(fix) cache sogo_folder_info records and avoid phantom subscriptions (fixes #4010)

SOPE/GDLContentStore/GCSFolderManager.h

@@ -77,6 +77,7 @@
 - (BOOL)folderExistsAtPath:(NSString *)_path;
 - (NSArray *)listSubFoldersAtPath:(NSString *)_path recursive:(BOOL)_flag;
 
+- (NSDictionary *) recordAtPath: (NSString *) _path;
 - (GCSFolder *)folderAtPath:(NSString *)_path;
 
 - (NSException *)createFolderOfType:(NSString *)_type withName:(NSString *)_name atPath:(NSString *)_path;

SOPE/GDLContentStore/GCSFolderManager.m

@@ -784,7 +784,7 @@ static BOOL       _singleStoreMode           = NO;
   return result;
 }
 
-- (GCSFolder *) folderAtPath: (NSString *) _path
+- (NSDictionary *) recordAtPath: (NSString *) _path
 {
   NSMutableString *sql;
   NSArray      *fnames, *records;
@@ -841,8 +841,13 @@ static BOOL       _singleStoreMode           = NO;
     [self debugWithFormat:@"found no record for path: '%@'", _path];
     return nil;
   }
-  
-  return [self folderForRecord:record];
+
+  return record;
+}
+
+- (GCSFolder *) folderAtPath: (NSString *) _path
+{
+  return [self folderForRecord: [self recordAtPath: _path]];
 }
 
 - (NSString *) baseTableNameWithUID: (NSString *) _uid

SoObjects/SOGo/SOGoGCSFolder.m

@@ -424,7 +424,23 @@ static NSArray *childRecordFields = nil;
 
 - (GCSFolder *) ocsFolderForPath: (NSString *) _path
 {
-  return [[self folderManager] folderAtPath: _path];
+  NSDictionary *record;
+  SOGoCache *cache;
+
+  cache = [SOGoCache sharedCache];
+  record = [[cache valueForKey: _path] objectFromJSONString];
+
+  if (!record)
+    {
+      record = [[self folderManager] recordAtPath: _path];
+
+      if (!record)
+	return nil;
+
+      [cache setValue: [record jsonRepresentation]  forKey: _path];
+    }
+
+  return [[self folderManager] folderForRecord: record];
 }
 
 - (BOOL) folderIsMandatory
@@ -578,6 +594,7 @@ static NSArray *childRecordFields = nil;
       [self removeFolderSettings: moduleSettings
                    withReference: [self folderReference]];
       [us synchronize];
+      [[SOGoCache sharedCache] removeValueForKey: ocsPath];
 
       if ([[context request] handledByDefaultHandler])
         [self sendFolderAdvisoryTemplate: @"Removal"];

SoObjects/SOGo/SOGoParentFolder.m

@@ -291,14 +291,8 @@ static SoSecurityManager *sm = nil;
   // This is important because user A could delete folder X, and user B has subscribed to it.
   // If the "default roles" are enabled for calendars/address books, -validatePersmission:.. will
   // work (grabbing the default role) and the deleted resource will be incorrectly returned.
-  //
-  // FIXME - 2015/01/29 - this fix (24c6c8c91d421594bd51f07904d4cd3911cd187c) was reverted. Normally, we should add
-  // [subscribedFolder ocsFolderForPath: [subscribedFolder ocsPath]] to check the existence of the folder but it causes
-  // massive SQL traffic.
-  // 
-  // The proper fix would be to check upon login and only upon login if GCS folders that we're subscribed to are still existent.
-  //
   if (subscribedFolder
+      && [subscribedFolder ocsFolderForPath: [subscribedFolder ocsPath]]
       && ![sm validatePermission: SOGoPerm_AccessObject
 			onObject: subscribedFolder
 		       inContext: context])