WriteableFile.h

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//==============================================================================================
//  FILENAME    :   WriteableFile.h
//  AUTHOR      :   vovechkin
//  CREATION    :   2004-09-28
//  Copyright (C) MicroStrategy Incorporated 2004
//  All Rights Reserved
//==============================================================================================
#ifndef MFileSystem_WriteableFile_h
#define MFileSystem_WriteableFile_h

#include "Base/Base/Timer.h"

#include "FileSystem.h" // for FILE_SYSTEM_DLL_EXPORT

#include "GenericFile.h"

namespace MFileSystem
{
    enum IF_COMMIT_AND_CLOSE_WAS_NOT_CALLED
    {
        IF_COMMIT_AND_CLOSE_WAS_NOT_CALLED_THEN_TRUNCATE_FILE,
        IF_COMMIT_AND_CLOSE_WAS_NOT_CALLED_THEN_DELETE_FILE,
        IF_COMMIT_AND_CLOSE_WAS_NOT_CALLED_THEN_PRESERVE_FILE
    };

    class WriteableFile:
        virtual public GenericFile
    {
    public:

        typedef MBase::StrongPtr<WriteableFile> Ptr;
        typedef MBase::ReturnPtr<WriteableFile> ReturnPtr;

        // virtual destructor is a must
        virtual ~WriteableFile() throw()
        {
        }

        virtual void Write(const char* ipString, size_t iLength = 0) = 0;

        virtual void Write(const void* ipData, size_t iByteLength) = 0;

        virtual void WriteLittleEndian(const unsigned Int32& irValue) = 0;

        virtual void Flush() = 0;

        virtual void Truncate() = 0;

        virtual void CommitAndClose() = 0;

        virtual const MBase::TotalTimer& GetWriteTimer() const = 0;

        virtual const MBase::TotalTimer& GetWriteLockTimer() const = 0;

        class DLL_FILE_SYSTEM_EXIM WriteSmartLock
        {
        public:
            WriteSmartLock(WriteableFile& irWriteableFile);
            ~WriteSmartLock() throw();

            void Unlock() throw();

        protected:

            WriteSmartLock();

            WriteableFile* mpWriteableFile;
            bool mIsLocked;
        };

        class DLL_FILE_SYSTEM_EXIM WriteSmartLock_NoWait:
            public WriteSmartLock
        {
        public:

            WriteSmartLock_NoWait(WriteableFile& irWriteableFile);

            bool IsLocked() const throw()
            {
                return mIsLocked;
            }
        };

    protected:

        friend class WriteSmartLock;
        friend class WriteSmartLock_NoWait;

        virtual bool WriteLock(bool iNoWait) = 0;
        virtual void WriteUnlock() throw() = 0;
    };

    DLL_FILE_SYSTEM_EXIM WriteableFile::ReturnPtr OpenWriteableFile(
        const char* ipPath,
        IF_COMMIT_AND_CLOSE_WAS_NOT_CALLED iWhatToDoIfCommitAndCloseWasNotCalled);
}

#endif // MFileSystem_WriteableFile_h