bp_document_mirror_text( $attachment_id )

function bp_document_mirror_text( $attachment_id ) {
	$mirror_text = '';

	$extension = bp_document_extension( $attachment_id );
	if ( isset( $extension ) && !empty( $extension ) && in_array( $extension, bp_get_document_preview_code_extensions() ) ) {
		$words = 8000;
		$more  = '...';
		$text  = get_post_meta( $attachment_id, 'document_preview_mirror_text', true );
		if ( $text ) {
			$mirror_text = strlen( $text ) > $words ? substr( $text, 0, $words ) . '...' : $text;
		} else {
			if ( file_exists( get_attached_file( $attachment_id ) ) ) {
				$image_data  = file_get_contents( get_attached_file( $attachment_id ) );
				$words       = 10000;
				$mirror_text = strlen( $image_data ) > $words ? substr( $image_data, 0, $words ) . '...' : $image_data;
				update_post_meta( $attachment_id, 'document_preview_mirror_text', $mirror_text );
			}
		}
	}

	return $mirror_text;
}