THotPDF.PrefetchLoadedPages Method

Provides prefetch loaded pages behaviour for the document creation workflow. Use it when the surrounding API family needs explicit control over PDF objects, page content, resources, conformance, or diagnostics

Declaration

procedure PrefetchLoadedPages(const PageRange: string= ''; DPI: Integer= 150);

Unit

HPDFDoc

Parameters

Return value

This member returns no value

Usage notes

• Starting a new request cooperatively cancels and joins the previous request before scheduling the new page set
• Foreground calls to RenderLoadedPageToBitmap, RenderLoadedPageToBitmapCached, and GetLoadedCachedRenderedBitmap preempt active prefetch work before rendering
• Cancellation checkpoints run through content tokenisation, display-list construction, and renderer playback, while individual codec, filter, source-read, and operating-system calls remain atomic
• Cache inspection and publication are serialised, but compilation and rasterisation run outside the cache lock so background work does not monopolise foreground rendering
• A foreground cached render may copy an existing immutable memory-cache bitmap whilst cancellation completes; it acquires the normal memory reservation before copying and waits for logical worker completion before returning
• A foreground cache miss waits for worker completion before new document work; explicit cancellation, replacement, reload and destruction still join and release retained worker threads
• Do not modify or reload the document whilst a prefetch request is active

Related APIs

• THotPDFCancelLoadedPagePrefetch
• THPDFPageGetLoadedPagePrefetchInfo
• THPDFLoadedPagePrefetchInfo
• Contents