PXCV_ReleaseCachedData

[jeffp]

I'm opening a large PDF and using DrawPageToDC on each page. I want to make sure that after drawing each page I clear as much overhead memory as possible. Here's what I'm currently doing.


hr := PXCV_DrawPageToDC(FDocID, APage - 1, B.Canvas.Handle, @AParams);

PXCV_ReleasePageCachedData(FDocID, APage - 1, pxvrcd_ReleaseDocumentImages);
PXCV_ReleaseCachedData(FDocID, pxvrcd_ReleaseDocumentImages);
PXCV_ReleaseCachedData(FDocID, pxvrcd_ReleaseDocumentFonts);

QUESTION: I'm not sure I follow completely what PXCV_ReleasePageCachedData and PXCV_ReleaseCachedData do. As such, can you tell me how I should call these two functions to ensure removing as much overhead as possible that comes from calling PXCV_DrawPageToDC.

Thanks.

[Ivan - Tracker Software]

PXCV_ReleaseCachedData releases memory used by parsed pages' contents, fonts and images. PXCV_ReleasePageCachedData does the same, but just for resources used by the specified page. You can use just one call to release as much memory as it is possible:

Code: Select all

PXCV_ReleaseCachedData(FDocID, pxvrcd_ReleaseDocumentImages + pxvrcd_ReleaseDocumentFonts);

Also you can add pxvrcd_ReleaseGlobalFonts flag, which will release memory used by system fonts used for rendering the PDF page.

[jeffp]

Perfect. I'll use all three flags.

[Tracker Supp-Stefan]

[Vasyl-Tracker Dev Team]

Hi jeffp.

Good solution for your case:

Code: Select all

for (int i = 0; i < pagesCount; ++)
{
     PXCV_DrawPageToDC(docID, i, hDC, pParams);
     PXCV_ReleasePageCachedData(docID, i, pxvrcd_ReleaseDocumentImages);
     if ((i % 20) == 0) // release document's fonts after each 20 pages (one font can be used on more pages, releasing document's fonts after drawing of each page - not effective solution)
     {
          PXCV_ReleaseCachedData(docID, pxvrcd_ReleaseDocumentFonts);
     }
}

PXCV_ReleaseCachedData(docID, pxvrcd_ReleaseDocumentImages | pxvrcd_ReleaseDocumentFonts);

HTH