Mike - can we please reserve this thread for a technical discussion of the merits of the proposal?
I'd be happy to have a conversation in a separate thread regarding how iText works. - K Mike Marchywka-2 wrote: > > > > > > > > > > > > > ---------------------------------------- >> Date: Sun, 25 Apr 2010 22:14:02 -0700 >> From: forum_...@trumpetinc.com >> To: itext-questions@lists.sourceforge.net >> Subject: Re: [iText-questions] Performance when flattening form fields >> >> >> After more digging, I'm wondering if the place to do this wouldn't be in >> the >> PdfCopy.PageStamp class? It seems like PageStamp.alterContents() could do >> the same flattening operation that PdfStamper does. >> >> The ideal would be to factor out the behavior so the code isn't >> duplicated >> in both PdfCopy and PdfStamper... > > I guess I have the larger question of exactly what parsing is? > That is, it seem generally you use itext to 1) read in somthing, often > an existing pdf, 2) do some stuff, then 3) write out a pdf. Presumably > as you go through step 2, you are assembling or compiling a bunch > of structures that allow you to do step 3 but are more optimized > for manipulation and editing the nascent PDF. > If I understand your earlier comments, you apparently don't actually > have a generic PDF parser to do step 1 that works with all sequences > you could put into step 2. Now, of course, more generally the > above approach doesn't scale as you would always hope to stream > to some extent- read what you need, write what you can etc. > However, that could probably be hidden somewhat into the implementation > for classes for each step. > So, instead of things like PdfCoolFeature.doSomething(byte[] pdffile) > you have PdfCoolFeadture.doSomething( ParsedPdfOperand pdflikething) > where the second signature take a parameter that is generally > optimized for a broad class of common operations. > >> >> Does anyone see any technical issues with this as a strategy? >> >> - K >> >> >> 'Kevin Day' wrote: >>> >>> >>> >>> >>> >>> >>> >>> >>> I've been doing some digging into the performance question that Giovanni >>> Azua has posted about. >>> >>> Some of his findings (using StringBuilder, etc...) are solid >>> improvements >>> to overall iText performance - however, the crux of the performance >>> difference he is seeing between iText and the competing solution is not >>> low level. It's a high level issue. >>> >>> Here's what's going on: >>> >>> His specific use case involves stamping headers and footers onto >>> pages. The footer contains AcroFields that must be flattened prior >>> to stamping. >>> >>> The performance hit is coming from the fact that, in order to flatten >>> and >>> apply the footer, he is having to: >>> >>> 1. Construct a PDF using PdfStamper >>> 2. Write output to a byte array output stream >>> 3. Re-parse the BAOS into a PdfReader >>> 4. Import the page from the reader for use as a stamp >>> >>> While this is functional, it is certainly not performant. >>> >>> A much, much faster technique would be to do the flattening to the >>> *reader*, then just import the page to the output writer. This >>> avoids the awkward creation of the temporary PdfReader. >>> >>> >>> So, the performance delta is not caused so much by iText's low level >>> implementation (although the performance improvements that Giovanni has >>> suggested will help to make iText even faster than it already is) - the >>> delta is really caused by an awkward operation forced on the user by the >>> framework. >>> >>> >>> So, are there any fundamental reasons to not do flattening, etc... to >>> the >>> PdfReader? My first look at the code indicates that it may be >>> possible to factor this out of PdfStamper (basically, instead of >>> adjusting >>> the AcroFields dictionary and content streams in the >>> PdfStamper/PdfCopy/etc... output, we'd make those adjustments to the >>> PdfReader). >>> >>> I'm thinking of something along the lines of: >>> >>> PdfFormFlattener(PdfReader).flatten(pageNumber) >>> >>> Maybe with supplemental methods for flattenNamedFields(pageNumber), >>> flattenFieldsOfType(pageNumber) >>> >>> Thoughts? >>> >>> - K >>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> >>> _______________________________________________ >>> iText-questions mailing list >>> iText-questions@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/itext-questions >>> >>> Buy the iText book: http://www.itextpdf.com/book/ >>> Check the site with examples before you ask questions: >>> http://www.1t3xt.info/examples/ >>> You can also search the keywords list: >>> http://1t3xt.info/tutorials/keywords/ >>> >> >> -- >> View this message in context: >> http://old.nabble.com/Performance-when-flattening-form-fields-tp28357673p28360908.html >> Sent from the iText - General mailing list archive at Nabble.com. >> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> iText-questions mailing list >> iText-questions@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/itext-questions >> >> Buy the iText book: http://www.itextpdf.com/book/ >> Check the site with examples before you ask questions: >> http://www.1t3xt.info/examples/ >> You can also search the keywords list: >> http://1t3xt.info/tutorials/keywords/ >> > _________________________________________________________________ > The New Busy is not the old busy. Search, chat and e-mail from your inbox. > http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_3 > ------------------------------------------------------------------------------ > _______________________________________________ > iText-questions mailing list > iText-questions@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/itext-questions > > Buy the iText book: http://www.itextpdf.com/book/ > Check the site with examples before you ask questions: > http://www.1t3xt.info/examples/ > You can also search the keywords list: > http://1t3xt.info/tutorials/keywords/ > > -- View this message in context: http://old.nabble.com/Performance-when-flattening-form-fields-tp28357673p28364718.html Sent from the iText - General mailing list archive at Nabble.com. ------------------------------------------------------------------------------ _______________________________________________ iText-questions mailing list iText-questions@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/itext-questions Buy the iText book: http://www.itextpdf.com/book/ Check the site with examples before you ask questions: http://www.1t3xt.info/examples/ You can also search the keywords list: http://1t3xt.info/tutorials/keywords/
