RingBuffer.h

00001 /*  
00002       This file is part of Smoothie (http://smoothieware.org/). The motion control part is heavily based on Grbl (https://github.com/simen/grbl).
00003       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.
00004       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.
00005       You should have received a copy of the GNU General Public License along with Smoothie. If not, see <http://www.gnu.org/licenses/>. 
00006       
00007       With chucks taken from http://en.wikipedia.org/wiki/Circular_buffer, see licence there also
00008 */
00009 
00010 #ifndef RINGBUFFER_H
00011 #define RINGBUFFER_H
00012 
00013 
00014 template<class kind, int length> class RingBuffer {
00015     public:
00016         RingBuffer();
00017         int          size();
00018         int          capacity();
00019         int          next_block_index(int index);
00020         int          prev_block_index(int index);
00021         void         push_back(kind object);
00022         void         pop_front(kind &object);
00023         void         get( int index, kind &object);
00024         kind*        get_ref( int index);
00025         void         delete_first();
00026 
00027         kind         buffer[length];
00028         int          head;
00029         int          tail;
00030 };
00031 
00032 
00033 template<class kind, int length> RingBuffer<kind, length>::RingBuffer(){
00034     this->head = this->tail = 0;
00035 }
00036 
00037 template<class kind, int length>  int RingBuffer<kind, length>::capacity(){
00038     return length-1;
00039 }
00040 
00041 template<class kind, int length>  int RingBuffer<kind, length>::size(){
00042 return((this->head>this->tail)?length:0)+this->tail-head;
00043 }
00044 
00045 template<class kind, int length> int RingBuffer<kind, length>::next_block_index(int index){
00046     index++;
00047     if (index == length) { index = 0; }
00048     return(index);
00049 }
00050 
00051 template<class kind, int length> int RingBuffer<kind, length>::prev_block_index(int index){
00052     if (index == 0) { index = length; }
00053     index--;
00054     return(index);
00055 }
00056 
00057 template<class kind, int length> void RingBuffer<kind, length>::push_back(kind object){
00058     this->buffer[this->tail] = object;
00059     this->tail = (tail+1)&(length-1);
00060 }
00061 
00062 template<class kind, int length> void RingBuffer<kind, length>::get(int index, kind &object){
00063     int j= 0;
00064     int k= this->head;
00065     while (k != this->tail){
00066         if (j == index) break;
00067         j++;
00068         k= (k + 1) & (length - 1);
00069     }
00070     if (k == this->tail){
00071         //return NULL; 
00072     }
00073     object = this->buffer[k];
00074 }
00075 
00076 
00077 template<class kind, int length> kind* RingBuffer<kind, length>::get_ref(int index){
00078     int j= 0;
00079     int k= this->head;
00080     while (k != this->tail){
00081         if (j == index) break;
00082         j++;
00083         k= (k + 1) & (length - 1);
00084     }
00085     if (k == this->tail){
00086         return NULL;
00087     }
00088     return &(this->buffer[k]);
00089 }
00090 
00091 template<class kind, int length> void RingBuffer<kind, length>::pop_front(kind &object){
00092     object = this->buffer[this->head]; 
00093     this->head = (this->head+1)&(length-1);
00094 }
00095 
00096 template<class kind, int length> void RingBuffer<kind, length>::delete_first(){
00097     //kind dummy;
00098     //this->pop_front(dummy);
00099     this->head = (this->head+1)&(length-1);
00100 }
00101 
00102 
00103 #endif