src/libs/RingBuffer.h

   1 /*
   2       This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
   3       Smoothie 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.
   4       Smoothie 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.
   5       You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>.
   6
   7       With chucks taken from http://en.wikipedia.org/wiki/Circular_buffer, see licence there also
   8 */
   9
  10 #ifndef RINGBUFFER_H
  11 #define RINGBUFFER_H
  12
  13
  14 template<class kind, int length> class RingBuffer {
  15     public:
  16         RingBuffer();
  17         int          size();
  18         int          capacity();
  19         void         push_back(kind object);
  20         void         pop_front(kind &object);
  21         void         get( int index, kind &object);
  22         kind*        get_ref( int index);
  23         void         delete_first();
  24
  25         kind         buffer[length];
  26         int          head;
  27         int          tail;
  28 };
  29
  30
  31 template<class kind, int length> RingBuffer<kind, length>::RingBuffer(){
  32     this->head = this->tail = 0;
  33 }
  34
  35 template<class kind, int length>  int RingBuffer<kind, length>::capacity(){
  36     return length-1;
  37 }
  38
  39 template<class kind, int length>  int RingBuffer<kind, length>::size(){
  40 return((this->head>this->tail)?length:0)+this->tail-head;
  41 }
  42
  43 template<class kind, int length> void RingBuffer<kind, length>::push_back(kind object){
  44     this->buffer[this->tail] = object;
  45     this->tail = (tail+1)&(length-1);
  46 }
  47
  48 template<class kind, int length> void RingBuffer<kind, length>::get(int index, kind &object){
  49     int j= 0;
  50     int k= this->head;
  51     while (k != this->tail){
  52         if (j == index) break;
  53         j++;
  54         k= (k + 1) & (length - 1);
  55     }
  56     if (k == this->tail){
  57         //return NULL;
  58     }
  59     object = this->buffer[k];
  60 }
  61
  62
  63 template<class kind, int length> kind* RingBuffer<kind, length>::get_ref(int index){
  64     int j= 0;
  65     int k= this->head;
  66     while (k != this->tail){
  67         if (j == index) break;
  68         j++;
  69         k= (k + 1) & (length - 1);
  70     }
  71     if (k == this->tail){
  72         return NULL;
  73     }
  74     return &(this->buffer[k]);
  75 }
  76
  77 template<class kind, int length> void RingBuffer<kind, length>::pop_front(kind &object){
  78     object = this->buffer[this->head];
  79     this->head = (this->head+1)&(length-1);
  80 }
  81
  82 template<class kind, int length> void RingBuffer<kind, length>::delete_first(){
  83     kind dummy;
  84     this->pop_front(dummy);
  85 }
  86
  87
  88 #endif