File.h

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/*********************************************************\
 *  File: File.h                                         *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLCORE_FILE_H__
#define __PLCORE_FILE_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLCore/File/FileObject.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLCore {


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Class for accessing a file in the file system
*/
class File : public FileObject {


    //[-------------------------------------------------------]
    //[ Public definitions                                    ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    File access flags
        */
        enum EAccess {
            FileRead    =  1,   /**< File can be read */
            FileWrite   =  2,   /**< File can be written */
            FileAppend  =  4,   /**< File will be appended */
            FileCreate  =  8,   /**< File will be created */
            FileText    = 16,   /**< File will be opened in text mode (whenever possible, don't set this flag because not each platform may support it) */
            FileMemBuf  = 32    /**< File will be opened memory buffered (only usable for reading!) */
        };

        /**
        *  @brief
        *    Seek position enumerations
        */
        enum ESeek {
            SeekSet = 0,    /**< Seek relative to the start of the file (default setting) */
            SeekCurrent,    /**< Seek relative to the current position */
            SeekEnd         /**< Seek relative to the end of the file */
        };


    //[-------------------------------------------------------]
    //[ Public static data                                    ]
    //[-------------------------------------------------------]
    public:
        static PLCORE_API File StandardInput;   /**< Standard OS input stream (stdin) */
        static PLCORE_API File StandardOutput;  /**< Standard OS output stream (stdout) */
        static PLCORE_API File StandardError;   /**< Standard OS error stream (stderr) */


    //[-------------------------------------------------------]
    //[ Public static functions                               ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Translates a given C file mode into access flags
        *
        *  @param[in] sMode
        *    C file mode ("r", "r+", "w", "w+", "a", "a+", "t", "r+t" etc. used for e.g. "fopen") to translate
        *
        *  @return
        *    The access flags (see EAccess)
        */
        static PLCORE_API uint32 CFileModeToAccessFlags(const String &sMode);


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        */
        inline File();

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] sUrl
        *    URL of a file
        *  @param[in] pAccess
        *    Additional file access information (can be a null pointer)
        */
        inline File(const String &sUrl, const FileAccess *pAccess = nullptr);

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] cUrl
        *    URL of a file
        *  @param[in] pAccess
        *    Additional file access information (can be a null pointer)
        */
        inline File(const Url &cUrl, const FileAccess *pAccess = nullptr);

        /**
        *  @brief
        *    Constructor for a standard OS stream
        *
        *  @param[in] pFile
        *    Standard stream pointer
        *  @param[in] nAccess
        *    Access flags that were used to open the stream
        */
        inline File(FILE *pFile, uint32 nAccess);

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] hFile
        *    OS file handle
        *
        *  @note
        *    - On Linux, the handle is a file handle of type int.
        *    - On Windows, the handle is a file handle of type HANDLE.
        *      Do not expect an int (fileno) here! If you need it to work with
        *      low level io functions, you need to convert the HANDLE to a
        *      file handle by yourself (see _open_osfhandle).
        */
        inline File(handle hFile);

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] pnData
        *    The file data, if a null pointer same as the standard constructor
        *  @param[in] nNumOfBytes
        *    Number of file data bytes, MUST be valid!
        *  @param[in] bCopy
        *    Copy the given data or use this one directly? Do ONLY set bCopy to 'false'
        *    if you are sure there can't go anything wrong. (data pointer MUST stay valid!)
        *  @param[in] sUrl
        *    URL of a file
        */
        PLCORE_API File(uint8 *pnData, uint32 nNumOfBytes, bool bCopy = true, const String &sUrl = "");

        /**
        *  @brief
        *    Destructor
        *
        *  @note
        *    - The file is closed automatically
        */
        inline virtual ~File();

        /**
        *  @brief
        *    Create file
        *
        *  @param[in] bAlways
        *    If 'true', the file is created (and therefore overwritten) if it already exists
        *
        *  @return
        *    'true', if all went fine, else 'false'
        */
        inline bool Create(bool bAlways = false);

        /**
        *  @brief
        *    Delete file
        *
        *  @return
        *    'true', if all went fine, else 'false'
        */
        inline bool Delete();

