Method loadOverlayImage

processor/vipsprocessor/overlay.go:17–68

loadOverlayImage loads a watermark overlay image using the image cache. Cache key is image path only. Size must be known (w > 0 && h > 0) to use the cache; unknown size or size exceeding cache max dims bypasses the cache.

(
	ctx context.Context, load imagor.LoadFunc,
	url string, w, h, n int, size vips.Size,
)

// Cache key is image path only. Size must be known (w > 0 && h > 0) to use the cache;
// unknown size or size exceeding cache max dims bypasses the cache.
func (v *Processor) loadOverlayImage(
	ctx context.Context, load imagor.LoadFunc,
	url string, w, h, n int, size vips.Size,
) (*vips.Image, error) {
	sizeKnown := w > 0 && h > 0

	// Unknown size or cache disabled: load directly.
	if !sizeKnown || v.cache == nil {
		blob, err := load(url)
		if err != nil {
			return nil, err
		}
		if sizeKnown {
			return v.NewThumbnail(ctx, blob, w, h, vips.InterestingNone, size, n, 1, 0)
		}
		return v.NewThumbnail(ctx, blob, v.MaxWidth, v.MaxHeight, vips.InterestingNone, vips.SizeDown, n, 1, 0)
	}

	// Size exceeds cache max dims — bypass cache, load directly at requested size.
	if w > v.CacheMaxWidth || h > v.CacheMaxHeight {
		blob, err := load(url)
		if err != nil {
			return nil, err
		}
		return v.NewThumbnail(ctx, blob, w, h, vips.InterestingNone, size, n, 1, 0)
	}

	// Cache hit — serve from cached memory blob without loading.
	if memBlob, ok := v.cache.Get(url); ok {
		return v.NewThumbnail(ctx, memBlob, w, h, vips.InterestingNone, size, 1, 1, 0)
	}

	// Cache miss: fetch and decode inside the singleflight to deduplicate concurrent
	// network requests. load is passed so loadOrCache can call it inside the singleflight.
	memBlob, origBlob, err := v.loadOrCache(nil, url, n, load)
	if err != nil {
		return nil, err
	}

	// Animated source — origBlob is set; fall back to direct thumbnail at w×h.
	if origBlob != nil {
		return v.NewThumbnail(ctx, origBlob, w, h, vips.InterestingNone, size, n, 1, 0)
	}

	if memBlob == nil {
		// Cache disabled or blob could not be loaded — should not happen here.
		return nil, imagor.ErrNotFound
	}

	// Static: resize from cached memory blob to requested w×h.
	return v.NewThumbnail(ctx, memBlob, w, h, vips.InterestingNone, size, 1, 1, 0)
}

// loadFilterImage runs the imagor pipeline for an image() filter using the image cache.
// Bypasses cache for unknown size, exceeds max dims, or requests that depend on