CBuffer.h

00001 /* Copyright (C) 2012 mbed.org, MIT License
00002  *
00003  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004  * and associated documentation files (the "Software"), to deal in the Software without restriction,
00005  * including without limitation the rights to use, copy, modify, merge, publish, distribute,
00006  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
00007  * furnished to do so, subject to the following conditions:
00008  *
00009  * The above copyright notice and this permission notice shall be included in all copies or
00010  * substantial portions of the Software.
00011  *
00012  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017  */
00018  
00019 #ifndef CIRCBUFFER_H_
00020 #define CIRCBUFFER_H_
00021  
00022 template <class T>
00023 class CircBuffer {
00024 public:
00025     CircBuffer(int length, void *addr = NULL) {
00026         write = 0;
00027         read = 0;
00028         size = length + 1;
00029         if (addr) {
00030             buf = (T *)addr;
00031         } else {
00032             buf = (T *)malloc(size * sizeof(T));
00033         }
00034         if (buf == NULL)
00035             error("Can't allocate memory");
00036     };
00037  
00038     bool isFull() {
00039         return (((write + 1) % size) == read);
00040     };
00041  
00042     bool isEmpty() {
00043         return (read == write);
00044     };
00045  
00046     bool queue(T k) {
00047         if (isFull()) {
00048             return false;
00049         }
00050         buf[write++] = k;
00051         write %= size;
00052         return true;
00053     }
00054     int queue(T *k, int size) {
00055         int i;
00056         for (i = 0; i < size; i ++) {
00057             if (queue(k[i]) == false) break;
00058         }
00059         return i;
00060     }
00061     
00062     void flush() {
00063         read = 0;
00064         write = 0;
00065     }
00066     
00067  
00068     uint32_t available() {
00069         return (write >= read) ? write - read : size - read + write;
00070     };
00071     uint32_t free() {
00072         return size - available() - 1;
00073     };
00074  
00075     bool dequeue(T * c) {
00076         bool empty = isEmpty();
00077         if (!empty) {
00078             *c = buf[read++];
00079             read %= size;
00080         }
00081         return(!empty);
00082     };
00083     int dequeue(T * c, int size) {
00084         int i;
00085         for (i = 0; i < size; i ++) {
00086             if (dequeue(&c[i]) == false) break;
00087         }
00088         return i;
00089     }
00090  
00091 private:
00092     volatile uint32_t write;
00093     volatile uint32_t read;
00094     uint32_t size;
00095     T * buf;
00096 };
00097  
00098 #endif