        /**
        *  @brief
        *    Open the file for reading and/or writing
        *
        *  @param[in] nAccess
        *    Access mode, combination of 'EAccess' flags
        *  @param[in] nStringFormat
        *    String encoding format to use when dealing with string functions (not supported by all file implementations)
        *
        *  @return
        *    'false' on error, else 'true'
        *
        *  @note
        *    - 'FileStandardInput', 'FileStandardOutput' and 'FileStandardError' are special access flags that can't
        *      be combined with other flags and the filename must be empty
        *    - It's not recommended to use Unicode by because internally wchar_t is used and this data type has not
        *      the same size on every platform (use ASCII or UTF8 instead)
        */
        PLCORE_API bool Open(uint32 nAccess, String::EFormat nStringFormat = String::ASCII);

        /**
        *  @brief
        *    Close the file
        */
        inline void Close();

        /**
        *  @brief
        *    Returns whether the file is memory buffered (opened with flag 'FileMemBuf')
        *
        *  @return
        *    'true', if the file is memory buffered, else 'false'
        *
        *  @see
        *    - GetMemoryBuffer()
        */
        inline bool IsMemoryBuffered() const;

        /**
        *  @brief
        *    Returns whether the file is open
        *
        *  @return
        *    'true', if the file is open, else 'false'
        */
        inline bool IsOpen() const;

        /**
        *  @brief
        *    Returns whether the file is readable
        *
        *  @return
        *    'true', if the file can be read, else 'false'
        */
        inline bool IsReadable() const;

        /**
        *  @brief
        *    Returns whether the file is writable
        *
        *  @return
        *    'true', if the file can be written, else 'false'
        */
        inline bool IsWritable() const;

        /**
        *  @brief
        *    Returns the string encoding format to use when dealing with string functions
        *
        *  @return
        *    String encoding format to use when dealing with string functions
        */
        inline String::EFormat GetStringFormat() const;

        /**
        *  @brief
        *    Returns whether end of file has been reached
        *
        *  @return
        *    'true', if the end of the file has been reached, else 'false'
        */
        inline bool IsEof() const;

        /**
        *  @brief
        *    Reads a character
        *
        *  @return
        *    A character from file, < 0 if there was an error
        */
        inline int GetC();

        /**
        *  @brief
        *    Writes a character
        *
        *  @param[in] nChar
        *    Character to write
        *
        *  @return
        *    'true' if all went fine, else 'false' (maybe file is read only)
        */
        inline bool PutC(int nChar);

        /**
        *  @brief
        *    Reads a string
        *
        *  @return
        *    Read string
        */
        inline String GetS();

        /**
        *  @brief
        *    Writes a string
        *
        *  @param[in] sString
        *    String which should be written into the file
        *
        *  @return
        *    Number of bytes written, 0 if nothing was written, < 0 if there was an error
        */
        inline int PutS(const String &sString);

        /**
        *  @brief
        *    Reads the given number of bytes
        *
        *  @param[out] pBuffer
        *    Buffer were the data should be copied in (MUST valid and large enough!)
        *  @param[in]  nSize
        *    Item size in bytes
        *  @param[in]  nCount
        *    Maximum number of items to be read
        *
        *  @return
        *    Number of fully read items, if != 'nCount' an error occurred
        */
        inline uint32 Read(void *pBuffer, uint32 nSize, uint32 nCount);

        /**
        *  @brief
        *    Writes the given number of bytes
        *
        *  @param[in] pBuffer
        *    Buffer with the data which should be written into the file (MUST valid and large enough!)
        *  @param[in] nSize
        *    Item size in bytes
        *  @param[in] nCount
        *    Maximum number of items to be written
        *
        *  @return
        *    Number of fully written items, if != 'nCount' an error occurred
        */
        inline uint32 Write(const void *pBuffer, uint32 nSize, uint32 nCount);

        /**
        *  @brief
        *    Flushes the file buffer
        *
        *  @return
        *    'true' if all went fine, else 'false'
        *
        *  @remarks
        *    Writes down all temporarily buffered data.
        */
        inline bool Flush();

        /**
        *  @brief
        *    Sets the starting position
        *
        *  @param[in] nOffset
        *    File offset in bytes relative to the given location
        *  @param[in] nLocation
        *    Location
        *
        *  @return
        *    'true' if all went fine, else 'false'
        */
        inline bool Seek(int32 nOffset = 0, ESeek nLocation = SeekSet);

