# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1204423716 -3600
# Node ID dfc1fd6a3298cfc301e1c7901ed1a3acb243abd9
# Parent  0fb526c272ae67a595bcbb6d5fc82bd3f5cd94cb
Switched to a single pickle file per poll, providing feedback to each user on
their previous choices.
Introduced lock usage to avoid potential concurrency issues.
Added a time dependency.

diff -r 0fb526c272ae -r dfc1fd6a3298 macros/VoteRecorder.py
--- a/macros/VoteRecorder.py	Sun Mar 02 02:04:56 2008 +0100
+++ b/macros/VoteRecorder.py	Sun Mar 02 03:08:36 2008 +0100
@@ -9,37 +9,62 @@
     counting, and the current state of the poll is not shown during voting.
 """
 
-from MoinMoin.util import filesys
+from MoinMoin.util import filesys, lock
 from MoinMoin import wikiutil
 import os
+try:
+    import cPickle as pickle
+except ImportError:
+    import pickle
 
-Dependencies = []
+Dependencies = ["time"]
 
-def get_vote_pathname(page, name):
+def get_vote_directory(page, name):
     votes_dir = page.getPagePath("poll")
     if not os.path.exists(votes_dir):
         filesys.makeDirs(votes_dir)
+    return votes_dir
+
+def get_vote_pathname(page, name):
+    votes_dir = get_vote_directory(page, name)
     filename = wikiutil.quoteWikinameFS(name)
     return os.path.join(votes_dir, filename)
 
-def save_vote(page, poll_name, username, vote):
-    path = get_vote_pathname(page, username)
-    f = open(path, "a")
+def get_lock_directory(page, name):
+    votes_dir = get_vote_directory(page, name)
+    return os.path.join(votes_dir, "__lock__")
+
+def save_votes(page, poll_name, votes):
+    vote_lock = lock.WriteLock(get_lock_directory(page, poll_name))
+    vote_lock.acquire()
     try:
-        f.write(poll_name + "\t" + vote + "\n")
+        _save_votes(page, poll_name, votes)
+    finally:
+        vote_lock.release()
+
+def _save_votes(page, poll_name, votes):
+    path = get_vote_pathname(page, poll_name)
+    f = open(path, "wb")
+    try:
+        pickle.dump(votes, f)
     finally:
         f.close()
 
-def get_votes(page, poll_name, username, vote):
-    path = get_vote_pathname(page, username)
-    f = open(path)
+def get_all_votes(page, poll_name):
+    vote_lock = lock.ReadLock(get_lock_directory(page, poll_name))
+    vote_lock.acquire()
     try:
-        voting = {}
-        for line in f.xreadlines():
-            line = line.strip()
-            if line:
-                poll_name, vote = line.split("\t")
-                voting[poll_name] = vote
+        return _get_all_votes(page, poll_name)
+    finally:
+        vote_lock.release()
+
+def _get_all_votes(page, poll_name):
+    path = get_vote_pathname(page, poll_name)
+    if not os.path.exists(path):
+        return {}
+    f = open(path, "rb")
+    try:
+        voting = pickle.load(f)
         return voting
     finally:
         f.close()
@@ -74,13 +99,15 @@
         return ''.join(output)
 
     username = request.user.name
+    votes = get_all_votes(page, poll_name)
 
     # Handle any vote.
 
     if form and form.has_key("vote") and form.has_key("poll"):
         poll = form["poll"][0]
         if poll == poll_name:
-            save_vote(page, poll, username, form["vote"][0])
+            votes[username] = int(form["vote"][0])
+            save_votes(page, poll_name, votes)
             output.append(fmt.emphasis(on=1))
             output.append(fmt.text("Vote submitted!"))
             output.append(fmt.emphasis(on=0))
@@ -97,14 +124,20 @@
 
     output.append(fmt.rawHTML('<form method="get" name="%(poll)s" action="%(url)s#%(poll)s">' % values))
     output.append(fmt.rawHTML('<input type="hidden" name="poll" value="%(poll)s">' % values))
+
     for choice in choices:
         values["choice"] = choice
+        if votes.has_key(username) and choice <= votes[username]:
+            values["default_image"] = values["on_image"]
+        else:
+            values["default_image"] = values["off_image"]
         output.append(
             fmt.rawHTML('''
-<input type="image" name="vote" value="%(choice)s" src="%(off_image)s"
-    onmouseover="this.src='%(on_image)s'"
-    onmouseout="this.src='%(off_image)s'">
+                <input type="image" name="vote" value="%(choice)s" src="%(default_image)s"
+                    onmouseover="this.src='%(on_image)s'"
+                    onmouseout="this.src='%(default_image)s'">
                 ''' % values))
+
     output.append(fmt.rawHTML('</form>'))
 
     return ''.join(output)