Interface IDrawableCache

Interface for caches that store pre-created drawable objects per (feature, style) combination. Different implementations can use different eviction strategies (e.g. strict iteration-based for regular layers, LRU for tile layers). Each entry is stamped with the iteration at which it was last used.

Inherited Members

IDisposable.Dispose()

Namespace: Mapsui.Rendering

Assembly: Mapsui.dll

Syntax

public interface IDrawableCache : IDisposable

Methods

Cleanup(long)

Evicts stale cache entries. The exact strategy depends on the implementation:

• DrawableCache: removes everything not stamped with currentIteration.
• TileDrawableCache: keeps a number of extra tiles and removes the oldest by iteration.

Declaration

void Cleanup(long currentIteration)

Parameters

Type	Name	Description
long	currentIteration

Clear()

Clears all cached entries and disposes them.

Declaration

void Clear()

Get(DrawableCacheKey, long)

Gets the drawable for a (feature, style) combination, or null if not cached. Stamps the entry with iteration so that Cleanup(long) knows the entry is still in use.

Declaration

IDrawable? Get(DrawableCacheKey key, long iteration)

Parameters

Type	Name	Description
DrawableCacheKey	key	The composite key of feature and style GenerationIds.
long	iteration	The current render iteration.

Returns

Type	Description
IDrawable

ReleaseReservation(DrawableCacheKey)

Releases a reservation previously acquired via TryReserve(DrawableCacheKey). Call this in a finally block after creation completes (success or failure).

Declaration

void ReleaseReservation(DrawableCacheKey key)

Parameters

Type	Name	Description
DrawableCacheKey	key	The composite key to release.

Set(DrawableCacheKey, IDrawable, long)

Stores a drawable for a (feature, style) combination. GenerationIds are immutable — each combination is only ever set once. If the entry already exists it is not replaced. The entry is stamped with iteration.

Declaration

void Set(DrawableCacheKey key, IDrawable drawable, long iteration)

Parameters

Type	Name	Description
DrawableCacheKey	key	The composite key of feature and style GenerationIds.
IDrawable	drawable	The drawable to cache.
long	iteration	The current render iteration.

TryReserve(DrawableCacheKey)

Attempts to reserve a key for creation. If the key is already reserved by another thread (creation in progress) or already exists in the cache, returns false. Use this before creating an expensive drawable to avoid duplicate work.

Declaration

bool TryReserve(DrawableCacheKey key)

Parameters

Type	Name	Description
DrawableCacheKey	key	The composite key of feature and style GenerationIds.

Returns

Type	Description
bool	True if the reservation was successful; false if already reserved or cached.

Extension Methods

DisposableExtension.DisposeIfDisposable(object?)