/***************************************************************************************
 * SAGE - Scalable Adaptive Graphics Environment
 *
 * Module:  sageBuf.h
 * Author : Byungil Jeong
 *
 *	Description: SAGE buffer classes
 *
 * Copyright (C) 2004 Electronic Visualization Laboratory,
 * University of Illinois at Chicago
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following disclaimer
 *    in the documentation and/or other materials provided with the distribution.
 *  * Neither the name of the University of Illinois at Chicago nor
 *    the names of its contributors may be used to endorse or promote
 *    products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Direct questions, comments etc about SAGE to sage_users@listserv.uic.edu or
 * http://www.evl.uic.edu/cavern/forum/
 *
*****************************************************************************************/

#ifndef _SAGE_BUF_H
#define _SAGE_BUF_H

#include "sageBase.h"

#define MAX_READER_NUM 100

typedef char* sageBufEntry;

/**
 * the abstract class of sage buffers
 */
class sageBuf {
protected:
	int readIdx;
	int writeIdx;
	int entryNum;
	int bufLen;
	int entrySize;
   sageBufEntry *entries;

	pthread_mutex_t bufLock;
	pthread_cond_t notEmpty;
	bool full, empty;

	void initArray(int size);

public:
   sageBuf();
	inline bool isEmpty() { return empty; }
	inline bool isFull()  { return full; }
	inline int  size()    { return bufLen; }
   inline void setEntryNum(int num) { entryNum = num; }
	inline int  getEntryNum() { return entryNum; }
   inline int  getReadIdx()  { return readIdx; }
   inline int  filled()  { return (entryNum*100)/bufLen; }

   sageBufEntry operator[](int idx);

	void reset();
	void resetIdx();
	int getStatus() { return entryNum*100/bufLen; }
   virtual void setBlockingFlag(bool blk) {}
	virtual bool pushBack(sageBufEntry entry) = 0;
   virtual sageBufEntry front() = 0;
   virtual bool next() = 0;
   virtual sageBufEntry front(int id) { return NULL; }
   virtual sageBufEntry next(int id) { return NULL; }
   //virtual int import(sageBuf *buf) = 0;
   virtual void releaseLock() = 0;
   ~sageBuf();
};

/**
 * no concurrent read and write
 */
class sageSerialBuf : public sageBuf {
public:
   sageSerialBuf(int len) { initArray(len); }
	bool pushBack(sageBufEntry entry);
   sageBufEntry front();
   bool next();
   //int import(sageBuf *buf);
   void releaseLock() {}
};

/**
 * sageCircBufSingle
 * instantiated in sageBlockBuf
 */
class sageCircBufSingle : public sageBuf {
public:
	int instID;

protected:
   bool blocking;
   bool active;

public:
   sageCircBufSingle(int len, bool blkRead) : blocking(blkRead), active(true), instID(-1)
      { initArray(len); }
	bool pushBack(sageBufEntry entry);
   sageBufEntry front();
   bool next();
   bool isActive()  { return active; }

   void setBlockingFlag(bool blk) { blocking = blk; }
   void releaseLock();
};

class sageCircBuf : public sageBuf {
protected:
	pthread_cond_t notFull;

public:
   sageCircBuf(int len);
   bool pushBack(sageBufEntry entry, bool blk);
   bool pushBack(sageBufEntry entry) { return pushBack(entry, false); }
	sageBufEntry front(bool blk);
   sageBufEntry front() { return front(false); }
   bool next();
   void releaseLock();
};

class sageRAB : public sageBuf {
protected:
   int *nextIdx;
   int head;
   int tail;
   int freeHead;
   int freeTail;

public:
   sageRAB(int len);

   bool insert(sageBufEntry entry);
   bool remove(int idx, int prev);
   inline int  start() { return head; }
   void next(int &idx);

   bool next() { return false; }
   sageBufEntry front() { return NULL; }
   bool pushBack(sageBufEntry entry) { return false; }
   void releaseLock() {}
};

class readerInfo {
public:
   int readIdx;
   bool empty;
   bool active;

   readerInfo() : readIdx(0), empty(true), active(false) {}
};

/**
 * circular buffer with multiple readers
 */
class sageCircBufMulti : public sageBuf {
private:
   sageBufEntry front() { return NULL; }
   bool next();
   //int import(sageBuf *buf) { return 0; }
   int distToWriteIdx(int ridx);

protected:
	bool blocking;
	int readerNum;
   int maxReaderID;

	readerInfo readers[MAX_READER_NUM];

public:
   sageCircBufMulti(int len, bool blkRead) : readerNum(0), blocking(blkRead), maxReaderID(-1)
      { initArray(len); }

	int addReader(int id);
	void removeReader(int id);
   inline bool isActive(int id) { return readers[id].active; }

   bool pushBack(sageBufEntry entry);
   sageBufEntry front(int id);
   sageBufEntry next(int id);

   void setBlockingFlag(bool blk) { blocking = blk; }
   void releaseLock() { blocking=false, empty=false, pthread_cond_broadcast(&notEmpty); }
};

#endif

/*
class sageBufMulti : public sageBuf {
protected:
	int readerNum;
	readerInfo readers[MAX_READER_NUM];

public:
   sageBufMulti(int len) : readerNum(1) { initArray(len); }
	bool pushBack(sageBufEntry entry);
   sageBufEntry front();
   bool next();
   int import(sageBuf *buf);
};
*/