require "active_storage/service" require "active_storage/filename" require "active_storage/purge_job" # Schema: id, key, filename, content_type, metadata, byte_size, checksum, created_at class ActiveStorage::Blob < ActiveRecord::Base self.table_name = "active_storage_blobs" has_secure_token :key store :metadata, coder: JSON class_attribute :service class << self def build_after_upload(io:, filename:, content_type: nil, metadata: nil) new.tap do |blob| blob.filename = filename blob.content_type = content_type blob.metadata = metadata blob.upload io end end def create_after_upload!(io:, filename:, content_type: nil, metadata: nil) build_after_upload(io: io, filename: filename, content_type: content_type, metadata: metadata).tap(&:save!) end def create_before_direct_upload!(filename:, byte_size:, checksum:, content_type: nil, metadata: nil) create! filename: filename, byte_size: byte_size, checksum: checksum, content_type: content_type, metadata: metadata end end # We can't wait until the record is first saved to have a key for it def key self[:key] ||= self.class.generate_unique_secure_token end def filename ActiveStorage::Filename.new(self[:filename]) end def url(expires_in: 5.minutes, disposition: :inline) service.url key, expires_in: expires_in, disposition: disposition, filename: filename end def url_for_direct_upload(expires_in: 5.minutes) service.url_for_direct_upload key, expires_in: expires_in, content_type: content_type, content_length: byte_size end def upload(io) self.checksum = compute_checksum_in_chunks(io) self.byte_size = io.size service.upload(key, io, checksum: checksum) end def download(&block) service.download key, &block end def delete service.delete key end def purge delete destroy end def purge_later ActiveStorage::PurgeJob.perform_later(self) end private def compute_checksum_in_chunks(io) Digest::MD5.new.tap do |checksum| while chunk = io.read(5.megabytes) checksum << chunk end io.rewind end.base64digest end end