# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1370295425 -7200
# Node ID ffd4c114650370cddbda81aad21931ecf7e1e785
# Parent  965d1f6ff37ae7611b78092ec527e85674ba3259
Added support for removing items from stores; made the __len__ method return the
number of items, not the next item number; added a keys method to expose the
item numbers being used.

diff -r 965d1f6ff37a -r ffd4c1146503 ItemSupport.py
--- a/ItemSupport.py	Fri May 31 02:07:53 2013 +0200
+++ b/ItemSupport.py	Mon Jun 03 23:37:05 2013 +0200
@@ -41,11 +41,17 @@
             self.write_next(next)
         return next
 
+    def get_keys(self):
+
+        "Return the item keys."
+
+        return [int(filename) for filename in os.listdir(self.path) if filename.isdigit()]
+
     def deduce_next(self):
 
         "Deduce the next item number from the existing item files."
 
-        return max([int(filename) for filename in os.listdir(self.path) if filename.isdigit()] or [-1]) + 1
+        return max(self.get_keys() or [-1]) + 1
 
     def read_next(self):
 
@@ -93,6 +99,12 @@
         finally:
             f.close()
 
+    def remove_item(self, number):
+
+        "Remove the item with the given item 'number'."
+
+        os.remove(self.get_item_path(number))
+
     def get_item_path(self, number):
 
         "Get the path for the given item 'number'."
@@ -122,15 +134,10 @@
     def __len__(self):
 
         """
-        Return the number of the next item (which should also be the number of
-        items).
+        Return the number of items.
         """
 
-        self.writelock.acquire()
-        try:
-            return self.get_next()
-        finally:
-            self.writelock.release()
+        return len(self.keys())
 
     def __iter__(self):
 
@@ -138,6 +145,16 @@
 
         return ItemIterator(self)
 
+    def keys(self):
+
+        "Return a list of keys for items in the store."
+
+        self.readlock.acquire()
+        try:
+            return self.get_keys()
+        finally:
+            self.readlock.release()
+
     def __getitem__(self, number):
 
         "Return the item with the given 'number'."
@@ -151,6 +168,32 @@
         finally:
             self.readlock.release()
 
+    def __delitem__(self, number):
+
+        "Remove the item with the given 'number' from the store."
+
+        self.writelock.acquire()
+        try:
+            try:
+                self.remove_item(number)
+            except (IOError, OSError):
+                raise IndexError, number
+        finally:
+            self.writelock.release()
+
+    def next(self):
+
+        """
+        Return the number of the next item (which should also be the number of
+        items if none have been deleted).
+        """
+
+        self.writelock.acquire()
+        try:
+            return self.get_next()
+        finally:
+            self.writelock.release()
+
 class ItemIterator:
 
     "An iterator over items in a store."
@@ -163,9 +206,9 @@
     def reset(self):
         if self.direction == 1:
             self._next = 0
-            self.final = len(self.store)
+            self.final = self.store.next()
         else:
-            self._next = len(self.store) - 1
+            self._next = self.store.next() - 1
             self.final = 0
 
     def more(self):
diff -r 965d1f6ff37a -r ffd4c1146503 MoinSupport.py
--- a/MoinSupport.py	Fri May 31 02:07:53 2013 +0200
+++ b/MoinSupport.py	Mon Jun 03 23:37:05 2013 +0200
@@ -1026,6 +1026,16 @@
         user = self.page.request.user
         return user and user.may.read(self.page.page_name)
 
+    def can_delete(self):
+
+        """
+        Return whether the user associated with the request can delete the
+        page owning this store.
+        """
+
+        user = self.page.request.user
+        return user and user.may.delete(self.page.page_name)
+
     # High-level methods.
 
     def append(self, item):
@@ -1039,10 +1049,7 @@
 
     def __len__(self):
 
-        """
-        Return the number of the next item (which should also be the number of
-        items).
-        """
+        "Return the number of items in the store."
 
         if not self.can_read():
             return 0
@@ -1058,4 +1065,13 @@
 
         return ItemDirectoryStore.__getitem__(self, number)
 
+    def __delitem__(self, number):
+
+        "Remove the item with the given 'number'."
+
+        if not self.can_delete():
+            return
+
+        return ItemDirectoryStore.__delitem__(self, number)
+
 # vim: tabstop=4 expandtab shiftwidth=4