whatsxmpp/utils.lisp

34 lines
1.3 KiB
Common Lisp
Raw Normal View History

(in-package :whatsxmpp)
(defun octets-to-lowercase-hex (buf)
"Formats BUF, a vector of octets, as a lowercase hex string and returns it."
(declare (type (vector (unsigned-byte 8)) buf))
(format nil "~(~{~2,'0X~}~)" (coerce buf 'list)))
(defun sha1-octets (buf)
"Returns the SHA1 of BUF, a vector of octets, in lowercase hex."
(octets-to-lowercase-hex (ironclad:digest-sequence :sha1 buf)))
(defun sha1-hex (str)
"Returns the SHA1 of STR, a string, in lowercase hex."
(sha1-octets (babel:string-to-octets str)))
(defun child-elements (node)
"Returns the child elements (excluding text nodes) of the CXML DOM node NODE."
(remove-if-not #'dom:element-p (dom:child-nodes node)))
(defun nil-empty (seq)
"If SEQ (a sequence) is empty, returns NIL; otherwise, returns SEQ."
(unless (eql (length seq) 0) seq))
(defmacro with-promise-from-thread (() &body forms)
"Return a promise that executes FORMS in a new thread, resolving the promise with the return value of (PROGN ,@FORMS) or rejecting it if an ERROR condition is thrown (with said condition)."
(let ((resolve (gensym))
(reject (gensym)))
`(with-promise (,resolve ,reject)
(bt:make-thread
(lambda ()
(handler-case
(,resolve (progn ,@forms))
(error (e) (,reject e))))))))