# HG changeset patch
# User Jun Wu <quark@fb.com>
# Date 1464715498 -3600
# Node ID b98ff95b5861aa8ec63fead28fd9ff4074db5ae7
# Parent  53e306a6086b31462432dca09a5b247e9f179970
maps: disable iterating methods of RevMap

Since __iter__ is disabled in SqliteRevMap, we want to avoid the pattern
iterating RevMap as well. This patch disables all entries to keys, values and
items and makes it possible to bypass the restriction by setting "_allowiter".

Developers looking for a way to iterate the RevMap should add a new method
in RevMap and SqliteRevMap instead.

The rebuildmeta test needs iteration so we enable it explicitly there.

diff --git a/hgsubversion/maps.py b/hgsubversion/maps.py
--- a/hgsubversion/maps.py
+++ b/hgsubversion/maps.py
@@ -355,6 +355,9 @@ class RevMap(dict):
         self._filepath = revmap_path
         self._lastpulled_file = lastpulled_path
         self._hashes = None
+        # disable iteration to have a consistent interface with SqliteRevMap
+        # it's less about performance since RevMap needs iteration internally
+        self._allowiter = False
 
         self.firstpulled = 0
         if os.path.isfile(self._filepath):
@@ -364,16 +367,16 @@ class RevMap(dict):
 
     def hashes(self):
         if self._hashes is None:
-            self._hashes = dict((v, k) for (k, v) in self.iteritems())
+            self._hashes = dict((v, k) for (k, v) in self._origiteritems())
         return self._hashes
 
     def branchedits(self, branch, rev):
         check = lambda x: x[0][1] == branch and x[0][0] < rev.revnum
-        return sorted(filter(check, self.iteritems()), reverse=True)
+        return sorted(filter(check, self._origiteritems()), reverse=True)
 
     def branchmaxrevnum(self, branch, maxrevnum):
         result = 0
-        for num, br in self.iterkeys():
+        for num, br in self._origiterkeys():
             if br == branch and num <= maxrevnum and num > result:
                 result = num
         return result
@@ -386,7 +389,7 @@ class RevMap(dict):
         return bin(lines[-1].split(' ', 2)[1])
 
     def revhashes(self, revnum):
-        for key, value in self.iteritems():
+        for key, value in self._origiteritems():
             if key[0] == revnum:
                 yield value
 
@@ -459,6 +462,24 @@ class RevMap(dict):
         if self._hashes is not None:
             self._hashes[ha] = (revnum, branch)
 
+    @classmethod
+    def _wrapitermethods(cls):
+        def wrap(orig):
+            def wrapper(self, *args, **kwds):
+                if not self._allowiter:
+                    raise NotImplementedError(
+                        'Iteration methods on RevMap are disabled ' +
+                        'to avoid performance issues on SqliteRevMap')
+                return orig(self, *args, **kwds)
+            return wrapper
+        methodre = re.compile(r'^_*(?:iter|view)?(?:keys|items|values)?_*$')
+        for name in filter(methodre.match, dir(cls)):
+            orig = getattr(cls, name)
+            setattr(cls, '_orig%s' % name, orig)
+            setattr(cls, name, wrap(orig))
+
+RevMap._wrapitermethods()
+
 
 class SqliteRevMap(collections.MutableMapping):
     """RevMap backed by sqlite3.
diff --git a/tests/comprehensive/test_rebuildmeta.py b/tests/comprehensive/test_rebuildmeta.py
--- a/tests/comprehensive/test_rebuildmeta.py
+++ b/tests/comprehensive/test_rebuildmeta.py
@@ -145,7 +145,12 @@ def _run_assertions(self, name, single, 
     srcbi = util.load(os.path.join(src.path, 'svn', 'branch_info'))
     destbi = util.load(os.path.join(dest.path, 'svn', 'branch_info'))
     self.assertEqual(sorted(srcbi.keys()), sorted(destbi.keys()))
-    revkeys = svnmeta.SVNMeta(dest).revmap.keys()
+    revmap = svnmeta.SVNMeta(dest).revmap
+    # revmap disables __iter__ intentionally to avoid possible slow code
+    # (not using database index in SqliteRevMap)
+    # we need to fetch all keys so enable it by setting _allowiter
+    revmap._allowiter = True
+    revkeys = revmap.keys()
     for branch in destbi:
         srcinfo = srcbi[branch]
         destinfo = destbi[branch]