From 868d4e734ed0f22221f25a1067fbf57141b64c21 Mon Sep 17 00:00:00 2001
From: Rob Crittenden <rcritten@redhat.com>
Date: Mon, 23 May 2011 15:07:03 -0400
Subject: Do a lazy retrieval of the LDAP schema rather than at module load.

Attempt to retrieve the schema the first time it is needed rather than
when Apache is started. A global copy is cached for future requests
for performance reasons.

The schema will be retrieved once per Apache child process.

ticket 583
---
 ipalib/plugins/baseldap.py |  2 ++
 ipaserver/plugins/ldap2.py | 43 +++++++++++++++++++++++++------------------
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/ipalib/plugins/baseldap.py b/ipalib/plugins/baseldap.py
index 053a0a5a3..3908dfe3e 100644
--- a/ipalib/plugins/baseldap.py
+++ b/ipalib/plugins/baseldap.py
@@ -600,6 +600,7 @@ class LDAPCreate(CallbackInterface, crud.Create):
                 )
 
         _check_single_value_attrs(self.params, entry_attrs)
+        ldap.get_schema()
         _check_limit_object_class(self.api.Backend.ldap2.schema.attribute_types(self.obj.limit_object_classes), entry_attrs.keys(), allow_only=True)
         _check_limit_object_class(self.api.Backend.ldap2.schema.attribute_types(self.obj.disallow_object_classes), entry_attrs.keys(), allow_only=False)
 
@@ -882,6 +883,7 @@ class LDAPUpdate(LDAPQuery, crud.Update):
 
         _check_single_value_attrs(self.params, entry_attrs)
         _check_empty_attrs(self.obj.params, entry_attrs)
+        ldap.get_schema()
         _check_limit_object_class(self.api.Backend.ldap2.schema.attribute_types(self.obj.limit_object_classes), entry_attrs.keys(), allow_only=True)
         _check_limit_object_class(self.api.Backend.ldap2.schema.attribute_types(self.obj.disallow_object_classes), entry_attrs.keys(), allow_only=False)
 
diff --git a/ipaserver/plugins/ldap2.py b/ipaserver/plugins/ldap2.py
index 58a9ab4f1..5556773c9 100644
--- a/ipaserver/plugins/ldap2.py
+++ b/ipaserver/plugins/ldap2.py
@@ -185,11 +185,8 @@ def get_schema(url, conn=None):
 
     return _ldap.schema.SubSchema(schema_entry[1])
 
-# cache schema when importing module
-try:
-    _schema = get_schema(api.env.ldap_uri)
-except AttributeError:
-    _schema = None
+# Global schema
+_schema = None
 
 # The UPG setting will be cached the first time a module checks it
 _upg = None
@@ -261,7 +258,7 @@ class ldap2(CrudBackend, Encoder):
 
     def get_syntax(self, attr, value):
         if not self.schema:
-            return None
+            self.get_schema()
         obj = self.schema.get_obj(_ldap.schema.AttributeType, attr)
         if obj is not None:
             return obj.syntax
@@ -270,7 +267,7 @@ class ldap2(CrudBackend, Encoder):
 
     def get_allowed_attributes(self, objectclasses):
         if not self.schema:
-            return []
+            self.get_schema()
         allowed_attributes = []
         for oc in objectclasses:
             obj = self.schema.get_obj(_ldap.schema.ObjectClass, oc)
@@ -287,10 +284,10 @@ class ldap2(CrudBackend, Encoder):
         If there is a problem loading the schema or the attribute is
         not in the schema return None
         """
-        if self.schema:
-            obj = self.schema.get_obj(_ldap.schema.AttributeType, attr)
-            return obj and obj.single_value
-        return None
+        if not self.schema:
+            self.get_schema()
+        obj = self.schema.get_obj(_ldap.schema.AttributeType, attr)
+        return obj and obj.single_value
 
     @encode_args(2, 3, 'bind_dn', 'bind_pw')
     def create_connection(self, ccache=None, bind_dn='', bind_pw='',
@@ -336,10 +333,8 @@ class ldap2(CrudBackend, Encoder):
         except _ldap.LDAPError, e:
             _handle_errors(e, **{})
 
-        if self.schema is None and _schema is None:
-            # explicitly use setattr here so the schema can be set after
-            # the object is finalized.
-            object.__setattr__(self, 'schema', get_schema(self.ldap_uri, conn))
+        if _schema:
+            object.__setattr__(self, 'schema', _schema)
         return conn
 
     def destroy_connection(self):
@@ -656,9 +651,21 @@ class ldap2(CrudBackend, Encoder):
         setattr(context, 'config_entry', copy.deepcopy(config_entry))
         return (cdn, config_entry)
 
-    def get_schema(self):
-        """Returns a copy of the current LDAP schema."""
-        return copy.deepcopy(self.schema)
+    def get_schema(self, deepcopy=False):
+        """Returns either a reference to current schema or its deep copy"""
+        global _schema
+        if not _schema:
+            _schema = get_schema(self.ldap_uri, self.conn)
+            if not _schema:
+                raise errors.DatabaseError(desc='Unable to retrieve LDAP schema', info='Unable to proceed with request')
+            # explicitly use setattr here so the schema can be set after
+            # the object is finalized.
+            object.__setattr__(self, 'schema', _schema)
+
+        if (deepcopy):
+            return copy.deepcopy(self.schema)
+        else:
+            return self.schema
 
     def has_upg(self):
         """Returns True/False whether User-Private Groups are enabled.
-- 
cgit