Function: nnvirtual-retrieve-headers

nnvirtual-retrieve-headers is a byte-compiled function defined in nnvirtual.el.gz.

Signature

(nnvirtual-retrieve-headers ARTICLES &optional NEWSGROUP SERVER FETCH-OLD)

Source Code

;; Defined in /usr/src/emacs/lisp/gnus/nnvirtual.el.gz
(deffoo nnvirtual-retrieve-headers (articles &optional _newsgroup
					     server _fetch-old)
  (when (nnvirtual-possibly-change-server server)
    (with-current-buffer nntp-server-buffer
      (erase-buffer)
      (if (stringp (car articles))
	  'headers
	(let ((vbuf (nnheader-set-temp-buffer
		     (gnus-get-buffer-create " *virtual headers*")))
	      (carticles (nnvirtual-partition-sequence articles))
	      (sysname (system-name))
	      cgroup carticle article result prefix)
	  (while carticles
	    (setq cgroup (caar carticles))
	    (setq articles (cdar carticles))
	    (pop carticles)
	    (when (and articles
		       (gnus-check-server
			(gnus-find-method-for-group cgroup) t)
		       (gnus-request-group cgroup t)
		       (setq prefix (gnus-group-real-prefix cgroup)
                             result (gnus-retrieve-headers
				     articles cgroup nil)))
	      (set-buffer nntp-server-buffer)
	      ;; If we got HEAD headers, we convert them into NOV
	      ;; headers.  This is slow, inefficient and, come to think
	      ;; of it, downright evil.  So sue me.  I couldn't be
	      ;; bothered to write a header parse routine that could
	      ;; parse a mixed HEAD/NOV buffer.
	      (when (eq result 'headers)
		(nnvirtual-convert-headers))
	      (goto-char (point-min))
	      (while (not (eobp))
		(delete-region (point)
			       (progn
				 (setq carticle (read nntp-server-buffer))
				 (point)))

		;; We remove this article from the articles list, if
		;; anything is left in the articles list after going through
		;; the entire buffer, then those articles have been
		;; expired or canceled, so we appropriately update the
		;; component group below.  They should be coming up
		;; generally in order, so this shouldn't be slow.
		(setq articles (delq carticle articles))

		(setq article (nnvirtual-reverse-map-article cgroup carticle))
		(if (null article)
		    ;; This line has no reverse mapping, that means it
		    ;; was an extra article reference returned by nntp.
		    (progn
		      (beginning-of-line)
		      (delete-region (point) (progn (forward-line 1) (point))))
		  ;; Otherwise insert the virtual article number,
		  ;; and clean up the xrefs.
		  (princ article nntp-server-buffer)
		  (nnvirtual-update-xref-header cgroup carticle
						prefix sysname)
		  (forward-line 1))
		)

	      (set-buffer vbuf)
	      (goto-char (point-max))
	      (insert-buffer-substring nntp-server-buffer))
	    ;; Anything left in articles is expired or canceled.
	    ;; Could be smart and not tell it about articles already known?
	    (when articles
	      (gnus-group-make-articles-read cgroup articles))
	    )

	  ;; The headers are ready for reading, so they are inserted into
	  ;; the nntp-server-buffer, which is where Gnus expects to find
	  ;; them.
	  (prog1
	      (with-current-buffer nntp-server-buffer
		(erase-buffer)
		(insert-buffer-substring vbuf)
                ;; FIXME: we should be able to sort faster than
		;; this if needed, since each cgroup is sorted, we just
		;; need to merge
		(sort-numeric-fields 1 (point-min) (point-max))
		'nov)
	    (kill-buffer vbuf)))))))