diff options
Diffstat (limited to 'wttrin.el')
| -rw-r--r-- | wttrin.el | 104 |
1 files changed, 93 insertions, 11 deletions
@@ -86,6 +86,20 @@ units (default)." :group 'wttrin :type 'string) + +(defcustom wttrin-cache-ttl 900 ; 15 minutes + "Time to live for cached weather data in seconds." + :group 'wttrin + :type 'integer) + +(defcustom wttrin-cache-max-entries 50 + "Maximum number of entries to keep in cache." + :group 'wttrin + :type 'integer) + +(defvar wttrin--cache (make-hash-table :test 'equal) + "Cache for weather data: cache-key -> (timestamp . data)") + (defun wttrin-additional-url-params () "Concatenates extra information into the URL." (concat "?" wttrin-unit-system)) @@ -96,7 +110,7 @@ units (default)." (url-user-agent "curl")) (with-current-buffer (url-retrieve-synchronously - (concat "https://wttr.in/" query "?A") + (concat "https://wttr.in/" query (wttrin-additional-url-params) "A") (lambda () (switch-to-buffer (current-buffer)))) (decode-coding-string (buffer-string) 'utf-8)))) @@ -118,13 +132,14 @@ units (default)." (defun wttrin-query (location-name) "Query weather of LOCATION-NAME via wttrin, display the result in new buffer." - (let ((raw-string (wttrin-fetch-raw-string location-name))) + (let ((raw-string (wttrin--get-cached-or-fetch location-name))) (if (string-match "ERROR" raw-string) (message "Cannot retrieve weather data. Perhaps the location was misspelled?") (let ((buffer (get-buffer-create (format "*wttr.in*"))) date-time-stamp location-info) (switch-to-buffer buffer) + (setq-local wttrin--current-location location-name) (setq buffer-read-only nil) (erase-buffer) @@ -153,17 +168,84 @@ misspelled?") ;; provide user instructions (goto-char (point-max)) - (insert "\nPress: [g] to query another location\n") - (insert " [q] to quit\n") + (insert "\nPress: [g] to query another location [r] to refresh [q] to quit")) - ;; align buffer to top - (goto-char (point-min)) + ;; align buffer to top + (goto-char (point-min)) - ;; create choice keymap and disallow modifying buffer - (use-local-map (make-sparse-keymap)) - (local-set-key "q" 'wttrin-exit) - (local-set-key "g" 'wttrin-requery) - (setq buffer-read-only t))))) + ;; create choice keymap and disallow modifying buffer + (use-local-map (make-sparse-keymap)) + (local-set-key "q" 'wttrin-exit) + (local-set-key "r" 'wttrin-requery-force) + (local-set-key "g" 'wttrin-requery) + (setq buffer-read-only t)))) + +(defun wttrin--make-cache-key (location) + "Create cache key from LOCATION and current settings." + (concat location "|" (or wttrin-unit-system "default"))) + +(defun wttrin--get-cached-or-fetch (location) + "Get cached weather for LOCATION or fetch if expired. +Returns the weather data string or nil on error." + (let* ((cache-key (wttrin--make-cache-key location)) + (cached (gethash cache-key wttrin--cache)) + (timestamp (car cached)) + (data (cdr cached)) + (now (float-time))) + (if (and cached + (< (- now timestamp) wttrin-cache-ttl) + (not wttrin--force-refresh)) + data + (condition-case err + (let ((fresh-data (wttrin-fetch-raw-string + (concat location (wttrin-additional-url-params))))) + (when fresh-data + (wttrin--cleanup-cache-if-needed) + (puthash cache-key (cons now fresh-data) wttrin--cache)) + fresh-data) + (error + ;; On error, return stale cache if available + (if cached + (progn + (message "Failed to fetch new data, using cached version") + data) + (signal (car err) (cdr err)))))))) + +(defvar wttrin--force-refresh nil + "When non-nil, bypass cache on next fetch.") + +(defun wttrin--cleanup-cache-if-needed () + "Remove old entries if cache exceeds max size." + (when (> (hash-table-count wttrin--cache) wttrin-cache-max-entries) + (let ((entries nil)) + (maphash (lambda (k v) + (push (cons k (car v)) entries)) + wttrin--cache) + (setq entries (sort entries (lambda (a b) (< (cdr a) (cdr b))))) + ;; Remove oldest 20% of entries + (dotimes (_ (/ (length entries) 5)) + (when entries + (remhash (caar entries) wttrin--cache) + (setq entries (cdr entries))))))) + +(defun wttrin-clear-cache () + "Clear the weather cache." + (interactive) + (clrhash wttrin--cache) + (message "Weather cache cleared")) + +(defvar-local wttrin--current-location nil + "Current location displayed in this weather buffer.") + +(defun wttrin-requery-force () + "Force refresh weather data for current location, bypassing cache." + (interactive) + (if wttrin--current-location + (let ((wttrin--force-refresh t)) + (message "Refreshing weather data...") + (wttrin-query wttrin--current-location) + (message nil)) + (message "No location to refresh"))) ;;;###autoload (defun wttrin (location) |