/***************************************************************************************[BoundedQueue.h]
 Glucose -- Copyright (c) 2009-2014, Gilles Audemard, Laurent Simon
                                CRIL - Univ. Artois, France
                                LRI  - Univ. Paris Sud, France (2009-2013)
                                Labri - Univ. Bordeaux, France

 Syrup (Glucose Parallel) -- Copyright (c) 2013-2014, Gilles Audemard, Laurent Simon
                                CRIL - Univ. Artois, France
                                Labri - Univ. Bordeaux, France

Glucose sources are based on MiniSat (see below MiniSat copyrights). Permissions and copyrights of
Glucose (sources until 2013, Glucose 3.0, single core) are exactly the same as Minisat on which it
is based on. (see below).

Glucose-Syrup sources are based on another copyright. Permissions and copyrights for the parallel
version of Glucose-Syrup (the "Software") are granted, free of charge, to deal with the Software
without restriction, including the rights to use, copy, modify, merge, publish, distribute,
sublicence, and/or sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

- The above and below copyrights notices and this permission notice shall be included in all
copies or substantial portions of the Software;
- The parallel version of Glucose (all files modified since Glucose 3.0 releases, 2013) cannot
be used in any competitive event (sat competitions/evaluations) without the express permission of
the authors (Gilles Audemard / Laurent Simon). This is also the case for any competitive event
using Glucose Parallel as an embedded SAT engine (single core or not).


--------------- Original Minisat Copyrights

Copyright (c) 2003-2006, Niklas Een, Niklas Sorensson
Copyright (c) 2007-2010, Niklas Sorensson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute,
sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 **************************************************************************************************/


#ifndef BoundedQueue_h
#define BoundedQueue_h


namespace Glucose {

template <class T>
class bqueue {
    vec<T>  elems;
    int     first;
    int     last;
    unsigned long long sumofqueue;
    int     maxsize;
    int     queuesize; // Number of current elements (must be < maxsize !)
    bool expComputed;
    double exp,value;
public:
    bqueue(void) : first(0), last(0), sumofqueue(0), maxsize(0), queuesize(0),expComputed(false) { }

    void initSize(int size) {
        growTo(size);    // Init size of bounded size queue
        exp = 2.0/(size+1);
    }

    void push(T x) {
        expComputed = false;
        if (queuesize==maxsize) {
            assert(last==first); // The queue is full, next value to enter will replace oldest one
            sumofqueue -= elems[last];
            if ((++last) == maxsize) last = 0;
        } else
            queuesize++;
        sumofqueue += x;
        elems[first] = x;
        if ((++first) == maxsize) {
            first = 0;
            last = 0;
        }
    }

    T peek() {
        assert(queuesize>0);
        return elems[last];
    }
    void pop() {
        sumofqueue-=elems[last];
        queuesize--;
        if ((++last) == maxsize) last = 0;
    }

    unsigned long long getsum() const {
        return sumofqueue;
    }
    unsigned int getavg() const {
        return (unsigned int)(sumofqueue/((unsigned long long)queuesize));
    }
    int maxSize() const {
        return maxsize;
    }
    double getavgDouble() const {
        double tmp = 0;
        for(int i=0; i<elems.size(); i++) {
            tmp+=elems[i];
        }
        return tmp/elems.size();
    }
    int isvalid() const {
        return (queuesize==maxsize);
    }

    void growTo(int size) {
        elems.growTo(size);
        first=0;
        maxsize=size;
        queuesize = 0;
        last = 0;
        for(int i=0; i<size; i++) elems[i]=0;
    }

    double getAvgExp() {
        if(expComputed) return value;
        double a=exp;
        value = elems[first];
        for(int i  = first; i<maxsize; i++) {
            value+=a*((double)elems[i]);
            a=a*exp;
        }
        for(int i  = 0; i<last; i++) {
            value+=a*((double)elems[i]);
            a=a*exp;
        }
        value = value*(1-exp)/(1-a);
        expComputed = true;
        return value;


    }
    void fastclear() {
        first = 0;    // to be called after restarts... Discard the queue
        last = 0;
        queuesize=0;
        sumofqueue=0;
    }

    int  size(void)    {
        return queuesize;
    }

    void clear(bool dealloc = false)   {
        elems.clear(dealloc);
        first = 0;
        maxsize=0;
        queuesize=0;
        sumofqueue=0;
    }

    void copyTo(bqueue &dest) const {
        dest.last = last;
        dest.sumofqueue = sumofqueue;
        dest.maxsize = maxsize;
        dest.queuesize = queuesize;
        dest.expComputed = expComputed;
        dest.exp = exp;
        dest.value = value;
        dest.first = first;
        elems.copyTo(dest.elems);
    }
};


}  // namespace Glucose


#endif
