FileLockTransaction.h   [plain text]

/*
 * Copyright (c) 2015 Apple Inc. All Rights Reserved.
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 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
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 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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#ifndef FileLockTransaction_h
#define FileLockTransaction_h

#if TARGET_OS_OSX

#include <security_cdsa_client/dlclient.h>
//
// This class performs a file lock transaction on a Cssm Db object.
//
// It will attempt to take the file lock upon creation.
//
// It will release the file lock upon destruction OR calling finalize().
//
// If you have called success(), it will tell the file lock transaction to commit
// otherwise, it will tell the file lock transaction to roll back.
//
// If you call setDeleteOnFailure(), and the transaction would normally roll
// back, this transaction will instead delete the Db's underlying file.
//
class FileLockTransaction {
public:
    FileLockTransaction(Security::CssmClient::Db& db);

    ~FileLockTransaction();

    // Everything has gone right; this transaction will commit.
    // If you don't call this, the transaction will roll back.
    void success();

    // Commit or rollback as appropriate
    void finalize();

    // After calling this method, if this class attempts to roll back the
    // transaction, it will also attempt to delete the database file.
    void setDeleteOnFailure();

protected:
    // Actually toggle autocommit using the dldbh
    void initialize();

    Security::CssmClient::Db mDb;

    bool mSuccess;
    bool mFinalized;
    bool mDeleteOnFailure;
};

#endif // TARGET_OS_OSX

#endif