* riece-lru.el: New file.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 08ea3d9..9a2922d 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,7 @@
 2005-11-18  Daiki Ueno  <ueno@unixuser.org>
 
+       * riece-lru.el: New file.
+
        * riece-develop.el: New file.
 
 2005-10-27  Masatake YAMATO  <jet@gyve.org>

diff --git a/lisp/riece-lru.el b/lisp/riece-lru.el
new file mode 100644 (file)
index 0000000..138d88d
--- /dev/null
+++ b/lisp/riece-lru.el
@@ -0,0 +1,133 @@
+(defun riece-lru-make-node (key value &optional previous next)
+  "Make riece-lru-node object."
+  (vector key value previous next))
+
+(defun riece-lru-node-key (node)
+  "Return key of NODE."
+  (aref node 0))
+
+(defun riece-lru-node-value (node)
+  "Return value of NODE."
+  (aref node 1))
+
+(defun riece-lru-node-next (node)
+  "Return next of NODE."
+  (aref node 3))
+
+(defun riece-lru-node-set-next (node next)
+  "Set next of NODE to NEXT."
+  (aset node 3 next))
+
+(defun riece-lru-node-previous (node)
+  "Return previous of NODE."
+  (aref node 2))
+
+(defun riece-lru-node-set-previous (node previous)
+  "Set previous of NODE to PREVIOUS."
+  (aset node 2 previous))
+
+(defun riece-lru-make-map (max-length)
+  "Make riece-lru-map object."
+  (vector max-length (make-vector (* max-length 2) 0) 0 nil nil))
+
+(defun riece-lru-map-max-length (map)
+  "Return max-length of MAP."
+  (aref map 0))
+
+(defun riece-lru-map-hash-obarray (map)
+  "Return hash-obarray of MAP."
+  (aref map 1))
+
+(defun riece-lru-map-hash-length (map)
+  "Return hash-length of MAP."
+  (aref map 2))
+
+(defun riece-lru-map-set-hash-length (map hash-length)
+  "Set hash-length of MAP to HASH-LENGTH."
+  (aset map 2 hash-length))
+
+(defun riece-lru-map-first (map)
+  "Return first of MAP."
+  (aref map 3))
+
+(defun riece-lru-map-set-first (map first)
+  "Set first of MAP to FIRST."
+  (aset map 3 first))
+
+(defun riece-lru-map-last (map)
+  "Return last of MAP."
+  (aref map 4))
+
+(defun riece-lru-map-set-last (map last)
+  "Set last of MAP to LAST."
+  (aset map 4 last))
+
+(defalias 'riece-make-lru 'riece-lru-make-map)
+
+(defun riece-lru-contains (map key)
+  (intern-soft key (riece-lru-map-hash-obarray map)))
+
+(defun riece-lru-get (map key)
+  (let ((node (riece-lru-get-node map key)))
+    (if node
+       (riece-lru-node-value node))))
+
+(defun riece-lru-get-node (map key)
+  (let ((symbol (intern-soft key (riece-lru-map-hash-obarray map)))
+       previous next first last node)
+    (when symbol
+      (setq node (symbol-value symbol)
+           previous (riece-lru-node-previous node)
+           next (riece-lru-node-next node)
+           first (riece-lru-map-first map)
+           last (riece-lru-map-last map))
+      (if previous
+         (riece-lru-node-set-next previous next))
+      (if next
+         (riece-lru-node-set-previous next previous))
+      (riece-lru-node-set-next node nil)
+      (riece-lru-node-set-previous node last)
+      (riece-lru-node-set-next last node)
+      (riece-lru-map-set-last map node)
+      (if (and (eq node (riece-lru-map-first map)) next)
+         (riece-lru-map-set-first map next))
+      node)))
+
+(defun riece-lru-delete (map key)
+  (let ((symbol (intern-soft key (riece-lru-map-hash-obarray map)))
+       previous next node)
+    (when symbol
+      (setq node (symbol-value symbol)
+           previous (riece-lru-node-previous node)
+           next (riece-lru-node-next node))
+      (if previous
+         (riece-lru-node-set-next previous next))
+      (if next
+         (riece-lru-node-set-previous next previous))
+      (if (eq (riece-lru-map-last map) node)
+         (riece-lru-map-set-last map previous))
+      (if (eq (riece-lru-map-first map) node)
+         (riece-lru-map-set-first map next))
+      (unintern symbol (riece-lru-map-hash-obarray map))
+      (riece-lru-map-set-hash-length map (1- (riece-lru-map-hash-length map)))
+      (riece-lru-node-value node))))
+
+(defun riece-lru-set (map key value)
+  (let ((node (riece-lru-get-node map key))
+       symbol)
+    (if node
+       (aset node 1 value)
+      (if (>= (riece-lru-map-hash-length map)
+             (riece-lru-map-max-length map))
+         (riece-lru-delete map (riece-lru-node-key
+                                (riece-lru-map-first map))))
+      (setq node (riece-lru-make-node key value (riece-lru-map-last map) nil))
+      (set (intern key (riece-lru-map-hash-obarray map)) node)
+      (riece-lru-map-set-hash-length map (1+ (riece-lru-map-hash-length map)))
+      (unless (riece-lru-map-first map)
+       (riece-lru-map-set-first map node))
+      (if (riece-lru-map-last map)
+         (progn
+           (riece-lru-node-set-next (riece-lru-map-last map) node)
+           (riece-lru-node-set-previous node (riece-lru-map-last map))))
+      (riece-lru-map-set-last map node))))