From 078bc676ae6ae7fafeef8890f2bfad03ef981e61 Mon Sep 17 00:00:00 2001
From: Valentin Lorentz <progval@gmail.com>
Date: Sun, 14 Nov 2010 15:06:17 +0100
Subject: [PATCH] SupyML: Add nesting control

---
 SupyML/config.py |  2 ++
 SupyML/plugin.py | 19 ++++++++++++++++---
 SupyML/test.py   | 13 ++++++++++++-
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/SupyML/config.py b/SupyML/config.py
index 9d5aefe..cf0b88d 100644
--- a/SupyML/config.py
+++ b/SupyML/config.py
@@ -55,5 +55,7 @@ SupyML = conf.registerPlugin('SupyML')
 # conf.registerGlobalValue(SupyML, 'someConfigVariableName',
 #     registry.Boolean(False, _("""Help for someConfigVariableName.""")))
 
+conf.registerGlobalValue(SupyML, 'maxnodes', registry.Integer(30, """Determines
+    the maximum number of nodes processed by the 'SupyML eval' command."""))
 
 # vim:set shiftwidth=4 tabstop=4 expandtab textwidth=79:
diff --git a/SupyML/plugin.py b/SupyML/plugin.py
index a4ff712..f43672e 100644
--- a/SupyML/plugin.py
+++ b/SupyML/plugin.py
@@ -32,6 +32,7 @@ import re
 import copy
 import time
 import Queue
+import supybot.conf as conf
 from xml.dom import minidom
 import supybot.world as world
 import supybot.utils as utils
@@ -60,6 +61,9 @@ class LoopError(Exception):
 class LoopTypeIsMissing(Exception):
     pass
 
+class MaximumNodesNumberExceeded(Exception):
+    pass
+
 parseMessage = re.compile('\w+: (?P<content>.*)')
 class FakeIrc():
     def __init__(self, irc):
@@ -87,19 +91,25 @@ class FakeIrc():
         return getattr(self.__dict__['_irc'], name)
 
 class SupyMLParser:
-    def __init__(self, plugin, irc, msg, code):
+    def __init__(self, plugin, irc, msg, code, maxNodes):
         self._plugin = plugin
         self._irc = irc
         self._msg = msg
         self._code = code
         self.warnings = []
+        self._maxNodes = maxNodes
+        self.nodesCount = 0
         self.data = self._parse(code)
 
+    def _startNode(self):
+        self.nodesCount += 1
+        if self.nodesCount >= self._maxNodes:
+            raise MaximumNodesNumberExceeded()
+
     def _run(self, code):
         """Runs the command using Supybot engine"""
         tokens = callbacks.tokenize(str(code))
         fakeIrc = FakeIrc(self._irc)
-        # TODO : add nested level
         self._plugin.Proxy(fakeIrc, self._msg, tokens)
         self.rawData = fakeIrc._rawData
         # TODO : don't wait if the plugin is not threaded
@@ -108,6 +118,7 @@ class SupyMLParser:
 
     def _parse(self, code, variables={}):
         """Returns a dom object from the code."""
+        self._startNode()
         dom = minidom.parseString(code)
         output = self._processDocument(dom, variables)
         return output
@@ -126,6 +137,7 @@ class SupyMLParser:
             return node.data
         output = node.nodeName + ' '
         for childNode in node.childNodes:
+            self._startNode()
             if not repr(node) == repr(childNode.parentNode):
                 continue
             if childNode.nodeName == 'loop':
@@ -204,7 +216,8 @@ class SupyML(callbacks.Plugin):
         """<SupyML script>
 
         Executes the <SupyML script>"""
-        parser = SupyMLParser(self, irc, msg, code)
+        parser = SupyMLParser(self, irc, msg, code,
+                              self.registryValue('maxnodes')+2)
         if world.testing and len(parser.warnings) != 0:
             print parser.warnings
         if parser.rawData is not None:
diff --git a/SupyML/test.py b/SupyML/test.py
index 8baacb3..909a8eb 100644
--- a/SupyML/test.py
+++ b/SupyML/test.py
@@ -36,7 +36,7 @@ class SupyMLTestCase(ChannelPluginTestCase):
     #################################
     # Utilities
     def _getIfAnswerIsEqual(self, msg):
-        time.sleep(0.2)
+        time.sleep(0.1)
         m = self.irc.takeMsg()
         while m is not None:
             if repr(m) == repr(msg):
@@ -137,5 +137,16 @@ class SupyMLTestCase(ChannelPluginTestCase):
                             '</echo>',
                             '45')
 
+    def testMaxNesting(self):
+        self.assertNotError('SupyML eval ' +
+                         '<echo>'*30+
+                            'foo' +
+                         '</echo>'*30
+                        )
+        self.assertError('SupyML eval ' +
+                         '<echo>'*31+
+                            'foo' +
+                         '</echo>'*31
+                        )
 
 # vim:set shiftwidth=4 tabstop=4 expandtab textwidth=79: