don't attach _fetch_dict to cursors, causes memory leak (all cursors are retained forever)

Daniel Kinzler · Daniel Kinzler · commit 9070459a6c8f · 2012-01-04T20:22:52.000Z
git-svn-id: https://svn.toolserver.org/svnroot/daniel/duesenstuff/trunk/gpClient@584 9f2c43bc-b3c0-43f4-b155-41619b16f219
diff --git a/python/gp/mysql.py b/python/gp/mysql.py
@@ -17,7 +17,7 @@ def next(self):
 		# XXX: if we knew that the order of fields in the result set is the same
 		#	  as the order given in self.table, we could just use result.fetchone()
 		
-		raw = self.result.fetch_dict(  )
+		raw = _fetch_dict( self.result )
 		
 		if not raw: 
 			raise StopIteration()
@@ -285,8 +285,17 @@ def getTableName (self):
 		return self.table
 		
 def _fetch_dict( cursor ):
+	try:
+		row = cursor.fetch_dict(  )
+		return row
+	except AttributeError:
+		pass
+		
 	r = cursor.fetchone()
 	if r is None: return None
+	
+	if hasattr(r, "has_key"):
+		return r # it's a dict!
 
 	row = {}
 	
@@ -388,8 +397,11 @@ def mysql_query( self, sql, unbuffered = None, dict_rows = False, cursor = None
 		
 		if not dict_rows:
 			# HACK: glue a fetch_dict method to a cursor that natively returns sequences from fetchone()
-			m = types.MethodType(_fetch_dict, cursor, cursor.__class__)
-			setattr(cursor, "fetch_dict", m)
+			# FIXME: if we do this, we for some reason retain a reference to the cursor forever!
+			#        
+			#m = types.MethodType(_fetch_dict, cursor, cursor.__class__)
+			#setattr(cursor, "fetch_dict", m)
+			pass
 		else:
 			# make fetch_dict an alias for fetchone
 			cursor.fetch_dict = cursor.fetchone # TESTME
@@ -712,7 +724,7 @@ def dump_result (self, res ):
 		
 		print ""
 		while True:
-			row = res.fetch_dict()
+			row = _fetch_dict(res)
 			if not row: break
 			
 			if keys is None :
diff --git a/python/gp/tests/mysql_test.py b/python/gp/tests/mysql_test.py
@@ -1,6 +1,7 @@
 from test_base import *
 from gp.client import *
 from gp.mysql import *
+from gp.mysql import _fetch_dict
 
 import unittest
 import sys
@@ -102,7 +103,7 @@ def test_UnbufferedSelectInto(self):
         self.assertEquals( [ ( 3, 8 ), ( 7, 9 ), ( 11, 11 ) ], data )
     
     def assertNextRowEquals(self, expected, res):
-        row = res.fetch_dict()
+        row = _fetch_dict(res)
         self.assertTrue( TestBase.dictEquals(expected, row), "expected row to be %s, got %s" % (expected, row) )
         
     def test_TempSink(self):
@@ -117,7 +118,7 @@ def test_TempSink(self):
         
         self.assertNextRowEquals({ 'a': 4, 'b': 5 }, res )
         self.assertNextRowEquals({ 'a': 6, 'b': 7 }, res )
-        self.assertFalse( res.fetch_dict(), "expected next row to be false" )
+        self.assertFalse( res.fetchone(), "expected next row to be false" )
         
         res.close()
         
@@ -228,7 +229,7 @@ def testSuccessorsToSinkObject(self):
         self.assertNextRowEquals({ 'n': 12L }, res )
         self.assertNextRowEquals({ 'n': 111L }, res )
         self.assertNextRowEquals({ 'n': 112L }, res )
-        self.assertFalse(  res.fetch_dict(), "expected next row to be False" )
+        self.assertFalse(  res.fetchone(), "expected next row to be False" )
         
         res.close()
         
@@ -247,7 +248,7 @@ def testSuccessorsToSinkObject(self):
         self.assertNextRowEquals({ 'n': 12 }, res )
         self.assertNextRowEquals({ 'n': 111 }, res )
         self.assertNextRowEquals({ 'n': 112 }, res )
-        self.assertFalse(  res.fetch_dict(), "expected next row to be False" )
+        self.assertFalse(  res.fetchone(), "expected next row to be False" )
         
         res.close()
     
@@ -272,7 +273,7 @@ def test_SuccessorsToSinkShorthand(self):
         self.assertNextRowEquals({ 'n': 12 }, res )
         self.assertNextRowEquals({ 'n': 111 }, res )
         self.assertNextRowEquals({ 'n': 112 }, res )
-        self.assertFalse(  res.fetch_dict(), "expected next row to be False" )
+        self.assertFalse(  res.fetchone(), "expected next row to be False" )
         
         res.close()
         snk.drop()
@@ -289,7 +290,7 @@ def test_SuccessorsToSinkShorthand(self):
         self.assertNextRowEquals({ 'n': 12 }, res )
         self.assertNextRowEquals({ 'n': 111 }, res )
         self.assertNextRowEquals({ 'n': 112 }, res )
-        self.assertFalse(  res.fetch_dict(), "expected next row to be False" )
+        self.assertFalse(  res.fetchone(), "expected next row to be False" )
         
         res.close()
         snk.drop()
@@ -306,7 +307,7 @@ def test_SuccessorsToSinkShorthand(self):
         self.assertNextRowEquals({ 'n': 12 }, res )
         self.assertNextRowEquals({ 'n': 111 }, res )
         self.assertNextRowEquals({ 'n': 112 }, res )
-        self.assertFalse(  res.fetch_dict(), "expected next row to be False" )
+        self.assertFalse(  res.fetchone(), "expected next row to be False" )
         
         res.close()
         snk.drop()
@@ -325,7 +326,7 @@ def test_SuccessorsToSinkShorthand(self):
         self.assertNextRowEquals({ 'n': 12 }, res )
         self.assertNextRowEquals({ 'n': 111 }, res )
         self.assertNextRowEquals({ 'n': 112 }, res )
-        self.assertFalse(  res.fetch_dict(), "expected next row to be False" )
+        self.assertFalse(  res.fetchone(), "expected next row to be False" )
         
         res.close()
     
