Author: cludwig Date: Sun Feb 1 21:48:06 2009 New Revision: 13 Log: check if we already imported any snapshot Modified: trunk/src/rest_interface/read.lisp Modified: trunk/src/rest_interface/read.lisp ============================================================================== --- trunk/src/rest_interface/read.lisp (original) +++ trunk/src/rest_interface/read.lisp Sun Feb 1 21:48:06 2009 @@ -83,39 +83,48 @@ (t (string-max (rest string-list) max)))) -(defun import-snapshots-feed (snapshot-feed-url &key tm-id) - ;this finds the most recent snapshot and imports that. It returns the entry - ;corresponding to that snapshot +(defun most-recent-entry (entry-list) + (let + ((most-recent-update (string-max (mapcar #'atom:updated entry-list)))) + (find most-recent-update entry-list :key #'updated :test #'string=))) + +(defun most-recent-imported-snapshot (all-snapshot-entries) + (let + ((all-imported-entries + (remove-if-not #'xtm-id-p all-snapshot-entries :key #'atom:id))) + (most-recent-entry all-imported-entries))) - (let +(defun import-snapshots-feed (snapshot-feed-url &key tm-id) + "checks if we already imported any of this feed's snapshots. If not, +finds the most recent snapshot and imports that. It returns the entry +corresponding to the snapshot imported (now or previously)." + (let* ((feed (read-snapshots-feed snapshot-feed-url)) - (revision (get-revision))) - (let* - ((most-recent-update (string-max (mapcar #'atom:updated (slot-value feed 'atom:entries)))) - (entry - (find - most-recent-update - (slot-value feed 'atom:entries) :key #'updated :test #'string=)) - (xtm-id (id entry))) - ;;that *should* be the algorithm... - ;; If a client has a local topic map that contains topic map - ;; data from more than one server and wants to fetch and update - ;; the latest full topic map from ONE source then it MUST do the - ;; following. Apply the delete topic algorithm from below, but - ;; apply it to the entire topic map. Then proceed in terms of 'A - ;; Clean Start', by fetching the topic map and merging it in - ;; (1b, 1.4.3.2) - (unless (xtm-id-p xtm-id) - (importer-xtm1.0 - (dom:document-element - (cxml:parse-rod (read-url (link entry)) (cxml-dom:make-dom-builder))) - :tm-id tm-id - :xtm-id xtm-id :revision revision)) - entry))) + (all-entries (slot-value feed 'atom:entries)) + (most-recent-imported-entry all-entries)) + (if most-recent-imported-entry + most-recent-imported-entry + (let* + ((entry (most-recent-entry all-entries)) + (snapshot-dom + (dom:document-element + (cxml:parse-rod (read-url (link entry)) (cxml-dom:make-dom-builder)))) + (xtm-id (id entry)) + (revision (get-revision))) + ;;that *should* be the algorithm... + ;; If a client has a local topic map that contains topic map + ;; data from more than one server and wants to fetch and update + ;; the latest full topic map from ONE source then it MUST do the + ;; following. Apply the delete topic algorithm from below, but + ;; apply it to the entire topic map. Then proceed in terms of 'A + ;; Clean Start', by fetching the topic map and merging it in + ;; (1b, 1.4.3.2) + (importer-xtm1.0 snapshot-dom :tm-id tm-id :xtm-id xtm-id :revision revision) + entry)))) (defun import-tm-feed (feed-url &optional (processed-feed-urls nil)) - "takes the feed url of a collection feed, imports the first snapshot if -necessary and then applies all fragments to it" + "takes the feed url of a collection feed, processes the dependencies, +imports the first snapshot if necessary and then applies all fragments to it" ;the implementation may be a bit brutal, but relies only on ;guaranteed rel-attributes on the links (let* @@ -146,7 +155,8 @@ (format t "Recursively processing feed ~a~&" dependent-feed-url) (import-tm-feed dependent-feed-url (append processed-feed-urls feed-url))))) - + ;; import a snapshot (if necessary) and the process all fragments more + ;; recent than the snapshot (let ((imported-snapshot-entry (import-snapshots-feed