How to calculate size of files stored in device faster while using "PHAsset"

Question

I have an array of PHAsset (Let's say, array size is greater than 50,000), and I want to know the file size of each PHAsset. I'm trying it using PHAssetResource.assetResources but it is taking much time. I want to know if there is any faster way of knowing file size. I'm including the code I tried below,

extension PHAsset {
    
    func getSize() -> Double {
        let resources = PHAssetResource.assetResources(for: self)
        var sizeOnDisk: Int64 = 0
        if let resource = resources.first {
            let unsignedInt64 = resource.value(forKey: "fileSize") as? CLong
            sizeOnDisk = Int64(bitPattern: UInt64(unsignedInt64!))
            let fileSize = Double(sizeOnDisk) / (1024.0 * 1024.0)
            return fileSize
        }
        return 0.0
    }
} 

To be specific this line is taking too much time. PHAssetResource.assetResources(for: self)