From b3f8f4313bca928f05cea6c6460e5757c75b5a86 Mon Sep 17 00:00:00 2001
From: Christophe Simonis <chs@openerp.com>
Date: Fri, 14 May 2010 15:15:06 +0200
Subject: [PATCH] [IMP] sql_db.py: backport changes from stable branch

bzr revid: chs@openerp.com-20100514131506-yx7qsu2nuylk1v5e
---
 bin/sql_db.py | 44 ++++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/bin/sql_db.py b/bin/sql_db.py
index 94336cde69a..19562b809f8 100644
--- a/bin/sql_db.py
+++ b/bin/sql_db.py
@@ -100,7 +100,7 @@ class Cursor(object):
             msg = "Cursor not closed explicitly\n"  \
                   "Cursor was created at %s:%s"
             self.__logger.warn(msg, *self.__caller)
-            self.close()
+            self._close(True)
 
     @check
     def execute(self, query, params=None):
@@ -177,6 +177,9 @@ class Cursor(object):
 
     @check
     def close(self):
+        return self._close(False)
+
+    def _close(self, leak=False):
         if not self._obj:
             return
 
@@ -194,7 +197,12 @@ class Cursor(object):
         # part because browse records keep a reference to the cursor.
         del self._obj
         self.__closed = True
-        self._pool.give_back(self._cnx)
+
+        if leak:
+            self._cnx.leaked = True
+        else:
+            keep_in_pool = self.dbname not in ('template1', 'template0', 'postgres')
+            self._pool.give_back(self._cnx, keep_in_pool=keep_in_pool)
 
     @check
     def autocommit(self, on):
@@ -214,6 +222,9 @@ class Cursor(object):
         return getattr(self._obj, name)
 
 
+class PsycoConnection(psycopg2.extensions.connection):
+    pass
+
 class ConnectionPool(object):
 
     __logger = logging.getLogger('db.connection_pool')
@@ -247,42 +258,47 @@ class ConnectionPool(object):
     def borrow(self, dsn):
         self._debug('Borrow connection to %s' % (dsn,))
 
-        result = None
+        # free leaked connections
+        for i, (cnx, _) in tools.reverse_enumerate(self._connections):
+            if getattr(cnx, 'leaked', False):
+                delattr(cnx, 'leaked')
+                self._connections.pop(i)
+                self._connections.append((cnx, False))
+                self._debug('Free leaked connection to %s' % (cnx.dsn,))
+
         for i, (cnx, used) in enumerate(self._connections):
             if not used and dsn_are_equals(cnx.dsn, dsn):
-                self._debug('Existing connection found at index %d' % i)
-
                 self._connections.pop(i)
                 self._connections.append((cnx, True))
+                self._debug('Existing connection found at index %d' % i)
 
-                result = cnx
-                break
-        if result:
-            return result
+                return cnx
 
         if len(self._connections) >= self._maxconn:
             # try to remove the oldest connection not used
             for i, (cnx, used) in enumerate(self._connections):
                 if not used:
-                    self._debug('Removing old connection at index %d: %s' % (i, cnx.dsn))
                     self._connections.pop(i)
+                    self._debug('Removing old connection at index %d: %s' % (i, cnx.dsn))
                     break
             else:
                 # note: this code is called only if the for loop has completed (no break)
                 raise PoolError('The Connection Pool Is Full')
 
-        self._debug('Create new connection')
-        result = psycopg2.connect(dsn=dsn)
+        result = psycopg2.connect(dsn=dsn, connection_factory=PsycoConnection)
         self._connections.append((result, True))
+        self._debug('Create new connection')
         return result
 
     @locked
-    def give_back(self, connection):
+    def give_back(self, connection, keep_in_pool=True):
         self._debug('Give back connection to %s' % (connection.dsn,))
         for i, (cnx, used) in enumerate(self._connections):
             if cnx is connection:
                 self._connections.pop(i)
-                self._connections.append((cnx, False))
+                if keep_in_pool:
+                    self._connections.append((cnx, False))
+                    self._debug('Put connection to %s in pool' % (cnx.dsn,))
                 break
         else:
             raise PoolError('This connection does not below to the pool')