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https://issues.apache.org/jira/browse/PDFBOX-2301?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14129954#comment-14129954
 ] 

Timo Boehme commented on PDFBOX-2301:
-------------------------------------

I'm also interested in fixing the RandomAccess buffer issue since the cloning 
work-around seems a bit problematic to me too. I did try to understand the 
issue for this workaround an came to following conclusions:
# problem is closing the buffer stream when closing a document but COS objects 
should be used somewhere else, needing access to the buffered data
# the work-around is implemented for COSStream objects only and clones buffer 
in case it is RandomAccessBuffer; in case of RandomAccessFile this is not done 
thus here the problem from point 1 still persists (?)
# since only COSStream will access the data it writes into buffer, why not 
simply create a new buffer object instead of cloning? At least this will not 
duplicate data already in buffer but not used by the stream. The buffer will be 
garbage collected when there is no reference to the COSStream or to any input 
stream created on the buffer

WDYT?

> RandomAccessBuffer consumes too much memory.
> --------------------------------------------
>
>                 Key: PDFBOX-2301
>                 URL: https://issues.apache.org/jira/browse/PDFBOX-2301
>             Project: PDFBox
>          Issue Type: Bug
>          Components: PDModel
>            Reporter: gee
>         Attachments: clone.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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