OSX/libsecurity_utilities/lib/FileLockTransaction.h

   1 /*
   2  * Copyright (c) 2015 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #ifndef FileLockTransaction_h
  25 #define FileLockTransaction_h
  26
  27 #include <security_cdsa_client/dlclient.h>
  28 //
  29 // This class performs a file lock transaction on a Cssm Db object.
  30 //
  31 // It will attempt to take the file lock upon creation.
  32 //
  33 // It will release the file lock upon destruction OR calling finalize().
  34 //
  35 // If you have called success(), it will tell the file lock transaction to commit
  36 // otherwise, it will tell the file lock transaction to roll back.
  37 //
  38 // If you call setDeleteOnFailure(), and the transaction would normally roll
  39 // back, this transaction will instead delete the Db's underlying file.
  40 //
  41 class FileLockTransaction {
  42 public:
  43     FileLockTransaction(Security::CssmClient::Db& db);
  44
  45     ~FileLockTransaction();
  46
  47     // Everything has gone right; this transaction will commit.
  48     // If you don't call this, the transaction will roll back.
  49     void success();
  50
  51     // Commit or rollback as appropriate
  52     void finalize();
  53
  54     // After calling this method, if this class attempts to roll back the
  55     // transaction, it will also attempt to delete the database file.
  56     void setDeleteOnFailure();
  57
  58 protected:
  59     // Actually toggle autocommit using the dldbh
  60     void initialize();
  61
  62     Security::CssmClient::Db mDb;
  63
  64     bool mSuccess;
  65     bool mFinalized;
  66     bool mDeleteOnFailure;
  67 };
  68
  69 #endif