kitepdf-core/io.github.yuroyami.kitepdf.core.render/KiteBitmapCache

KiteBitmapCache

class KiteBitmapCache<T : Any>(budgetBytes: Long = DEFAULT_BUDGET_BYTES)(source)

Platform bitmaps that a canvas built from images, so that an image drawn many times on a page, such as a tiled background or a row of icons, converts once (#117). A viewer can keep one cache across draws without retaining decoded source images (#371).

A bitmap is kept for one image identity and one KiteImageSampling: the same image drawn at another size needs another bitmap. The cache holds at most budgetBytes of bitmaps and drops the bitmap used least recently first. A bitmap larger than the whole budget is not kept. A nonpositive budget disables retention. Entries retain only opaque identities and bitmaps, never source image buffers. Map operations are synchronized; conversions and size callbacks run outside the lock.

Constructors

KiteBitmapCache

constructor(budgetBytes: Long = DEFAULT_BUDGET_BYTES)

Types

Companion

object Companion

Properties

heldBytes

val heldBytes: Long

The bytes of the bitmaps that the cache holds.

Functions

clear

fun clear()

Releases every retained bitmap. A conversion already running may return its bitmap, but cannot repopulate this cleared generation. This does not recycle native resources: a recorded page or another caller may still be drawing a returned bitmap.

getOrPut

fun getOrPut(image: KiteImageData, sampling: KiteImageSampling, sizeOf: (T) -> Long, build: () -> T?): T?

The bitmap for image drawn with sampling. On a miss, build makes it and sizeOf gives its size in bytes. Returns null when build does. A nonpositive size is not retained. Concurrent misses may build twice; the first retained result wins and both callers receive it. No callback runs while the cache lock is held.