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https://issues.apache.org/jira/browse/PDFBOX-4883?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17135228#comment-17135228
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Alfred edited comment on PDFBOX-4883 at 6/14/20, 4:45 PM:
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I am not sure I understood the code correctly.
I think we are trying to keep COSFloat between +/-MIN_NORMAL and +/-MAX_VALUE
all the time.
At the same time, we have a COSFloat.doubleValue()
In PDFBox, .doubleValue() is used only in tests.
The Preflight project uses .doubleValue(), but only to compare it with
+/-32767f
A float is enough for that comparison, no need for a double.
Apart form that, doubleValue is not used anywhere.
Does PDF processing require more precision that we can get from a float?
was (Author: faltiska):
I am not sure I understood the code correctly.
I think we are trying to keep COSFloat between +/-MIN_NORMAL and +/-MAX_VALUE
all the time.
At the same time, we have a COSFloat.doubleValue
DoubleValue is used which is used only in tests in PDFBox.
The Preflight project uses doubleValue, but only to compare it with +/-32767f
A float is enough for that comparison, no need for a double.
Apart form that, doubleValue is not used anywhere.
Does PDF processing require more precision that we can get from a float?
> COSFloat is extremely slow
> --------------------------
>
> Key: PDFBOX-4883
> URL: https://issues.apache.org/jira/browse/PDFBOX-4883
> Project: PDFBox
> Issue Type: Bug
> Components: PDModel
> Affects Versions: 2.0.20, 3.0.0 PDFBox
> Reporter: Alfred
> Assignee: Andreas Lehmkühler
> Priority: Major
> Labels: display, optimization, parsing, textextraction
> Attachments: After.png, Before.png, PDFBOX-4883.patch
>
>
> I am testing text extraction from PDF and profiling the execution.
> I found that biggest time consumer is the COSFloat class.
>
> All other improvements I suggested so far are small compared to this.
> But this is the also the most complex one.
>
> I have attached te profiler output for the same text extraction, with and
> without the COSFloat changes.
> The time to extract the same text was 4 times long with the original COSFlow,
> because of its use of BigDecimal.
> I will try to write extra tests for all cases I see in the original COSFLoat
> code, if they are not already tested.
> Then I will submit for review a new COSFloat version.
>
> I think this affects parsing and displaying PDFs too, not just text
> extraction.
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