FileType.h

/*
 *  Copyright (C) 2010  Regents of the University of Michigan
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef __FILETYPE_H__
#define __FILETYPE_H__

#include <stdint.h>

class FileType
{
public:
    FileType();
    virtual ~FileType();

    virtual bool operator == (void * rhs) = 0;

    virtual bool operator != (void * rhs) = 0;

    // Close the file.
    virtual int close() = 0;

    // Reset to the beginning of the file.
    virtual void rewind() = 0;

    // Check to see if we have reached the EOF.
    virtual int eof() = 0;

    // Check to see if the file is open.
    virtual bool isOpen() = 0;

    // Write to the file.
    virtual unsigned int write(const void * buffer, unsigned int size) = 0;

    // Read into a buffer from the file.
    virtual int read(void * buffer, unsigned int size) = 0;

    // Get current position in the file.
    // -1 return value indicates an error.
    virtual int64_t tell() = 0;

    // Seek to the specified offset from the origin.
    // origin can be any of the following:
    // Note: not all are valid for all filetypes.
    //   SEEK_SET - Beginning of file
    //   SEEK_CUR - Current position of the file pointer
    //   SEEK_END - End of file
    // Returns true on successful seek and false on a failed seek.
    virtual bool seek(int64_t offset, int origin) = 0;

    // Set by the InputFile to inform this class if buffering
    // is used.  Maybe used by child clases (bgzf) to disable 
    // tell.  NOTE: this class does no buffering, the
    // buffering is handled by the calling class.
    void setBuffered(bool buffered);

    //
    // When caller catches an exception, it may call this method.
    // It is implemented only in BgzfFileTypeRecovery.
    //
    virtual bool attemptRecoverySync(bool (*checkSignature)(void *data) , int length);

protected:
    // Set by the InputFile to inform this class if buffering
    // is used.  Maybe used by child clases (bgzf) to disable 
    // tell.
    bool myUsingBuffer;
};

#endif