THotPDF.PrefetchLoadedPages Method

Warms the loaded-page raster cache asynchronously without holding the render-cache lock during display-list compilation or playback

Declaration

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

HPDFDoc

Name	Purpose
`PageRange`	One-based page range accepted by the standard page-range parser, or every loaded page when empty
`DPI`	Raster resolution used for every scheduled cache entry, with invalid values replaced by 150

This member does not return a value

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 tokenization, display-list construction, and renderer playback, while individual codec, filter, source-read, and operating-system calls remain atomic
Cache inspection and publication are serialized, but compilation and rasterization run outside the cache lock so background work does not monopolize foreground rendering
A foreground cached render may copy an existing immutable memory-cache bitmap while 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 while a prefetch request is active