        /**
        *  @brief
        *    Gets the current position of the file pointer
        *
        *  @return
        *    The current byte position of the file pointer, < 0 if there was an error
        */
        inline int32 Tell() const;

        /**
        *  @brief
        *    Returns the file size
        *
        *  @return
        *    File size in bytes
        */
        inline uint32 GetSize() const;

        /**
        *  @brief
        *    Writes a string into the file
        *
        *  @param[in] sString
        *    String which should be written into the file
        *
        *  @return
        *    'true' if all went fine, else 'false'
        */
        inline bool Print(const String &sString);

        /**
        *  @brief
        *    Writes a string and a newline into the file
        *
        *  @param[in] sString
        *    String which should be written into the file
        *
        *  @return
        *    'true' if all went fine, else 'false'
        */
        inline bool PrintLn(const String &sString);

        /**
        *  @brief
        *    Returns a pointer to the buffer for memory buffered file
        *
        *  @return
        *    Pointer to the buffer for memory buffered file, a null pointer if there's no such buffer
        *
        *  @see
        *    - IsMemoryBuffered()
        */
        inline const uint8 *GetMemoryBuffer() const;

        /**
        *  @brief
        *    Returns the complete content of the file as string
        *
        *  @return
        *    The complete file content as string, empty string on error or if the file is just empty
        */
        PLCORE_API String GetContentAsString();


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Copy constructor
        *
        *  @param[in] cSource
        *    Source to copy from
        */
        File(const File &cSource);

        /**
        *  @brief
        *    Copy operator
        *
        *  @param[in] cSource
        *    Source to copy from
        *
        *  @return
        *    Reference to this instance
        */
        File &operator =(const File &cSource);

        /**
        *  @brief
        *    Open the file (for memory buffered files)
        *
        *  @param[in] nAccess
        *    Access mode (see EAccess)
        *  @param[in] nStringFormat
        *    String encoding format to use when dealing with string functions
        *
        *  @return
        *    'false' on error, else 'true'
        */
        bool MemBufOpen(uint32 nAccess, String::EFormat nStringFormat = String::ASCII);

        /**
        *  @brief
        *    Close the file (for memory buffered files)
        */
        PLCORE_API void MemBufClose();

        /**
        *  @brief
        *    Reads a character (for memory buffered files)
        *
        *  @return
        *    A character from file, < 0 if there was an error
        */
        PLCORE_API int MemBufGetC();

        /**
        *  @brief
        *    Reads a string (for memory buffered files)
        *
        *  @return
        *    Read string
        */
        PLCORE_API String MemBufGetS();

        /**
        *  @brief
        *    Reads the given number of bytes (for memory buffered files)
        *
        *  @param[out] pBuffer
        *    Buffer were the data should be copied in (MUST valid and large enough!)
        *  @param[in]  nSize
        *    Item size in bytes
        *  @param[in]  nCount
        *    Maximum number of items to be read
        *
        *  @return
        *    Number of fully read items, if != 'nCount' an error occurred
        */
        PLCORE_API uint32 MemBufRead(void *pBuffer, uint32 nSize, uint32 nCount);

        /**
        *  @brief
        *    Sets the starting position (for memory buffered files)
        *
        *  @param[in] nOffset
        *    File offset in bytes relative to the given location
        *  @param[in] nLocation
        *    Location
        *
        *  @return
        *    'true' if all went fine, else 'false'
        */
        PLCORE_API bool MemBufSeek(int32 nOffset, ESeek nLocation);


    //[-------------------------------------------------------]
    //[ Private definitions                                   ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    File internal access flags
        */
        enum EInternalAccess {
            FileMemBufShared = 64   /**< Opened memory buffered is shared and is NOT allowed to be destroyed by this file object! */
        };


    //[-------------------------------------------------------]
    //[ Private data                                          ]
    //[-------------------------------------------------------]
    private:
        uint8  *m_pMemBuf;          /**< Buffer for memory buffered file, can be a null pointer */
        uint32  m_nMemBufSize;      /**< Size of memory buffered file */
        uint32  m_nMemBufPos;       /**< Seek position for memory buffered file */
        uint32  m_nMemBufAccess;    /**< Access flags for memory buffered file */


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLCore


//[-------------------------------------------------------]
//[ Implementation                                        ]
//[-------------------------------------------------------]
#include "PLCore/File/File.inl"


#endif // __PLCORE_FILE_H__