# File activestorage/lib/active_storage/service/s3_service.rb, line 17
    def initialize(bucket:, upload: {}, public: false, **options)
      @client = Aws::S3::Resource.new(**options)
      @bucket = @client.bucket(bucket)

      @multipart_upload_threshold = upload.delete(:multipart_threshold) || 100.megabytes
      @public = public

      @upload_options = upload
      @upload_options[:acl] = "public-read" if public?
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 100
    def compose(source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
      content_disposition = content_disposition_with(type: disposition, filename: filename) if disposition && filename

      object_for(destination_key).upload_stream(
        content_type: content_type,
        content_disposition: content_disposition,
        part_size: MINIMUM_UPLOAD_PART_SIZE,
        metadata: custom_metadata,
        **upload_options
      ) do |out|
        source_keys.each do |source_key|
          stream(source_key) do |chunk|
            IO.copy_stream(StringIO.new(chunk), out)
          end
        end
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 62
    def delete(key)
      instrument :delete, key: key do
        object_for(key).delete
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 68
    def delete_prefixed(prefix)
      instrument :delete_prefixed, prefix: prefix do
        bucket.objects(prefix: prefix).batch_delete!
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 40
    def download(key, &block)
      if block_given?
        instrument :streaming_download, key: key do
          stream(key, &block)
        end
      else
        instrument :download, key: key do
          object_for(key).get.body.string.force_encoding(Encoding::BINARY)
        rescue Aws::S3::Errors::NoSuchKey
          raise ActiveStorage::FileNotFoundError
        end
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 54
    def download_chunk(key, range)
      instrument :download_chunk, key: key, range: range do
        object_for(key).get(range: "bytes=#{range.begin}-#{range.exclude_end? ? range.end - 1 : range.end}").body.string.force_encoding(Encoding::BINARY)
      rescue Aws::S3::Errors::NoSuchKey
        raise ActiveStorage::FileNotFoundError
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 74
    def exist?(key)
      instrument :exist, key: key do |payload|
        answer = object_for(key).exists?
        payload[:exist] = answer
        answer
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 94
    def headers_for_direct_upload(key, content_type:, checksum:, filename: nil, disposition: nil, custom_metadata: {}, **)
      content_disposition = content_disposition_with(type: disposition, filename: filename) if filename

      { "Content-Type" => content_type, "Content-MD5" => checksum, "Content-Disposition" => content_disposition, **custom_metadata_headers(custom_metadata) }
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 28
    def upload(key, io, checksum: nil, filename: nil, content_type: nil, disposition: nil, custom_metadata: {}, **)
      instrument :upload, key: key, checksum: checksum do
        content_disposition = content_disposition_with(filename: filename, type: disposition) if disposition && filename

        if io.size < multipart_upload_threshold
          upload_with_single_part key, io, checksum: checksum, content_type: content_type, content_disposition: content_disposition, custom_metadata: custom_metadata
        else
          upload_with_multipart key, io, content_type: content_type, content_disposition: content_disposition, custom_metadata: custom_metadata
        end
      end
    end

# File activestorage/lib/active_storage/service/s3_service.rb, line 82
    def url_for_direct_upload(key, expires_in:, content_type:, content_length:, checksum:, custom_metadata: {})
      instrument :url, key: key do |payload|
        generated_url = object_for(key).presigned_url :put, expires_in: expires_in.to_i,
          content_type: content_type, content_length: content_length, content_md5: checksum,
          metadata: custom_metadata, whitelist_headers: ["content-length"], **upload_options

        payload[:url] = generated_url

        generated_url
      end
    end