialPDFParser doesn't
follow that idea (anymore). At the end of "parse" it iterates over all pages
and loads all needed data. More important seems to be the fact that the pdf is
closed at the end of "parse", so that "parseObjectDynamically" doesn't work
after the "parse" is finished. Even if it would work, the current idea is just
half the battle. We need to find a way to free resourcen after a page isn't
needed anymore.
IMO there is more than one issue to be solved
- the internal handling of compressed/uncompressed stream within COSStream
(there is already a FIXME for a long time)
- scratch file usage
- find a way to release resourcen during processing a pdf, e.g. after each page
- on demand parser feature
> RandomAccessBuffer consumes too much memory.
> --------------------------------------------
>
> Key: PDFBOX-2301
> URL: https://issues.apache.org/jira/browse/PDFBOX-2301
> Project: PDFBox
> Issue Type: Bug
> Components: PDModel
> Affects Versions: 1.8.6, 2.0.0
> Reporter: gee
> Assignee: Andreas Lehmkühler
> Fix For: 2.0.0
>
> Attachments: clone.diff, clone2.diff, clone3.diff
>
>
> RandomAccessBuffer holds uncompressed image during operation because it is
> what exactly pdfbox ExtractImages do.
> but holding uncompressed image instead of compressed one in memory consumes
> too much memory, not excluding many PDF XObjects that can use filter to
> compress itself. It would be good if pdfbox provides option that reverts to
> COSObject state just before the RandomAccess object created(the state that
> pdf XObject stream parsed and COSDictionary objects haven't created because
> user doesn't requested it using get____() method.) It is crucial feature so
> that pdfbox can analyze huge pdf file(>100MB).
> In current source, one must close COSStream unless required(and I know closed
> stream cannot reopened again.)
> Class Name
>
>
> |
> Shallow Heap | Retained Heap
> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> org.apache.pdfbox.cos.COSObject @ 0x5ad4940
>
>
> |
> 24 | 8,187,264
> |- <class> class org.apache.pdfbox.cos.COSObject @ 0x58c4020
>
>
> |
> 0 | 0
> |- generationNumber org.apache.pdfbox.cos.COSInteger @ 0x5ad0080
>
>
> |
> 24 | 24
> |- baseObject org.apache.pdfbox.cos.COSStream @ 0x5b25ea0
>
>
> |
> 32 | 8,187,216
> | |- <class> class org.apache.pdfbox.cos.COSStream @ 0x58c3e00
>
>
> |
> 8 | 8
> | |- items java.util.LinkedHashMap @ 0x5b2a0f0
>
>
> |
> 56 | 552
> | |- file org.apache.pdfbox.io.RandomAccessBuffer @ 0x5b2a128
>
>
> |
> 48 | 8,186,528
> | | |- <class> class org.apache.pdfbox.io.RandomAccessBuffer @ 0x5ad2b00
>
>
> |
> 8 | 8
> | | |- currentBuffer byte[16384] @ 0x590f360 16,400 | 16,400
> | | |- bufferList java.util.ArrayList @ 0x5b2e200
>
>
> |
> 24 | 8,170,080
> | | '- Total: 3 entries
>
>
> |
> |
> | |- filteredStream org.apache.pdfbox.io.RandomAccessFileOutputStream @
> 0x5b2a158
>
>
> | 32 | 32
> | |- decodeResult org.apache.pdfbox.filter.DecodeResult @ 0xa65f618
>
>
> |
> 16 | 16
> | |- unFilteredStream org.apache.pdfbox.io.RandomAccessFileOutputStream @
> 0xa71ab18
>
> |
> 32 | 32
> | '- Total: 6 entries
>
>
> |
> |
> |- objectNumber org.apache.pdfbox.cos.COSInteger @ 0x5b25ec0
>
>
> |
> 24 | 24
> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
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