[ 
https://issues.apache.org/jira/browse/FOP-2211?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13581324#comment-13581324
 ] 

Chris Bowditch commented on FOP-2211:
-------------------------------------

Hi Alex,

I agree that Print Streams can get very large and holding them in memory is not 
a good idea. Actually for cloud environments we don't plan to hold such files 
in memory, but rather in a virtual file system, one that is ring fenced for 
each tenant. Unlike a file system, where every tenant can see the files for 
every other tenant on the system, the virtual file system protects against 
this. The virtual file system is typically implemented using a Database. 
Hopefully this helps clarifies our intentions from a requirements perspective. 
I cannot comment on the lower level details.

Thanks,

Chris
                
> [PATCH] Fix & improve the handling of temporary files using the new URI 
> resource resolvers
> ------------------------------------------------------------------------------------------
>
>                 Key: FOP-2211
>                 URL: https://issues.apache.org/jira/browse/FOP-2211
>             Project: Fop
>          Issue Type: Bug
>          Components: general
>    Affects Versions: trunk
>            Reporter: Alexios Giotis
>             Fix For: trunk
>
>         Attachments: fop.patch, xgc.patch
>
>
> As written in http://markmail.org/message/zelumstxxsdyvkcz , after the merge 
> of the Temp_URI_Resolution branch (Sept 2012), the actual pattern of using 
> temp files has changed from:
> {code}
> File tmpFile = File.createTempFile(....);
> // Write and read from the file
> tmpFile.delete();
> {code}
> to:
> {code}
> File tmpFile = new File(System.getProperty("java.io.tmpdir"), 
> counterStartingFrom1AsString);
> tmpFile.deleteOnExit();
> // Write and read from the file
> {code}
> This is fine when FOP is executed from the command line (which I guess this 
> is how most people use it) but it introduces a number of bad side effects for 
> long running processes that use FOP embedded.
>  
> 1. Different FOP processes can't be executed in parallel on the same system 
> because creating the same temp file fails.
> 2. If the JVM is not normally terminated, the temp files are never deleted 
> and the next invocation of the JVM fails to run.
> 3. deleteOnExit() keeps for the life of the JVM an unknown number of temp 
> files both on disk and a reference in memory.
> There should not be a need to implement a custom resource resolver when using 
> FOP embedded in order to fix those issues. The default implementation should 
> work at least as good as it worked in FOP 1.1 or earlier. 
> Attached are 2 patches, one for XGC and one for FOP that should fix and 
> improve the handling of at least the temporary files.
> For reference, [1] lists some reasons for implementing the new URI resource 
> resolvers.
> [1] http://wiki.apache.org/xmlgraphics-fop/URIResolution

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to