Don't calculate blurhashes on things we wouldn't thumbnail

pipelines/_steps/upload/blurhash_async.go

@@ -10,7 +10,7 @@ import (
 	"github.com/turt2live/matrix-media-repo/database"
 )
 
-func CalculateBlurhashAsync(ctx rcontext.RequestContext, reader io.Reader, sha256hash string) chan struct{} {
+func CalculateBlurhashAsync(ctx rcontext.RequestContext, reader io.Reader, sizeBytes int64, sha256hash string) chan struct{} {
 	var err error
 	opChan := make(chan struct{})
 	go func() {
@@ -21,6 +21,9 @@ func CalculateBlurhashAsync(ctx rcontext.RequestContext, reader io.Reader, sha25
 		if !ctx.Config.Features.MSC2448Blurhash.Enabled {
 			return
 		}
+		if ctx.Config.Thumbnails.MaxSourceBytes <= sizeBytes {
+			return
+		}
 
 		var img image.Image
 		img, err = imaging.Decode(reader)

pipelines/pipeline_upload/pipeline.go

@@ -150,7 +150,7 @@ func Execute(ctx rcontext.RequestContext, origin string, mediaId string, r io.Re
 	}
 
 	// Step 10: Asynchronously calculate blurhash
-	bhChan := upload.CalculateBlurhashAsync(ctx, bhR, sha256hash)
+	bhChan := upload.CalculateBlurhashAsync(ctx, bhR, sizeBytes, sha256hash)
 
 	// Step 11: Asynchronously upload to cache
 	cacheChan := upload.PopulateCacheAsync(ctx, cacheR, sizeBytes, sha256hash)