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  * Modifyed by Suga
00020  */
00021 
00022 #ifndef CIRCBUFFER_H_
00023 #define CIRCBUFFER_H_
00024 
00025 template <class T>
00026 class CircBuffer {
00027 public:
00028     CircBuffer(int length, void *addr = NULL) {
00029         write = 0;
00030         read = 0;
00031         size = length + 1;
00032         if (addr) {
00033             buf = (T *)addr;
00034         } else {
00035             buf = (T *)malloc(size * sizeof(T));
00036         }
00037         if (buf == NULL)
00038             error("Can't allocate memory");
00039     };
00040 
00041     bool isFull() {
00042         return (((write + 1) % size) == read);
00043     };
00044 
00045     bool isEmpty() {
00046         return (read == write);
00047     };
00048 
00049     void queue(T k) {
00050         if (isFull()) {
00051 //            read++;
00052 //            read %= size;
00053             return;
00054         }
00055         buf[write++] = k;
00056         write %= size;
00057     }
00058     
00059     void flush() {
00060         read = 0;
00061         write = 0;
00062     }
00063     
00064 
00065     uint32_t available() {
00066         return (write >= read) ? write - read : size - read + write;
00067     };
00068 
00069     bool dequeue(T * c) {
00070         bool empty = isEmpty();
00071         if (!empty) {
00072             *c = buf[read++];
00073             read %= size;
00074         }
00075         return(!empty);
00076     };
00077 
00078 private:
00079     volatile uint32_t write;
00080     volatile uint32_t read;
00081     uint32_t size;
00082     T * buf;
00083 };
00084 
00085 #endif