CircularBuffer.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2015 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_CIRCULARBUFFER_H
00017 #define MBED_CIRCULARBUFFER_H
00018 
00019 namespace mbed {
00020 
00021 /** Templated Circular buffer class
00022  */
00023 template<typename T, uint32_t BufferSize, typename CounterType = uint32_t>
00024 class CircularBuffer {
00025 public:
00026     CircularBuffer() : _head(0), _tail(0), _full(false) {
00027     }
00028 
00029     ~CircularBuffer() {
00030     }
00031 
00032     /** Push the transaction to the buffer. This overwrites the buffer if it's
00033      *  full
00034      *
00035      * @param data Data to be pushed to the buffer
00036      */
00037     void push(const T& data) {
00038         if (full()) {
00039             _tail++;
00040             _tail %= BufferSize;
00041         }
00042         _pool[_head++] = data;
00043         _head %= BufferSize;
00044         if (_head == _tail) {
00045             _full = true;
00046         }
00047     }
00048 
00049     /** Pop the transaction from the buffer
00050      *
00051      * @param data Data to be pushed to the buffer
00052      * @return True if the buffer is not empty and data contains a transaction, false otherwise
00053      */
00054     bool pop(T& data) {
00055         if (!empty()) {
00056             data = _pool[_tail++];
00057             _tail %= BufferSize;
00058             _full = false;
00059             return true;
00060         }
00061         return false;
00062     }
00063 
00064     /** Check if the buffer is empty
00065      *
00066      * @return True if the buffer is empty, false if not
00067      */
00068     bool empty() {
00069         return (_head == _tail) && !_full;
00070     }
00071 
00072     /** Check if the buffer is full
00073      *
00074      * @return True if the buffer is full, false if not
00075      */
00076     bool full() {
00077         return _full;
00078     }
00079 
00080     /** Reset the buffer
00081      *
00082      */
00083     void reset() {
00084         _head = 0;
00085         _tail = 0;
00086         _full = false;
00087     }
00088 
00089 private:
00090     T _pool[BufferSize];
00091     volatile CounterType _head;
00092     volatile CounterType _tail;
00093     volatile bool _full;
00094 };
00095 
00096 }
00097 
00098 #endif