cache

Overview ¶

Package cache provides caching mechanisms for rendered sprites and images.

The cache package implements an LRU (Least Recently Used) cache for Ebiten images, specifically designed for caching procedurally generated sprites, animation frames, and composite images. This reduces redundant generation and improves performance.

Phase 44 enhancements:

• Support for 64x64 sprites (16KB each)
• MemoryMonitor for automatic cleanup (<300MB limit)
• PreGenerator for batch sprite pre-generation
• Enhanced statistics and monitoring

Key features:

• LRU eviction policy to manage memory usage
• Size-based limits (configurable max cache size in bytes)
• Thread-safe operations with fine-grained locking
• Cache hit/miss statistics for monitoring
• Memory monitoring with soft/hard limits
• Batch pre-generation for cache warming

Basic Usage:

cache := cache.NewSpriteCache(300 * 1024 * 1024) // 300MB limit
key := cache.GenerateKey(seed, "idle", 0)

// Try to get from cache
if img, ok := cache.Get(key); ok {
    return img // Cache hit
}

// Generate and store in cache
img := generateSprite(seed, "idle", 0)
cache.Put(key, img)

// Check statistics
stats := cache.Stats()
fmt.Printf("Hit rate: %.2f%%\n", stats.HitRate()*100)

Memory Monitoring (Phase 44):

monitor := cache.NewMemoryMonitor(cache)
monitor.SetLimits(250*1024*1024, 300*1024*1024) // 250MB soft, 300MB hard
monitor.Start()
defer monitor.Stop()

// Check health
if monitor.IsHealthy() {
    fmt.Printf("Cache usage: %.1f%%\n", monitor.UsagePercentage())
}

Pre-Generation (Phase 44):

pregen := cache.NewPreGenerator(cache)

// Queue sprites for pre-generation
for i := 0; i < 100; i++ {
    key := cache.GenerateKey(int64(i), "idle", 0)
    pregen.Queue(key, func() (*ebiten.Image, error) {
        return generateSprite(i), nil
    })
}

// Generate in batch
count := pregen.Generate()
fmt.Printf("Pre-generated %d sprites\n", count)