whatsxmpp/nix/etld.nix
eta 7e457266f8 nix: add Nix derivation for whatsxmpp (yay!)
- Using tazjin's buildLisp.nix (you need the TVL Monorepo installed
  as <depot>), we have a derivation for whatsxmpp and its million
  dependencies.
- The derivation currently just assumes whatscl is in ../whatscl,
  but we'll fix that eventually.
- Also there are tons of buildLisp derivations in here, and even
  two instances where we had to vendor stuff in order to get it to
  work with nix (usually because it had some data file).
- But yay, we can build via docker and it's not utter trash!
2020-07-06 22:44:28 +01:00

94 lines
3.2 KiB
Nix

{ tld-names, pkgs ? import <nixpkgs> {} }:
pkgs.writeText "etld.lisp" ''
(in-package :cl-user)
(defpackage quri.etld
(:use :cl)
(:import-from :alexandria
:starts-with-subseq
:ends-with-subseq)
(:export :parse-domain))
(in-package :quri.etld)
(eval-when (:compile-toplevel :load-toplevel :execute)
(defvar *default-etld-names* "${tld-names}")
(defun load-etld-data (&optional (etld-names-file *default-etld-names*))
(with-open-file (in etld-names-file
:element-type #+lispworks :default #-lispworks 'character
:external-format #+clisp charset:utf-8 #-clisp :utf-8)
(loop with special-tlds = nil
with normal-tlds = (make-hash-table :test 'equal)
with wildcard-tlds = (make-hash-table :test 'equal)
for line = (read-line in nil nil)
while line
unless (or (= 0 (length line))
(starts-with-subseq "//" line))
do (cond
((starts-with-subseq "*" line)
(setf (gethash (subseq line 2) wildcard-tlds) t))
((starts-with-subseq "!" line)
(push (subseq line 1) special-tlds))
(t
(setf (gethash line normal-tlds) t)))
finally (return (list normal-tlds wildcard-tlds special-tlds))))))
(defvar *etlds*
#-abcl '#.(load-etld-data)
#+abcl (load-etld-data))
(defun next-subdomain (hostname &optional (start 0))
(let ((pos (position #\. hostname :start start)))
(when pos
(incf pos)
(values (subseq hostname pos)
pos))))
(defun make-subdomain-iter (hostname)
(let ((current-pos 0)
(first t))
(lambda ()
(block nil
(when first
(setq first nil)
(return hostname))
(multiple-value-bind (subdomain pos)
(next-subdomain hostname current-pos)
(when subdomain
(setf current-pos pos)
subdomain))))))
(defun parse-domain (hostname)
(dolist (tld (third *etlds*))
(when (ends-with-subseq tld hostname)
(if (= (length tld) (length hostname))
(return-from parse-domain hostname)
(when (char= (aref hostname (- (length hostname) (length tld) 1))
#\.)
(return-from parse-domain
(subseq hostname
(- (length hostname) (length tld))))))))
(loop with iter = (make-subdomain-iter hostname)
with pre-prev-subdomain = nil
with prev-subdomain = nil
for subdomain = (funcall iter)
while subdomain
if (gethash subdomain (second *etlds*)) do
(return pre-prev-subdomain)
else if (gethash subdomain (first *etlds*)) do
(return (if (string= subdomain hostname)
nil
prev-subdomain))
do (setf pre-prev-subdomain prev-subdomain
prev-subdomain subdomain)
finally
(let* ((pos (position #\. hostname :from-end t))
(pos (and pos
(position #\. hostname :from-end t :end pos))))
(return
(if pos
(subseq hostname (1+ pos))
hostname)))))
''