Class UnityAchievementScreenshotLoader

Reads a stored unlock screenshot back as a UnityEngine.Sprite the achievements view can show, and owns the textures it created until they are released.

Inheritance

object

UnityAchievementScreenshotLoader

Inherited Members

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

Namespace: Serenity.Achievements.Infrastructure.Services

Assembly: Serenity.UnityAchievements.Infrastructure.dll

Syntax

public class UnityAchievementScreenshotLoader

Remarks

Keyed by the screenshot key the unlock record carries rather than by achievement id: the key is what the record actually stores, it stays right when the signed-in player changes, and it is the only thing the blob store can be addressed by. Every key is checked against AchievementScreenshotKey first — it comes out of persisted data, and a view that renders whatever a save file names is a view that reads arbitrary files.

Every load is cached, misses and undecodable bytes included — a record whose blob is gone must not re-hit the disk once per list rebuild — and concurrent requests for one key share a single read. The cache is capped at MaximumCachedSprites and evicts the oldest entry, because a project with hundreds of achievements would otherwise hold every full-size thumbnail texture it ever showed for the rest of the session.

The shared read runs on None on purpose. One caller's token must not cancel a read every other caller is awaiting, and the read is a bounded blob fetch whose result is cached — so the worst a caller that walked away costs is one decoded sprite that the eviction policy will reclaim.

Sprites and their textures are created here, so nothing else may destroy them: call Release() when the view that showed them goes away. Main thread only, and unsynchronized because of it: everything it produces is a UnityEngine.Object, which may only be created there anyway.

Constructors

UnityAchievementScreenshotLoader(BlobAchievementScreenshotStore, ILogService)

Initializes a new instance of the UnityAchievementScreenshotLoader class.

Declaration

public UnityAchievementScreenshotLoader(BlobAchievementScreenshotStore screenshotStore, ILogService logService = null)

Parameters

Type	Name	Description
BlobAchievementScreenshotStore	screenshotStore	The store the bytes are read from.
ILogService	logService	Service used to report a refused key or bytes that would not decode. May be null.

Exceptions

Type	Condition
ArgumentNullException	Thrown when screenshotStore is null.

Fields

MaximumCachedSprites

How many decoded screenshots are held before the oldest is destroyed.

Declaration

public const int MaximumCachedSprites = 128

Field Value

Type	Description
int

Properties

CachedSpriteCount

How many decoded screenshots the loader is currently holding.

Declaration

public int CachedSpriteCount { get; }

Property Value

Type	Description
int

Methods

LoadAsync(string, CancellationToken)

Loads the screenshot stored under a key, or hands back null when there is none to show.

Declaration

public Task<Sprite> LoadAsync(string screenshotKey, CancellationToken cancellationToken)

Parameters

Type	Name	Description
string	screenshotKey	The key the unlock record carries.
CancellationToken	cancellationToken	Token checked before the read starts; the shared read itself is not bound to it.

Returns

Type	Description
Task<Sprite>	The sprite to show, or null when the key is not ours, nothing was stored, or the bytes would not decode.

Release()

Destroys every sprite and texture this loader created and forgets what it read.

Declaration

public void Release()

Remarks

Also the way to react to the signed-in player changing: the keys of the previous player mean nothing to the new one, and their textures are the loader's to free.

TryGetLoaded(string, out Sprite)

Hands back an already-loaded screenshot without touching the store, so a view can draw a row synchronously and only start a load for the rows it has never shown.

Declaration

public bool TryGetLoaded(string screenshotKey, out Sprite sprite)

Parameters

Type	Name	Description
string	screenshotKey	The key the unlock record carries.
Sprite	sprite	The loaded sprite, or null when the key is known to have no readable screenshot.

Returns

Type	Description
bool	True when this key has already been loaded, successfully or not.