redAcore/BufferCore.h

/*
 * BufferCore.h
 *
 *  Created on: 18 May 2016
 *      Author: wentzelc
 */

#ifndef REDACORE_BUFFERCORE_H_
#define REDACORE_BUFFERCORE_H_

// redA Libraries
/* none */

// Standard C/C++ Libraries
/* none */

//---------------------------------------------------------------------------

/** Shift and Rolling buffer class
 *
 * Shifting buffer:
 *   Data is either set at start of buffer or appended to buffer
 *   Start of buffered data is always at beginning of buffer
 *   Never rolls over (option to over overwrite if data longer than buffer)
 *   Shifts unsused data to left when clearing used data
 *   Always zero terminates buffer
 *   Can look directly at buffer
 *
 * Rolling buffer:
 *   Data is continuosly assigned to buffer
 *   Start of buffer is tracked by references (can be anywhere)
 *   Data rolls over to start of buffer if end of buffer reached (option to overwrite start)
 *   Data is never shifted/moved inside buffer, only references are adjusted
 *   Never zero terminates buffer
 *   Can only look at data by copying (stitching) to another buffer
 */

class CRollingBuffer
{
private:
    // Buffer Definition
    char        * Buffer;   // Memory allocated to buffer
    const int   BufSize;    // Size of allocated buffer
    int         BufLen;     // Total unread characters in buffer

    // Temporary output buffer
    char    * OutBuffer;    // Temporary output buffer for "stitched" (rollover) data

    // Buffer pointers
    int     BufStart;       // First unread characters in buffer
    int     BufEnd;         // Next write position for new data (End of unread data + 1)

public:
    // Life Cycle
    CRollingBuffer( int BufferSize );
    virtual ~CRollingBuffer();

    // Direct Operations
    int Reset();                                                        // Clear buffer and reset all pointers to start of buffer

    // Reading from buffer
    char PeekChar( int Pos = 0 );                                       // Return one character from buffer (do not remove from buffer
    int  PeekDirect( char ** Data, int PeekPos = 0 );                   // Return contiguous data pointer direct to buffer (continguous data couont returned)
    int  Peek( char ** Data, int PeekPos = 0, int MaxLen = -1 );        // Return stiched data copied to temporary output buffer
    int  PeekCopy( char ** Data, int PeekPos = 0, int MaxLen = -1 );    // Return stiched data copied to supplied pointer (create if not exist)

    bool FindStr( const char * SearchStr, int SearchLen, int &FoundPos, int StartPos = 0 );   // Search buffer directly

    // Change data on buffer
    virtual int Push( bool Overwrite, const char * Data, int Len = -1 );
    virtual int Clear( int ClearLen = -1 );

    virtual int Pop( char ** Data, int MaxLen = -1 );
    virtual int PopCopy( char ** Data, int MaxLen = -1 );

    // File operations
    virtual int ReadFromFD( int Handle, int MaxRead = -1, bool Overwrite = false );
    virtual int WriteToFD( int Handle, int MaxWrite = -1 );

    // Miscellaneous
    int Size()        { return BufSize; };
    int Len()         { return BufLen; };
};
//---------------------------------------------------------------------------

class CShiftBuffer
{
private:
    // Buffer Definition
    char        * Buffer;   // Memory allocated to buffer
    const int   BufSize;    // Size of allocated buffer
    int         BufLen;     // Total unread characters in buffer

    // Temporary output buffer
    char    * OutBuffer;    // Temporary output buffer for "stitched" (rollover) data

public:
    // Life Cycle
    CShiftBuffer( int BufferSize );
    virtual ~CShiftBuffer();

    // Direct Operations
    int Reset();                                                        // Clear buffer and reset all pointers to start of buffer

    // Reading from buffer
    char PeekChar( int Pos = 0 );                                       // Return one character from buffer (do not remove from buffer
    int  PeekDirect( char ** Data, int PeekPos = 0 );                   // Return contiguous data pointer direct to buffer (continguous data couont returned)
    int  Peek( char ** Data, int PeekPos = 0, int MaxLen = -1 );        // Return stiched data copied to temporary output buffer
    int  PeekCopy( char ** Data, int PeekPos = 0, int MaxLen = -1 );    // Return stiched data copied to supplied pointer (create if not exist)

    bool FindStr( const char * SearchStr, int SearchLen, int &FoundPos, int StartPos = 0 );   // Search buffer directly

    // Chagne data on buffer
    virtual int Push( bool Overwrite, const char * Data, int Len = -1 );
    virtual int Clear( int ClearLen = -1 );

    virtual int Pop( char ** Data, int MaxLen = -1 );
    virtual int PopCopy( char ** Data, int MaxLen = -1 );

    // File operations
    virtual int ReadFromFD( int Handle, int MaxRead = -1 );
    virtual int WriteToFD( int Handle, int MaxWrite = -1 );

    // Miscellaneous
    int Size()        { return BufSize; };
    int Len()         { return BufLen; };
};
//---------------------------------------------------------------------------

#endif /* REDACORE_BUFFERCORE_H_ */